Session 2: Knee I
Ondag den 26. oktober
09:00 – 10:30
Lokale: Stockholm/Copenhagen
Chairmen: Henrik Schrøder / Ashir Ejaz
Martin Lindberg-Larsen, Mette Hornsleth, Jens Bagger, Susanne van der Mark
Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg; Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg; Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg; Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg
Background: The Danish Knee Arthroplasty Annual Report 2015 indicated a high 30 day readmission rate after primary total knee arthroplasty (TKA) performed at Bispebjerg Hospital in 2014.
Purpose / Aim of Study: To investigate causes of prolonged length of stay (LOS) and readmissions ≤30 days post-operatively.
Materials and Methods: A retrospective analysis of 175 patients operated with TKA in 2014. Patient characteristics were available from The Lundbeck Foundation Centre for Fast-Track Hip and Knee Replacement Database (LCDB) and readmissions/transferals from Danish National Patient Register and patient files.
Findings / Results: Comparing patient characteristics with the LCDB population, we found that 43% lived alone (vs 31%, p=0.019), 20% smoked (vs 13%, p=0.027) and 16% were alcohol abusers (vs 7%, p<0.001). Median LOS was 2 days, but 29 patients were internally transfered from the elective fast-track unit to other wards resulting in increased LOS (13 to ortho-geriatric unit). Main causes of transferal were need of further mobilization (9) and serious medical complications (13). A total of 19 (10.9%) patients were readmitted ¡Ü30 days postoperatively. Most frequent causes of readmissions were suspected DVT (8), suspected infection (1) or suspected myocardial infarction (1), but disproved in all cases. Need of further mobilization caused readmission in 4 cases. More serious causes of readmission were infection (1), fall (1), anaemia (1), hypoglycemia (1) and gastro-intestinal bleeding (1).
Conclusions: 17% of the patients could not adhere to the fast-track protocol and >50% of readmissions were non-serious and should not have caused readmission. Preventing unnecessary readmissions is a future focus as well as further improvement of the combined ortho- geriatric and fast-track set-up to optimize the treatment of elderly patients with increased co-morbidity.
Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg; Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg; Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg; Department of Orthopaedic Surgery, Copenhagen University Hospital Bispebjerg
Background: The Danish Knee Arthroplasty Annual Report 2015 indicated a high 30 day readmission rate after primary total knee arthroplasty (TKA) performed at Bispebjerg Hospital in 2014.
Purpose / Aim of Study: To investigate causes of prolonged length of stay (LOS) and readmissions ≤30 days post-operatively.
Materials and Methods: A retrospective analysis of 175 patients operated with TKA in 2014. Patient characteristics were available from The Lundbeck Foundation Centre for Fast-Track Hip and Knee Replacement Database (LCDB) and readmissions/transferals from Danish National Patient Register and patient files.
Findings / Results: Comparing patient characteristics with the LCDB population, we found that 43% lived alone (vs 31%, p=0.019), 20% smoked (vs 13%, p=0.027) and 16% were alcohol abusers (vs 7%, p<0.001). Median LOS was 2 days, but 29 patients were internally transfered from the elective fast-track unit to other wards resulting in increased LOS (13 to ortho-geriatric unit). Main causes of transferal were need of further mobilization (9) and serious medical complications (13). A total of 19 (10.9%) patients were readmitted ¡Ü30 days postoperatively. Most frequent causes of readmissions were suspected DVT (8), suspected infection (1) or suspected myocardial infarction (1), but disproved in all cases. Need of further mobilization caused readmission in 4 cases. More serious causes of readmission were infection (1), fall (1), anaemia (1), hypoglycemia (1) and gastro-intestinal bleeding (1).
Conclusions: 17% of the patients could not adhere to the fast-track protocol and >50% of readmissions were non-serious and should not have caused readmission. Preventing unnecessary readmissions is a future focus as well as further improvement of the combined ortho- geriatric and fast-track set-up to optimize the treatment of elderly patients with increased co-morbidity.
Christian Skovgaard Nielsen, Kirill Gromov, Jans Oeivind , Anders Troelsen , Husted Henrik
Department of Orthopedics , Copenhagen University Hospital, Hvidovre, Denmark ; Department of Orthopedics , Copenhagen University Hospital, Hvidovre, Denmark; Section for Surgical Pathophysiology 4074, Rigshospitalet, Copenhagen University, Copenhagen, Denmark; Department of Orthopedics , Copenhagen University Hospital, Hvidovre, Denmark; Department of Orthopedics , Copenhagen University Hospital, Hvidovre, Denmark
Background: Postoperative anemia is frequent after revision of total knee arthroplasty (TKA) with reported transfusion rates up to 83 %. Despite increased efforts of reducing blood loss and enhancing fast recovery within the fast-track setup, a considerable transfusion rate is still evident.
Purpose / Aim of Study: The aim of this study was therefore to evaluate the effect of a bipolar sealer on blood loss and transfusion in revision TKA.
Materials and Methods: In this single-center prospective cohort study with retrospective controls, 51 patients were enrolled in a fast-track setup for revision TKA without the use of a tourniquet. Twenty-five prospectively enrolled patients received treatment with both a bipolar sealer and electrocautery, whereas 26 patients had received treatment with a conventional electrocautery only in the retrospective group.
Findings / Results: No significant differences were found neither for calculated blood loss, with 1397 (SD±452) ml in the bipolar sealer group versus 1452 (±530) mL in the control group (p = 0.66), nor for blood transfusion rates of 53% and 46% (p = 0.89), respectively. Four controls were readmitted within 90 days follow up.
Conclusions: The use of a bipolar sealer in a TKA revision setting without the use of tourniquet did not reduce blood loss or blood transfusion rates.
