Session 7: Hip
Torsdag den 22. oktober
13:00 – 14:30
Lokale: Reykjavik
Chairmen: Ole Ovesen / Claus Varnum
Christine Kruse, Signe Rosenlund, Leif Broeng, Søren Overgaard
Department of Orthopedic Surgery and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Denmark
Background: The two most common surgical approaches for total hip arthroplasty (THA) are the posterior and lateral approach. Differences in cup placement may contribute to differences in clinical outcomes between the two approaches. Improper placement of the cup can cause dislocation and reduced hip abductor strength.
Purpose / Aim of Study: The aim of this study was to compare cup position in the two approaches. A secondary aim was to compare changes in femoral offset (FO), cup offset (CO), total offset (TO) and abductor moment arm (AM), and to evaluate intra- and interobserver reliability of the methods used.
Materials and Methods: In a randomized controlled trial, 80 patients diagnosed with primary hip osteoarthritis scheduled for THA were assigned to operation with posterior or modified direct lateral approach. 38 patients were included in each group for the measurement cup position. FO, CO, TO and AM were measured on pre- and postoperative radiographs in 28 patients in each group. Unpaired t-tests were used to evaluate differences between the groups. An ICC value of ≥0.81 was considered excellent strength of agreement.
Findings / Results: In the posterior group, anteversion was 4.8° larger than in the lateral group (p=0.006) but inclination was 4.9° less steep (p<0.001). A larger FO of 4.3mm (p=0.006), TO of 6.3mm (p<0.001) and AM of 4.8mm (p=0.001) was found in the posterior group. There was no significant difference in CO (p=0.08). Intra- and interobserver reliability were excellent for all measurements (ICC 0.93-1.00).
Conclusions: We found a statistically significant difference in cup position between the two approaches. Femoral offset and abductor moment arm were restored after THA using the lateral approach but significantly increased when using the posterior approach.
Department of Orthopedic Surgery and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Denmark
Background: The two most common surgical approaches for total hip arthroplasty (THA) are the posterior and lateral approach. Differences in cup placement may contribute to differences in clinical outcomes between the two approaches. Improper placement of the cup can cause dislocation and reduced hip abductor strength.
Purpose / Aim of Study: The aim of this study was to compare cup position in the two approaches. A secondary aim was to compare changes in femoral offset (FO), cup offset (CO), total offset (TO) and abductor moment arm (AM), and to evaluate intra- and interobserver reliability of the methods used.
Materials and Methods: In a randomized controlled trial, 80 patients diagnosed with primary hip osteoarthritis scheduled for THA were assigned to operation with posterior or modified direct lateral approach. 38 patients were included in each group for the measurement cup position. FO, CO, TO and AM were measured on pre- and postoperative radiographs in 28 patients in each group. Unpaired t-tests were used to evaluate differences between the groups. An ICC value of ≥0.81 was considered excellent strength of agreement.
Findings / Results: In the posterior group, anteversion was 4.8° larger than in the lateral group (p=0.006) but inclination was 4.9° less steep (p<0.001). A larger FO of 4.3mm (p=0.006), TO of 6.3mm (p<0.001) and AM of 4.8mm (p=0.001) was found in the posterior group. There was no significant difference in CO (p=0.08). Intra- and interobserver reliability were excellent for all measurements (ICC 0.93-1.00).
Conclusions: We found a statistically significant difference in cup position between the two approaches. Femoral offset and abductor moment arm were restored after THA using the lateral approach but significantly increased when using the posterior approach.
Eva Natalia Glassou, Torben Bæk Hansen, Keijo Mäkelä, Leif Ivar Havelin, Johan Kärrholm, Alma Becic Pedersen
Department of Orthopedic Surgery, Regional Hospital West Jutland, Denmark; Department of Orthopaedics and Traumatology, Turku University Hospital, Turku, Finland; Institute of Clinical Sciences, Department of Orthopaedics, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Clinical Epidemiology, Aarhus University Hospital, Denmark
Background: The outcome after total hip arthroplasty (THA) depend on factors related to the patient, the surgeon, the implant and the organization of the health care system. It has been suggested that the annual number of procedures per hospital affects the prognosis.
Purpose / Aim of Study: The aim was to examine if hospital procedure volume was associated with the risk of revision after THA in the Nordic countries from 1995 to 2011.
Materials and Methods: The Nordic Arthroplasty Register Association database provided information about primary THA, type of fixation, revisions and annual hospital volume in the Nordic countries. Hospitals were divided into 5 volume groups (1-50, 51-100, 101-200, 201- 300, >300). Primary outcome was the cumulative incidence of revision from all causes 1, 2, 5, 10 and 15 years after primary procedure. Multivariable regression was used to assess the relative risk of revision (RR).
