Comparison between passive knee kinematics during surgery and active knee kinematics during walking: A preliminary study.

Recovery of function is among a patient's main expectations when undergoing total knee arthroplasty (TKA). However, normal gait knee function is not always completely restored, which can affect patient satisfaction and quality of life. Computer-assisted surgery (CAS) allows surgeons to evaluate passive knee kinematics intra-operatively. Understanding associations between knee kinematics measured during surgery and during daily activities, such as walking, could help define criteria for success based on knee function and not only on the correct alignment of the implant or the leg. This preliminary study compared passive knee kinematics measured during surgery with active kinematics measured during walking. Eight patients underwent a treadmill gait analysis using the KneeKG™ system both before surgery and three months afterwards. Knee kinematics were measured during CAS both before and after TKA implantation. The anatomical axes of the KneeKG™ and CAS systems were homogenised using a two-level, multi-body kinematics optimisation with a kinematic chain based on the calibration measured during CAS. A Bland-Altman analysis was performed before and after TKA for adduction-abduction angle, internal-external rotation, and anterior-posterior displacement over the whole gait cycle, at the single stance phase and at the swing phase. Homogenising the anatomical axes between CAS and treadmill gait led to limited median bias and limits of agreement (post-surgery -0.6 ± 3.6 deg, -2.7 ± 3.6 deg, and -0.2 ± 2.4 mm for adduction-abduction, internal-external rotation and anterior-posterior displacement, respectively). At the individual level, correlations between the two systems were mostly weak (R2 < 0.3) over the whole gait cycle, indicating low kinematic consistency between the two measurements. However, correlations were better at the phase level, especially the swing phase. The multiple sources of differences did not enable us to conclude whether they came from anatomical and biomechanical differences or from measurement system errors.

Consistent indications, targets and techniques for double-level osteotomy of the knee: a systematic review.

PURPOSE: To systematically review and critically appraise the literature on double-level osteotomy (DLO) of the knee, and determine the indications, contraindications, targets and outcomes. MATERIALS AND METHODS: A systematic literature search was performed on PubMed, Embase®, and Cochrane for studies that reported on DLO by any technique or approach, including indications, contraindications, and targets for DLO, as well as patient-reported outcome measures (pROMS) and radiographic angles. RESULTS: Twelve eligible studies were found: 9 case series and 3 studies that compared DLO to high-tibial osteotomy (HTO). In all studies, DLO was performed by medial opening-wedge tibial osteotomy and lateral closing-wedge femoral osteotomy. Seven specified that DLO was performed if simple HTO would exceed thresholds of postoperative medial proximal tibial angle (MPTA), lateral distal femoral angle (LDFA), and/or predicted wedge size. The targets were 88°-95° for MPTA, 84°-89° for LDFA, and 0°-4° for hip-knee-ankle (HKA) angle. The 3 comparative studies reported lower MPTA after DLO (89.6°-92.5°) than after HTO (91.5°-98.3°). All 3 reported similar postoperative HKA after DLO (0.2°-4.4°) as HTO (0.4°-4.8°); only 2 compared postoperative LDFA, which was lower after DLO (85.4° and 84.9°) than HTO (88.7° and 88.8°). Two comparative studies reported postoperative overall KOOS which was slightly lower after DLO (351-403) than HTO (368-410); only 1 study reported separate items of the KOOS. CONCLUSION: There was relative consistency between studies on the indications, targets and techniques for DLO. Furthermore, while the comparative studies reported similar preoperative MPTA, LDFA and HKA, the postoperative MPTA and LDFA were lower after DLO than after HTO, though both treatments achieved equivalent postoperative HKA. LEVEL OF EVIDENCE: IV, systematic review.

Clinical and objective gait outcomes remained stable seven years after total knee arthroplasty: A prospective longitudinal study of 28 patients.