Department of Orthopedics , Copenhagen University Hospital, Hvidovre, Denmark ; Department of Orthopedics , Copenhagen University Hospital, Hvidovre, Denmark; Section for Surgical Pathophysiology 4074, Rigshospitalet, Copenhagen University, Copenhagen, Denmark; Department of Orthopedics , Copenhagen University Hospital, Hvidovre, Denmark; Department of Orthopedics , Copenhagen University Hospital, Hvidovre, Denmark
Background: Postoperative anemia is frequent after revision of total knee arthroplasty (TKA) with reported transfusion rates up to 83 %. Despite increased efforts of reducing blood loss and enhancing fast recovery within the fast-track setup, a considerable transfusion rate is still evident.
Purpose / Aim of Study: The aim of this study was therefore to evaluate the effect of a bipolar sealer on blood loss and transfusion in revision TKA.
Materials and Methods: In this single-center prospective cohort study with retrospective controls, 51 patients were enrolled in a fast-track setup for revision TKA without the use of a tourniquet. Twenty-five prospectively enrolled patients received treatment with both a bipolar sealer and electrocautery, whereas 26 patients had received treatment with a conventional electrocautery only in the retrospective group.
Findings / Results: No significant differences were found neither for calculated blood loss, with 1397 (SD±452) ml in the bipolar sealer group versus 1452 (±530) mL in the control group (p = 0.66), nor for blood transfusion rates of 53% and 46% (p = 0.89), respectively. Four controls were readmitted within 90 days follow up.
Conclusions: The use of a bipolar sealer in a TKA revision setting without the use of tourniquet did not reduce blood loss or blood transfusion rates.
Anette Liljensøe, Jens Ole Laursen, Henning Bliddal, Kjeld Søballe, Inger Mechlenburg
Department of Ortopaedics, Aarhus University Hospital; Emergency Medicine, University of Southern Denmark; Department of Rheumatology, Copenhagen University Hospital Bispebjerg Frederiksberg; Department of Ortopaedics, Aarhus University Hospital; Department of Ortopaedics, Aarhus University Hospital
Background: Obesity increasingly leads to problems in patients after Total knee replacement (TKR). Several observational studies have shown that obesity is associated with poor health- related quality of life (QoL), physical function, and more pain after surgery than in patients with BMI < 30.
Purpose / Aim of Study: To investigate whether weight loss interventions before primary TKR would improve QoL, knee function, mobility, and body composition 1 year after surgery.
Materials and Methods: Patients scheduled for TKR due to osteoarthritis (OA) of the knee and obesity were randomized to a control group with standard care or to an 8-week low-energy 810kcal/d liquid diet before TKR. Patient-reported QoL, 6 Minutes’ Walk Test (6MW), and body composition by dual energy X-ray absorptiometry (DXA) were assessed before intervention for the diet group, and within 1 week preoperatively for both groups, and the change in outcome from baseline to 1 year after TKR were compared between groups.
Findings / Results: The results showed large improvement in both study groups in QoL and knee function, with no statistical differences between the groups 1 year after TKR. The average weight loss after 8-week preoperatively intervention was 10.7 kg, and consisted of a 6.7 kg reduction in fat mass. 20% more subjects mobilized immediately after surgery in the diet group than in the control group. 1 year after TKR the participants in the diet group managed to maintain the weight reduction, whereas there was no change in the control group.
Conclusions: An 8-week pre-operative intervention resulted in a 10% body weight loss, improved body composition, cardiovascular risk factors and s-leptin sustained after TKA surgery for one year. One year after surgery the weight loss group did not achieve a greater improvement in QoL and knee function than the control usual care group.
Department of Ortopaedics, Aarhus University Hospital; Emergency Medicine, University of Southern Denmark; Department of Rheumatology, Copenhagen University Hospital Bispebjerg Frederiksberg; Department of Ortopaedics, Aarhus University Hospital; Department of Ortopaedics, Aarhus University Hospital
Background: Obesity increasingly leads to problems in patients after Total knee replacement (TKR). Several observational studies have shown that obesity is associated with poor health- related quality of life (QoL), physical function, and more pain after surgery than in patients with BMI < 30.
Purpose / Aim of Study: To investigate whether weight loss interventions before primary TKR would improve QoL, knee function, mobility, and body composition 1 year after surgery.
Materials and Methods: Patients scheduled for TKR due to osteoarthritis (OA) of the knee and obesity were randomized to a control group with standard care or to an 8-week low-energy 810kcal/d liquid diet before TKR. Patient-reported QoL, 6 Minutes’ Walk Test (6MW), and body composition by dual energy X-ray absorptiometry (DXA) were assessed before intervention for the diet group, and within 1 week preoperatively for both groups, and the change in outcome from baseline to 1 year after TKR were compared between groups.
Findings / Results: The results showed large improvement in both study groups in QoL and knee function, with no statistical differences between the groups 1 year after TKR. The average weight loss after 8-week preoperatively intervention was 10.7 kg, and consisted of a 6.7 kg reduction in fat mass. 20% more subjects mobilized immediately after surgery in the diet group than in the control group. 1 year after TKR the participants in the diet group managed to maintain the weight reduction, whereas there was no change in the control group.
Conclusions: An 8-week pre-operative intervention resulted in a 10% body weight loss, improved body composition, cardiovascular risk factors and s-leptin sustained after TKA surgery for one year. One year after surgery the weight loss group did not achieve a greater improvement in QoL and knee function than the control usual care group.