Findings / Results: 417,687 THA were included. The cumulative incidence of revision increased from 1.4% (CI 1.3 – 1.5) after 1 year to 9.2% (CI 8.9 – 9.4) after 15 years. After 1 and 2 years no differences were seen between the volume groups. After 5 years RR were reduced for group 51-100 (0.9, CI 0.8 – 1.0), group 101-200 (0.8, CI 0.7 – 0.9), group 201-300 (0.8, CI 0.7 – 1.0) and group >300 (0.8, CI 0.7 – 1.0) compared to group 1-50. Same pattern were seen after 10 and 15 years.
Conclusions: We found a consistent association between hospital volume and long term risk of revision. Hospitals operating 50 procedures or less per year had an increased risk of revision 5, 10 and 15 years after primary procedure.
Department of Orthopedic Surgery, Regional Hospital West Jutland, Denmark; Department of Orthopaedics and Traumatology, Turku University Hospital, Turku, Finland; Institute of Clinical Sciences, Department of Orthopaedics, Sahlgrenska University Hospital, Gothenburg, Sweden; Department of Clinical Epidemiology, Aarhus University Hospital, Denmark
Background: The outcome after total hip arthroplasty (THA) depend on factors related to the patient, the surgeon, the implant and the organization of the health care system. It has been suggested that the annual number of procedures per hospital affects the prognosis.
Purpose / Aim of Study: The aim was to examine if hospital procedure volume was associated with the risk of revision after THA in the Nordic countries from 1995 to 2011.
Materials and Methods: The Nordic Arthroplasty Register Association database provided information about primary THA, type of fixation, revisions and annual hospital volume in the Nordic countries. Hospitals were divided into 5 volume groups (1-50, 51-100, 101-200, 201- 300, >300). Primary outcome was the cumulative incidence of revision from all causes 1, 2, 5, 10 and 15 years after primary procedure. Multivariable regression was used to assess the relative risk of revision (RR).
Findings / Results: 417,687 THA were included. The cumulative incidence of revision increased from 1.4% (CI 1.3 – 1.5) after 1 year to 9.2% (CI 8.9 – 9.4) after 15 years. After 1 and 2 years no differences were seen between the volume groups. After 5 years RR were reduced for group 51-100 (0.9, CI 0.8 – 1.0), group 101-200 (0.8, CI 0.7 – 0.9), group 201-300 (0.8, CI 0.7 – 1.0) and group >300 (0.8, CI 0.7 – 1.0) compared to group 1-50. Same pattern were seen after 10 and 15 years.
Conclusions: We found a consistent association between hospital volume and long term risk of revision. Hospitals operating 50 procedures or less per year had an increased risk of revision 5, 10 and 15 years after primary procedure.
Inger Mechlenburg, Peter Bo Jørgensen, Kasper Stentz-Olesen, Marianne Tjur, Bernd Grimm, Kjeld Søballe
Orthopaedic Research Unit, Aarhus University Hospital; ATRIUM Medical Center, AHORSE Foundation, The Netherlands
Background: Good clinical and radiological outcome have been reported after periacetabular osteotomy (PAO) but little is known about objectively measured physical function.
Purpose / Aim of Study: To investigate changes in leg power, pelvic movement, physical activity and patient-reported outcome in patients with hip dysplasia one year after PAO.
Materials and Methods: Forty-one patients (7 males) with a mean age of 28.8 years scheduled for PAO were included consecutively. Patients were tested before PAO, and 4 and 12 months after. Leg power was tested in a leg extension power rig and pelvic range of motion was measured with an intertia-based measurement unit. Patient-reported outcome was assessed with the Hip and Groin Outcome Score (HAGOS). Physical activity was monitored at 4 and 12 months with tri- axial accelerometers.
Findings / Results: One year after surgery power in the operated leg had improved (p=0.004) and there was no significant difference between power in the operated leg and contralateral leg (p=0.22). In the frontal plane, pelvic range of motion decreased significant during stair- climbing and stepping down. The same pattern was seen in the sagittal plane but the changes were non- significant. All subscales on the HAGOS improved significantly over time (p<0.001). Accelerometer data showed no significant change in time spent sitting (p=0.24), standing (p=0.59), walking (p=0.57), cycling (p=0.27) and high impact (p=0.73).
Conclusions: One year after PAO, the operated leg regained power and reached the level of the contralateral leg. Pelvic range of motion in the frontal plane was decreased during stair-climbing and stepping down. Patient-reported hip function and quality of life increased substantially after PAO but there was no evidence of increased physical activity from 4 to 12 months. Unfortunately, we do not have baseline data on activity.
Orthopaedic Research Unit, Aarhus University Hospital; ATRIUM Medical Center, AHORSE Foundation, The Netherlands
Background: Good clinical and radiological outcome have been reported after periacetabular osteotomy (PAO) but little is known about objectively measured physical function.
Purpose / Aim of Study: To investigate changes in leg power, pelvic movement, physical activity and patient-reported outcome in patients with hip dysplasia one year after PAO.
