Session 4: Knee II
Onsdag den 25. oktober
11:00-12:00
Lokale: Reykjavik
Chairmen: Lasse Enkebølle Rasmussen og Anders Odgaard
Lasse E. Rasmussen, Thomas Lind-Hansen, Claus Varnum, Per Wagner Kristensen
Orthopedic Dept. , Sygehus Lillebælt, Vejle Hospital; Orthopedic Dept., Sygehus Lillebælt, Vejle Hospital; Orthopedic Dept., Sygehus Lillebælt, Vejle Hospital; Orthopedic Dept., Sygehus Lillebælt, Vejle Hospital
Background: We shifted from the cemented to the cementless Oxford unicompartmental knee replacement (OUKR) in January 2015 to reduce the risk of cementing errors and mistaken revision from radiolucent lines. Upon the change we experienced a number of tibial fractures and tibial component subsidence. In September 2015 we altered our surgical technique, by gently tapping down the tibial component and moving the vertical cut as lateral as possible, to ensure the largest possible component.
Purpose / Aim of Study: To investigate if the new surgical approach altered the occurrence of tibial component subsidence and, in the case of subsidence, to investigate the 1-year outcome.
Materials and Methods: We performed a prospective intervention study. X-rays were taken postoperatively at 4 weeks and 1 year for all cementless OUKR operated in 2015 and 2016. 1 year after surgery, all patients were interviewed regarding satisfaction. Results were compared before and after the intervention.
Findings / Results: Subsidence occurred within 4 weeks in 42/187 women and 28/166 men. Subsidence before September 2015; 28/105 = 27%. After September 2015; 42/250 = 17%; (p =0,037). The tibial component subsided within the first 4 weeks; hereafter it remained stabile for the following 11 months in 49 (98%) of the cases. 38 patients (78%) were extremely satisfied, 8 (16%) were satisfied, and 4 (8%) were less satisfied. Two of the less satisfied patients were due to neuroma formation. The level of satisfaction was similar in patients before and after the intervention in September 2015.
Conclusions: Valgus subsidence of the tibial component in cementless OUKR may depend on the surgical technique. It may occur within the first 4 weeks postoperatively whereafter the component stabilizes. Valgus subsidence does not seem to affect patient-reported outcome 1 year postoperatively.
Orthopedic Dept. , Sygehus Lillebælt, Vejle Hospital; Orthopedic Dept., Sygehus Lillebælt, Vejle Hospital; Orthopedic Dept., Sygehus Lillebælt, Vejle Hospital; Orthopedic Dept., Sygehus Lillebælt, Vejle Hospital
Background: We shifted from the cemented to the cementless Oxford unicompartmental knee replacement (OUKR) in January 2015 to reduce the risk of cementing errors and mistaken revision from radiolucent lines. Upon the change we experienced a number of tibial fractures and tibial component subsidence. In September 2015 we altered our surgical technique, by gently tapping down the tibial component and moving the vertical cut as lateral as possible, to ensure the largest possible component.
Purpose / Aim of Study: To investigate if the new surgical approach altered the occurrence of tibial component subsidence and, in the case of subsidence, to investigate the 1-year outcome.
Materials and Methods: We performed a prospective intervention study. X-rays were taken postoperatively at 4 weeks and 1 year for all cementless OUKR operated in 2015 and 2016. 1 year after surgery, all patients were interviewed regarding satisfaction. Results were compared before and after the intervention.
Findings / Results: Subsidence occurred within 4 weeks in 42/187 women and 28/166 men. Subsidence before September 2015; 28/105 = 27%. After September 2015; 42/250 = 17%; (p =0,037). The tibial component subsided within the first 4 weeks; hereafter it remained stabile for the following 11 months in 49 (98%) of the cases. 38 patients (78%) were extremely satisfied, 8 (16%) were satisfied, and 4 (8%) were less satisfied. Two of the less satisfied patients were due to neuroma formation. The level of satisfaction was similar in patients before and after the intervention in September 2015.