Henriette Appel Holm, Lasse Enkebølle Rasmussen, Per Wagner Kristensen
Ortopeadic , Vejle ; Ortopeadic , Vejle; Ortopeadic , Vejle
Background: Low knee awareness after TKR has become the ultimate goal in trying to achieve a natural feeling knee. With improving patient outcome after TKR new assessment tools with increased discriminatory power especially in well- performing patients are desirable. The Forgotten Joint Score (FJS) is a new patient reported tool to determine outcomes. It evaluates to what extend the patients are aware of the artificial knee and if the knee feels natural.
Purpose / Aim of Study: To compare FJS with OKS in patients treated with TKR 5 years postoperatively.
Materials and Methods: PROM Survey. In 2015 a number of 175 consecutive patients were enrolled in a Joint Awareness Study (100 females,75 males). All patients received the OKS and the FJS questionnaire > 5 years postoperatively. Responds rate 91%.
Findings / Results: Overall satisfaction: OKS 85,5% compared to FJS 71,4%, p<0,001. 21 patients in both OKS and FJS obtained a 100 % satisfaction, however only15 patients had the maximum score in both questionnaires. Highest satisfaction in both score systems is achieved in personal washing/showering. OKS 83,5%, FJS 72,5%. Lowest satisfaction was kneeling, using a dustpan OKS 18%, and rising from low position FJS 27%. FJS takes sports activity into account and regarding awareness in performing favourite sport 51% are rarely aware of the knee.
Conclusions: In this study a significant higher OKS compared to FJS is shown. Questions with the highest and lowest satisfaction cover similar areas in both questionnaires. FJS is a more sensitive tool to measure patient related outcome, it picks up subtle differences and a less ceiling effect is shown. FJS is appealing to measure outcome in patients with high performance.
Ortopeadic , Vejle ; Ortopeadic , Vejle; Ortopeadic , Vejle
Background: Low knee awareness after TKR has become the ultimate goal in trying to achieve a natural feeling knee. With improving patient outcome after TKR new assessment tools with increased discriminatory power especially in well- performing patients are desirable. The Forgotten Joint Score (FJS) is a new patient reported tool to determine outcomes. It evaluates to what extend the patients are aware of the artificial knee and if the knee feels natural.
Purpose / Aim of Study: To compare FJS with OKS in patients treated with TKR 5 years postoperatively.
Materials and Methods: PROM Survey. In 2015 a number of 175 consecutive patients were enrolled in a Joint Awareness Study (100 females,75 males). All patients received the OKS and the FJS questionnaire > 5 years postoperatively. Responds rate 91%.
Findings / Results: Overall satisfaction: OKS 85,5% compared to FJS 71,4%, p<0,001. 21 patients in both OKS and FJS obtained a 100 % satisfaction, however only15 patients had the maximum score in both questionnaires. Highest satisfaction in both score systems is achieved in personal washing/showering. OKS 83,5%, FJS 72,5%. Lowest satisfaction was kneeling, using a dustpan OKS 18%, and rising from low position FJS 27%. FJS takes sports activity into account and regarding awareness in performing favourite sport 51% are rarely aware of the knee.
Conclusions: In this study a significant higher OKS compared to FJS is shown. Questions with the highest and lowest satisfaction cover similar areas in both questionnaires. FJS is a more sensitive tool to measure patient related outcome, it picks up subtle differences and a less ceiling effect is shown. FJS is appealing to measure outcome in patients with high performance.
Birgit Skoffer, Ulrik Dalgas, Thomas Maribo, Kjeld Søballe, Inger Mechlenburg
Department of Physical and Occupational Therapy, Aarhus University Hospital, Denmark; Section for Sport Science, Department of Public Health, Aarhus University, Denmark ; Rehabilitation Center Marselisborg, Department of Public Health, Section of social medicine and rehabilitation, Aarhus University, Denmark; Orthopaedic Research Centre, Aarhus University Hospital, Denmark ; Orthopaedic Research Centre, Aarhus University Hospital, Denmark
Background: Preoperative progressive resistance training (PRT) is controversial in patients scheduled for total knee arthroplasty (TKA).
Purpose / Aim of Study: To examine if PRT initiated 5 weeks prior to TKA 1) would exacerbate pain and knee effusion and 2) would allow a progressively increased training load throughout the training period that would subsequently increase muscle strength.
Materials and Methods: Thirty patients scheduled for TKA underwent unilateral PRT (3 sessions/week). Exercise loading was 12 repetition maximum (RM) with progression towards 8RM. The training program consisted of 6 exercises performed unilaterally. Before and after each training session, knee joint pain, effusion, and training load were recorded. The first and last training session were initiated by 1RM testing of unilateral leg press, knee extension and knee flexion.
Findings / Results: Median differences of the knee pain at rest from before to after each training session varied from 0-2. Knee joint pain after the training session was unchanged over time, p = 0.99. Mean differences of the knee joint circumference from before to after each training session varied from 0-0.4 cm. Knee joint circumference after the training session was unchanged over time, p = 0.99. Training load generally increased and maximal muscle strength improved; unilateral leg press mean 18% ± 30 (p = 0.03), knee extension mean 81% ± 156 (p < 0.0001) and knee flexion mean 53% ± 57 (p < 0.001).
Conclusions: PRT of the affected leg initiated shortly before TKA does not exacerbate knee joint pain and effusion despite a substantial general load progression and increased muscle strength.
Department of Physical and Occupational Therapy, Aarhus University Hospital, Denmark; Section for Sport Science, Department of Public Health, Aarhus University, Denmark ; Rehabilitation Center Marselisborg, Department of Public Health, Section of social medicine and rehabilitation, Aarhus University, Denmark; Orthopaedic Research Centre, Aarhus University Hospital, Denmark ; Orthopaedic Research Centre, Aarhus University Hospital, Denmark
Background: Preoperative progressive resistance training (PRT) is controversial in patients scheduled for total knee arthroplasty (TKA).