Materials and Methods: Forty-one patients (7 males) with a mean age of 28.8 years scheduled for PAO were included consecutively. Patients were tested before PAO, and 4 and 12 months after. Leg power was tested in a leg extension power rig and pelvic range of motion was measured with an intertia-based measurement unit. Patient-reported outcome was assessed with the Hip and Groin Outcome Score (HAGOS). Physical activity was monitored at 4 and 12 months with tri- axial accelerometers.
Findings / Results: One year after surgery power in the operated leg had improved (p=0.004) and there was no significant difference between power in the operated leg and contralateral leg (p=0.22). In the frontal plane, pelvic range of motion decreased significant during stair- climbing and stepping down. The same pattern was seen in the sagittal plane but the changes were non- significant. All subscales on the HAGOS improved significantly over time (p<0.001). Accelerometer data showed no significant change in time spent sitting (p=0.24), standing (p=0.59), walking (p=0.57), cycling (p=0.27) and high impact (p=0.73).
Conclusions: One year after PAO, the operated leg regained power and reached the level of the contralateral leg. Pelvic range of motion in the frontal plane was decreased during stair-climbing and stepping down. Patient-reported hip function and quality of life increased substantially after PAO but there was no evidence of increased physical activity from 4 to 12 months. Unfortunately, we do not have baseline data on activity.
Janus Duus Christiansen, Michael Ulrich Jensen, Ashir Ejaz, Mogens Berg Laursen, Poul Torben Nielsen
Northern Ortopaedic Division, Aalborg University Hospital
Background: Total hip arthroplasty gives immediate pain relief and restoration of mobility in patients with end stage osteoarthritis. If the patient returns for revision, the bone stock left for reimplantation may be compromised. The Primoris ® stem is developed to preserve metaphysial and diaphysial bone stock.
Purpose / Aim of Study: In patients with the Primoris ® stem, we monitored changes in bone mineral densities (BMD) in the proximal femur at 6 weeks, 6 months, 1 year and 2 years postoperatively.
Materials and Methods: A prospective cohort study of 52 patients scheduled for surgery with the femoral neck-preserving Primoris ® stem was carried out. Patients were studied with DEXA-scans, RSA-analysis, Harris hip score, UCLA activity score, WOMAC, EQ5D health questionnaire and Oxford Hip scores. Results from DEXA-scanner were measured in 3 specific regions of interest (ROI) – the medial region of calcar and trochanter minor (ROI1), the lateral counterpart (ROI2), and a diaphysial area (ROI3). Postoperative BMD results from day one, 6 weeks, 6 months, 1 year and 2 years were analyzed.
Findings / Results: 3 patients were excluded, leaving 49 patients for BMD-analysis. A slightly non significant decrease was found at 6 months FU compared to day one in ROI1 and ROI2. A significant increase was found at 1 year and 2 year FU compared to day one in all regions of interest. A non significant gain of BMD was found at 2 years FU compared to 1 year FU in all regions of interest.
Conclusions: As to bone preservation the results are encouraging. Later follow up will be performed to evaluate if the bone stock remains. If the proximal femoral bone stock is preserved and diaphysis is not compromised then the potential for successful future revision is present.
Northern Ortopaedic Division, Aalborg University Hospital
Background: Total hip arthroplasty gives immediate pain relief and restoration of mobility in patients with end stage osteoarthritis. If the patient returns for revision, the bone stock left for reimplantation may be compromised. The Primoris ® stem is developed to preserve metaphysial and diaphysial bone stock.
Purpose / Aim of Study: In patients with the Primoris ® stem, we monitored changes in bone mineral densities (BMD) in the proximal femur at 6 weeks, 6 months, 1 year and 2 years postoperatively.
Materials and Methods: A prospective cohort study of 52 patients scheduled for surgery with the femoral neck-preserving Primoris ® stem was carried out. Patients were studied with DEXA-scans, RSA-analysis, Harris hip score, UCLA activity score, WOMAC, EQ5D health questionnaire and Oxford Hip scores. Results from DEXA-scanner were measured in 3 specific regions of interest (ROI) – the medial region of calcar and trochanter minor (ROI1), the lateral counterpart (ROI2), and a diaphysial area (ROI3). Postoperative BMD results from day one, 6 weeks, 6 months, 1 year and 2 years were analyzed.
Findings / Results: 3 patients were excluded, leaving 49 patients for BMD-analysis. A slightly non significant decrease was found at 6 months FU compared to day one in ROI1 and ROI2. A significant increase was found at 1 year and 2 year FU compared to day one in all regions of interest. A non significant gain of BMD was found at 2 years FU compared to 1 year FU in all regions of interest.
Conclusions: As to bone preservation the results are encouraging. Later follow up will be performed to evaluate if the bone stock remains. If the proximal femoral bone stock is preserved and diaphysis is not compromised then the potential for successful future revision is present.