BACKGROUND: There is a paucity of data on mid to long-term gait outcomes after total knee arthroplasty. The aims of this longitudinal study were: to assess the evolution of both clinical and gait outcomes before and up to seven years after primary total knee arthroplasty (TKA) in a cohort of patients with knee osteoarthritis. METHODS: This study included 28 patients evaluated before and up to seven years after primary TKA with both gait analysis and patient reported outcomes; of these, 20 patients were evaluated one year after surgery as well. Kinematic outcomes during gait (gait velocity, dimensionless gait veolicity, maximal knee flexion and knee range of motion), pain relief, Western Ontario and MacMaster Osteoarthritis Index (WOMAC), quality of life and patient satisfaction were assessed and compared at each visit with the paired Wilcoxon signed rank test (p < 0.05). RESULTS: The significant improvement achieved at one year after TKA was stable up to seven years after surgery, with all clinical and kinematic outcomes unchanged, except for gait velocity, with a significant decrease over time (1.3 (1.1-1.4) m/s one year after TKA versus 1.0 (0.9-1.1) m/s, p < 0.05 up to seven years after). CONCLUSION: Patients with knee osteoarthritis significantly improve their clinical and kinematic outcomes at one year postoperatively and maintain the gain up to seven years after primary TKA, except for gait velocity which decreases over time, most likely along with ageing.

[Lessons learned from 25 years of an institutional hip and knee arthroplasty registry]. / Leçons apprises par 25 ans d'un registre institutionnel des prothèses de hanche et de genou.

Since 1996, the Geneva Arthroplasty Registry at the University Hospitals of Geneva (HUG) has been collecting, archiving and disseminating relevant high-quality information on primary total hip and knee arthroplasties and revision procedures performed at the Division of Orthopaedics and Traumatology. Patients are followed throughout their lifetime with the prosthesis. The registry has been essential to better understand and subsequently improve the care of patients with hip and knee replacements. It will continue to fulfil its mission and to work towards an even more effective transfer of the knowledge obtained to all stakeholders and as well as towards its implementation.

Depuis 1996, le registre genevois des arthroplasties aux HUG recueille, archive et diffuse des informations pertinentes de haute qualité concernant les arthroplasties primaires de la hanche et du genou ainsi que les procédures de révision réalisées au Service de chirurgie orthopédique et traumatologie de l'appareil moteur. Les patients sont suivis pendant toute leur vie avec la prothèse. Le registre a été essentiel pour mieux comprendre et ensuite améliorer la prise en charge de patients avec arthroplastie de hanche et de genou. Il continuera à remplir sa mission et à assurer une transmission encore plus efficace des connaissances obtenues vers tous les groupes concernés (stakeholders) et à leur implémentation.

History of previous surgery is associated with higher risk of revision after primary total knee arthroplasty: a cohort study from the Geneva Arthroplasty Registry.

Background and purpose - Prior to primary total knee arthroplasty (pTKA), 6-34% of patients have undergone surgical procedure(s) of their knee. We investigated whether history of previous surgeries influences the risk of revision of pTKA, the risk according to the type of previous surgery, and how previous surgery influences specific causes of revision and the time of revision.Patients and methods - This is a prospective cohort study from the Geneva Arthroplasty Registry. All pTKA between 2000 and 2016 were included and followed until December 31, 2019. Outcomes were risk of revision, evaluated using Kaplan-Meier survival and Cox and competing risks regression, the specific causes, and time of revision.Results - Of 3,945 pTKA included (mean age 71 years, 68% women), 21% had a history of previous surgery, with 8.3% revisions vs. 4.3%, at 3-20 years' follow-up (mean 8.6). 5- and 10-year cumulative failure by previous surgery (yes vs. no) were 6.6% (95% CI 5.1-8.5) vs. 3.3% (CI 2.7-4.0), and 8.4% (CI 6.6-10.6) vs. 4.5% (CI 3.8-5.4). Baseline differences explained only part of the higher risk (adjusted HR 1.5, CI 1.1-2.1). The risk of failure was higher for all causes of revision considered. Patients in the previous surgery group had a higher risk of an early revision.Interpretation - A history of previous surgery adversely affected the outcome with a 1.5 times higher cumulative risk of all-cause revision over the course of up to 20 years after index surgery. The increased risk was seen for all causes of revision and was highest in the first years.