Purpose / Aim of Study: To examine if PRT initiated 5 weeks prior to TKA 1) would exacerbate pain and knee effusion and 2) would allow a progressively increased training load throughout the training period that would subsequently increase muscle strength.
Materials and Methods: Thirty patients scheduled for TKA underwent unilateral PRT (3 sessions/week). Exercise loading was 12 repetition maximum (RM) with progression towards 8RM. The training program consisted of 6 exercises performed unilaterally. Before and after each training session, knee joint pain, effusion, and training load were recorded. The first and last training session were initiated by 1RM testing of unilateral leg press, knee extension and knee flexion.
Findings / Results: Median differences of the knee pain at rest from before to after each training session varied from 0-2. Knee joint pain after the training session was unchanged over time, p = 0.99. Mean differences of the knee joint circumference from before to after each training session varied from 0-0.4 cm. Knee joint circumference after the training session was unchanged over time, p = 0.99. Training load generally increased and maximal muscle strength improved; unilateral leg press mean 18% ± 30 (p = 0.03), knee extension mean 81% ± 156 (p < 0.0001) and knee flexion mean 53% ± 57 (p < 0.001).
Conclusions: PRT of the affected leg initiated shortly before TKA does not exacerbate knee joint pain and effusion despite a substantial general load progression and increased muscle strength.
Lasse E. Rasmussen, Bjørn Gotlieb Jensen, Claus Varnum
Orthopedic dept. , Sygehus Lillebælt, Vejle; Orthopedic dept. , Sygehus Lillebælt, Vejle; Orthopedic dept., Sygehus Lillebælt, Vejle
Background: Clinical and radiological data from a design centre of unicompartmental knee replacement (UKR) show as good as, or even better outcome of the cementless compared to the cemented UKR. Our institution (a high volume hospital with UKR surgeons performing on average 40 UKRs per year) changed from cemented to cementless UKR in 2015 with a concomitant occurrence of fractures and subscidence of the tibial implant, not previously observed in the cemented UKR.
Purpose / Aim of Study: To elucidate whether or not a learning curve relates to early failures in cementless UKR.
Materials and Methods: Since January 2015, we investigated clinical and x-ray outcome after 4 weeks and 1 year in all patients, receiving a cementless UKR at our institution
Findings / Results: From Jan, 2015 to March 2016, 216 cementless UKR were implanted by 5 knee surgeons. All the surgeons had patients with early periprosthetic fracture or subscidence. Within 6 months of primary UKR, 4.2% (9 of 216) underwent revision due to either fracture or instability from subscidence. Periprostetic fractures 4/216 = 1,9%, (3 revised, 1 not revised), Subscidence with the occurrence of instability and concomitant revision: 6 / 216 = 2,8%. Radiological subscidence (not revised) 11/216 = 5 % In September 2015 we altered the surgical technique, taking extreme care in tapping down the tibial component, and the company provided coating on the lateral wall of the tibial implant. Hereafter: Revision due to fractures = 0 %. 1 patient was revised due to subscidence and instability.
Conclusions: Even in high volume hospitals with experienced UKR surgeons, shifting from cemented to cementless UKR may increase failure rate as a part of a learning curve. Whether the implant design influenced the early failures remains to be elucidated.
Orthopedic dept. , Sygehus Lillebælt, Vejle; Orthopedic dept. , Sygehus Lillebælt, Vejle; Orthopedic dept., Sygehus Lillebælt, Vejle
Background: Clinical and radiological data from a design centre of unicompartmental knee replacement (UKR) show as good as, or even better outcome of the cementless compared to the cemented UKR. Our institution (a high volume hospital with UKR surgeons performing on average 40 UKRs per year) changed from cemented to cementless UKR in 2015 with a concomitant occurrence of fractures and subscidence of the tibial implant, not previously observed in the cemented UKR.
Purpose / Aim of Study: To elucidate whether or not a learning curve relates to early failures in cementless UKR.
Materials and Methods: Since January 2015, we investigated clinical and x-ray outcome after 4 weeks and 1 year in all patients, receiving a cementless UKR at our institution
Findings / Results: From Jan, 2015 to March 2016, 216 cementless UKR were implanted by 5 knee surgeons. All the surgeons had patients with early periprosthetic fracture or subscidence. Within 6 months of primary UKR, 4.2% (9 of 216) underwent revision due to either fracture or instability from subscidence. Periprostetic fractures 4/216 = 1,9%, (3 revised, 1 not revised), Subscidence with the occurrence of instability and concomitant revision: 6 / 216 = 2,8%. Radiological subscidence (not revised) 11/216 = 5 % In September 2015 we altered the surgical technique, taking extreme care in tapping down the tibial component, and the company provided coating on the lateral wall of the tibial implant. Hereafter: Revision due to fractures = 0 %. 1 patient was revised due to subscidence and instability.
Conclusions: Even in high volume hospitals with experienced UKR surgeons, shifting from cemented to cementless UKR may increase failure rate as a part of a learning curve. Whether the implant design influenced the early failures remains to be elucidated.
Kristian Horsager, Bart L. Kaptein, Peter Bo Jørgensen, Maiken Stilling
Department of Orthopedic Research, Aarhus University Hospital; Biomechanics and Imaging Group, Department of Orthopedic Surgery, Leiden University Medical Center; Department of Orthopedic Research, Aarhus University Hospital; Department of Orthopedic Research, Aarhus University Hospital
Background: The Oxford Unicompartmental Knee (UKA) is designed fully congruent, with the purpose of minimizing wear and wear related revisions. No study has investigated this design feature in-vivo.