Jeannette Penny, Ole Oversen, Søren Overgaard
Dept. of Orthopedic Surgery, Næstved/Odense Universitets Hospital; Dept. of Orthopaedic Surgery,, Odense Universitet Hospital
Background: Resurfacing Hip Arthroplasty (RHA) transfer load and stresses to the proximal femur different from the total hip arthroplasty (THA) resulting in different patterns of bone mineral density (BMD) loss. Less is known about large diameter head MoM THA’s (LDH- THA).
Purpose / Aim of Study: To compare 5 year BMD of the proximal femur and the acetabulum around LDH-THA to RHA and THA.
Materials and Methods: 54 patients, median age 57, with primary osteoarthritis were randomized in two locations to a LDH-THA (n=16), RHA (n=19) or THA (n=19). BMD was measured in 4 acetabular (W1-4), 6 neck (L&M1-3) and 7 zones in the proximal femur (G1-7) after 3 days, 8 w, and at 1, 2 and 5 years. Between data was regressed by ANCOVA and baseline to five years by t-test.
Findings / Results: Around the acetabulum the LDH-THA increased BMD in W1 at one and five years compared to the other components (p<0.01). No difference was found in the remaining 3 regions. Overall the acetabular LDH-THA BMD was 99% at 5 year compared to 97% and 93% for THA and RHA (p<0.05). On the femoral side the LDH-THA increased BMD at the tip of the stem but lost 17% at the calcar, as did the THA. The RHA preserved/increased the medial/calcar BMD substantially better than the other types (p=0.01). Around the femoral neck the RHA maintained BMD medial for the pin and increased 15- 23% lateral to the pin. Only minor changes were observed between 2 and 5 years.
Conclusions: In this study, LDH-THA maintain acetabular BMD where THA and RHA declines. The RHA displays the lowest acetabular BMD, it declined further from 2 to 5 years and is the only hydroxyapatite covered cup. The between-group difference is not statistically significant, so we cannot conclude that the 3 concepts affect the acetabulum differently at five years. However the RHA has known design flaws and we´ll continue monitoring BMD.
Dept. of Orthopedic Surgery, Næstved/Odense Universitets Hospital; Dept. of Orthopaedic Surgery,, Odense Universitet Hospital
Background: Resurfacing Hip Arthroplasty (RHA) transfer load and stresses to the proximal femur different from the total hip arthroplasty (THA) resulting in different patterns of bone mineral density (BMD) loss. Less is known about large diameter head MoM THA’s (LDH- THA).
Purpose / Aim of Study: To compare 5 year BMD of the proximal femur and the acetabulum around LDH-THA to RHA and THA.
Materials and Methods: 54 patients, median age 57, with primary osteoarthritis were randomized in two locations to a LDH-THA (n=16), RHA (n=19) or THA (n=19). BMD was measured in 4 acetabular (W1-4), 6 neck (L&M1-3) and 7 zones in the proximal femur (G1-7) after 3 days, 8 w, and at 1, 2 and 5 years. Between data was regressed by ANCOVA and baseline to five years by t-test.
Findings / Results: Around the acetabulum the LDH-THA increased BMD in W1 at one and five years compared to the other components (p<0.01). No difference was found in the remaining 3 regions. Overall the acetabular LDH-THA BMD was 99% at 5 year compared to 97% and 93% for THA and RHA (p<0.05). On the femoral side the LDH-THA increased BMD at the tip of the stem but lost 17% at the calcar, as did the THA. The RHA preserved/increased the medial/calcar BMD substantially better than the other types (p=0.01). Around the femoral neck the RHA maintained BMD medial for the pin and increased 15- 23% lateral to the pin. Only minor changes were observed between 2 and 5 years.
Conclusions: In this study, LDH-THA maintain acetabular BMD where THA and RHA declines. The RHA displays the lowest acetabular BMD, it declined further from 2 to 5 years and is the only hydroxyapatite covered cup. The between-group difference is not statistically significant, so we cannot conclude that the 3 concepts affect the acetabulum differently at five years. However the RHA has known design flaws and we´ll continue monitoring BMD.
Nicolai Kjærgaard, Christian Lund Petersen, Jonas Bruun Kjærsgaard, Michael Ulrich Jensen, Mogens Berg Laursen
Department of Health Science and Technology, Aalborg University; Department of Orthopaedic Surgery, Aalborg University Hospital
Background: No universal method for choosing patients for post-operative evaluation of THR and TKR in Danish hospitals exists. Most methods currently used are time consuming and the number of patients in need of re-evaluation is relatively small and hence does not fully satisfy the time and resources spent. Previous studies have identified OKS and OHS thresholds to aid the clinician in presenting the expected outcome of surgery in a meaningful way to the patient. However, the thresholds may have other possible applications.
Purpose / Aim of Study: To detect thresholds to distinguish patients with or without a satisfactory outcome after TKR and THR based on PROMS (Oxford knee score, OKS, and Oxford hip score, OHS) and pain, using patient satisfaction and patient perceived function as global transition items. The thresholds are intended to be used as a tool in the process of determining which patients are in need of a post-operative out-patient evaluation.
