Advertisement for orthosearch.org.uk
Results 1 - 20 of 98
Results per page:
Orthopaedic Proceedings
Vol. 106-B, Issue SUPP_8 | Pages 23 - 23
10 May 2024
Leary J Lynskey T Muller A
Full Access

Objective. Carpal tunnel release surgery is a commonly performed procedure for alleviating symptoms of median nerve compression and restoring hand function. With pressure on theatre time these procedures are now commonly performed in a step-down out-patient facility under local anaesthetic. The choice of suture for skin closure in this procedure can impact the quality of wound healing, patient outcomes and the follow-up required however the question of the best type of suture remains unanswered. The purpose of this study was to compare the outcomes of absorbable and non-absorbable sutures using a randomised control trial design. Methods. Eighty patients diagnosed with bilateral carpal tunnel syndrome were enrolled and underwent outpatient carpal tunnel release surgery under local anaesthetic in a staged fashion. Random number generation was used to assign each hand to receive interrupted nylon or Vicryl Rapide sutures. Pre-operative data collection included patient demographics, ASA, inflammatory conditions, smoking status as well as a Boston Carpal Tunnel Questionnaire (BCTQ) for each hand. Patients were followed up at 2 and 6 weeks after each operation and the BCTQ was repeated along with the Patient and Observer Scar Assessment Scale and the VAS score for wound discomfort. This study has approval from the DHB ethics committee, Local Iwi, HDC and ANZ Clinical Trials:ACTRN12623000100695. Results. Statistical analysis assessed patient preference and the scores between the groups. Multi-variate analysis was performed to assess the factors that may be contributing to patient choice. Conclusion. Insights into patient preference and clinical outcomes associated with absorbable sutures and non-absorbable sutures in the setting of out-patient surgery are discussed


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_2 | Pages 108 - 108
10 Feb 2023
Guo J Blyth P Clifford K Hooper N Crawford H
Full Access

Augmented reality simulators offer opportunities for practice of orthopaedic procedures outside of theatre environments. We developed an augmented reality simulator that allows trainees to practice pinning of paediatric supracondylar humeral fractures (SCHF) in a radiation-free environment at no extra risk to patients. The simulator is composed of a tangible child's elbow model, and simulated fluoroscopy on a tablet device. The treatment of these fractures is likely one of the first procedures involving X-ray guided wire insertion that trainee orthopaedic surgeons will encounter. This study aims to examine the extent of improvement simulator training provides to real-world operating theatre performance. This multi-centre study will involve four cohorts of New Zealand orthopaedic trainees in their SET1 year. Trainees with no simulator exposure in 2019 - 2021 will form the comparator cohort. Trainees in 2022 will receive additional, regular simulator training as the intervention cohort. The comparator cohort's performance in paediatric SCHF surgery will be retrospectively audited using routinely collected operative outcomes and parameters over a six-month period. The performance of the intervention cohorts will be collected in the same way over a comparable period. The data collected for both groups will be used to examine whether additional training with an augmented reality simulator shows improved real-world surgical outcomes compared to traditional surgical training. This protocol has been approved by the University of Otago Health Ethics committee, and the study is due for completion in 2024. This study is the first nation-wide transfer validity study of a surgical simulator in New Zealand. As of September 2022, all trainees in the intervention cohort have been recruited along with eight retrospective trainees via email. We present this protocol to maintain transparency of the prespecified research plans and ensure robust scientific methods. This protocol may also assist other researchers conducting similar studies within small populations


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_15 | Pages 42 - 42
7 Nov 2023
Simmons D Robertson A Milner B
Full Access

Child abuse is an essential discussion within society and poses many challenges. The international literature describes patient and family based risk factors and suspicious injuries. We have created a protocol for the identification and investigation of children with suspected non-accidental injuries. The paediatric orthopaedic ward experiences many children being delayed in the ward once fit for discharge. This study aimed to quanitify those delayed discharges and describe the demographics and risk factors for abuse within the local population. After obtaining ethics clearance, we conducted a retrospective review of records from the Teddy Bear Clinic, as well as admission records. The study examined demographic characteristics, family, injury characteristics and referral to Child Welfare. The delay of discharge from hospital was quantified and was compared to those characteristics. Records were collected from 1 January 2015 to 31 December 2021. Seventy-nine complete records were included. There were 40 males and 39 females with an average age of 20 months. 75.9% were under 36 months old. 94.1% of the cases sustained lower limb fractures. Fifty-two cases had a delayed discharge. The delay ranged from 1 to 233 days. There was an association between an age less than 36 months and delayed discharge. There were no significant correlations between caregiver characteristics and delayed discharge. The later the completion of investigations, the more likely there would be a delay. There was also a significant correlation between referral to Child Welfare and delayed discharge. Children under 36 months on this remain at highest risk for non-accidental injury. Delayed discharge was associated with age less than 36 months, upper limb fractures and referral to Child Welfare. Despite the delayed discharge, most children returned to the same home environments


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_2 | Pages 42 - 42
10 Feb 2023
Fary C Abshagen S Van Andel D Ren A Anderson M Klar B
Full Access

Advances in algorithms developed with sensor data from smart phones demonstrates the capacity to passively collect qualitative gait metrics. The purpose of this feasibility study was to assess the recovery of these metrics following joint reconstruction. A secondary data analysis of an ethics approved global, multicenter, prospective longitudinal study evaluating gait quality data before and after primary total knee arthroplasty (TKA, n=476), partial knee arthroplasty (PKA, n=139), and total hip arthroplasty (THA, n=395). A minimum 24 week follow-up was required (mean 45±12, range 24 - 78). Gait bouts and gait quality metrics (walking speed, step length, timing asymmetry, and double support percentage) were collected from a standardized smartphone operating system. Pre- and post-operative values were compared using paired-samples t-tests (p<0.05). A total of 595 females and 415 males with a mean age of 61.9±9.3 years and mean BMI of 30.2±6.1 kg/m. 2. were reviewed. Walking speeds were lowest at post-operative week two (all, p<.001). Speeds exceeded pre-operative means consistently by week 21 (p=0.015) for PKA, and week 13 (p=0.007) for THA. The average weekly step length was lowest in post-operative week two (all, p<0.001). PKA and THA cases achieved pre-operative step lengths by week seven (p=0.064) and week 9 (p=0.081), respectively. The average weekly gait asymmetry peaked at week two post-operatively (all, p <0.001). Return to pre-operative baseline asymmetry was achieved by week 11 (p=0.371) for TKA, week six (p=0.541) for PKA, and week eight (p=.886) for THA. Double limb support percentages peaked at week two (all, p<0.001) and returned to pre-operative levels by week 24 (p=0.089) for TKA, week 12 (p=0.156) for PKA, and week 10 (p=0.143) for THA. Monitoring gait quality in real-world settings following joint reconstruction using smartphones is feasible, and may provide the advantage of removing the Hawthorne effect related to typical gait assessments and in-clinic observations