Conclusions: Valgus subsidence of the tibial component in cementless OUKR may depend on the surgical technique. It may occur within the first 4 weeks postoperatively whereafter the component stabilizes. Valgus subsidence does not seem to affect patient-reported outcome 1 year postoperatively.
Hannes Torngren, Sara Kamilla Clausen, Anders Odgaard, Thomas Lind
Orthopaedic department, Gentofte Hospital; Orthopaedic department, Gentofte Hospital; orthopaedic department, Gentofte Hospital; orthopaedic departmento, Gentofte Hospital
Background: Total knee arthroplasty (TKA) is a surgical procedure routinely performed, primarily as end-stage treatment for osteoarthritis, resulting in approximately 8000 primary procedures every year in Denmark. While many aspects of causes and risk factors for infections and TKAs have been extensively examined, none have, to the authors’ knowledge, sufficiently explored\r\nthe relationship between seasonality and risk of perioperative infections
Purpose / Aim of Study: We performed a retrospective study to determine the rate of revision due to deep infection, defined as those revised within the first 2 year, for each month of the year . The aim of the study was to investigate wether there is a variation in infection rate after primary TKA based on the month the primary surgery was done
Materials and Methods: The study was based on a large dataset from the national Danish Knee Arthroplasty Registry (DKR). We received data on a total of 124.484 procedures and set out to identify all patients who, between January 1st 1997 and December 31st 2014, had undergone primary TKA resulting in revision surgery due to infection. The revision rate and relative risk for infection for each month were calculated and analyzed with Pearsons chi-square test.
Findings / Results: The revision rate due to infection was calculated for each season. Of procedures performed during summer, 1,02% ended in revision due to infection. In comparison, the remainder of the seasons had revision rates of 0,73% (fall), 0,82% (winter) and 0,80% (spring) (P = 0.013) The relative risiko between summer vs the rest was 1.31 [95% CI, 1.10 - 1.55]
Conclusions: The relative risk of revision surgery due to infection is 1.31 times higher if the primary TKA surgery is performed during the summer months compared to the remainder of the year. The reason for the increased infection rate is yet to be determined
Orthopaedic department, Gentofte Hospital; Orthopaedic department, Gentofte Hospital; orthopaedic department, Gentofte Hospital; orthopaedic departmento, Gentofte Hospital
Background: Total knee arthroplasty (TKA) is a surgical procedure routinely performed, primarily as end-stage treatment for osteoarthritis, resulting in approximately 8000 primary procedures every year in Denmark. While many aspects of causes and risk factors for infections and TKAs have been extensively examined, none have, to the authors’ knowledge, sufficiently explored\r\nthe relationship between seasonality and risk of perioperative infections
Purpose / Aim of Study: We performed a retrospective study to determine the rate of revision due to deep infection, defined as those revised within the first 2 year, for each month of the year . The aim of the study was to investigate wether there is a variation in infection rate after primary TKA based on the month the primary surgery was done
Materials and Methods: The study was based on a large dataset from the national Danish Knee Arthroplasty Registry (DKR). We received data on a total of 124.484 procedures and set out to identify all patients who, between January 1st 1997 and December 31st 2014, had undergone primary TKA resulting in revision surgery due to infection. The revision rate and relative risk for infection for each month were calculated and analyzed with Pearsons chi-square test.
Findings / Results: The revision rate due to infection was calculated for each season. Of procedures performed during summer, 1,02% ended in revision due to infection. In comparison, the remainder of the seasons had revision rates of 0,73% (fall), 0,82% (winter) and 0,80% (spring) (P = 0.013) The relative risiko between summer vs the rest was 1.31 [95% CI, 1.10 - 1.55]
Conclusions: The relative risk of revision surgery due to infection is 1.31 times higher if the primary TKA surgery is performed during the summer months compared to the remainder of the year. The reason for the increased infection rate is yet to be determined
Kristoffer Weisskirchner Barfod, Lars Blønd
Dept. of Orthopedic Surgery, Zealand University Hospital; Dept. of Orthopedic Surgery, Zealand University Hospital
Background: Treatment of knee osteoarthritis (OA) with minimally manipulated cell therapies have gained increasing popularity. The stromal vascular fraction of abdominal Adipose tissue (SVF) is a rich source of mesenchymal stem cells. Studies using SVF have shown promising results.