Gait Analysis 1 Year after Primary TKA: No Difference between Gap Balancing and Measured Resection Technique.

Mechanical alignment in total knee arthroplasty (TKA) can be achieved using dependent bone cuts. The hypothesis is that patients have a better balanced TKA, as a result. The aim of this study was to determine if this technique is superior to an independent bone cut technique in terms of gait parameters, patient-reported outcome measures (PROMs), and satisfaction assessed before surgery and at 1-year follow-up. A total of 58 patients were evaluated before and 1 year following TKA, using the Press Fit Condylar (PFC) Sigma posterior stabilizer (PS) design; 39 (70 ± 8 years; 27 women) with independent bone cuts and 19 (71 ± 7 years; 12 women) with dependent bone cuts using the Specialist TRAM. Gait was evaluated with a three-dimensional motion analysis system for spatiotemporal and kinematics parameters. Pain and functional levels were assessed using the Western Ontario and McMaster Universities arthritis index (WOMAC); general health was assessed by the short form (SF)-12. Global satisfaction, as well as patient satisfaction, related to pain and functional levels were assessed using a five-point Likert's scale. No significant difference was found between both groups in terms of age, body mass index, pain, and functional levels at baseline. At 1-year follow-up, despite an overall improvement in gait, WOMAC, SF-12 physical score and pain, none of the patients showed gait parameters comparable to a healthy control group. No surgical technique effect was observed on gait, clinical outcomes, and satisfaction level. While observing an overall improvement at 1-year follow-up, we did not find any significant difference between the two surgical techniques in terms of gait parameters, patients' outcomes, and satisfaction.

Walking Speed and Maximal Knee Flexion During Gait After Total Knee Arthroplasty: Minimal Clinically Important Improvement Is Not Determinable; Patient Acceptable Symptom State Is Potentially Useful.

BACKGROUND: Total knee arthroplasty (TKA) is the operation of choice in patients with end-stage knee osteoarthritis (OA). Up to 1 in 5 patients still encounter functional limitations after TKA, partly explaining patient dissatisfaction. Which gait ability to target after TKA remains unclear. To determine whether Minimal Clinical Important Improvement (MCII) or Patient Acceptable Symptom State (PASS) values could be derived from gait parameters recorded in patients with TKA. And, if so, to define those values. METHODS: In this ancillary study, we retrospectively analyzed gait parameters of patients scheduled for a unilateral TKA between 2011 and 2013. We investigated MCII and PASS values for walking speed and maximal knee flexion using anchor-based methods: 5 anchoring questions based on perceived body function and patients' satisfaction. RESULTS: Over the study period, 79 patients performed a clinical gait analysis the week before and 1 year after surgery, and were included in the present study. All clinical and gait parameters improved 1 year after TKA. Nevertheless, changes in gait outcomes were not associated with perceived body function or patients' satisfaction, precluding any MCII estimation in gait parameters. PASS values, however, could be determined as 1.2 m/s for walking speed and 50° for maximal knee flexion. CONCLUSION: In this study, we found that MCII and PASS values are not necessarily determinable for gait parameters after TKA in patients with end-stage OA. Using anchor questions based on perceived body function and patient's satisfaction, MCII could not be defined while PASS values were potentially useful. LEVEL OF EVIDENCE: Level III.

Total knee arthroplasty in achondroplasia without deformity correction: A case report with 11 years' follow-up.

Knee osteoarthritis in patients with achondroplasia is rare. Bowleg deformity is typical but corrective surgery is limited. Thus, primary total knee arthroplasty (TKA) might be challenging due to the particular anatomy. We report on a patient with 11 year's follow-up after a TKA performed maintaining bowleg alignment, using a posterior stabilized, fixed-bearing design. Sequential X-rays showed radiolucencies on the femoral component within two years postoperatively, slightly increasing over time but stable at last follow-up. The Oxford Knee Score showed an excellent result at 11 years. Despite the peculiarities of a case report, TKA without concomitant osteotomies might be an option for such patients. Nevertheless, a thorough discussion about pros and cons is paramount.

