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Bone & Joint Research
Vol. 5, Issue 6 | Pages 232 - 238
1 Jun 2016
Tanaka A Yoshimura Y Aoki K Kito M Okamoto M Suzuki S Momose T Kato H

Objectives. Our objective was to predict the knee extension strength and post-operative function in quadriceps resection for soft-tissue sarcoma of the thigh. Methods. A total of 18 patients (14 men, four women) underwent total or partial quadriceps resection for soft-tissue sarcoma of the thigh between 2002 and 2014. The number of resected quadriceps was surveyed, knee extension strength was measured with the Biodex isokinetic dynamometer system (affected side/unaffected side) and relationships between these were examined. The Musculoskeletal Tumor Society (MSTS) score, Toronto Extremity Salvage Score (TESS), European Quality of Life-5 Dimensions (EQ-5D) score and the Short Form 8 were used to evaluate post-operative function and examine correlations with extension strength. The cutoff value for extension strength to expect good post-operative function was also calculated using a receiver operating characteristic (ROC) curve and Fisher’s exact test. Results. Extension strength decreased when the number of resected quadriceps increased (p < 0.001), and was associated with lower MSTS score, TESS and EQ-5D (p = 0.004, p = 0.005, p = 0.006, respectively). Based on the functional evaluation scales, the cutoff value of extension strength was 56.2%, the equivalent to muscle strength with resection of up to two muscles. Conclusion. Good post-operative results can be expected if at least two quadriceps muscles are preserved. Cite this article: A. Tanaka, Y. Yoshimura, K. Aoki, M. Kito, M. Okamoto, S. Suzuki, T. Momose, H. Kato. Knee extension strength and post-operative functional prediction in quadriceps resection for soft-tissue sarcoma of the thigh. Bone Joint Res 2016;5:232–238. DOI: 10.1302/2046-3758.56.2000631


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_10 | Pages 138 - 138
1 May 2016
Yamaura K Muratsu H Tsubosaka M Annziki K Kudo K Minamino S Oshima T Matsumoto T Maruo A Miya H Kuroda R Kurosaka M
Full Access

Introduction

As the aging society progresses rapidly, the number of patients underwent total knee arthroplasty (TKA) is increasing especially for the elderly population. In Japan, the average age for TKA is around 75 years old. Japanese Orthopaedic Association indicated a new clinical entity of musculoskeletal ambulation disability symptom complex (MADS) to define the higher risk of fall and ambulatory disability in the elderly population in 2006. The diagnosing criteria for MADS consists of 2 simple performance tests. 3m timed up and go test (TUG) evaluates ambulatory function, and one leg standing time (ST) assesses balancing ability.

Objective

In this study, we analyzed the effect of TKA on the ambulatory function by quantitative measurement using 2 simple performances test: TUG and ST.


Orthopaedic Proceedings
Vol. 93-B, Issue SUPP_II | Pages 144 - 144
1 May 2011
Jensen C Haughton B Bull D Reed M Muller S
Full Access

Introduction: Prophylactic systemic antibiotics are commonly used peri-operatively in primary hip and knee arthroplasty in the UK. ‘Fast-Track’ (FT) peri-operative care – a multimodal concept aiming to accelerate postoperative rehabilitation and reduce general morbidity – is also becoming more common in arthroplasty surgery. There are no published reports of acute kidney injury (AKI) as a result of a single-dose prophylactic Gentamicin. The renal impact of hypotensive anaesthesia and reduced routine post-operative intravenous fluid therapy, both features of FT protocol, has not yet been reported. Aim: To evaluate the renal impact of prophylactic Gentamicin and FT perioperative care in hip and knee arthroplasty surgery.

Methods: Four hundred and eighty-four total hip/knee arthroplasty patients had their pre-operative, first and third post-operative day serum creatinine concentration measured and recorded. The first 180 patients (group A) received 1.5g Cefuroxime at induction and two further doses of 750mg at 8 hours and 16 hours post-operatively as antibiotic prophylaxis. The next 160 patients (Group B) received 5mg/kg single-dose Gentamicin at induction instead of Cefuroxime. These patients (Group A and B) were not treated as per FT protocol. The final 144 patients (Group C) received the same Gentamicin as Group B and were treated as per FT protocol. Outcome measures were overall change and an increase of > 30 μmol/L, the latter signifying an AKI.

Results: Mean creatinine change at day 1 was −4.63 in Group A, −3.95 in Group B and 4.19 in Group C. Mean creatinine change by day 3 was −5.28 in Group A, −2.53 in Group B and 8.89 in Group C. No patients in Group A, 4 patients (2.56%) in Group B and 9 patients (6.66%) in Group C had a rise of > 30 μmol/L in day 1 creatinine concentrations.

Conclusions: Comparing the groups, there was no statistically significance change in the day 1 creatinine when Gentamicin replaced Cefuroxime (p=0.625,) however this became significant once FT was also introduced (p=0.001.) In terms of an important creatinine rise (AKI,) the change to Gentamicin produced a statistically significant rise in the number of patients with a day 1 creatinine rise > 30 μmol/L (p=0.048.) By day 3 there is no significant difference in the number of patients with a creatinine rise > 30 μmol/L.

Discussion: FT protocol aims to encourage haemostatic surgery and early ambulant patients (free from drip stands) at the expense of mild hypovolaemia. When these patients are also receiving Gentamicin, the kidneys are concentrating urine and Gentamicin in the tubules thus causing and AKI in some cases. It appears that Gentamicin and FT are cumulative in their effect on renal function.