Purpose / Aim of Study: To investigate the feasibility and safety issues of treatment of knee OA with intra-articular injection with SVF harvested and prepared using the Lipogems System.
Materials and Methods: The study was performed as a prospective cohort study with follow up after 3, 6 and 12 months. Primary endpoint was any adverse event at 3 months. Secondary endpoint was KOOS. Patients aged 18-70 years were eligible for inclusion if they had been diagnosed with osteoarthritis. Exclusion criteria were malalignment of the knee > 5 degrees, instability or BMI > 35. SVF was harvested through two stab incision just below the umbilicus and prepared for implantation using the Lipogems system; an enzyme-free technology that works through a mild mechanical tissue cluster size reduction. Implantation of 8- 16ml SVF in the knee was performed using a 21 gauge syringe.
Findings / Results: 20 patients were included and 19 participated in follow up. Mean (SD) age was 49 (9), weight 89kg (22), height 170cm (23). One adverse event was registered as a patient complaint of cosmetically changes to the abdominal subcutaneous tissue. 13 of 19 would go for the procedure again. At 3 months KOOS Pain increased 9 (p=0.003) points, Symptoms 4 (p=0.197), ADL 9 (p=0.008), Sport 13 (p=0.002) and QOL 15 (p=0.008). Differences dropped to border significant values at 6 and 12 months.
Conclusions: Treatment of knee OA with intra-articular injection with SVF harvested and prepared using the Lipogems System is feasible and safe. Efficiency of the treatment is questionable and is not evaluated in the present study.
Dept. of Orthopedic Surgery, Zealand University Hospital; Dept. of Orthopedic Surgery, Zealand University Hospital
Background: Treatment of knee osteoarthritis (OA) with minimally manipulated cell therapies have gained increasing popularity. The stromal vascular fraction of abdominal Adipose tissue (SVF) is a rich source of mesenchymal stem cells. Studies using SVF have shown promising results.
Purpose / Aim of Study: To investigate the feasibility and safety issues of treatment of knee OA with intra-articular injection with SVF harvested and prepared using the Lipogems System.
Materials and Methods: The study was performed as a prospective cohort study with follow up after 3, 6 and 12 months. Primary endpoint was any adverse event at 3 months. Secondary endpoint was KOOS. Patients aged 18-70 years were eligible for inclusion if they had been diagnosed with osteoarthritis. Exclusion criteria were malalignment of the knee > 5 degrees, instability or BMI > 35. SVF was harvested through two stab incision just below the umbilicus and prepared for implantation using the Lipogems system; an enzyme-free technology that works through a mild mechanical tissue cluster size reduction. Implantation of 8- 16ml SVF in the knee was performed using a 21 gauge syringe.
Findings / Results: 20 patients were included and 19 participated in follow up. Mean (SD) age was 49 (9), weight 89kg (22), height 170cm (23). One adverse event was registered as a patient complaint of cosmetically changes to the abdominal subcutaneous tissue. 13 of 19 would go for the procedure again. At 3 months KOOS Pain increased 9 (p=0.003) points, Symptoms 4 (p=0.197), ADL 9 (p=0.008), Sport 13 (p=0.002) and QOL 15 (p=0.008). Differences dropped to border significant values at 6 and 12 months.
Conclusions: Treatment of knee OA with intra-articular injection with SVF harvested and prepared using the Lipogems System is feasible and safe. Efficiency of the treatment is questionable and is not evaluated in the present study.