Purpose / Aim of Study: We aimed to evaluate if the articulating surfaces of the Oxford UKA stayed fully connected (no contactloss) during bicycle- and step-cycle motion.
Materials and Methods: Fifteen patients (12 males, mean age: 69 years) with an Oxford UKA (mean in-situ: 4.4 years) participated in this cross-sectional study. Each patient was recorded with dynamic RSA (10 fr/sec) during bicycle- and step-cycle motion (step-up, stand, step- down). The recordings were analyzed with Model-based RSA, which allowed the quantification of contactloss (joint space width) between the articulating surfaces. Polyethylene (PE) wear was measured from standing RSA examinations. Clinical outcomes were evaluated with American Knee Society Score (AKSS) and Oxford Knee Score (OKS).
Findings / Results: Contactloss was seen in all patients during both exercises (p<0.001). Median contactloss was 0.8mm (95%PI: 0.3; 1.5) for bicycle motion and 0.3mm (95%PI: 0.24; 0.35) for step-cycle motion. Contactloss occurred during the late- upstroke for bicycle motion, and during initialization, stand and end of step-cycle motion. The linear PE wear rate of 0.06 mm/year (95%CI: 0.04; 0.08) was not correlated with contactloss (r<0.1, p>0.8). OKS (mean 44, range: 24; 48) and AKSS Function score (mean 94, range: 30; 100) correlated with contactloss during step-cycle motion (r<-0.55, p<0.035).
Conclusions: All Oxford UKA displayed contactloss during bicycle- and step-cycle motion. The size of contactloss during step-cycle motion correlated with poorer OKS and AKSS function scores. Contactloss did not correlate with PE wear rate.
Department of Orthopedic Research, Aarhus University Hospital; Biomechanics and Imaging Group, Department of Orthopedic Surgery, Leiden University Medical Center; Department of Orthopedic Research, Aarhus University Hospital; Department of Orthopedic Research, Aarhus University Hospital
Background: The Oxford Unicompartmental Knee (UKA) is designed fully congruent, with the purpose of minimizing wear and wear related revisions. No study has investigated this design feature in-vivo.
Purpose / Aim of Study: We aimed to evaluate if the articulating surfaces of the Oxford UKA stayed fully connected (no contactloss) during bicycle- and step-cycle motion.
Materials and Methods: Fifteen patients (12 males, mean age: 69 years) with an Oxford UKA (mean in-situ: 4.4 years) participated in this cross-sectional study. Each patient was recorded with dynamic RSA (10 fr/sec) during bicycle- and step-cycle motion (step-up, stand, step- down). The recordings were analyzed with Model-based RSA, which allowed the quantification of contactloss (joint space width) between the articulating surfaces. Polyethylene (PE) wear was measured from standing RSA examinations. Clinical outcomes were evaluated with American Knee Society Score (AKSS) and Oxford Knee Score (OKS).
Findings / Results: Contactloss was seen in all patients during both exercises (p<0.001). Median contactloss was 0.8mm (95%PI: 0.3; 1.5) for bicycle motion and 0.3mm (95%PI: 0.24; 0.35) for step-cycle motion. Contactloss occurred during the late- upstroke for bicycle motion, and during initialization, stand and end of step-cycle motion. The linear PE wear rate of 0.06 mm/year (95%CI: 0.04; 0.08) was not correlated with contactloss (r<0.1, p>0.8). OKS (mean 44, range: 24; 48) and AKSS Function score (mean 94, range: 30; 100) correlated with contactloss during step-cycle motion (r<-0.55, p<0.035).
Conclusions: All Oxford UKA displayed contactloss during bicycle- and step-cycle motion. The size of contactloss during step-cycle motion correlated with poorer OKS and AKSS function scores. Contactloss did not correlate with PE wear rate.
Birgit Skoffer, Thomas Maribo, Inger Mechlenburg, Kjeld Søballe, Ulrik Dalgas
Department of Physical and Occupational Therapy, Aarhus University Hospital, Denmark; Rehabilitation Center Marselisborg, Department of Public Health, Section of social medicine and rehabilitation, Aarhus University, Denmark; Orthopaedic Research Centre, Aarhus University Hospital, Denmark; Orthopaedic Research Centre, Aarhus University Hospital, Denmark; Section of Sport Science, Department of Public Health, Aarhus University, Denmark
Background: Efficacy of pre-operative progressive resistance training (PRT) on functional performance and muscle strength was previously demonstrated six and twelve weeks after total knee arthroplasty (TKA).
Purpose / Aim of Study: To investigate the efficacy of PRT one year post-operatively in patients undergoing total knee arthroplasty.
Materials and Methods: 59 patients were included in a single- blind, randomized, clinical, controlled trial. Participants were randomized to preoperative PRT (PRT group) or to a control group who “lived as usual” the last 4 weeks before TKA. The PRT group comprised 4-weeks of pre- operative and 4 weeks of post- operative progressive resistance training (PRT) compared to 4 weeks of post-operative PRT in the control group, and outcome measures were functional performance, e.g. 30s chair stand test (30sCST), knee extensor and knee flexor muscle strength and patient-reported outcomes. The differences between one year data and baseline data were compared between the PRT group and the control group with 30sCST as primary outcome. Statistical analyses were performed according to intention-to-treat.
Findings / Results: 15 patients were lost to one year follow- up. The PRT group had significantly higher normalized knee extensor muscle strength (0.5 Nm/kg (0.4;0.6) vs. 0.2 Nm/kg (0.1;0.3), p=0.002) and higher normalized knee flexor muscle strength (0.3 Nm/kg (0.2;0.4) vs. 0.2 Nm/kg (0.0;0.3), p=0.042) in the operated leg compared to the control group leg. A borderline significant group difference was found in regard to 30sCST (4.0 rep. (2.7;5.2) vs. 2.3 (0.9;3.6), p=0.067).