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_12 | Pages 58 - 58
1 Dec 2022
Lemieux V Afsharpour S Nam D Elmaraghy A
Full Access

Operative management of clavicle fractures is increasingly common. In the context of explaining the risks and benefits of surgery, understanding the impact of incisional numbness as it relates to the patient experience is key to shared decision making. This study aims to determine the prevalence, extent, and recovery of sensory changes associated with supraclavicular nerve injury after open reduction and plate internal fixation of middle or lateral clavicle shaft fractures. Eighty-six patients were identified retrospectively and completed a patient experience survey assessing sensory symptoms, perceived post-operative function, and satisfaction. Correlations between demographic factors and outcomes, as well as subgroup analyses were completed to identify factors impacting patient satisfaction. Ninety percent of patients experienced sensory changes post-operatively. Numbness was the most common symptom (64%) and complete resolution occurred in 32% of patients over an average of 19 months. Patients who experienced burning were less satisfied overall with the outcome of their surgery whereas those who were informed of the risk of sensory changes pre-operatively were more satisfied overall. Post-operative sensory disturbance is common. While most patients improve, some symptoms persist in the majority of patients without significant negative effects on satisfaction. Patients should always be advised of the risk of persistent sensory alterations around the surgical site to increase the likelihood of their satisfaction post-operatively


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_7 | Pages 19 - 19
1 Jul 2020
Schemitsch C Nauth A Chahal J Henry P Davis A Da Costa D Nowak L
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Rotator cuff injuries represent a significant burden to the health care system, affecting more than 30% of the population over the age of sixty. Despite the advanced surgical techniques that are available, poor results are sometimes seen in a subset of patients receiving surgical treatment for their rotator cuff disease. The reasons for this failure of treatment remain unclear, particularly if the surgery was ‘technically’ successful. An increasing body of evidence has demonstrated a strong correlation between pre-operative psychological factors and functional outcome following several orthopaedic procedures. This association, however, has not been fully demonstrated or effectively investigated in the context of rotator cuff treatment. The main objective for this study was to conduct a systematic review to determine the impact of psychosocial factors on the outcome of treatment in patients with rotator cuff disease. A systematic search was conducted of Medline, CINAHL, and PsychInfo databases for articles published from database inception until September 2018. The titles and abstracts were screened for all of the studies obtained from the initial search. Inclusion and exclusion criteria were applied, and a full text review was conducted on those studies meeting the eligibility criteria. A total of 1252 studies were identified. Following removal of duplicates and application of the inclusion and exclusion criteria, 46 studies underwent a full-text review. Ten studies were included in the final analysis. A total of 1,206 patients, with a mean follow-up of 13 months, were included. Three studies examined patient expectations prior to treatment. All three found that higher expectations prior to treatment led to a significantly improved outcome following both operative and non-operative treatment. Three studies assessed the association between pre-operative general psychological measures and post-operative pain and function. All three studies found patients with worse pre-operative general psychological scores demonstrated increased post-operative pain. Two of the studies also found a negative association with post-operative function, while one of the studies found no association with post-operative function. Three studies assessed the impact of pre-operative anxiety and depression on outcomes following surgical treatment of rotator cuff disease. Only one of the studies found a negative association with post-operative pain and function. The remaining two studies found no association between anxiety or depression and any outcomes following surgery. Finally, one study examined the impact of general distress on outcomes following the surgical treatment of rotator cuff disease and found no association with post-operative levels of pain or function. The results of this systematic review indicate that there is somewhat conflicting and contradictory evidence within the literature. Overall, however, there does appear to be an association between pre-operative psychological factors and post-operative function and pain, in that higher levels of pre-operative psychological dysfunction are predictive of poorer function and increased pain following the treatment of rotator cuff disease


Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_7 | Pages 35 - 35
1 Jul 2022
Bua N Kwok M Wignadasan W Iranpour F Subramanian P
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Abstract. Background. The incidence of periprosthetic fractures of the femur around a total knee arthroplasty (TKA) is rising and this is owed to the increased longevity that today's TKA implants allow for, as well as an aging population. These injuries are significant as they are related to increased morbidity and mortality. Methods. We retrospectively reviewed all periprosthetic fractures around a TKA that presented to our NHS Trust between 2011 to 2020. Medical records were reviewed. Treatment, complications and mortality were noted. Results. 37 patients (34 females) with an average age of 84 (range 65–99) met the inclusion criteria for this study. 17 patients (45.9%) underwent open reduction and internal fixation (ORIF), eight patients (21.6%) underwent revision arthroplasty to a distal femoral replacement (DFR) and 12 patients (32.4%) were treated non-operatively. 10 (58.8%) of the 17 patients that were treated with ORIF were discharged from hospital to a rehabilitation facility rather than their usual residence. In comparison, 3 (37.5%) of the patients that were treated with a DFR were discharged to a rehabilitation facility. one-year mortality rate in the ORIF group was 29.4 compared to 12.5% in those that had a DFR. Conclusion. Revision arthroplasty using a DFR should be considered in patients with periprosthetic fractures around a TKR, as it is associated with lower mortality rates and higher immediate post-operative function