Iben Rønne Jessing, Mette Mikkelsen, Kirill Gromov, Henrik Husted, Thomas Kallemose, Anders Troelsen
Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital; Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital; Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital; Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital; Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital; Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital
Background: The osteoarthritic (OA) disease pattern of the knee is one of the determinants for choice of arthroplasty concept when knee replacement is indicated, but whether the disease pattern has a direct effect on postoperative outcome has not previously been investigated.
Purpose / Aim of Study: The aim was to investigate if different OA disease patterns and severity of osteoarthritis had an effect on postoperative outcome after receiving total knee arthroplasty (TKA).
Materials and Methods: 472 patients with complete pre- and 1-year postoperative patient reported outcome measures (PROM's) undergoing TKA surgery from January 2013 to November 2015 at one hospital were retrospectively identified and classification of the OA disease pattern were made on preoperative full weight bearing radiographs. During the investigated period no partial knee replacements were performed and measured resection was the universal technical approach. The outcome was development in PROM scores from pre- to 1-year postoperatively.
Findings / Results: The key findings showed the greatest improvement in mean PROM scores for anteromedial OA (AMOA) compared with other OA disease patterns; 3.2 points (95 % confidence interval (CI) 1.5-4.9, p < 0.001) in Oxford Knee score, 8.2 points (95 % CI 2.6-18.9, p = 0.135) in Forgotten Joint score and 0.08 points (95 % CI 0.02-0.14, p = 0.002) in EQ-5D score. Similar results were observed favoring bone-on-bone AMOA compared with AMOA that had only partial thickness cartilage loss.
Conclusions: Patients classified with AMOA achieve greater improvement in PROM scores after TKA surgery compared with other OA disease patterns. This finding has important implications for reporting, risk stratification and interpretation in TKA outcome studies, including randomized trials.
Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital; Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital; Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital; Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital; Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital; Clinical Orthopaedic Research Hvidovre, Hvidovre Hospital
Background: The osteoarthritic (OA) disease pattern of the knee is one of the determinants for choice of arthroplasty concept when knee replacement is indicated, but whether the disease pattern has a direct effect on postoperative outcome has not previously been investigated.
Purpose / Aim of Study: The aim was to investigate if different OA disease patterns and severity of osteoarthritis had an effect on postoperative outcome after receiving total knee arthroplasty (TKA).
Materials and Methods: 472 patients with complete pre- and 1-year postoperative patient reported outcome measures (PROM's) undergoing TKA surgery from January 2013 to November 2015 at one hospital were retrospectively identified and classification of the OA disease pattern were made on preoperative full weight bearing radiographs. During the investigated period no partial knee replacements were performed and measured resection was the universal technical approach. The outcome was development in PROM scores from pre- to 1-year postoperatively.
Findings / Results: The key findings showed the greatest improvement in mean PROM scores for anteromedial OA (AMOA) compared with other OA disease patterns; 3.2 points (95 % confidence interval (CI) 1.5-4.9, p < 0.001) in Oxford Knee score, 8.2 points (95 % CI 2.6-18.9, p = 0.135) in Forgotten Joint score and 0.08 points (95 % CI 0.02-0.14, p = 0.002) in EQ-5D score. Similar results were observed favoring bone-on-bone AMOA compared with AMOA that had only partial thickness cartilage loss.
Conclusions: Patients classified with AMOA achieve greater improvement in PROM scores after TKA surgery compared with other OA disease patterns. This finding has important implications for reporting, risk stratification and interpretation in TKA outcome studies, including randomized trials.
Sofie Ryaa, Lina H. Ingelsrud, Søren T. Skou, Ewa M. Roos, Anders Troelsen
Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre; Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre; Department of Sports Science and Clinical Biomechanics AND Department of Physiotherapy and Occupational Therapy, University of Southern Denmark AND Næstved-Slagelse-Ringsted Hospitals; Research Unit for Musculoskeletal Function and Physiotherapy, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark; Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre
Background: The Good Life with osteoArthritis in Denmark (GLA:D) programme consists of patient education and supervised exercise therapy and adheres to clinical guidelines for knee osteoarthritis (OA). Non-operative treatments like GLA:D may be beneficial when surgery is not considered timely.