Full Access

Hallux valgus surgery can result in moderate to severe post-operative pain requiring the use of narcotic medication. The percutaneous distal metatarsal osteotomy is a minimally invasive approach which offers many advantages including minimal scarring, immediate weight bearing and decreased post-operative pain. The goal of this study is to determine whether the use of narcotics can be eliminated using an approach combining multimodal analgesia, ankle block anesthesia and a minimally invasive surgical approach. Following ethics board approval, a total of 160 ambulatory patients between the ages of 18-70 with BMI ≤ 40 undergoing percutaneous hallux valgus surgery are to be recruited and randomized into Narcotic-free (NF) or Standard (S) groups. To date, 72 patients have been recruited (38 NF and 34 S). The NF group received acetaminophen, naproxen, pregabalin 75mg and 100mg Ralivia (tramadol extended release) before surgery and acetaminophen, naproxen, pregabalin 150mg one dose and Ralivia 100mg BID for five days, as well as a rescue narcotic (hydromorphone, 1mg pills) after surgery. The S group received acetaminophen and naproxen prior to surgery and acetaminophen, naproxen and hydromorphone (1mg pills) post-operatively, our current standard. Visual analog scales (VAS) were used to assess pain and narcotic consumption was recorded at 6, 12, 24, 36, 48, 72 hours and seven days post-operatively. Patients wore a smart watch to record the number of daily steps and sleep hours. A two-sided t-test was used to compare the VAS scores and narcotic consumption. During the first post-operative week, the NF group consumed in total an average of 6.5 pills while the S group consumed in total an average of 16 pills and this difference was statistically significant (p-value=0.001). Importantly, 19 patients (50%) in the NF group and four patients (12%) in the S group did not consume any narcotics post-operatively. For the VAS scores at 24, 48, 72 hours and seven days the NF group's average scores were 2.17, 3.17, 2.92, 2.06 respectively and the S group's average scores were 3.97, 4.2, 3.23, 1.97. There was a statistically significant difference between the groups at 24 and 48hours (the NF group scored lower on the VAS) with a p-value of 0.0008 and 0.04 respectively, but this difference is not considered clinically significant as the minimal clinically important difference reported in the literature is a two-point differential. The NF group walked an average of 1985.75 steps/day and slept an average of 8h01 minute/night, while the S group walked an average of 1898.26 steps/day and slept an average of 8h26 minutes/night in the first post-operative week. Hallux valgus remains a common orthopedic foot problem for which surgical treatment results in moderate to severe post-operative pain. This study demonstrates that with the use of multimodal analgesia, ultrasound guided ankle blocks and a percutaneous surgical technique, narcotic requirements decreased post-operatively. The use of long-acting tramadol further decreased the need for narcotic consumption. Despite decreased use of narcotics, this combined novel approach to hallux valgus surgery allows for early mobilization and excellent pain control


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 78 - 78
1 Dec 2022
Willms S Matovinovic K Kennedy L Yee S Billington E Schneider P
Full Access

The widely used Fracture Risk Assessment Tool (FRAX) estimates a 10-year probability of major osteoporotic fracture (MOF) using age, sex, body mass index, and seven clinical risk factors, including prior history of fracture. Prior fracture is a binary variable in FRAX, although it is now clear that prior fractures affect future MOF risk differently depending on their recency and site. Risk of MOF is highest in the first two years following a fracture and then progressively decreases with time – this is defined as imminent risk. Therefore, the FRAX tool may underestimate true fracture risk and result in missed opportunities for earlier osteoporosis management in individuals with recent MOF. To address this, multipliers based on age, sex, and fracture type may be applied to baseline FRAX scores for patients with recent fractures, producing a more accurate prediction of both short- and long-term fracture risk. Adjusted FRAX estimates may enable earlier pharmacologic treatment and other risk reduction strategies. This study aimed to report the effect of multipliers on conventional FRAX scores in a clinical cohort of patients with recent non-hip fragility fractures. After obtaining Research Ethics Board approval, FRAX scores were calculated both before and after multiplier adjustment, for patients included in our outpatient Fracture Liaison Service who had experienced a non-hip fragility fracture between June 2020 and November 2021. Patients age 50 years or older, with recent (within 3 months) forearm (radius and/or ulna) or humerus fractures were included. Exclusion criteria consisted of patients under the age of 50 years or those with a hip fracture. Age- and sex-based FRAX multipliers for recent forearm and humerus fractures described by McCloskey et al. (2021) were used to adjust the conventional FRAX score. Low, intermediate and high-risk of MOF was defined as less than 10%, 10-20%, and greater than 20%, respectively. Data are reported as mean and standard deviation of the mean for continuous variables and as proportions for categorical variables. A total of 91 patients with an average age of 64 years (range = 50-97) were included. The majority of patients were female (91.0%), with 73.6% sustaining forearm fractures and 26.4% sustaining humerus fractures. In the forearm group, the average MOF risk pre- and post-multiplier was 16.0 and 18.8, respectively. Sixteen percent of patients (n = 11) in the forearm group moved from intermediate to high 10-year fracture risk after multiplier adjustment. Average FRAX scores before and after adjustment in the humerus group were 15.7 and 22.7, respectively, with 25% (n = 6) of patients moving from an intermediate risk to a high-risk score. This study demonstrates the clinically significant impact of multipliers on conventional FRAX scores in patients with recent non-hip fractures. Twenty-five percent of patients with humerus fractures and 16% of patients with forearm fractures moved from intermediate to high-risk of MOF after application of the multiplier. Consequently, patients who were previously ineligible for pharmacologic management, now met criteria. Multiplier-adjusted FRAX scores after a recent fracture may more accurately identify patients with imminent fracture risk, facilitating earlier risk reduction interventions


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_13 | Pages 82 - 82
1 Dec 2022
Negm A Schneider S Vaile K Yee S Lienhard K Schneider P
Full Access