Associations between gait analysis parameters and patient satisfaction one year following primary total knee arthroplasty.

BACKGROUND: The purpose of this prospective study was to understand the relation between gait outcomes and patient satisfaction one year after total knee arthroplasty (TKA). METHODS: Seventy-nine patients were evaluated before and one year after TKA using clinical gait analysis. Specific gait outcomes were analyzed: gait speed, stance phase, range of motion (ROM) knee flexion and maximal knee flexion. The parameters of interest selected for the statistical analysis were: gait speed and maximal knee flexion during gait. The Western Ontario and MacMaster Osteoarthritis Index (WOMAC) and patient satisfaction were also assessed. The satisfaction was evaluated using a questionnaire and was splited in five categories: very unsatisfied, unsatisfied, neutral, satisfied or very satisfied. To assess associations between patient satisfaction and maximal knee flexion during gait and gait speed, an unadjusted ordinal logistic regression analysis was used. The analysis was then adjusted for covariates: age and Body Mass Index (BMI) before surgery and WOMAC pain one year after surgery. RESULTS: All gait outcomes after TKA had significantly improved. The ordinal logistic regression analysis found significant associations between patient satisfaction and maximal knee flexion after TKA (unadjusted and adjusted) but not for gait speed. CONCLUSION: These findings show that all patients improved their gait outcomes one year after TKA but only a higher maximal knee flexion during gait may influence the level of patient satisfaction.

The impact of body-mass index on the frontal knee alignment estimation using three-dimensional reconstruction based on movement analysis.

BACKGROUND: We evaluated the influence of the body-mass index (BMI) on the estimation of the static frontal knee alignment (FKA) using three-dimensional (3D) reconstruction method based on movement analysis. METHODS: Two-hundred nineteen knees (120 individuals with end-stage osteoarthritis) were analyzed. The validity of the 3D method was evaluated under comparison with a reference method based on weight bearing full-leg length radiography. Extensive statistical analyses (Pearson's correlation, one-way ANOVA, linear regression, boxplot diagram) over four groups of BMI (normal, overweight, obese class I and obese classes II and III) were performed. RESULTS: For BMI below 25 kg/m2, the validity of the 3D method was confirmed. For BMI over 25 kg/m2, there was an increasing error of the 3D method, especially for the obese groups affected with a large varus alignment. CONCLUSIONS: In a biomechanical context of movement analysis, the results of the study suggest that the 3D method may represent a satisfying alternative to the full-leg radiograph method with limitations regarding to BMI over 25 kg/m2.

Non-hip/non-vertebral fractures - How to treat best?

Fractures of the extremities in the elderly constitute more than two-thirds of all fragility fractures befalling frail, osteoporotic and sarcopenic patients. Although treatment controversies abound, consensus exists. Upper extremity fractures hinder activities of daily living and are debilitating. Open fractures or displaced fractures will need surgical intervention. Wrist fractures treated operatively allow early use of the hand. Most pelvic fractures are treated conservatively. In the lower extremities, fractures of the long bones, tibia and femur need surgical intervention. Non-displaced fractures around the foot may be treated with immobilisation and avoidance of full weight-bearing. As a rule, fractures take four months for consolidation. Individually tailored solutions are needed for frail patients with comorbidities. Maintaining joint mobility and muscle strength preserves mobility and autonomy. Caring for extremities trauma is team work, involving family and health care providers. Prevention efforts are mandatory.

Symptoms of osteoarthritis influence mental and physical health differently before and after joint replacement surgery: A prospective study.