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_9 | Pages 97 - 97
17 Apr 2023
Gupta P Butt S Mahajan R Galhoum A Lakdawala A
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Prompt mobilisation after the Fracture neck of femur surgery is one of the important key performance index (‘KPI caterpillar charts’ 2021) affecting the overall functional outcome and mortality. Better control of peri-operative blood pressure and minimal alteration of renal profile as a result of surgery and anaesthesia may have an implication on early post-operative mobilisation. Aim was to evaluate perioperative blood pressure measurements (duration of fall of systolic BP below the critical level of 90mmHg) and effect on the post-operative renal profile with the newer short acting spinal anaesthetic agent (prilocaine and chlorprocaine) used alongside the commonly used regional nerve block. 20 patients were randomly selected who were given the newer short acting spinal anaesthetic agent along with a regional nerve block between May 2019 and February 2020. Anaesthetic charts were reviewed from all patients for data collection. The assessment criteria for perioperative hypotension: Duration of systolic blood pressure less than 90 mm of Hg and change of pre and post operative renal functions. Only one patient had a significant drop in systolic BP less than 90mmHg (25 minutes). 3 other patients had a momentary fall of systolic BP of less than 5 minutes. None of the above patients had mortality and had negligible change in pre and post op renal function. Only one patient in this cohort had elevation of post-operative creatinine levels but did not have any mortality. Only 1 patient died on day 3 post operatively who had multiple comorbidities and was under evaluation for GI cancer. Even in this patient the peri-operative blood pressure was well maintained (never below 90mmHg systolic) and post-operative renal function was also shown to have improved (309 pre-operatively to 150 post-operatively) in this patient. The use of short-acting spinal anaesthesia has shown to be associated with a better control of blood pressure and end organ perfusion, less adverse effects on renal function leading to early mobilisation and a more favourable patient outcome with reduced mortality, earlier mobilisation, shorter hospital stay and earlier discharge in this elderly patient cohort


Orthopaedic Proceedings
Vol. 105-B, Issue SUPP_4 | Pages 12 - 12
3 Mar 2023
Dewhurst H Boktor J Szomolay B Lewis P
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Background. In recent years, ‘Get It Right First Time (GIRFT)’ have advocated cemented replacements in femoral part of Total hip arthroplasty (THA) especially in older patients. However, many studies were unable to show any difference in outcomes and although cemented prostheses may be associated with better short-term pain outcomes there is no clear advantage in the longer term. It is not clear when and why to do cemented instead of cementless. Aim. To assess differences in patient reported outcomes in uncemented THAs based on patient demographics in order to decide when cementless THA can be done safely. Method. Prospective data collection of consecutive 1079 uncemented THAs performed for 954 patients in single trust between 2010 and 2020. Oxford Hip Score (OHS) and complications were analysed against demographic variables (age, sex, BMI, ASA) and prosthesis features (femoral and acetabular size, offset and acetabular screws). Results. The mean pre-operative OHS was 14.6 which improved to 39.0 at 1 year follow up (P Value=0.000). There was no statistically significant difference between OHS outcome in patients aged over 70 versus younger groups. With a small number of revisable complications increase with age from 50s upwards. Male patients’ OHS score was on average 2.4 points higher than women. Men, however were 2.9 times more likely to experience fractures and high offset hips were 2.5 times more likely to experience dislocations. DAIR, intraoperative calcar fractures, post-operative fractures and dislocations were not associated with worse OHS. Patients with increased BMI had worse pre and post-operative hip functions yet, there was a significant multivariate association between increased BMI and increased improvement in OHS from pre-op to 1 year in women aged 55–80 and men under the age of 60. Femoral stem size increases with age but decreases in male patients over 80. There was no difference found in OHS between bilateral hip replacements and unilateral, nor was there any change found with laterality side of the replacement. Conclusions. This study suggests that ageing >70 is not associated with poorer outcomes despite small number of revisable complication rates that increase with age from 50 upwards. Men had marginally higher average OHS than women At 1 year. Higher BMI or ASA scores are associated with worse pre-operative hips and worse final outcome score. Despite this, the Delta OHS increases with increased BMI shown in the 55–80 year old female patients and male patients under 60. Key Words: THR, Uncemented, Oxford hip score, outcome


Orthopaedic Proceedings
Vol. 94-B, Issue SUPP_XXIX | Pages 4 - 4
1 Jul 2012
van der Linden M Wade F Lawson G Nutton R
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The aim of this study was to explore the pre-operative predictors of the function component of the WOMAC one year after total knee arthroplasty (TKA) using a hierarchical regression model. The pre-operative and one year post-operative results of 71 patients with knee osteoarthritis who underwent TKA were analysed. First the correlation between the post-operative function component of the WOMAC and a range of pre-operative measures were calculated to determine the independent variables for the hierarchical regression model. Independent pre-operative measures which showed a significant correlation with post-operative function were then entered in the model. Pre-operative measures were divided into three types according to International Classification of Health: (i) Personal characteristics, (ii) body structures and function and (iii) Psychosocial variables. The following pre-operative measures were correlated with post-operative function: Knee flexion (r=-0.254), extensor strength (r=-0.338), flexor strength (r=-0.257), mental health component of the SF36 (r=-0.304), Tampa scale (fear of movement), (r=0.261), the sense of helplessness due to pain (r=0.264) and Stanford arthritis Self-Efficacy Pain Scale (r=-0.343). This scale is a measure of the person's belief in their capability to cope with their arthritis pain. The higher the score the better the person's self-efficacy. Only independent pre-operative measures were entered in the models. In step 0, we controlled for age and Body Mass Index (BMI), in step 1 we entered knee flexion and extensor strength (model 1) and in step 2 Self-Efficacy was entered in the model (model2). In model1 extensor strength was a significant predictor of post-operative function (beta =-0.242, p=0.028). In the final model (model3) pre-operative extensor strength (beta =-0.242, p=0.07) and Self-Efficacy (beta -0.266, p=0.046) were the strongest predictors of post-operative function. Conclusions. We found that pre-operative muscle strength and psychosocial measures such as the perceived ability to cope with the effects of arthritis pain (Pain Self-Efficacy) were the most meaningful predictors of outcome one year after total knee arthroplasty