Materials and Methods: In a prospective cohort study, TKR and THR patients who had completed a pre-operative questionnaire containing the OKS or OHS questionnaire and pain VAS scales were invited to complete the same questionnaire and supplementary questions at a mean of six (4 to 9) months after surgery. Thresholds were established by ROC analysis, using multiple anchor-based approaches. A total number of 73 knee patients and 103 hip patients were included.
Findings / Results: Significant correlations were found between outcome measures and anchors. Thresholds were determined for outcome measures coupled with satisfaction, patient perceived function and a combination thereof using a cut-off of 50 and 70.
Conclusions: We have established a set of clinically meaningful thresholds for Oxford scores and VAS pain scores that may help determine which TKR and THR patients are in need of post-operative evaluation.
Department of Health Science and Technology, Aalborg University; Department of Orthopaedic Surgery, Aalborg University Hospital
Background: No universal method for choosing patients for post-operative evaluation of THR and TKR in Danish hospitals exists. Most methods currently used are time consuming and the number of patients in need of re-evaluation is relatively small and hence does not fully satisfy the time and resources spent. Previous studies have identified OKS and OHS thresholds to aid the clinician in presenting the expected outcome of surgery in a meaningful way to the patient. However, the thresholds may have other possible applications.
Purpose / Aim of Study: To detect thresholds to distinguish patients with or without a satisfactory outcome after TKR and THR based on PROMS (Oxford knee score, OKS, and Oxford hip score, OHS) and pain, using patient satisfaction and patient perceived function as global transition items. The thresholds are intended to be used as a tool in the process of determining which patients are in need of a post-operative out-patient evaluation.
Materials and Methods: In a prospective cohort study, TKR and THR patients who had completed a pre-operative questionnaire containing the OKS or OHS questionnaire and pain VAS scales were invited to complete the same questionnaire and supplementary questions at a mean of six (4 to 9) months after surgery. Thresholds were established by ROC analysis, using multiple anchor-based approaches. A total number of 73 knee patients and 103 hip patients were included.
Findings / Results: Significant correlations were found between outcome measures and anchors. Thresholds were determined for outcome measures coupled with satisfaction, patient perceived function and a combination thereof using a cut-off of 50 and 70.
Conclusions: We have established a set of clinically meaningful thresholds for Oxford scores and VAS pain scores that may help determine which TKR and THR patients are in need of post-operative evaluation.
Martin Lamm, Stig Storgaard Jakobsen , Dovydas Vainorius, Kjeld Søballe, Maiken Stilling
Department of Orthopedic Surgery, Aarhus University Hospital
Background: The Trilogy acetabular cup (Zimmer) has been extensively used national as well as international. Recently, the performance of the Trilogy cup has been debated with regards to early failure. We here report early result of the Trilogy cup, with radiostereometrical (RSA), dual energy X- ray absorptiometry (DXA), and functional outcome.
Purpose / Aim of Study: To evaluate the early term fixation of cementless Trilogy cup with RSA, DXA, and functional outcome measures.
Materials and Methods: A consecutive cohort of 48 patients (20 men) with primary hip OA, age > 70 years, and T-score above -2.5 according to pre- operative DXA, was operated with THA using cementless Trilogy cup HXLPE-liner, 36mm metal head, and CPT stem (Zimmer). 1-2mm under-reaming and optional screw fixation was used. Mean age 76 years (range 71-87). Mean BMI 28 (range 21-42). Patients were followed with model-based RSA and PROMs.
Findings / Results: At 6 months total cup translation (TT) was 0.54mm (SD 0.3), and mean 0.15mm (SD 0.36) in TT at 1-year follow-up (p=0.009). Medial cup migration was 0.05mm (SD 0.38) at 6 months and 0.27mm (SD 0.55) at 1 year (p=0.008). Proximal cup migration at group-level was 0.14mm (SD 0.20) at 6 months and comparable (p=0.85) 0.13mm (SD 0.18) at 1 year. Proximal cup migration was higher (p=0.04) at 6 months and 1 year in patients with osteopenia. OHS and HHS improved significantly (p=0.00). There were no revisions, no infections and no dislocations at 1-year follow-up. Mean cup-size was 55 (range 50- 60) and mean T-score was -1 (range -2.4– 1). No cases required additional screw fixation.
Conclusions: This study proved, at 1-year follow-up that migration of the Trilogy cup was below cut- offs predictive of premature failure when inserted 1-2mm press fit. Interestingly, we also found an increased proximal cup movement in osteopenic patients that need further elucidating.
Department of Orthopedic Surgery, Aarhus University Hospital
Background: The Trilogy acetabular cup (Zimmer) has been extensively used national as well as international. Recently, the performance of the Trilogy cup has been debated with regards to early failure. We here report early result of the Trilogy cup, with radiostereometrical (RSA), dual energy X- ray absorptiometry (DXA), and functional outcome.