Guidelines for the use of preoperative blood tests for elective surgery were established. However, there is less evidence and no guidelines regarding using these tests when a young, healthy patient undergoes minor orthopaedic trauma surgery. Bloodwork is often ordered routinely, regardless of medical history or the nature of the injury. We hypothesized that unnecessary blood work is requested for younger pre-operative patients, and their results will not change peri-operative management. This practice is not a judicious use of healthcare resources. This study aimed to evaluate the frequency, type, cost, and impact on clinical decisions if standard preoperative bloodwork was completed in healthy patients requiring surgical management of a minor fracture or dislocation. After the approval of our institutional ethics board, a retrospective chart review was conducted. Inclusion criteria were patients aged 18-60 years, who had an isolated minor orthopaedic trauma requiring outpatient surgery, who were American Society of Anesthesiologists (ASA) class 1. ASA class 1 is defined as “a normal healthy patient, without any clinically important comorbidity and without a clinically significant past/present medical history.” Data records from January 1, 2016, to December 31, 2018, were extracted from a provincial database (the Analytics Data Integration, Measurement and Reporting) for five hospitals. Data including demographics, surgical treatment, type and number of blood tests ordered, and ordering physician were collected. Any abnormal test results were checked to see whether they led to a change in patient management or related to a postoperative adverse event. Independent samples t-tests and Chi-square tests were used to compare the characteristics of patients who had preoperative bloodwork versus those who did not. The cost of preoperative blood work was estimated. During these two years, 627 patients met inclusion criteria, and 27% (n=168) of these patients had bloodwork completed pre-operatively, while only 34% (n=57) of these had one or more abnormal laboratory parameters. These abnormalities were minor and did not alter clinical management or result in repeated bloodwork peri-operatively. Patients who had bloodwork were significantly older (40.2 years) compared with patients without preoperative blood work (37.8 years; p=0.03), but there was no difference in sex between those who had bloodwork (53.4% male) and those who did not (51.4% male; p=0.63). The most common blood test ordered was a complete blood count, and the most commonly abnormal result was a mildly elevated white blood cell count (19%; n= 29). The most common patients to receive bloodwork were those with ankle (34%) and distal radius (34%) fractures. The bloodwork was primarily ordered by clinical associates (26%; n=46) and emergency department physicians (22%; n=38). Without considering lab personnel, consumables, and analysis time, the cost of this bloodwork was approximately $7685, an average of $45 per patient. Pre-operative bloodwork in young, healthy, asymptomatic patients requiring outpatient surgery for minor orthopaedic trauma had no clinical significance and did not change patient management. Rigorous prospective research is warranted to establish national guidelines for appropriate pre-operative bloodwork ordering to minimize unnecessary and costly investigations


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_10 | Pages 22 - 22
1 Jun 2023
North A Stratton J Moore D McCann M
Full Access

Introduction. External fixators are attached to bones with percutaneous pins and wires inserted through soft tissues and bone increasing the risk of infections. Such infections compromise patient outcomes e.g., through pin loosening or loss, failure of fixator to stabilise the fracture, additional surgery, increased pain, and delayed mobilisation. These infections also impact the healthcare system for example, increased OPD visits, hospitalisations, treatments, surgeries and costs. Nurses have a responsibility in the care and management of patients with external fixators and ultimately in the prevention of pin-site infection. Yet, evidence on best practices in the prevention of pin-site infection is limited and variation in pin-site management practices is evident. Various strategies are used for the prevention of pin-site infection including the use of different types of non-medicated and medicated wound dressings. The aim of this retrospective study was to investigate the use of dry gauze or iodine tulle dressings for the prevention of pin-site infections in patients with lower limb external fixators. Methodology. A retrospective study of patients with lower limb external fixators who attended the research site between 2015–2022. Setting & Sample: The setting was the outpatient's (OPD) orthopaedic clinic in a University Teaching Hospital in Dublin, Ireland. Eligibility Criteria:. Over the age of 16, treated with an Ilizarov, Taylor Spatial frame (TSF) or Limb Reconstruction System (LRS) external fixators on lower limbs,. Pin-sites dressed with dry gauze or iodine tulle,. Those with pre-existing infected wounds close to the pin site and/or were on long term antibiotics were excluded. Follow Up Period: From time of external fixator application to first pin-site infection or removal of external fixator. Outcome Assessment: The primary outcome was pin-site infection, secondary outcomes included but were not limited to frequency of pin-site infection according to types of bone fixation, frequency of pin/wire removal and hospitalisation due to infection. Data analysis: IBM SPSS Version 25 was used for statistical analysis. Descriptive and inferential statistics were conducted as appropriate. Categorical data were analysed by counting the frequencies (number and percentages) of participants with an event as opposed to counting the number of episodes for each event. Differences between groups were analysed using Chi-square test or Fisher's exact test, where appropriate. Continuous variables were reported using mean and standard deviations and difference analysed using a two-sample independent t-test or non-parametric test (Mann-Whitney), where appropriate. Using Kaplan-Meier, survival analysis explored time to development of infection. Ethical approval: granted by local institute Research Ethics Committee on 12th March 2018. Results. During the study period, 97 lower limb external fixators were applied with 43 patients meeting the study eligibility criteria. The mean age was 38 (SD 14.1; median 37) and the majority male (n=32, 74%). At least 50% (n=25) of participants had an IIizarov fixator, with 56% (n=24) of all fixators applied to the tibia and fibula. Pin/wire sites were dressed using iodine (n=26, 61%) or dry gauze dressings (n=15, 35%). The mean age of participants in the iodine group was significantly higher than the dry gauze group (p=.012). The only significant difference between the iodine and dry gauze dressing groups at baseline was age. A total of 30 (70%) participants developed a pin-site infection with 26% (n=11) classified as grade 2 infection. Clinical presentation included redness (n=18, 42%), discharge (n=16, 37%) and pain (n=15, 35%). Over half of participants were prescribed oral antibiotics (n=28, 65%); one required intravenous antibiotics and hospitalization due to pin-site infection. Ten (23%) participants required removal of pin/wires; two due to pin-site infection. There was no association between baseline data and pin-site infection. The median time to developing an infection was 7 weeks (95%, CI 2.7 to 11.29). Overall, there were 21 (81%, n=26) pin-site infections in the iodine group and nine (60%, n=15) in the dry gauze group, difference in proportion and relative risk between the dressing groups were not statistically significant (RR 1.35, 95% CI 0.86–2.12; p= .272). There was no association between baseline data, pin-site infection, and type of dressing. Conclusions. At the research site, patients are referred to the OPD orthopaedic clinic from internal and external clinical sites e.g., from Hospital Consultants, General Practitioners and occasionally from multidisciplinary teams, throughout Ireland. Our retrospective observation study found that 97 lower limb external fixators were applied over a seven-year period which is lower than that reported in the literature. However, the study period included the COVID pandemic years (2020 and 2021) which saw a lower number of external fixators applied due to lack of theatre availability, cancelled admissions and social/travel restrictions that resulted in fewer accidents and lower limb trauma cases requiring external fixator application. The study highlighted a high infection rate with 70% of participants developing pin-site infection which is in keeping with findings reporting in other studies. Our study showed that neither an iodine nor dry gauze dressing was successful in preventing pin-site infection. In the iodine group 81% of participants developed infection compared to 60% in the dry gauze group. Given the lack of difference between the two groups consideration needs to be given to the continued use of iodine dressings in the prevention of pin-site infection. Pin-site infections result in a high portion of participants being prescribed antibiotics and, in an era, that stresses the importance of antimicrobial stewardship there is a need to implement effective infection prevention and control strategies that minimise infection. Further research is therefore needed to investigate more innovative medicated dressings such as those that contain anti-microbial or anti-bacterial agents