Conclusions: Supervised pre-operative PRT is an efficacious intervention for improving long term effect on muscle strength and a borderline long-time effect on functional performance in patients undergoing TKA.
Department of Physical and Occupational Therapy, Aarhus University Hospital, Denmark; Rehabilitation Center Marselisborg, Department of Public Health, Section of social medicine and rehabilitation, Aarhus University, Denmark; Orthopaedic Research Centre, Aarhus University Hospital, Denmark; Orthopaedic Research Centre, Aarhus University Hospital, Denmark; Section of Sport Science, Department of Public Health, Aarhus University, Denmark
Background: Efficacy of pre-operative progressive resistance training (PRT) on functional performance and muscle strength was previously demonstrated six and twelve weeks after total knee arthroplasty (TKA).
Purpose / Aim of Study: To investigate the efficacy of PRT one year post-operatively in patients undergoing total knee arthroplasty.
Materials and Methods: 59 patients were included in a single- blind, randomized, clinical, controlled trial. Participants were randomized to preoperative PRT (PRT group) or to a control group who “lived as usual” the last 4 weeks before TKA. The PRT group comprised 4-weeks of pre- operative and 4 weeks of post- operative progressive resistance training (PRT) compared to 4 weeks of post-operative PRT in the control group, and outcome measures were functional performance, e.g. 30s chair stand test (30sCST), knee extensor and knee flexor muscle strength and patient-reported outcomes. The differences between one year data and baseline data were compared between the PRT group and the control group with 30sCST as primary outcome. Statistical analyses were performed according to intention-to-treat.
Findings / Results: 15 patients were lost to one year follow- up. The PRT group had significantly higher normalized knee extensor muscle strength (0.5 Nm/kg (0.4;0.6) vs. 0.2 Nm/kg (0.1;0.3), p=0.002) and higher normalized knee flexor muscle strength (0.3 Nm/kg (0.2;0.4) vs. 0.2 Nm/kg (0.0;0.3), p=0.042) in the operated leg compared to the control group leg. A borderline significant group difference was found in regard to 30sCST (4.0 rep. (2.7;5.2) vs. 2.3 (0.9;3.6), p=0.067).
Conclusions: Supervised pre-operative PRT is an efficacious intervention for improving long term effect on muscle strength and a borderline long-time effect on functional performance in patients undergoing TKA.
Viktoria Lindberg-Larsen, Thomas Bandholm, Camilla Zilmer, Hornsleth Mette, Bagger Jens, Kehlet Henrik
Section for Surgical Pathophysiology, and The Lundbeck Foundation Centre for Fast-Track Hip and Knee Arthroplasty, Copenhagen University Hospital, Rigshospitalet; Physical Medicine & Rehabilitation Research-Copenhagen (PMR-C), Department of Physical Therapy, Clinical Research Centre, and Department of Orthopedic Surgery, Copenhagen University Hospital, Hvidovre; Department of Physical Therapy, Copenhagen University Hospital, Bispebjerg; Department of Orthopedic Surgery, Copenhagen University Hospital, Bispebjerg; Department of Orthopedic Surgery, Copenhagen University Hospital, Bispebjerg; Section for Surgical Pathophysiology, and The Lundbeck Foundation Centre for Fast-Track Hip and Knee Arthroplasty, Copenhagen University Hospital, Rigshospitalet
Background: Early mobilization and functional performance is delayed due to postoperative quadriceps weakness after total knee arthroplasty (TKA). Central activation failure of the quadriceps muscle due to neuro- inflammation seems to contribute considerably to the decrease in knee- extension strength.
Purpose / Aim of Study: The purpose was to evaluate the efficacy of a single preoperative dose of systemic methylprednisolone (MP) on knee-extension strength after fast- track TKA.
Materials and Methods: 70 patients undergoing elective unilateral TKA at a single center were randomized (1:1) receiving preoperative MP 125 mg IV (group M) or isotonic saline IV (group C). All procedures were performed under spinal anesthesia without Tourniquet, and a standardized, multimodal analgesic regime was used. The primary outcome was change in knee- extension strength between groups from baseline to 48 hours postoperatively. Secondary outcomes were knee joint circumference, functional performance (Timed Up and Go (TUG)), plasma C-reactive protein (CRP) concentration, pain during aforementioned tests and rescue analgesic requirements. Trial ID: NCT02319343
Findings / Results: MP significantly reduced the inflammatory response (CRP): 24 hours postoperatively; group M 33 (IQR 21-50) mg/l vs. group C 72 (IQR 58-92) mg/l, p<0.001, and 48 hours postoperatively; group M 83 (IQR 56- 125) mg/l vs. group C 192 (IQR 147- 265) mg/l, p<0.001, but loss in quadriceps muscle strength did not differ between groups: group M 1.04 (SD 0.42) Nm/kg vs. group C 1.02 (SD 0.35) Nm/kg, p=0.843. No between- group differences were observed for knee circumference, TUG, and pain scores.
Conclusions: Preoperative systemic administration of MP 125 mg reduced the inflammatory response but was not superior to placebo in reducing the loss of knee-extension strength and functional performance early after fast- track TKA.