Purpose / Aim of Study: To evaluate the early term fixation of cementless Trilogy cup with RSA, DXA, and functional outcome measures.
Materials and Methods: A consecutive cohort of 48 patients (20 men) with primary hip OA, age > 70 years, and T-score above -2.5 according to pre- operative DXA, was operated with THA using cementless Trilogy cup HXLPE-liner, 36mm metal head, and CPT stem (Zimmer). 1-2mm under-reaming and optional screw fixation was used. Mean age 76 years (range 71-87). Mean BMI 28 (range 21-42). Patients were followed with model-based RSA and PROMs.
Findings / Results: At 6 months total cup translation (TT) was 0.54mm (SD 0.3), and mean 0.15mm (SD 0.36) in TT at 1-year follow-up (p=0.009). Medial cup migration was 0.05mm (SD 0.38) at 6 months and 0.27mm (SD 0.55) at 1 year (p=0.008). Proximal cup migration at group-level was 0.14mm (SD 0.20) at 6 months and comparable (p=0.85) 0.13mm (SD 0.18) at 1 year. Proximal cup migration was higher (p=0.04) at 6 months and 1 year in patients with osteopenia. OHS and HHS improved significantly (p=0.00). There were no revisions, no infections and no dislocations at 1-year follow-up. Mean cup-size was 55 (range 50- 60) and mean T-score was -1 (range -2.4– 1). No cases required additional screw fixation.
Conclusions: This study proved, at 1-year follow-up that migration of the Trilogy cup was below cut- offs predictive of premature failure when inserted 1-2mm press fit. Interestingly, we also found an increased proximal cup movement in osteopenic patients that need further elucidating.
Martin Vesterby, Preben Ulrich Pedersen, Lene Bastrup Jørgensen
INNO-X Healthcare, Department of Clinical Medicine, Aarhus University Hospital; Department of Health Science and Technology, The Faculty of Medicine, Aalborg University; Center for Elective Surgery, Regional Hospital Silkeborg
Background: The healthcare sector faces a wide range of challenges that are all costly and demanding. Developing new ways of treating, supporting and rehabilitating patients are necessary. We found that no one had looked in to the possibilities of applying telemedicine and using the significant others (SO) - spouse, other relative or friend as a resource in connection with fast track orthopedics and elective surgery
Purpose / Aim of Study: To investigate the efficacy of an intervention, including telemedicine and the SO as a resource for patients receiving total hip replacement; and to evaluate outcomes of this intervention on length of stay, adverse effects, HRQOL and the participant’s perception of cost/benefit of the procedure
Materials and Methods: The design was a randomized clinical trial. 72 couples of patients and SO were randomized to receive either the telemedicine-supported intervention or the existing intervention. Follow-up was 12 months. A cost-minimization evaluation was conducted as a piggyback study
Findings / Results: Median length of stay was halved in the group receiving the telemedicine-supported intervention; patient safety and quality were preserved. The cost- evaluation documented cost-minimization favoring the intervention. The SO perceived the workload undertaken significantly less than the people in the control group did. The perception of cost/benefit were equal for both patients and SO as was the substantial improvement in health related quality of life
Conclusions: A multimodal intervention including use of telemedicine and actively including the SO as a resource, can be used to successfully bring forward the day of the patient’s discharge after major surgery at lower cost. Patients and their SO can under the right circumstances be given more tasks and responsibility without negatively affecting their perception of benefit
INNO-X Healthcare, Department of Clinical Medicine, Aarhus University Hospital; Department of Health Science and Technology, The Faculty of Medicine, Aalborg University; Center for Elective Surgery, Regional Hospital Silkeborg
Background: The healthcare sector faces a wide range of challenges that are all costly and demanding. Developing new ways of treating, supporting and rehabilitating patients are necessary. We found that no one had looked in to the possibilities of applying telemedicine and using the significant others (SO) - spouse, other relative or friend as a resource in connection with fast track orthopedics and elective surgery
Purpose / Aim of Study: To investigate the efficacy of an intervention, including telemedicine and the SO as a resource for patients receiving total hip replacement; and to evaluate outcomes of this intervention on length of stay, adverse effects, HRQOL and the participant’s perception of cost/benefit of the procedure
Materials and Methods: The design was a randomized clinical trial. 72 couples of patients and SO were randomized to receive either the telemedicine-supported intervention or the existing intervention. Follow-up was 12 months. A cost-minimization evaluation was conducted as a piggyback study
Findings / Results: Median length of stay was halved in the group receiving the telemedicine-supported intervention; patient safety and quality were preserved. The cost- evaluation documented cost-minimization favoring the intervention. The SO perceived the workload undertaken significantly less than the people in the control group did. The perception of cost/benefit were equal for both patients and SO as was the substantial improvement in health related quality of life
Conclusions: A multimodal intervention including use of telemedicine and actively including the SO as a resource, can be used to successfully bring forward the day of the patient’s discharge after major surgery at lower cost. Patients and their SO can under the right circumstances be given more tasks and responsibility without negatively affecting their perception of benefit
Rasmus Kreipke, Alma Becic Pedersen, Cecilia Rogmark, Johan Kärrholm, Leif Ivar Havelin, Søren Overgaard
Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Denmark; Department of Clinical Epidemiology, Aarhus University Hospital, Denmark; Department of Orthopaedics, Skåne University Hospital, Sweden, Swedish Hip Arthroplasty Register and The Sahlgrenska Academy, University of Gothenburg, Sweden; Department of Orthopaedics, Sahlgrenska University Hospital, Mölndal, Sweden, Swedish Hip Arthroplasty Register and The Sahlgrenska Academy, University of Gothenburg, Sweden; The Norwegian Arthroplasty Register, Department of Orthopaedic Surgery, Haukeland University Hospita, Department of Clinical Medicine, University of Bergen, Bergen, Norway.; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Odense
Background: Dual Mobility acetabular cups (DMC) are designed to reduce the risk of total hip arthroplasty (THA) instability and has gained popularity in both primary and revision THA.