Bone & Joint Research
Vol. 3, Issue 5 | Pages 161 - 168
1 May 2014
Mundi R Chaudhry H Mundi S Godin K Bhandari M

High-quality randomised controlled trials (RCTs) evaluating surgical therapies are fundamental to the delivery of evidence-based orthopaedics. Orthopaedic clinical trials have unique challenges; however, when these challenges are overcome, evidence from trials can be definitive in its impact on surgical practice. In this review, we highlight several issues that pose potential challenges to orthopaedic investigators aiming to perform surgical randomised controlled trials. We begin with a discussion on trial design issues, including the ethics of sham surgery, the importance of sample size, the need for patient-important outcomes, and overcoming expertise bias. We then explore features surrounding the execution of surgical randomised trials, including ethics review boards, the importance of organisational frameworks, and obtaining adequate funding. Cite this article: Bone Joint Res 2014;3:161–8


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_4 | Pages 140 - 140
1 Apr 2019
Wakelin E Walter W Bare J Theodore W Twiggs J Miles B
Full Access

Introduction. Kinematics post-TKA are complex; component alignment, component geometry and the patient specific musculoskeletal environment contribute towards the kinematic and kinetic outcomes of TKA. Tibial rotation in particular is largely uncontrolled during TKA and affects both tibiofemoral and patellofemoral kinematics. Given the complex nature of post- TKA kinematics, this study sought to characterize the contribution of tibial tray rotation to kinematic outcome variability across three separate knee geometries in a simulated framework. Method. Five 50. th. percentile knees were selected from a database of planned TKAs produced as part of a pre-operative dynamic planning system. Virtual surgery was performed using Stryker (Kalamazoo, MI) Triathlon CR and PS and MatOrtho (Leatherhead, UK) SAIPH knee medially stabilised (MS) components. All components were initially planned in mechanical alignment, with the femoral component neutral to the surgical TEA. Each knee was simulated through a deep knee bend, and the kinematics extracted. The tibial tray rotational alignment was then rotated internally and externally by 5° & 10°. The computational model simulates a patient specific deep knee bend and has been validated against a cadaveric Oxford Knee Rig. Preoperative CT imaging was obtained, landmarking to identify all patient specific axes and ligament attachment sites was performed by pairs of trained biomedical engineers. Ethics for this study is covered by Bellberry Human Research Ethics Committee application number 2012-03-710. Results and Discussion. From the 360 Knee Systems database, 1847 knees were analysed, giving an average coronal alignment of 4.25°±5.66° varus. Five knees were selected with alignments between 4.1° and 4.3° varus. Kinematic outcomes were averaged over the 5 knees. The component geometries resulted in characteristically distinct kinematics, in which femoral rollback was most constrained by the PS components, whereas tibiofemoral axial rotation was most constrained in MS components. Patella lateral shift was comparable amongst all components in extension, medialising in flexion. Patella shift remained more lateral in MS components compared to PS and CR. Average patella lateral shift, medial and lateral facet rollback separated by tibial tray rotation are shown for all component systems in Figure 1. Medial and lateral facet rollback in the PS and CR components are symmetrical and opposite, indicating that with tibial tray rotation, the tibiofemoral articulation point balances between component rotation and neutral alignment, reflecting the restoring force exerted by the simulated collateral ligaments. As such, with higher internal tibial rotation and subsequent lateralisation of the tubercle, patella lateral shift increases. MS medial and lateral facet rollback however are not symmetrical nor opposite, reflecting the chirality of the tibiofemoral articulation. With internal tibial tray rotation, relatively high lateral facet rollback is observed, lateralising the femoral component centre, giving the patella component a relatively more medial position. Conclusions. Component geometry was found here to produce characteristically distinct tibiofemoral and patellofemoral kinematics. Medial stabilised components reported asymmetric kinematic changes, compared to either CR or PS components, in which a higher rate of change was observed for internal tray rotation, indicating that neutral or external rotation of medial stabilised components will result in more predictable kinematic outcomes


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_13 | Pages 13 - 13
1 Nov 2019
Saini UC Kumar AS S Prakash M Aggarwal AK
Full Access

Advanced osteoarthritis of knee is associated with low-backache in a significant number of patients and adversely affects the quality of life. There is a paucity of literature describing outcomes of backache after total-knee-arthroplasty (TKA). We evaluated backache in patients of advanced knee-osteoarthritis and their functional and radiological outcomes after TKA after approval from Institutional ethics committee. Fifty-nine patients (40 females and 19 males) were included. Mean body-mass index was 28.7. Mean visual analogue score (VAS) for knee-pain was 7.98 preoperatively and 1.6 in follow-up. For chronic backache, the mean VAS score improved from 6.08 to 2.4, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) improved from 67.5 to 37.8, Knee society score (KSS) from 49.8 to 76.6, Oswestry Disability Index (ODI) Score from 55.44 to 34.65 and SF-36 Quality-of-life score from 44.95 to 74.63. There was a significant correlation between in knee and low-back functional scores. Magnetic resonance imaging-based scoring of degenerative changes (Pfirrmann grading) showed improvement only in 13.5% patients; 56% showed no change and 30.5% showed deterioration of scores. Chronic low backache is a significant co-morbidity in advanced knee-osteoarthritis. TKA has the potential to relieve backache along with knee-pain and improves quality of life


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_8 | Pages 80 - 80
1 Aug 2020
Montgomery S Schneider P Kooner S
Full Access