Purpose / Aim of Study: To present the clinical course of action taken by patients advised to participate in GLA:D by an orthopaedic surgeon before deciding on undergoing knee replacement.
Materials and Methods: Patient records from all patients with knee OA consulting one orthopaedic surgeon in 2015 were reviewed to detect those being advised GLA:D participation. Radiologic OA was classified with Kellgren-Lawrence (KL) grade 0-4, none-severe. Results after 3 months were extracted from the GLA:D database, including a visual analogue scale (VAS) for knee pain (0-100, best-worst), and the Knee injury and Osteoarthritis Outcome score knee-related quality of life (QOL) subscale (0-100, worst-best).
Findings / Results: Out of 142 patients with primary referrals due to knee OA, 83 (58.5%) were advised to participate in GLA:D. They had a mean (SD) age of 65.0 (10.7) and 59 (62.8%) were female. They were either not eligible for surgery, or pending surgical decision and 34 (44.8%) had a KL grade 3-4. Only 18 (22%) patients participated in GLA:D, and 14 (17%) completed 3 months follow-up. For these patients, the mean (SD) VAS pain score improved from 61.4 (18.6) to 42.7 (25.1) (p<0.001), while knee-related QOL remained unchanged (from 41.5 (16.2) to 43.8 (12.3) (p=0.535)).
Conclusions: The majority of patients did not follow the surgeon’s advice on non-surgical treatment. In those who did the significant pain reduction found indicates patient education and supervised exercise therapy being beneficial in patients prior to deciding on knee replacement, or if surgery is not indicated.
Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre; Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre; Department of Sports Science and Clinical Biomechanics AND Department of Physiotherapy and Occupational Therapy, University of Southern Denmark AND Næstved-Slagelse-Ringsted Hospitals; Research Unit for Musculoskeletal Function and Physiotherapy, Department of Sports Science and Clinical Biomechanics, University of Southern Denmark; Department of Orthopaedic surgery, Copenhagen University Hospital Hvidovre
Background: The Good Life with osteoArthritis in Denmark (GLA:D) programme consists of patient education and supervised exercise therapy and adheres to clinical guidelines for knee osteoarthritis (OA). Non-operative treatments like GLA:D may be beneficial when surgery is not considered timely.
Purpose / Aim of Study: To present the clinical course of action taken by patients advised to participate in GLA:D by an orthopaedic surgeon before deciding on undergoing knee replacement.
Materials and Methods: Patient records from all patients with knee OA consulting one orthopaedic surgeon in 2015 were reviewed to detect those being advised GLA:D participation. Radiologic OA was classified with Kellgren-Lawrence (KL) grade 0-4, none-severe. Results after 3 months were extracted from the GLA:D database, including a visual analogue scale (VAS) for knee pain (0-100, best-worst), and the Knee injury and Osteoarthritis Outcome score knee-related quality of life (QOL) subscale (0-100, worst-best).
Findings / Results: Out of 142 patients with primary referrals due to knee OA, 83 (58.5%) were advised to participate in GLA:D. They had a mean (SD) age of 65.0 (10.7) and 59 (62.8%) were female. They were either not eligible for surgery, or pending surgical decision and 34 (44.8%) had a KL grade 3-4. Only 18 (22%) patients participated in GLA:D, and 14 (17%) completed 3 months follow-up. For these patients, the mean (SD) VAS pain score improved from 61.4 (18.6) to 42.7 (25.1) (p<0.001), while knee-related QOL remained unchanged (from 41.5 (16.2) to 43.8 (12.3) (p=0.535)).
Conclusions: The majority of patients did not follow the surgeon’s advice on non-surgical treatment. In those who did the significant pain reduction found indicates patient education and supervised exercise therapy being beneficial in patients prior to deciding on knee replacement, or if surgery is not indicated.