Purpose / Aim of Study: Our aim was to evaluate the survival of primary DMC implanted in patients with primary osteoarthritis (OA).
Materials and Methods: 2955 patients who had had primary THA with DMC were identified the Nordic Arthroplasty Registry Association (NARA) database. 2568 of these patients were matched with an equally sized control group by propensity score matching with regard to, gender, age, stem fixation and cup fixation. We used competing risk survival analyses to compare the two groups with revision or death as endpoints given as adjusted relative risk (ARR) and 95% confidence interval (CI). Surgical approach was adjusted for when appropriate.
Findings / Results: Mean follow-up time was 3.8 years (SD = 2.9) for the DMC group and 4.2 years (SD = 3.4) for the control group. No significant difference in overall revision risk between DMC and control group was found (p = 0.82, ARR, 95% CI = 0.97; 0.73-1.28). DMC significantly reduced risk of revision due to dislocation (p < 0.01, ARR, 95% CI = 12.15; 3.65-40.50) but had significantly higher risk of revision due to infection (p < 0.01, ARR, 95% CI = 0.31; 0.11-0.67). No significant difference in mortality between the DMC-group and control group was found. Posterior approach had no association with risk of revision.
Conclusions: The study showed no difference between DMC and control group in overall risk of revision but DMC reduced the risk of revision due to dislocation. DMC cups were associated with an increased risk of revision due to infection. Add. co-authors: Kaijo Mäkelä, Dep. of Ortho. and Traumatology, Turku Uni. Hosp., Finland. Geir Hallan, The Norwegian Arthroplasty Register, Dep. of Ortho. Surgery, Haukeland Uni. Hosp, Bergen, Norway.
Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Denmark; Department of Clinical Epidemiology, Aarhus University Hospital, Denmark; Department of Orthopaedics, Skåne University Hospital, Sweden, Swedish Hip Arthroplasty Register and The Sahlgrenska Academy, University of Gothenburg, Sweden; Department of Orthopaedics, Sahlgrenska University Hospital, Mölndal, Sweden, Swedish Hip Arthroplasty Register and The Sahlgrenska Academy, University of Gothenburg, Sweden; The Norwegian Arthroplasty Register, Department of Orthopaedic Surgery, Haukeland University Hospita, Department of Clinical Medicine, University of Bergen, Bergen, Norway.; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark, Odense
Background: Dual Mobility acetabular cups (DMC) are designed to reduce the risk of total hip arthroplasty (THA) instability and has gained popularity in both primary and revision THA.
Purpose / Aim of Study: Our aim was to evaluate the survival of primary DMC implanted in patients with primary osteoarthritis (OA).
Materials and Methods: 2955 patients who had had primary THA with DMC were identified the Nordic Arthroplasty Registry Association (NARA) database. 2568 of these patients were matched with an equally sized control group by propensity score matching with regard to, gender, age, stem fixation and cup fixation. We used competing risk survival analyses to compare the two groups with revision or death as endpoints given as adjusted relative risk (ARR) and 95% confidence interval (CI). Surgical approach was adjusted for when appropriate.
Findings / Results: Mean follow-up time was 3.8 years (SD = 2.9) for the DMC group and 4.2 years (SD = 3.4) for the control group. No significant difference in overall revision risk between DMC and control group was found (p = 0.82, ARR, 95% CI = 0.97; 0.73-1.28). DMC significantly reduced risk of revision due to dislocation (p < 0.01, ARR, 95% CI = 12.15; 3.65-40.50) but had significantly higher risk of revision due to infection (p < 0.01, ARR, 95% CI = 0.31; 0.11-0.67). No significant difference in mortality between the DMC-group and control group was found. Posterior approach had no association with risk of revision.