Orthopaedic Proceedings
Vol. 101-B, Issue SUPP_4 | Pages 60 - 60
1 Apr 2019
Ta M LaCour M Sharma A Komistek R
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Currently, hip implant designs are evaluated experimentally using mechanical simulators or cadavers, and total hip arthroplasty (THA) postoperative outcomes are evaluated clinically using long-term follow-up. However, these evaluation techniques can be both costly and time-consuming. Neither can provide an assessment of post-operative results at the onset of implant development. More recently, a forward-solution mathematical model was developed that functions as theoretical joint simulator, providing instant feedback to designers and surgeons alike. This model has been validated by comparing the model predictions with kinematic results from fluoroscopy for both implanted and non-implanted hips and kinetics from a telemetric hip. The model allows surgical technique modifications and implant component placement under in vivo conditions. The objective of this study was to further expand the capabilities of the model to function as an intraoperative virtual surgical tool (Figure 1). This new module allows the surgeon to simulate surgery, then predict, compare, and optimize postoperative THA outcomes based on component placement, sizing choices, reaming and cutting locations, and surgical methods. This virtual surgery tool simulates the quadriceps, hamstring, gluteus, iliopsoas, tensor fasciae latae, and an adductor muscle groups, as well as the hip capsular ligament groups. The model can simulate resecting, weakening, loosening, or tightening of soft tissues based on surgical techniques. Additionally, the model can analyze a variety of activities, including gait and deep flexion activities. Initially, the virtual surgery module offers theoretical surgery tools that allow surgeons to alter surgical alignments, component designs, offsets, as well as reaming and cutting simulations. The virtual model incorporates a built-in CT scan bone database which will assist in determining muscle and ligament attachment sites as well as bony landmarks. The virtual model can be used to assist in the placement of both the femoral component and the acetabular cup (Figure 2). Moreover, once the surgeon has decided on the placements of the components, they can use the simulation capabilities to run virtual human body maneuvers based on the chosen parameters. The simulations will reveal force, contact stress, and motion predictions of the hip joint (Figure 3). The surgeon can then choose to modify the positions accordingly or proceed with the surgery. This new virtual surgical tool will allow surgeons to gain a better understanding of possible post-operative outcomes under pre-operative conditions or intra-operatively. Simulations using the virtual surgery model has revealed that improper component placement may lead to non-ideal post-operative function, which has been simulated using the model. Further evaluation is ongoing so that this new module can reveal more information pre-operatively, allowing a surgeon to gain ample information before surgery, especially with difficult and revision cases


Orthopaedic Proceedings
Vol. 102-B, Issue SUPP_11 | Pages 31 - 31
1 Dec 2020
Shah DS Taylan O Berger P Labey L Vandenneucker H Scheys L
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Orthopaedic training sessions, vital for surgeons to understand post-operative joint function, are primarily based on passive and subjective joint assessment. However, cadaveric knee simulators, commonly used in orthopaedic research,. 1. could potentially benefit surgical training by providing quantitative joint assessment for active functional motions. The integration of cadaveric simulators in orthopaedic training was explored with recipients of the European Knee Society Arthroplasty Travelling Fellowship visiting our institution in 2018 and 2019. The aim of the study was to introduce the fellows to the knee joint simulator to quantify the surgeon-specific impact of total knee arthroplasty (TKA) on the dynamic joint behaviour, thereby identifying potential correlations between surgical competence and post-operative biomechanical parameters. Eight fellows were assigned a fresh-frozen lower limb each to plan and perform posterior-stabilised TKA using MRI-based patient-specific instrumentation. Surgical competence was adjudged using the Objective Structured Assessment of Technical Skills (OSATS) adapted for TKA. 2. All fellows participated in the in vitro specimen testing on a validated knee simulator,. 3. which included motor tasks – passive flexion (0°-120°) and active squatting (35°-100°) – and varus-valgus laxity tests, in both the native and post-operative conditions. Tibiofemoral kinematics were recorded with an optical motion capture system and compared between native and post-operative conditions using a linear mixed model (p<0.05). The Pearson correlation test was used to assess the relationship between the OSATS scores for each surgeon and post-operative joint kinematics of the corresponding specimen (p<0.05). OSATS scores ranged from 79.6% to 100% (mean=93.1, SD=7.7). A negative correlation was observed between surgical competence and change in post-operative tibial kinematics over the entire range of motion during passive flexion – OSATS score vs. change in tibial abduction (r=−0.87; p=0.003), OSATS score vs. change in tibial rotation (r=−0.76; p=0.02). When compared to the native condition, post-operative tibial internal rotation was higher during passive flexion (p<0.05), but lower during squatting (p<0.033). Post-operative joint stiffness was greater in extension than in flexion, without any correlation with surgical competence. Although trained at different institutions, all fellows followed certain standard intraoperative guidelines during TKA, such as achieving neutral tibial abduction and avoiding internal tibial rotation,. 4. albeit at a static knee flexion angle. However, post-operative joint kinematics for dynamic motions revealed a strong correlation with surgical competence, i.e. kinematic variability over the range of passive flexion post-TKA was lower for more skilful surgeons. Moreover, actively loaded motions exhibited stark differences in post-operative kinematics as compared to those observed in passive motions. In vitro testing on the knee simulator also introduced the fellows to new quantitative parameters for post-operative joint assessment. In conclusion, the inclusion of cadaveric simulators replicating functional joint motions could help quantify training paradigms, thereby enhancing traditional orthopaedic training, as was also the unanimous opinion of all participating fellows in their positive feedback