Section for Surgical Pathophysiology, and The Lundbeck Foundation Centre for Fast-Track Hip and Knee Arthroplasty, Copenhagen University Hospital, Rigshospitalet; Physical Medicine & Rehabilitation Research-Copenhagen (PMR-C), Department of Physical Therapy, Clinical Research Centre, and Department of Orthopedic Surgery, Copenhagen University Hospital, Hvidovre; Department of Physical Therapy, Copenhagen University Hospital, Bispebjerg; Department of Orthopedic Surgery, Copenhagen University Hospital, Bispebjerg; Department of Orthopedic Surgery, Copenhagen University Hospital, Bispebjerg; Section for Surgical Pathophysiology, and The Lundbeck Foundation Centre for Fast-Track Hip and Knee Arthroplasty, Copenhagen University Hospital, Rigshospitalet
Background: Early mobilization and functional performance is delayed due to postoperative quadriceps weakness after total knee arthroplasty (TKA). Central activation failure of the quadriceps muscle due to neuro- inflammation seems to contribute considerably to the decrease in knee- extension strength.
Purpose / Aim of Study: The purpose was to evaluate the efficacy of a single preoperative dose of systemic methylprednisolone (MP) on knee-extension strength after fast- track TKA.
Materials and Methods: 70 patients undergoing elective unilateral TKA at a single center were randomized (1:1) receiving preoperative MP 125 mg IV (group M) or isotonic saline IV (group C). All procedures were performed under spinal anesthesia without Tourniquet, and a standardized, multimodal analgesic regime was used. The primary outcome was change in knee- extension strength between groups from baseline to 48 hours postoperatively. Secondary outcomes were knee joint circumference, functional performance (Timed Up and Go (TUG)), plasma C-reactive protein (CRP) concentration, pain during aforementioned tests and rescue analgesic requirements. Trial ID: NCT02319343
Findings / Results: MP significantly reduced the inflammatory response (CRP): 24 hours postoperatively; group M 33 (IQR 21-50) mg/l vs. group C 72 (IQR 58-92) mg/l, p<0.001, and 48 hours postoperatively; group M 83 (IQR 56- 125) mg/l vs. group C 192 (IQR 147- 265) mg/l, p<0.001, but loss in quadriceps muscle strength did not differ between groups: group M 1.04 (SD 0.42) Nm/kg vs. group C 1.02 (SD 0.35) Nm/kg, p=0.843. No between- group differences were observed for knee circumference, TUG, and pain scores.
Conclusions: Preoperative systemic administration of MP 125 mg reduced the inflammatory response but was not superior to placebo in reducing the loss of knee-extension strength and functional performance early after fast- track TKA.
Anders El-Galaly, Steffen Haldrup Andersen, Alma Becic Pedersen, Andreas Kappel, Poul Torben Nielsen, Michael-Ulrich Jensen
Department of Orthopaedic Surgery, Aalborg University Hospital; Department of Economics and Business Economics, Aarhus University; Department of Epidemiology, Aarhus University Hospital; Department of Orthopaedic Surgery, Aalborg University Hospital; Department of Orthopaedic Surgery, Aalborg University Hospital; Department of Orthopaedic Surgery, Aalborg University Hospital
Background: Previous minor studies have reported an inferior survival of total knee arthroplasties (TKA) inserted due to post-traumatic osteoarthritis (PTA) when compared to TKA inserted due to primary osteoarthritis (OA).
Purpose / Aim of Study: We conducted a population-based study with the aim of confirming the previous findings on a larger cohort. In addition, we hypothesize that the need for additional component supplementation (CS) during surgery were more pronounced in patients with PTA and that this might be associated with the inferior survival.
Materials and Methods: 52.876 primary TKAs inserted between 1997 and 2013 were withdrawn from the Danish Knee Arthroplasty Registry. 1.423 were inserted due to PTA and 51.453 were inserted due to OA. We examined short- (0-1 year), mid- (1-5 years) and long term (+5 years) implant survival using cumulative incidence and adjusted hazard ratio (HR) with revision as endpoint and death as competing risk. The analyses were repeated after dividing the patients by the need for additional CS.
Findings / Results: An inferior survival of TKAs inserted due PTA was present in all follow-ups. The five-year cumulative incidence was 9% in the PTA-group and 4% in the OA-group, with a corresponding adjusted HR of 1,93. Additional CS was needed in 22% of the PTA-group and in 4% of the OA-group, and the five-year cumulative incidence in these cases were 33% and 40%, respectively. An adjusted HR of 2,41 was calculated for TKAs inserted with the need for additional CS. All reported results were significant with p<0,001.
Conclusions: The study confirmed the inferior survival of TKAs inserted due to PTA, and found that this is strongly related to the need for additional CS. To our knowledge this relationship has not previous been described and should be remembered when informing the patient prior and following surgery.
Department of Orthopaedic Surgery, Aalborg University Hospital; Department of Economics and Business Economics, Aarhus University; Department of Epidemiology, Aarhus University Hospital; Department of Orthopaedic Surgery, Aalborg University Hospital; Department of Orthopaedic Surgery, Aalborg University Hospital; Department of Orthopaedic Surgery, Aalborg University Hospital
Background: Previous minor studies have reported an inferior survival of total knee arthroplasties (TKA) inserted due to post-traumatic osteoarthritis (PTA) when compared to TKA inserted due to primary osteoarthritis (OA).
Purpose / Aim of Study: We conducted a population-based study with the aim of confirming the previous findings on a larger cohort. In addition, we hypothesize that the need for additional component supplementation (CS) during surgery were more pronounced in patients with PTA and that this might be associated with the inferior survival.
Materials and Methods: 52.876 primary TKAs inserted between 1997 and 2013 were withdrawn from the Danish Knee Arthroplasty Registry. 1.423 were inserted due to PTA and 51.453 were inserted due to OA. We examined short- (0-1 year), mid- (1-5 years) and long term (+5 years) implant survival using cumulative incidence and adjusted hazard ratio (HR) with revision as endpoint and death as competing risk. The analyses were repeated after dividing the patients by the need for additional CS.