BACKGROUND: Patient-reported outcomes are increasingly used in evaluations of joint replacement surgery, but it is unclear if symptoms of osteoarthritis (i.e., pain and dysfunction) influence health perceptions similarly before and after surgery. METHODS: In this prospective study based on a hospital-based arthroplasty registry, patients with primary total hip or knee arthroplasty (THA, N = 990, and TKA, N = 907) completed the WOMAC Pain and Function scales, and the SF12 Physical and Mental Component Scores (PCS and MCS), before surgery and one year later. Associations between WOMAC and SF12 scales were examined using mixed linear regression models. RESULTS: All patient-reported outcomes improved following total joint arthroplasty, but the associations between symptom scales and global health perceptions were altered. Mental health scores at a given level of pain or function were lower after surgery than before, by about 4-5 points, a clinically meaningful and statistically significant difference. In contrast, the associations between WOMAC scales and the PCS remained stable. These findings were observed in both cohorts of patients. CONCLUSIONS: After total joint arthroplasty, mental health scores were lower than would have been expected given the symptomatic improvement. This suggests that relationships between patient-reported outcomes are context-dependent, and that care should be exerted when interpreting changes in patient-reported outcomes over time.

[Robotic surgery : the future of prosthetic surgery ?] / Chirurgie robotique : l'avenir de la chirurgie prothétique ?

Indications for hip and knee replacement will continue to grow over the next few years. Robotic systems have been developed since the early 1990s in order to optimize implant positioning, to potentially improve clinical results, and to reduce perioperative morbidity. Currently, the different available systems certainly improve the accuracy and reproducibility of prosthetic components placement. However, the cost of robotic surgery remains very high. Early results in terms of implant survival, postoperative pain, mobility, and length of stay are encouraging. Long-term studies are needed to validate the clinical efficacy and to perform a medico-economic evaluation of robots in orthopedic surgery.

Les indications de mise en place des prothèses de hanche et de genou ne cesseront de croître au cours des prochaines années. Afin de parfaire la technique d'implantation, d'améliorer les résultats cliniques et de réduire la morbidité périopératoire, l'emploi de systèmes robotiques fait l'objet d'un intérêt grandissant depuis le début des années 90. Actuellement, les différents systèmes disponibles permettent assurément d'améliorer la reproductibilité et la précision de l'implantation des prothèses aux dépens de coûts encore élevés. Les résultats précoces en termes de survie des implants, de douleur et de mobilité post-opératoires sont encourageants. Des études au long terme seront nécessaires afin de confirmer ces derniers et valider l'efficacité clinique ainsi que l'intérêt médico-économique des robots en chirurgie orthopédique.

Third-generation pure alumina and alumina matrix composites in total hip arthroplasty: What is the evidence?

Wear, corrosion and periprosthetic osteolysis are important causes of failure in joint arthroplasty, especially in young patients.Ceramic bearings, developed 40 years ago, are an increasingly popular choice in hip arthroplasty. New manufacturing procedures have increased the strength and reliability of ceramic materials and reduced the risk of complications.In recent decades, ceramics made of pure alumina have continuously improved, resulting in a surgical-grade material that fulfills clinical requirements.Despite the track record of safety and long-term results, third-generation pure alumina ceramics are being replaced in clinical practice by alumina matrix composites, which are composed of alumina and zirconium.In this review, the characteristics of both materials are discussed, and the long-term results with third-generation alumina-on-alumina bearings and the associated complications are compared with those of other available ceramics. Cite this article: EFORT Open Rev 2018;3:7-14. DOI: 10.1302/2058-5241.3.170034.

[Does total knee arthroplasty meet patient's expectations ?] / La prothèse totale du genou répond-elle aux attentes des patients ?

Total knee arthroplasty has grown considerably over the past decade, due to the aging of the population, the increase in the prevalence of obesity, and an increasing demand. The 10-year revision rate is less than 5%. Functional outcomes, assessed by range of motion measures and functional scores, were significantly improved with the advent of more reliable and less invasive surgical techniques, better management of postoperative pain, and early high-intensity rehabilitation protocols. However, 20% of patients say they are dissatisfied with their knee replacement, either because of the persistence of pain, or because their function does not match their preoperative expectations. Improved preoperative communication between patient and surgeon is essential to match patients' expectations to realistic treatment outcomes.