Orthopaedic Proceedings
Vol. 91-B, Issue SUPP_I | Pages 6 - 6
1 Mar 2009
Nicoll D Mahayni H Rowley D
Full Access

This study was carried out to evaluate the impact of Socio-Economic Status (SES) and the influence of geographic access to health services on the possible outcomes of total knee replacement (TKR). Data on 345 patients with one year follow-up were collected from the database of the orthopaedic department. TKR outcomes were assessed according to Knee Society Score (KSS). A postcode was assigned to each patient depending on the residential area and data from the last census was used to calculate Scottish Index of Multiple Deprivation Score (SIMD) and its rating score for geographic access to health services. The results show that the SES and the geographic access to medical services have significant impact on Function Scores but do not influence Knee Scores. Patients living in the least deprived regions had a better post-operative Function Scores compared to those living in more deprived regions with differences of up to 13 points between groups (p< 0.001). Similarly the improvement in Function Scores was dependant on deprivation score. (p=0.015). Pre-operative Knee Score, post-operative Knee Score and improvement in Knee Scores were not influenced by deprivation score. Patients living in rural regions had better post-operative Function Scores and greater improvements in Function Score compared to urban dweller patients (p≤0.011) with differences of up to 17 points. The Knee Score was not influenced by these variables. These results suggest that SES and the region of residence should be considered when assessing the outcomes of TKR


Orthopaedic Proceedings
Vol. 100-B, Issue SUPP_10 | Pages 84 - 84
1 Jun 2018
Rodriguez J
Full Access

Knee replacement is a proven and reproducible procedure to alleviate pain, re-establish alignment and restore function. However, the quality and completeness to which these goals are achieved is variable. The idea of restoring function by reproducing condylar anatomy and asymmetry has been gaining favor. As knee replacements have evolved, surgeons have created a set of principles for reconstruction, such as using the femoral transepicondylar axis (TEA) in order to place the joint line of the symmetric femoral component parallel to the TEA, and this has been shown to improve kinematics. However, this bony landmark is really a single plane surrogate for independent 3-dimensional medial and lateral femoral condylar geometry, and a difference has been shown to exist between the natural flexion-extension arc and the transepicondylar axis. The TEA works well as a surrogate, but the idea of potentially replicating normal motion by reproducing the actual condylar geometry and its involved, individual asymmetry has great appeal. Great variability in knee anatomy can be found among various populations, sizes, and genders. Each implant company creates their specific condylar geometry, or “so called” J curves, based on a set of averages measured in a given population. These condylar geometries have traditionally been symmetric, with the individualised spatial placement of the (symmetric) curves achieved through femoral component sizing, angulation, and rotation performed at the time of surgery. There is an inherent compromise in trying to achieve accurate, individual medial and lateral condylar geometry reproduction, while also replicating size and avoiding component overhang with a set implant geometry and limited implant sizes. Even with patient-specific instrumentation using standard over-the-counter implants, the surgeon must input his/her desired endpoints for bone resection, femoral rotation, and sizing as guidelines for compromise. When all is done, and soft tissue imbalance exists, soft tissue release is the final, common compromise. The custom, individually made knee design goals include reproducible mechanical alignment, patient-specific fit and positioning, restoration of articular condylar geometry, and thereby, more normal kinematics. A CT scan allows capture of three-dimensional anatomical bony details of the knee. The individual J curves are first noted and corrected for deformity, after which they are anatomically reproduced using a Computer-Aided Design (CAD) file of the bones in order to maximally cover the bony surfaces and concomitantly avoid implant overhang. No options for modifications are offered to the surgeon, as the goal is anatomic restoration. In summary, the use of custom knee technology to more closely reproduce an individual patient's anatomy holds great promise in improving the quality and reproducibility of post-operative function. Compromises of fit and rotation are minimised, and implant overhang is potentially eliminated as a source of pain. Early results have shown objective improvements in clinical outcomes. Admittedly, this technology is limited to those patients with mild to moderate deformity at this time, since options like constraint and stems are not available. Yet these are the patients who can most clearly benefit from a higher functional state after reconstruction. Time will reveal if this potential can become a reproducible reality


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_15 | Pages 35 - 35
1 Aug 2017
Rodriguez J
Full Access