Three dimensional printing is an emerging new technology in medicine and the current educational value of 3D printed fracture models is unknown. The delayed surgery and need for CT imaging make calcaneal fractures an ideal scenario for preoperative 3D printed (3Dp) fracture models. The goal of this study is to assess if improvements in fracture understanding and surgical planning can be realized by trainees when they are given standard CT imaging and a 3Dp model compared to standard CT imaging and a virtual 3D rendering (3D CT). Ethics approval was granted for a selection of calcaneal fracture imaging studies to be collected through a practice audit of a senior orthopaedic trauma surgeon. 3Dp models were created in house. Digital Imaging and Communications in Medicine (DICOM) files of patient CT scans were obtained from local servers in an anonymized fashion. DICOM files were then converted to .STL models using the Mimics inPrint 2.0 (Materialise NV, Leuven, Belgium) software. Models were converted into a .gcode file through a slicer program (Simplify3D, Blue Ash, OH USA). The .gcode files were printed on a TEVO Little Monster Delta FDM printer (TEVO USA, CO USA) using 1.75mm polylactic acid (PLA) filament. Study participants rotated through 10 workstations viewing CT images and either a digital 3D volume rendering or 3Dp model of the fractured calcaneus. A questionnaire at each workstation assessed fracture classification, proposed method of treatment, confidence with fracture understanding and satisfaction with the accuracy of the 3Dp model or 3D volume rendering. Participants included current orthopaedic surgery trainees and staff surgeons. A total of 16 residents and five staff completed the study. Ten fracture cases were included in the analysis for time, confidence of fracture understanding, perceived model accuracy and treatment method. Eight fracture cases were included for assessment of diagnosis. There were no cases that obtained universal agreement on either Sanders classification or treatment method from staff participants. Residents in their final year of studies had the quickest mean time of assessment (60 +/− 24 sec.) and highest percentage of correct diagnoses (83%) although these did not reach significance compared to the other residency years. There was a significant increase in confidence of fracture understanding with increasing residency year. Also, confidence was improved in cases where a 3Dp model was available compared to conventional CT alone although this improvement diminished with increasing residency year. Perceived accuracy of the cases with 3Dp models was significantly higher than cases without models (7 vs 5.5 p < 0.0001). This is the first study to our knowledge to assess trainee confidence as a primary outcome in the assessment of the educational value of 3Dp models. This study was able to show that a 3Dp model aides in the perceived accuracy of fracture assessment and showed an improvement in trainee confidence, although the effect on confidence seems to diminish with increasing residency year. We propose that 3D printed calcaneal fracture models are a beneficial educational tool for junior level trainees and the role of 3Dp models for other complex orthopaedic presentations should be explored


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 36 - 36
1 Jul 2020
Mahmood F Clarke J Riches P
Full Access

The meniscus is comprised largely of type I collagen, as well as fibrochondrocytes and proteoglycans. In articular cartilage and intervertebral disc, proteoglycans make a significant contribution to mechanical stiffness of the tissue via negatively charged moieties which generate Donnan osmotic pressures. To date, such a role for proteoglycans in meniscal tissue has not been established. This study aimed to investigate whether meniscal proteoglycans contribute to mechanical stiffness of the tissue via electrostatic effects. Following local University Ethics Committee approval, discs of meniscal tissue two millimetres thick and of five millimetres diameter were obtained from 12 paired fresh frozen human menisci, from donors < 6 5 years of age, with no history of osteoarthritis or meniscal injury. Samples were taken from anterior, middle and posterior meniscal regions. Each disc was placed within a custom confined compression chamber, permeable at the top and bottom only and then bathed in one of three solutions − 0.14M PBS (mimics cellular environment), deionised water (negates effect of mobile ions) or 3M PBS (negates all ionic effects). The apparatus was mounted within a Bose Electroforce 3100 materials testing machine and a 0.3N preload was applied. The sample was allowed to reach equilibrium, before being subjected to a 10% ramp compressive strain followed by a 7200 second hold phase. Equal numbers of samples from each meniscus and meniscal region were tested in each solution. Resultant stress relaxation curves were fitted to a nonlinear poroviscoelastic model with strain dependent permeability using FEBio finite element modelling software. Goodness of fit (R2) was assessed using a coefficient of determination. All samples were assayed for proteoglycan content. Comparison of resultant mechanical parameters was undertaken using multivariate ANOVA with Bonferroni adjustment for multiple comparisons. 36 samples were tested. A significant difference (p < 0 .05) was observed in the value of the Young's modulus (E) between samples tested in deionised water compared to 0.14M/3M PBS, with the meniscus found to be stiffest in deionised water (E = 1.15 MPa) and least stiff in 3M PBS (E = 0.43 MPa), with the value of E in 0.14M PBS falling in between (0.68 MPa). No differences were observed in the zero strain permeability or the exponential strain dependent/stiffening coefficients. The viscoelastic coefficient and relaxation time values were not found to improve model fit and were thus held at zero. The mean R2 value was 0.78, indicating a good fit and did not differ significantly between solutions. Proteoglycan content was not found to differ with solution, but was found to be significantly increased in the middle region of both menisci. Proteoglycans make a significant electrostatic contribution to mechanical stiffness of the meniscus, increasing it by 58% in the physiological condition, and are hence integral to its function. It is important to include the influence of ionic effects when modelling meniscus, particularly where fluid flow or localised strain is modelled. From a clinical perspective, it is critical that meniscal regeneration strategies such as scaffolds or allografts attempt to preserve, or compensate for, the function of proteoglycans to ensure normal meniscal function


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 115 - 115
1 Jul 2020
Jhirad A Wohl G
Full Access