L'arthroplastie du genou connaît un essor considérable en raison du vieillissement de la population, de l'augmentation de la prévalence de l'obésité et de l'augmentation de la demande. Le taux de reprise à 10 ans est inférieur à 5 %. Les résultats fonctionnels ont été incontestablement améliorés grâce à des techniques chirurgicales plus fiables et moins invasives, à une meilleure gestion de la douleur postopératoire, et à l'instauration d'une physiothérapie intense et précoce. Cependant, 20 % des patients se disent insatisfaits après prothèse totale du genou, soit en raison de la persistance de douleurs, soit en raison d'une fonction qui ne correspond pas à leurs attentes. L'adéquation des attentes, évaluées lors de la consultation préopératoire, avec un niveau de performance réaliste apparaît comme un gage de satisfaction postopératoire.

[Do degenerative meniscal tears need surgery ?] / Faut-il opérer les lésions dégénératives du ménisque ?

Degenerative meniscal tears (DMT) are common, often asymptomatic, and are associated with early-stage knee osteoarthritis in patients over 35 years of age. Conservative treatment, including exercise, physiotherapy and pain medication, should be offered as a first management approach for patients with symptomatic DMT. The indication for partial arthroscopic meniscectomy should be considered carefully, and based on specific criteria. Recently, several randomized controlled studies comparing partial medial meniscectomy to conservative treatment or to a sham procedure have questioned the effectiveness of surgical treatment of these lesions.The purpose of this article is to provide an update on the diagnosis and treatment of DMT.

Les lésions méniscales dégénératives (LMD) sont fréquentes, souvent asymptomatiques et considérées comme une préarthrose chez le patient de plus de 35 ans. Lorsqu'elles sont associées à une douleur du genou, le traitement conservateur est le premier choix. En cas d'échec, l'indication à une méniscectomie partielle par arthroscopie doit être réfléchie et repose sur des critères précis. Récemment, plusieurs études randomisées ont remis en cause l'efficacité du traitement chirurgical de ces lésions. Celui-ci n'apporterait pas de bénéfice par rapport au traitement médical ou à une chirurgie « placebo ¼. Le but de cet article est de faire le point sur le diagnostic et la prise en charge des LMD.

Influence of Body Mass Index on Sagittal Knee Range of Motion and Gait Speed Recovery 1-Year After Total Knee Arthroplasty.

BACKGROUND: The purpose of this prospective study was to investigate the influence of body mass index (BMI) on gait parameters preoperatively and 1 year after total knee arthroplasty (TKA). METHODS: Seventy-nine patients were evaluated before and 1 year after TKA using clinical gait analysis. The gait velocity, the knee range of motion (ROM) during gait, their gains (difference between baseline and 1 year after TKA), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), quality of life, and patient satisfaction were assessed. Nonobese (BMI <30 kg/m2) and obese patients (BMI ≥30 kg/m2) were compared. Healthy controls were also assessed. Univariate and multivariate linear regression analyses were used to assess the association between gait speed and ROM gains. Adjustment was performed for gender, age, and WOMAC pain improvement. RESULTS: At baseline, gait velocity and knee ROM were significantly lower in obese compared with those in the nonobese patients (0.99 ± 0.27 m/s vs 1.11 ± 0.18 m/s; effect size, 0.53; P = .021; and ROM, 41.33° ± 9.6° vs 46.05° ± 8.39°; effect size, 0.52; P = .022). Univariate and multivariate linear regressions did not show any significant relation between gait speed gain or knee ROM gain and BMI. At baseline, obese patients were more symptomatic than nonobese (WOMAC pain: 36.1 ± 14.0 vs 50.4 ± 16.9; effect size, 0.9; P < .001), and their improvement was significantly higher (WOMAC pain gain, 44.5 vs 32.3; effect size, 0.59; P = .011). CONCLUSION: These findings show that all patients improved biomechanically and clinically, regardless of their BMI.