Knee replacement is a proven and reproducible procedure to alleviate pain, re-establish alignment and restore function. However, the quality and completeness to which these goals are achieved is variable. The idea of restoring function by reproducing condylar anatomy and asymmetry has been gaining favor As knee replacements have evolved, surgeons have created a set of principles for reconstruction, such as using the femoral transepicondylar axis (TEA) in order to place the joint line of the symmetric femoral component parallel to the TEA, and this has been shown to improve kinematics. However, this bony landmark is really a single plane surrogate for 3-dimensional medial and lateral femoral condylar geometry, and a difference has been shown to exist between the natural flexion-extension arc and the TEA. The TEA works well as a surrogate, but the idea of potentially replicating normal motion by reproducing the actual condylar geometry and its involved, individual asymmetry has great appeal. Great variability in knee anatomy can be found among various populations, sizes, and genders. Each implant company creates their specific condylar geometry, or “so called” J curves, based on a set of averages measured in a given population. These condylar geometries have traditionally been symmetric, with the individualised spatial placement of the (symmetric) curves achieved through femoral component sizing, angulation, and rotation performed at the time of surgery. There is an inherent compromise in trying to achieve accurate, individual medial and lateral condylar geometry reproduction, while also replicating size and avoiding component overhang with a set implant geometry and limited implant sizes. Even with patient-specific instrumentation using standard over-the-counter implants, the surgeon must input his/her desired endpoints for bone resection, femoral rotation, and sizing as guidelines for compromise. When all is done, and soft tissue imbalance exists, soft tissue release is the final, common compromise. The custom, individually made knee design goals include reproducible mechanical alignment, patient-specific fit and positioning, restoration of articular condylar geometry, and thereby, more normal kinematics. A CT scan allows capture of three-dimensional anatomical bony details of the knee. The individual J curves are first noted and corrected for deformity, after which they are anatomically reproduced using a Computer-Aided Design (CAD) file of the bones in order to maximally cover the bony surfaces and concomitantly avoid implant overhang. No options for modifications are offered to the surgeon, as the goal is anatomic restoration. Given these ideals, to what extent are patients improved? The concept of reproducing bony anatomy is based on the pretext that form will dictate function, such that normal-leaning anatomy will tend towards normal-leaning kinematics. Therefore, we seek to evaluate knee function based on objective assessments of movement or kinematics. The use of custom knee technology to more closely reproduce an individual patient's anatomy holds great promise in improving the quality and reproducibility of post-operative function. Compromises of fit and rotation are minimised, and implant overhang is potentially eliminated as a source of pain. Early results have shown objective improvements in clinical outcomes. Admittedly, this technology is limited to those patients with mild to moderate deformity at this time, since options like constraint and stems are not available. Yet these are the patients who can most clearly benefit from a higher functional state after reconstruction. Time will reveal if this potential can become a reproducible reality


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_7 | Pages 77 - 77
1 Apr 2017
Rodriguez J
Full Access

Knee replacement is a proven and reproducible procedure to alleviate pain, re-establish alignment and restore function. However, the quality and completeness to which these goals are achieved is variable. The idea of restoring function by reproducing condylar anatomy and asymmetry has been gaining favor. As knee replacements have evolved, surgeons have created a set of principles for reconstruction, such as using the femoral transepicondylar axis (TEA) in order to place the joint line of the symmetric femoral component parallel to the TEA, and this has been shown to improve kinematics. However, this bony landmark is really a single plane surrogate for 3-dimensional medial and lateral femoral condylar geometry, and a difference has been shown to exist between the natural flexion-extension arc and the TEA. The TEA works well as a surrogate, but the idea of potentially replicating normal motion by reproducing the actual condylar geometry and its involved, individual asymmetry has great appeal. Great variability in knee anatomy can be found among various populations, sizes, and genders. Each implant company creates their specific condylar geometry, or “so called” J curves, based on a set of averages measured in a given population. These condylar geometries have traditionally been symmetric, with the individualised spatial placement of the (symmetric) curves achieved through femoral component sizing, angulation, and rotation performed at the time of surgery. There is an inherent compromise in trying to achieve accurate, individual medial and lateral condylar geometry reproduction, while also replicating size and avoiding component overhang with a set implant geometry and limited implant sizes. Even with patient-specific instrumentation using standard over-the-counter implants, the surgeon must input his/her desired endpoints for bone resection, femoral rotation, and sizing as guidelines for compromise. When all is done, and soft tissue imbalance exists, soft tissue release is the final, common compromise. The custom, individually made knee design goals include reproducible mechanical alignment, patient-specific fit and positioning, restoration of articular condylar geometry, and thereby, more normal kinematics. A CT scan allows capture of three-dimensional anatomical bony details of the knee. The individual J curves are first noted and corrected for deformity, after which they are anatomically reproduced using a Computer-Aided Design (CAD) file of the bones in order to maximally cover the bony surfaces and concomitantly avoid implant overhang. No options for modifications are offered to the surgeon, as the goal is anatomic restoration. Given these ideals, to what extent are patients improved? The concept of reproducing bony anatomy is based on the pretext that form will dictate function, such that normal-leaning anatomy will tend towards normal-leaning kinematics. Therefore, we seek to evaluate knee function based on objective assessments of movement or kinematics. In summary, the use of custom knee technology to more closely reproduce an individual patient's anatomy holds great promise in improving the quality and reproducibility of post-operative function. Compromises of fit and rotation are minimised, and implant overhang is potentially eliminated as a source of pain. Early results have shown objective improvements in clinical outcomes. Admittedly, this technology is limited to those patients with mild to moderate deformity at this time, since options like constraint and stems are not available. Yet these are the patients who can most clearly benefit from a higher functional state after reconstruction. Time will reveal if this potential can become a reproducible reality