In osteoporosis treatment, current interventions, including pharmaceutical treatments and exercise protocols, suffer from challenges of guaranteed efficacy for patients and poor patient compliance. Moreover, bone loss continues to be a complicating factor for conditions such as spinal cord injury, prescribed bed-rest, and space flight. A low-cost treatment modality could improve patient compliance. Electrical stimulation has been shown to improve bone mass in animal models of disuse, but there have been no studies of the effects of electrical stimulation on bone in the context of bone loss under hormone deficiency such as in post-menopausal osteoporosis. The purpose of this study was to explore the effects of electrical stimulation on changes in bone mass in the ovariectomized rat model of post-menopausal osteoporosis. All animal protocols were approved by the institutional Animal Research Ethics Board. We developed a custom electrical stimulation device capable of delivering a constant current, 15 Hz sinusoidal signal. We used 30 female Sprague Dawley rats (12–13 weeks old). Half (n=15) were ovariectomized (OVX), and half (n=15) underwent sham OVX surgery (SHAM). Three of each OVX and SHAM animals were sacrificed at baseline. The remaining 24 rats were separated into four equal groups (n=6 per group): OVX electrical stimulation (OVX-stim), OVX no stimulation (OVX-no stim), SHAM electrical stimulation (SHAM-stim), and SHAM no stimulation (SHAM-no stim). While anaesthetized, stimulation groups received transdermal electrical stimulation to the right knee through bilateral skin-mounted electrodes (10 × 10 mm) with electrode gel. The left knee served as a non-stimulated contralateral control. The no-stimulation groups had electrodes placed on the right knee, but not connected. Rats underwent the stim/no-stim procedure for one hour per day for six weeks. Rats were sacrificed (CO2) after six weeks. Femurs and tibias were scanned by microCT focussed on the proximal tibia and distal femur. MicroCT data were analyzed for trabecular bone measures of bone volume fraction (BV/TV), thickness (Tb.Th), and anisotropy, and cortical bone cross-sectional area and second moment of area. Femurs and tibias from OVX rats had significantly less trabecular bone than SHAM (femur BV/TV = −74.1%, tibia BV/TV = −77.6%). In the distal femur of OVX-stim rats, BV/TV was significantly greater in the stimulated right (11.4%, p < 0 .05) than the non-stimulated contralateral (left). BV/TV in the OVX-stim right femur also tended to be greater than that in the OVX-no-stim right femur, but the difference was not significant (17.7%, p=0.22). There were no differences between stim and no-stim groups for tibial trabecular measures, or cortical bone measures in either the femur or the tibia. This study presents novel findings that electrical stimulation can partially mitigate bone loss in the OVX rat femur, a model of human post-menopausal bone loss. Further work is needed to explore why there was a differential response of the tibial and femoral bone, and to better understand how bone cells respond to electrical stimulation. The long-term goal of this work is to determine if electrical stimulation could be used as a complementary modality for preventing post-menopausal bone loss


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 49 - 49
1 Jul 2020
Gascoyne T Parashin S Teeter M Bohm E Laende E Dunbar MJ Turgeon T
Full Access

The purpose of this study was to examine the influence of weight-bearing on the measurement of in vivo wear of total knee replacements using model-based RSA at 1 and 2 years following surgery. Model-based RSA radiographs were collected for 106 patients who underwent primary TKR at a single institution. Supine RSA radiographs were obtained post-operatively and at 6-, 12-, and 24-months. Standing (weight-bearing) RSA radiographs were obtained at 12-months (n=45) and 24-months (n=48). All patients received the same knee design with a fixed, conventional PE insert of either a cruciate retaining or posterior stabilized design. Ethics approval for this study was obtained. In order to assess in vivo wear, a highly accurate 3-dimensional virtual model of each in vivo TKA was developed. Coordinate data from RSA radiographs (mbRSA v3.41, RSACore) were applied to digital implant models to reconstruct each patient's replaced knee joint in a virtual environment (Geomagic Studio, 3D Systems). Wear was assessed volumetrically (digital model overlap) on medial and lateral condyles separately, across each follow-up. Annual rate of wear was calculated for each patient as the slope of the linear best fit between wear and time-point. The influence of weight-bearing was assessed as the difference in annual wear rate between standing and supine exams. Age, BMI, and Oxford-12 knee improvement were measured against wear rates to determine correlations. Weight bearing wear measurement was most consistent and prevalent in the medial condyle with 35% negative wear rates for the lateral condyle. For the medial condyle, standing exams revealed higher mean wear rates at 1 and 2 years, supine, 16.3 mm3/yr (SD: 27.8) and 11.2 mm3/yr (SD: 18.5) versus standing, 51.3 mm3/yr (SD: 55.9) and 32.7 mm3/yr (SD: 31.7). The addition of weight-bearing increased the measured volume of wear for 78% of patients at 1 year (Avg: 32.4 mm3/yr) and 71% of patients at 2 years (Avg: 48.9 mm3/yr). There were no significant (95% CI) correlations between patient demographics and wear rates. Volumetric, weight-bearing wear measurement of TKR using model-based RSA determined an average of 33 mm3/yr at 2 years post-surgery for a modern, non-cross-linked polyethylene bearing. This value is comparable to wear rates obtained from retrieved TKRs. Weight-bearing exams produced better wear data with fewer negative wear rates and reduced variance. Limitations of this study include: supine patient imaging performed at post-op, no knee flexion performed, unknown patient activity level, and inability to distinguish wear from plastic creep or deformation under load. Strengths of this study include: large sample size of a single TKR system, linear regression of wear measurements and no requirement for implanted RSA beads with this method. Based on these results, in vivo volumetric wear of total knee replacement polyethylene can be reliably measured using model-based RSA and weight-bearing examinations in the short- to mid–term. Further work is needed to validate the accuracy of the measurements in vivo


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_7 | Pages 71 - 71
1 Jul 2020
Vissa D Lin C Ganapathy S Bryant D Adhikari D MacDonald S Lanting B Vasarhelyi E Howard J
Full Access

Dexmedetomidine, an alpha 2 agonist, has been approved for providing sedation in the intensive care unit. Along with sedative properties, it has analgesic activity through its highly selective action on alpha 2 receptors. Recent studies have examined the use of dexmedetomidine as an adjuvant to prolong the duration of peripheral nerve blocks. Studies showing effectiveness of dexmedetomidine for adductor canal block in knee surgery are small. Also, its effectiveness has not been compared to Epinephrine which is a strong alpha and beta receptor agonist. In a previous study, we showed that motor sparing knee blocks significantly increased the duration of analgesia compared with periarticular knee infiltration using local anesthetic mixture containing Epinephrine following total knee arthroplasty (TKA). In this study, we compared two local anesthetic mixtures: one containing Dexmedetomidine and the other Epinephrine for prolongation of motor sparing knee block in primary TKA patients. After local ethics board approval and gaining Notice of Compliance (NOC) from Health Canada for use of Dexmedetomidine perineurally, 70 patients between the ages 18 – 95 of ASA class I to III undergoing unilateral primary total knee arthroplasty were enrolled. Motor sparing knee block − 1) Adductor canal continuous catheter 2) Single shot Lateral Femoral Cutaneous Nerve block 3) Single shot posterior knee infiltration was performed in all patients using 60 ml mixture of 0.5% Ropivacaine, 10 mg Morphine, 30 mg Ketorolac. Patients randomized into the Dexmedetomidine group (D) received, in addition to the mixture, 1mcg/kg Dexmedetomidine and the Epinephrine (E) group received 200mcg in the mixture. The primary outcome was time to first rescue analgesia as a surrogate for duration of analgesia and secondary outcomes were NRS pain scores up to 24 hours and opioid consumption. The time to first rescue analgesia was not significantly different between Epinephrine and dexmedetomidine groups, Mean and SD 18.45 ± 12.98 hours vs 16.63 ± 11.80 hours with a mean difference of 1.82 hours (95% CI −4.54 to 8.18 hours) and p value of 0.57. Pain scores at 4, 6, 12, 18 and 24 hours were comparable between groups. Mean NRS pain scores Epinephrine vs Dexmedetomidine groups were 1.03 vs 0.80 at 4 hours, 1.48 vs 3.03 at 6 hours, 3.97 vs 4.93 at 12 hours, 5.31 vs 6.18 and 6.59 v 6.12 at 24 hours. Opioid consumption was also not statistically significant between both groups at 6, 12 18, 24 hours (p values 0.18, 0.88, 0.09, 0.64 respectively). Dexmedetomidine does not prolong the duration of knee motor sparing blocks when compared to Epinephrine for total knee arthroplasty. Pain scores and opioid consumption was also comparable in both groups. Further studies using higher dose of dexmedetomidine are warranted