Mie Christina Hansen, Rasmus Malik Thaarup Høegh, Jacob Fyhring Mortensen, Helge Bjarup Dissing Sørensen, Anders Odgaard
Ortopædkirurgisk afdeling, Herlev-Gentofte Hospital, Gentofte; Department of Electrical Engineering, Technical University of Demark (DTU); Ortopædkirurgisk afdeling, Herlev-Gentofte Hospital, Gentofte; Department of Electrical Engineering, Technical University of Demark (DTU); Ortopædkirurgisk afdeling, Herlev-Gentofte Hospital, Gentofte
Background: Range of motion (ROM) under specific activities may be related to patients' experience of the quality of knee function. It may be superior compared to measurements of passive ROM in an ambulatory.
Purpose / Aim of Study: The objective of this study is to investigate and develop a new method to determine dynamic knee function using wearable sensors.
Materials and Methods: 35 subjects aged 60-75 were included in the study. They met 1 of 3 criteria: Healthy (normal functioning knee), pre-operative or 3 months post-operative. We used 2 sensors with a magneto-, accelero- and gyrometer that measure the angle between the femur and tibia. With 2 sensors taped to the skin, patients performed 2 exercises; walk on treadmill 2 km/h and individually chosen fast pace. For reproducibility the exercises were carried out twice.
Findings / Results: Significant difference in knee function between the 3 groups was found. Subjects with healthy knee had significant higher active ROM (mean = 53.6°), angular velocity and acceleration than the 2 other groups. The post-operative’s active ROM (mean = 43.4°) were significantly higher than the pre-operative group (mean = 37.4°), but the angular velocity and acceleration were not significantly different from the pre-operative group. Retests showed the method to be highly reproducible. The largest difference between the groups was observed when instructed to walk at a fast pace.
Conclusions: The sensors measures of dynamic ROM were reproducible and consistent with the degree of pathology. This method is simple and allows gait analysis to be telemetric in the patient's daily life, and it thus fundamentally differs from costly laboratory tests. The method can be used to monitor patients both pre- and postoperatively. Further studies will investigate whether the application of machine learning on the data can predict Oxford Knee Score.
Ortopædkirurgisk afdeling, Herlev-Gentofte Hospital, Gentofte; Department of Electrical Engineering, Technical University of Demark (DTU); Ortopædkirurgisk afdeling, Herlev-Gentofte Hospital, Gentofte; Department of Electrical Engineering, Technical University of Demark (DTU); Ortopædkirurgisk afdeling, Herlev-Gentofte Hospital, Gentofte
Background: Range of motion (ROM) under specific activities may be related to patients' experience of the quality of knee function. It may be superior compared to measurements of passive ROM in an ambulatory.
Purpose / Aim of Study: The objective of this study is to investigate and develop a new method to determine dynamic knee function using wearable sensors.
Materials and Methods: 35 subjects aged 60-75 were included in the study. They met 1 of 3 criteria: Healthy (normal functioning knee), pre-operative or 3 months post-operative. We used 2 sensors with a magneto-, accelero- and gyrometer that measure the angle between the femur and tibia. With 2 sensors taped to the skin, patients performed 2 exercises; walk on treadmill 2 km/h and individually chosen fast pace. For reproducibility the exercises were carried out twice.
Findings / Results: Significant difference in knee function between the 3 groups was found. Subjects with healthy knee had significant higher active ROM (mean = 53.6°), angular velocity and acceleration than the 2 other groups. The post-operative’s active ROM (mean = 43.4°) were significantly higher than the pre-operative group (mean = 37.4°), but the angular velocity and acceleration were not significantly different from the pre-operative group. Retests showed the method to be highly reproducible. The largest difference between the groups was observed when instructed to walk at a fast pace.