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_4 | Pages 99 - 99
1 Feb 2017
Lamontagne M Kowalski E Dervin G
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Introduction. Patients undergoing a total knee arthroplasty (TKA) are now living longer and partaking in more active lifestyles. They expect a high level of post-operative function and long term durability of their implant. Using electromyography (EMG) analysis helps further explain biomechanical findings by giving insight as to what is occurring at the level of the muscles. Normal biomechanics are not restored post-TKA as patients have reduced knee flexion and weakened quadriceps muscles compared to their healthy peers. Purpose. The purpose of this study was to compare muscle activation in TKA patients who received a medial pivot (MP) or posterior stabilized (PS) implant to those of healthy controls (CTRL) during a stair ascent task. Methods. A total of 12 patients were assigned to either a MP or PS TKA operated by the same surgeon. Approximately 9 months following surgery, the 12 patients along with 6 CTRL patients completed an EMG analysis during a stair ascent task (Table 1). Wireless EMG electrodes were placed on 4 muscles: vastus medialis (VM), vastus lateralis (VL), biceps femoris long head (BF), and semimembranosus (SM) muscles. All participants completed maximal voluntary contractions (MVICs) during knee flexion and extension while seated with the knee flexed at 60°. Following the MVICs, participants completed 5 trials of a 3-step stair ascent task. TKA patients were instructed to make the first step onto the staircase with their operated limb. EMG data were processed in Matlab. Peak muscle activity (PeakLE EMG) and total muscle activity (iEMG) from each muscle was obtained during stance phase. Data were averaged between left and right limbs for the CTRL group and compared to the operated limb of TKA groups. Non-parametric Kruskal Wallace ANOVA tests were used to test for statistical significance between groups and Wilcoxon rank sum tests were used to identify differences with α=0.05. Results. Both TKA groups had significantly greater PeakLE EMG of the quadriceps muscles compared to the CTRL group (Figure 1). PeakLE EMG of the BF and VM muscles were significantly greater in the PS group compared to both CTRL and MP groups. The PS group had significantly greater iEMG of the BF, VL and VM muscles compared to the CTRL group (Figure 2) whereas the PS group had significantly greater iEMG of the SM and VM muscles compared to the MP group. Conclusion. The MP group had lower PeakLE EMG for both VM and BF muscles compared to the PS group, indicating that the MP group activates these muscles less to achieve the stair ascent task. BF muscle stabilizes the knee roll-back motion while the VM muscle extends the leg to clear the steps. iEMG for the VM and BF muscles were greater for the PS group indicating that they have to activate their muscles longer and to a greater extent in order to stabilize the joint. This increased stability in MP implants is achieved through the concave aspect on the medial tibial plateau for the femoral condyle to pivot in. This will reduce implant wear, prolonging implant longevity


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_3 | Pages 2 - 2
1 Feb 2014
Jenkins P Ramaesh R Lane J Knight S MacDonald D Howie C
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Many psychological factors have been associated with function after joint replacement. Personality is a stable pattern of responses to external conditions and stimuli. The aim of this study was to investigate the relationship between personality, joint function, and general physical in patients undergoing total hip (THR) and knee replacement (TKR). We undertook a prospective cohort study of 184 patients undergoing THA and 205 undergoing TKA. Personality was assesed using the Eysneck Personality Questionaire, brief version (EPQ-BV). Physical health was measured using the EuroQol (EQ-5D). Joint function was measured using the relevant Oxford Score. Outcomes were assessed at six months. Multivariable models were constructed. The stable introvert personality was most common. Unstable introverts had poorer pre-operative function with hip arthrosis, but not knee arthrosis. Personality was not directly associated with post-operative function – the only independent predictors were pre-operative function (p=0.002) and comorbidity (p<0.001). While satisfaction after TKR was associated with personality (p=0.026), there was no association after THR (p=0.453). The poorest satisfaction was in those with the unstable introvert personality type. Personality was a predictor of preoperative status. It did not have a direct association with postoperative status, but may have as preoperative function was the main predictor of postoperative function, personality may have had an indirect effect. Personality was also a predictor of satisfaction after TKR. This suggests that predicting satisfaction after knee replacement is more complex. Therefore certain patient may benefit from a tailored preoperative education to explore and manage expectations


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_10 | Pages 52 - 52
1 May 2016
Stiegel K Ismaily S Noble P
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Introduction. Patients who undergo hip resurfacing, total hip arthroplasty (THA), and total knee arthroplasty (TKA) are frequently assessed post-operatively using objective scoring indices. A small yet significant percentage of these patients report specific unfulfilled functions following surgery, indicating unmet expectations. The purpose of this study was to examine the types of functional deficits reported for each class of surgery, how frequently these limitations occur, and the demographic of patients who experience/report these limitations. Methods. Four groups of subjects were enrolled in this study: (i) 111 hip resurfacing patients at an average of 14 months after resurfacing, (ii) 170 patients at an average of 16 months post-primary THA, (iii) 61 patients at an average of 12 months post-primary TKA, and (iv) 64 control subjects with no history of hip or knee surgery or pathology. Each participant completed a self-administered Hip Function Questionnaire, Knee Function Questionnaire, or Hip Resurfacing Questionnaire which assessed each subject's overall satisfaction and expectations following surgery. The questionnaires included numerical scores of post-operative function as well as an open-ended question which inquired “Is there anything your knee/hip keeps you from doing?”. Results. A population of patients self-reported specific functional deficits after surgery, including 29 (26.1%) resurfacing, 5 (2.9%) THA, and 32 (52.5%) TKA. The unfulfilled functions varied based on the procedure, with most resurfacing and THA patients reporting trouble with running/jogging, while TKA patients experienced difficulty kneeling. Patients who reported functional deficits also tended to endorse lower overall satisfaction levels after surgery; the mean satisfaction score for hip resurfacing in those who reported deficits was 4.03 (scale of 1–5) versus 4.50 (p=0.09) in those who denied a functional deficit, 2.20 versus 4.47 (p=0.003) in THA patients, and 4.10 versus 4.36 (p=0.35) in TKA patients. The demographic of patients who reported limitations varied based on the type of surgery. After hip resurfacing 19.0% (4/21) of female patients reported specific deficits compared to 27.3% (23/84) of male patients; 6.1% (5/81) of female THA patients reported compared to 0% (0/84) of males, and 48.6% (18/37) of female TKA patients reported compared to 58.3% (14/24) of males. The mean age of those who reported deficits versus those who did not report deficits was not significant. Conclusions. Despite advances in arthroplasty and resurfacing techniques, a significant portion of patients are experiencing functional limitations following hip resurfacing, TKA, and THA procedures. The frequency and types of limitations reported vary based on the surgery, with TKA patients reporting deficits with the highest frequency and THA patients reporting with the lowest frequency. The gender of the patient appears to play a role in whether specific functional deficits are reported or not, with female patients more likely to report after THA and male patients slightly more likely to report after either hip resurfacing or TKA. Summary. A small portion of hip resurfacing, THA, and TKA patients report specific unfulfilled functions following surgery. The frequency and types of deficits, and the demographic of patients reporting them, varies based on the procedure