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_14 | Pages 1 - 1
1 Dec 2019
Vanhouteghem K Olyslaegers C Fortems Y van Eynde E Willems P van Schaeren J Vanherendael B
Full Access

Aim. Microbiological culture of intraoperative periprosthetic tissue samples (IPTS) is one of the main criteria in diagnosing prosthetic joint infections (PJI) as stated by different guidelines. The current techniques are labor-intensive, prone for contamination and show low sensitivity. The aim of this study was to evaluate the added value of beadmill processing of IPTS and culturing in blood culture bottles (BCBs) over the conventional method of standard agar and broth alone. Method. We conducted a single-center prospective study from May 2017 to January 2018 at the GZA Hospitals, a secondary care hospital (1012 beds) in Antwerp, Belgium. IPTS from patients undergoing revision arthroplasty were consecutively processed. Each IPTS was aseptically divided in two equal parts: one was processed by direct inoculation on agar and in broths (non-homogenized method); the other was transferred in a sterile vial with saline solution and glass beads (EOLabs), homogenized using a mechanic cell disruptor for 30s (Disruptor genie, Scientific Industries), 2mL of the suspension was inoculated in (an)aerobic BCBs, agar plates and broths (homogenized method). Agar plates were incubated for 4d; broths and BCBs in BacT/Alert (bioMerieux) for 14d. Micro-organisms were identified using MALDI-TOF MS (Bruker). Sensitivity (Se) and specificity (Sp) were calculated against the IDSA definition of PJI for different culture sets: non-homogenized and agar/broth; homogenized processing and agar/broth, agar/broth/BCB, agar/BCB. Ethics committee approved the study. Results. Overall, 122 IPTS from 32 episodes from 29 patients were included; 14 subjects met the IDSA PJI criteria. No difference (Se71.4%, Sp88.8%) was observed between the conventional method and the homogenized method for the agar and broth set. An increased sensitivity was observed for the homogenized method with addition of BCBs (Se85.7%) in contrast to agars and broths alone (Se71.4%). The homogenized method with BCBs and agar plates showed an excellent specificity and positive-predictive value, indicating the lower contamination risk and facilitating the microbiological diagnosis. Adding broths to this combination increases the false positivity rate (Sp94.4%). A false positivity rate of 15/122 IPTS was observed for broths alone, in contrast to 2/122 for BCBs alone. Also, one case (1/14) would have been missed when using the homogenized method with agars and broths alone. Conclusions. Beadmill processing of IPTS and culturing in BCBs is a sensitive and highly specific culture method for diagnosis of PJI. The superior specificity versus conventional methods minimizes false positive results, which frequently lead to erroneous clinical decisions. Furthermore, this makes semi-automated laboratory processing possible


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_6 | Pages 83 - 83
1 Jul 2020
Yao H Xu J Qin L Zheng N Wang J Ho KW
Full Access

Previous study reported that intra-articular injection of MgSO4 could alleviate pain related behaviors in a collagenase induced OA model in rats. It provided us a good description on the potential of Mg2+ in OA treatment. However, the specific efficiency of Mg2+ on OA needs to be further explored and confirmed. The underlying mechanisms should be elucidated as well. Increasing attention has been paid on existence of synovial fluid MSCs (SF-MSCs) (not culture expanded) which may participate in endogenous reparative capabilities of the joint. On the other hand, previous studies demonstrated that Mg2+ not only promoted the expression of integrins but also enhanced the strength of fibronectin-integrin bonds that indicated the promotive effect of Mg2+ on cell adhesion, moreover, Mg2+ was proved could enhance chondrogenic differentiation of synovial membrane derived MSCs by modulating integrins. Based on these evidence, we hypothesize herein intra-articular injection of Mg2+ can attenuate cartilage degeneration in OA rat through modulating the biological behavior of SF-MSCs. Human and rat SF-MSCs were collected after obtaining Experimental Ethics approval. The biological behaviors of both human and rat SF-MSCs including multiple differentiation, adhesion, colony forming, proliferation, etc. were determined in vitro in presence or absence of Mg2+ (10 mmol/L). Male SD rats (body weight: 450–500 g) were used to establish anterior cruciate ligament transection and partial medial meniscectomy (ACLT+PMM) OA models. The rats received ACLT+PMM were randomly divided into saline (control) group and MgCl2 (0.5 mol/L) group (n=6 per group). Intra-articular injection was performed on week 4 post-operation, twice per week for two weeks. Knee samples were harvested on week 2, 4, 8, 12 and 16 after injection for histological analysis for assessing the progression of OA. On week 2 and 4 after injection, the rat SF-MSCs were also isolated before the rats were sacrificed for assessing the abilities of chondrogenic differentiation, colony forming and adhesion in vitro. Statistical analysis was done using Graphpad Prism 6.01. Unpaired t test was used to compare the difference between groups. Significant difference was determined at P < 0 .05. The adhesion and chondrogenic differentiation ability of both human and rat SF-MSCs were significantly enhanced by Mg2+ (10 mmol/L) supplementation in vitro. However, no significant effects of Mg2+ (10 mmol/L) on the osteogenic and adipogenic differentiation as well as the colony forming and proliferation. In the animal study, histological analysis by Saffranin O and Toluidine Blue indicated the cartilage degeneration was significantly alleviated by intra-articular injection of Mg2+, in addition, the expression of Col2 in cartilage was also increased in MgCl2 group with respect to control group indicated by immunohistochemistry. Moreover, the OARSI scoring was decreased in MgCl2 group as well. Histological analysis and RT-qPCR indicated that the chondrogenic differentiation of SF-MSCs isolated from Mg2+ treated rats were significantly enhanced compare to control group. In the current study, we have provided direct evidence supporting that Mg2+ attenuated the progression of OA. Except for the effect of Mg2+ on preventing cartilage degeneration had been demonstrated in this study, for the first time, we demonstrated the promoting effect of Mg2+ on adhesion and chondrogenic differentiation of endogenous SF-MSCs within knee joint that may favorite cartilage repair. We have confirmed that the anti-osteoarthritic effect of Mg2+ involves the multiple actions which refer to prevent cartilage degeneration plus enhance the adhesion and chondrogenic differentiation of SF-MSCs in knee joint to attenuate the progression of OA. These multiple actions of Mg2+ may be more advantage than traditional products. Besides, this simple, widely available and inexpensive administration of Mg2+ has the potential on reducing the massive heath economic burden of OA. However, the current data just provided a very basic concept, the exact functions and underlying mechanisms of Mg2+ on attenuating OA progression still need to be further explored both in vitro and in vivo. Formula of Mg2+ containing solution also need to be optimized, for example, a sustained and controlled release delivery system need to be developed for improving the long-term efficacy