Findings / Results: An inferior survival of TKAs inserted due PTA was present in all follow-ups. The five-year cumulative incidence was 9% in the PTA-group and 4% in the OA-group, with a corresponding adjusted HR of 1,93. Additional CS was needed in 22% of the PTA-group and in 4% of the OA-group, and the five-year cumulative incidence in these cases were 33% and 40%, respectively. An adjusted HR of 2,41 was calculated for TKAs inserted with the need for additional CS. All reported results were significant with p<0,001.
Conclusions: The study confirmed the inferior survival of TKAs inserted due to PTA, and found that this is strongly related to the need for additional CS. To our knowledge this relationship has not previous been described and should be remembered when informing the patient prior and following surgery.
Karina Nørgaard Linde, Katriina Bøcker Puhakka, Bente Lomholt Langdahl, Kjeld Søballe, Inger Krog-Mikkelsen, Maiken Stilling
Orthopedic Research Unit and Department of Clinical Medicine, Aarhus University Hospital and Aarhus University, Denmark; Department of Radiology, Aarhus University Hospital, Denmark; Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Denmark; Department of Orthopaedic Surgery and Department of Clinical Medicine, Aarhus University Hospital and Department of Clinical Medicine, Aarhus University, Denmark; Orthopedic Research Unit, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark
Background: Bone quality is probably important for the survival of knee arthroplasty (KA), however little is known about preoperative bone mass, bone turnover and vitamin D status.
Purpose / Aim of Study: To explore the prevalence of osteoporosis and preoperative bone turnover in relation to knee osteoarthritis (OA) grade in patients scheduled for KA.
Materials and Methods: Prospective preoperative evaluation of patients with OA scheduled for KA between 2014- 2016. 475 patients (281 females) were examined with standing knee radiography, DXA (BMD lowest T-score of hip or spine), and biomarkers for bone turnover (CTX, P1NP) and vitamin D. OA grading on the first 184 patients was made in consensus with an experienced radiologist by use of the Altman Atlas (AA). Grading is currently ongoing towards the full cohort.
Findings / Results: Mean patient age was 67.8 years (CI95 66.8;68.8). The proportion of patients with osteoporosis (OP) was 10.2% (CI95 7.4;12.9), while the proportion of patients with osteopenia was 36.2% (CI95 32.0; 40.7). Mean BMD T-score was 0.7 lower in women than in men (p<0.0001). After adjustment for age mean BMD T-score was 0.44 (CI95 0.05;0.83) lower when attrition (AA) was present medially or laterally compared to not present (p=0.026). Altman total grade and CTX and P1NP had a weak but significant correlation (p<0.001). After adjustment for age P1NP was 11% higher (p=0.16) when attrition (AA) was present compared to not present. No difference in CTX with the presence of attrition (p=0.53). Serum vitamin D was 78.9 (CI95 76.1;81.7) nmol/L. There was no association between vitamin D and AA grade (p>0.34).
Conclusions: Bone mass was lower with severe knee osteoarthritis (attrition). There was a trend towards higher bone turnover biomarker (P1NP) with higher grade of knee osteoarthritis. 10% of patients had osteoporosis.
Orthopedic Research Unit and Department of Clinical Medicine, Aarhus University Hospital and Aarhus University, Denmark; Department of Radiology, Aarhus University Hospital, Denmark; Department of Endocrinology and Internal Medicine, Aarhus University Hospital, Denmark; Department of Orthopaedic Surgery and Department of Clinical Medicine, Aarhus University Hospital and Department of Clinical Medicine, Aarhus University, Denmark; Orthopedic Research Unit, Aarhus University Hospital, Denmark; Department of Clinical Medicine, Aarhus University, Denmark
Background: Bone quality is probably important for the survival of knee arthroplasty (KA), however little is known about preoperative bone mass, bone turnover and vitamin D status.
Purpose / Aim of Study: To explore the prevalence of osteoporosis and preoperative bone turnover in relation to knee osteoarthritis (OA) grade in patients scheduled for KA.
Materials and Methods: Prospective preoperative evaluation of patients with OA scheduled for KA between 2014- 2016. 475 patients (281 females) were examined with standing knee radiography, DXA (BMD lowest T-score of hip or spine), and biomarkers for bone turnover (CTX, P1NP) and vitamin D. OA grading on the first 184 patients was made in consensus with an experienced radiologist by use of the Altman Atlas (AA). Grading is currently ongoing towards the full cohort.
Findings / Results: Mean patient age was 67.8 years (CI95 66.8;68.8). The proportion of patients with osteoporosis (OP) was 10.2% (CI95 7.4;12.9), while the proportion of patients with osteopenia was 36.2% (CI95 32.0; 40.7). Mean BMD T-score was 0.7 lower in women than in men (p<0.0001). After adjustment for age mean BMD T-score was 0.44 (CI95 0.05;0.83) lower when attrition (AA) was present medially or laterally compared to not present (p=0.026). Altman total grade and CTX and P1NP had a weak but significant correlation (p<0.001). After adjustment for age P1NP was 11% higher (p=0.16) when attrition (AA) was present compared to not present. No difference in CTX with the presence of attrition (p=0.53). Serum vitamin D was 78.9 (CI95 76.1;81.7) nmol/L. There was no association between vitamin D and AA grade (p>0.34).
Conclusions: Bone mass was lower with severe knee osteoarthritis (attrition). There was a trend towards higher bone turnover biomarker (P1NP) with higher grade of knee osteoarthritis. 10% of patients had osteoporosis.