Conclusions: The sensors measures of dynamic ROM were reproducible and consistent with the degree of pathology. This method is simple and allows gait analysis to be telemetric in the patient's daily life, and it thus fundamentally differs from costly laboratory tests. The method can be used to monitor patients both pre- and postoperatively. Further studies will investigate whether the application of machine learning on the data can predict Oxford Knee Score.
Amir Pasha Attarzadeh, Amin Bakhtyar Baram, Thorbjørn Gantzel Christiansen, Thomas Lind
Orthopedic department, Herlev og Gentofte Hospital; Orthopedic department, Herlev og Gentofte Hospital; Orthopedic department, Herlev og Gentofte Hospital; Orthopedic department, Herlev og Gentofte Hospital
Background: Patients with Total Knee Arthroplasty (TKA) can be revised with isolated polyethylene liner exchange. The indication varies from pain, stiffness, recurrent effusion, wear or instability. The effectiveness of this procedure is quite controversial. An analysis of results based on these subgroups may give us knowledge about the best indication.
Purpose / Aim of Study: The aim of this study is to evaluate the results of isolated polyethylene exchange in patients with instability and pain.
Materials and Methods: From out database we identified all patients who underwent revision of a TKA with liner exchange in our institution in the period from 2010 to 2013. We included all patients with instability and pain as described by the surgeon. We excluded all patients who had other interventions. Patient reported outcome was evaluated with a KOOS and a Oxford Knee Score questionnaire and clinical assessment was conducted using Knee Society Score.
Findings / Results: We had a population of 19 patients, 12 women and 7 men. One patient had bilateral liner exchange. Mean increase in liner thickness was 5,8mm (2,5- 7,5mm). Mean follow-up time after revision was 44 months (30-60). Mean KOOS for categories Pain, other Symptoms and ADL was 62-64 but for Function in Sport and Recreation and for Quality of Life it was 27 and 43. Mean Knee Society Score and Function score was 66 and 69. Mean Oxford Knee Score was 29. Postoperatively, mean VAS in rest was 1 and in activity 4. Average time between the operations was 24 months.
Conclusions: Our results reveal poor outcome when isolated polyethylene liner exchange is performed on the indication instability and pain. Careful patient selection for this procedure may yield better results. Further studies are needed to confirm this.
Orthopedic department, Herlev og Gentofte Hospital; Orthopedic department, Herlev og Gentofte Hospital; Orthopedic department, Herlev og Gentofte Hospital; Orthopedic department, Herlev og Gentofte Hospital
Background: Patients with Total Knee Arthroplasty (TKA) can be revised with isolated polyethylene liner exchange. The indication varies from pain, stiffness, recurrent effusion, wear or instability. The effectiveness of this procedure is quite controversial. An analysis of results based on these subgroups may give us knowledge about the best indication.
Purpose / Aim of Study: The aim of this study is to evaluate the results of isolated polyethylene exchange in patients with instability and pain.
Materials and Methods: From out database we identified all patients who underwent revision of a TKA with liner exchange in our institution in the period from 2010 to 2013. We included all patients with instability and pain as described by the surgeon. We excluded all patients who had other interventions. Patient reported outcome was evaluated with a KOOS and a Oxford Knee Score questionnaire and clinical assessment was conducted using Knee Society Score.
Findings / Results: We had a population of 19 patients, 12 women and 7 men. One patient had bilateral liner exchange. Mean increase in liner thickness was 5,8mm (2,5- 7,5mm). Mean follow-up time after revision was 44 months (30-60). Mean KOOS for categories Pain, other Symptoms and ADL was 62-64 but for Function in Sport and Recreation and for Quality of Life it was 27 and 43. Mean Knee Society Score and Function score was 66 and 69. Mean Oxford Knee Score was 29. Postoperatively, mean VAS in rest was 1 and in activity 4. Average time between the operations was 24 months.
Conclusions: Our results reveal poor outcome when isolated polyethylene liner exchange is performed on the indication instability and pain. Careful patient selection for this procedure may yield better results. Further studies are needed to confirm this.