Orthopaedic Proceedings
Vol. 95-B, Issue SUPP_22 | Pages 26 - 26
1 May 2013
Su E
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Surface replacement of the hip has become established as an alternative treatment to total hip replacement in the younger, active, male patient. By the very nature of preserving the femoral head and neck, there may be failures due to femoral neck fracture and femoral component loosening. Additionally, revisions of hip resurfacing for acetabular loosening may be necessary. Other scientific papers have described problems that may arise as a result of the metal-on-metal bearing either due to excess metal production or an immunologic-mediated reaction to the metal debris. Grammatopolous et al. describe poor results of revisions of surface replacements due to massive tissue destruction at the time of revision surgery, persistent pain, and swelling. In my experience with hip resurfacing, this complication is extremely rare. In my series of 925 resurfacings with a minimum of 2 year follow up, 12 revisions (1.3%) have been performed. Of these revisions, only 3 (0.3%) were for complications related to the metal-on-metal bearing; 2 for edge-loading and excess metal production, and 1 for metal hypersensitivity. None of the revision cases have had abductor destruction, or nerve/vascular involvement. Reconstruction of the joint was carried out with standard and revision components; post-operative function of these patients has been comparable to that of a primary total hip replacement. With careful monitoring of the post-operative resurfacing patient, problems can be identified early and surface replacement conversion can be performed with excellent results


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_1 | Pages 13 - 13
1 Jan 2016
Al-Khateeb H Howard J Naudie D McCalden RW MacDonald S
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Introduction. Total knee arthroplasty (TKA) has proven clinical success with reported longterm survivorship of 92% in the elderly population. Concerns regarding increased loosening rates and potential need for multiple revision surgeries in patients younger than 60 years have traditionally discouraged TKA in younger patients. The purpose of this study was to review the longterm clinical and radiographic results of patients under the age of 45 yrs who underwent a total knee replacement. Materials and Methods. A retrospective review of our institutional database was performed between January 1996 and December 2004 The criteria for inclusion in the study were as follows: age 45 years or younger at index arthroplasty, cemented condylar prosthesis, and a minimum follow-up of 9 years. A total of 39 consecutive primary cemented condylar knee arthroplasties in patients with end stage arthritis were performed in 36 patients who were 45 years or younger. The median length of followup was 13.6 years. There were 18 men and 21 women. The mean age was 40.6 years (range, 28–44). There were 23 right, 16 left, and 3 bilateral procedures. The mean body mass index was 31.2 kg/m2. Clinical and radiological evaluations were performed before surgery and at 6 weeks, 3 months, 1 year and every 2 years subsequently. Knee scores were calculated using the Knee Society Clinical Rating Scores (KSCRS), SF-12 and WOMAC scores to assess pre, and post-operative function. Postoperative anteroposterior and lateral views were assessed for femoral and tibial component position, alignment, and presence or progression of radiolucent lines at the bone-cement and prosthesis-cement interfaces. Statistical analysis was performed using the 2-sample test or Wilcoxon rank sum test for comparison of continuous variables. Kaplan-Meier analysis of implant survival was performed with failure defined as femoral component revision due to any cause. Results. There was a statistically significant improvement in clinical outcome measures between pre and post-operative SF-12, WOMAC, and KSCRS validated scoring systems. 41% of patients had previous surgery prior to the TKA with 87% of patients receiving a cruciate sacrificing TKA and 64% of patients receiving a patellar resurfacing. There were 4 revisions in total, 2 patients were revised for pain, 1 for instability and 1 for infection treated with a single stage revision, the average time to revision was 3 years. There were no cases of aseptic loosening with an overall survival of 89.8% at an average follow-up of 13.6 yrs. The Kaplan-Meier estimated survival rate to revision was estimated to be % at 10 years and % at 15 years Radiographic assessment did not reveal any evidence of component migration, malalignment or radiolucencies at final follow up. There was no evidence of progressive radiolucencies noted on zonal analysis around both tibial and femoral components on serial radiographs in any patient. Conclusion. Excellent clinical outcomes are reported for patients 45 years of age or less who have undergone TKA. For the young patient who is not a candidate for other joint conserving or preserving procedures, Total Knee Replacements provide a successful longterm outcome