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_2 | Pages 73 - 73
1 Feb 2020
Gascoyne T Parashin S Teeter M Bohm E Laende E Dunbar M Turgeon T
Full Access

Purpose. The purpose of this study was to examine the influence of weight-bearing on the measurement of in vivo wear of total knee replacements using model-based RSA at 1 and 2 years following surgery. Methods. Model-based RSA radiographs were collected for 106 patients who underwent primary TKR at a single institution. Supine RSA radiographs were obtained post-operatively and at 6-, 12-, and 24-months. Standing (weight-bearing) RSA radiographs were obtained at 12-months (n=45) and 24-months (n=48). All patients received the same knee design with a fixed, conventional PE insert of either a cruciate retaining or posterior stabilized design. Ethics approval for this study was obtained. In order to assess in vivo wear, a highly accurate 3-dimensional virtual model of each in vivoTKA was developed. Coordinate data from RSA radiographs (mbRSA v3.41, RSACore) were applied to digital implant models to reconstruct each patient's replaced knee joint in a virtual environment (Geomagic Studio, 3D Systems). Wear was assessed volumetrically (digital model overlap) on medial and lateral condyles separately, across each follow-up. Annual rate of wear was calculated for each patient as the slope of the linear best fit between wear and time-point. The influence of weight-bearing was assessed as the difference in annual wear rate between standing and supine exams. Age, BMI, and Oxford-12 knee improvement were measured against wear rates to determine correlations. Results. Weight bearing wear measurement was most consistent and prevalent in the medial condyle with 0–4% of calculated wear rates being negative compared to 29–39% negative wear rates for the lateral condyle. For the medial condyle, standing exams revealed higher mean wear rates at 1 and 2 years; supine, 16.3 mm. 3. /yr (SD: 27.8) and 11.2 mm. 3. /yr (SD: 18.5) versus standing, 51.3 mm. 3. /yr (SD: 55.9) and 32.7 mm. 3. /yr (SD: 31.7). The addition of weight-bearing increased the measured volume of wear for 78% of patients at 1 year (Avg: 32.4 mm. 3. /yr) and 71% of patients at 2 years (Avg: 48.9 mm. 3. /yr). There were no significant (95% CI) correlations between patient demographics and wear rates. Discussion and Conclusion. This study demonstrated TKA wear to occur at a rate of approximately 10 mm. 3. /year and 39 mm. 3. /year in patients imaged supine versus standing, respectively, averaged over 2 years of clinical follow-up. In an effort to eliminate the effect of PE creep and deformation, wear was also calculated between 12 and 24 months as 9.3 mm. 3. (standing examinations), This value is comparable to wear rates obtained from retrieved TKRs. Weight-bearing exams produced better wear data with fewer negative wear rates and reduced variance. Limitations of this study include: supine patient imaging performed at post-op, no knee flexion performed, and unknown patient activity level. Strengths of this study include: large sample size of a single TKR system, linear regression of wear measurements and no requirement for implanted RSA beads with this method. Based on these results, in vivo volumetric wear of total knee replacement polyethylene can be reliably measured using model-based RSA and weight-bearing examinations in the short- to mid–term. For any figures or tables, please contact authors directly


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_13 | Pages 45 - 45
1 Sep 2014
Potgieter N
Full Access

Abstract Detail. Interim results on a prospective, randomised, single-blinded pilot study to compare implant alignment using a patient-matched cutting guide versus a computer-assisted navigation system following total knee arthroplasty. Purpose of Study. To compare implant alignment using a patient-matched cutting guide (Visionaire) versus a computer-assisted navigation system (CAS) following total knee arthroplasty (TKA). Description of methods. Ethics approval was sought and granted by the South African Medical Association Research Ethics Committee. Patient consent for participation was obtained. Patients were randomized to TKA using Visionaire or CAS. Mechanical alignment was evaluated pre-operatively and at 3 months with a full leg X-Ray. Operative and post-operative parameters relating to resource utilization were captured. Clinical status according to the Knee Society Clinical Rating System (KSCRS) was assessed pre-operatively and at 3 months. Adverse events were noted. An independent Contract Research Organisation was used to monitor the site. Summary of results. Ten unique patients were enrolled, of whom 5 were randomized to Visionaire and 5 to CAS. Two patients in the Visionaire group have not yet reached their 3-month assessment. No significant difference in mechanical alignment between the 2 groups at 3 months was observed. The median duration of surgery was significantly shorter for the patient-matched cutting guide group across all assessed parameters (theatre time: 117 versus 150 minutes, p=0.009; operative time: 85 versus 108 minutes, p=0.0088; tourniquet time: 73 versus 99 minutes, p=0.009; and anaesthetist time: 117 versus 150 minutes, p=0.009). No other significant differences in operative or post-operative cost-drivers were noted between the 2 groups. No significant difference in KSCRS scores between the 2 groups at 3 months was observed. Two adverse were reported, one in each group, both unrelated to the medical devices, and both of which have resolved. Conclusion. While implant alignment appears consistent and comparable in both groups at 3 months, the median duration of surgery was significantly shorter for the Visionaire group. DISCLOSURE: Assistance and funding was received from Smith & Nephew