Conclusions: The study showed no difference between DMC and control group in overall risk of revision but DMC reduced the risk of revision due to dislocation. DMC cups were associated with an increased risk of revision due to infection. Add. co-authors: Kaijo Mäkelä, Dep. of Ortho. and Traumatology, Turku Uni. Hosp., Finland. Geir Hallan, The Norwegian Arthroplasty Register, Dep. of Ortho. Surgery, Haukeland Uni. Hosp, Bergen, Norway.
Carsten Juhl
Orthopedic department, Herlev and Gentofte Hospital
Background: Technology assisted exercise are increasingly used in exercise rehabilitation without appropriate clinical evaluation.
Purpose / Aim of Study: To assess the effectiveness of a technology assisted exercise intervention (ICURA) compared to usual care in total hip arthroplasty (THA).
Materials and Methods: Participants after THA admitted to rehabilitation in 4 municipalities in Copenhagen were randomized to either ICURA or usual care for 6 weeks. The ICURA group received one supervised group session every week and was instructed to perform exercise at home using a predefined exercise program in a smartphone app. Exercise performance was monitored via sensor technology. Physical therapists monitor exercise progression on a website and adjust with the patient on the weekly exercise session. The usual care group received supervised group exercise twice weekly. Primary outcome were 10 meters walk, secondary was sit-to-stand and 2.45 meters “Up and Go” and Hip disability and Osteoarthritis Outcome Score (HOOS). Difference in outcomes after 6 weeks was adjusted for baseline, municipality, sex and age. Analysis was firstly performed as completer analysis and secondly as intention-to-treat using a worst case - best case approach and a predefined equality was set to 20%
Findings / Results: 171 THA patients were included (87 to ICURA and 84 to usual care) and 148 (77 and 71 respectively) completed the intervention. No significant post intervention group differences were found for any outcomes in the completer-analysis. Differences in the worst case- best case analyses were except for the HOOS domains quality of life and sport and recreation smaller than the predefined equality point and both domains were in favour of ICURA.
Conclusions: Similar results were seen in THA receiving either ICURA or usual care and ICURA is a flexible alternative to usual care for THA.
Orthopedic department, Herlev and Gentofte Hospital
Background: Technology assisted exercise are increasingly used in exercise rehabilitation without appropriate clinical evaluation.
Purpose / Aim of Study: To assess the effectiveness of a technology assisted exercise intervention (ICURA) compared to usual care in total hip arthroplasty (THA).
Materials and Methods: Participants after THA admitted to rehabilitation in 4 municipalities in Copenhagen were randomized to either ICURA or usual care for 6 weeks. The ICURA group received one supervised group session every week and was instructed to perform exercise at home using a predefined exercise program in a smartphone app. Exercise performance was monitored via sensor technology. Physical therapists monitor exercise progression on a website and adjust with the patient on the weekly exercise session. The usual care group received supervised group exercise twice weekly. Primary outcome were 10 meters walk, secondary was sit-to-stand and 2.45 meters “Up and Go” and Hip disability and Osteoarthritis Outcome Score (HOOS). Difference in outcomes after 6 weeks was adjusted for baseline, municipality, sex and age. Analysis was firstly performed as completer analysis and secondly as intention-to-treat using a worst case - best case approach and a predefined equality was set to 20%
Findings / Results: 171 THA patients were included (87 to ICURA and 84 to usual care) and 148 (77 and 71 respectively) completed the intervention. No significant post intervention group differences were found for any outcomes in the completer-analysis. Differences in the worst case- best case analyses were except for the HOOS domains quality of life and sport and recreation smaller than the predefined equality point and both domains were in favour of ICURA.
Conclusions: Similar results were seen in THA receiving either ICURA or usual care and ICURA is a flexible alternative to usual care for THA.
Signe Rosenlund, Leif Broeng, Carsten Jensen, Anders Holsgaard-Larsen, Søren Overgaard
Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark and Køge
Background: The posterior approach (PA) and the lateral approach (LA) are commonly used worldwide in total hip arthroplasty (THA), but the impact on both subjective and objective outcome is widely debated. The LA may be associated with reduced patient reported outcomes whereas PA may be associated with increased risk of dislocation. However, the effect of surgical approach on patient reported outcome measures (PROM) has not been investigated with 12 month follow-up in a randomized controlled trail.
Purpose / Aim of Study: The primary aim was to investigate the effect of PA versus LA on patient reported physical function after 12 months. Secondary to investigate the effect of approach on patient reported pain and quality of life.
Materials and Methods: Eighty patients with unilateral primary hip osteoarthritis scheduled for THA surgery were randomized to operation with either PA or modified direct LA. The primary outcome was patient reported physical function measured with HOOS-physical function-Short Form (HOOS-PS) (0=extreme symptoms; 100=no symptoms). Secondary outcomes were HOOS-Pain, HOOS-QOL, EQ-5D- index and EQ5D-VAS. All outcomes were measured pre-operatively 3, 6 and 12 months after surgery.
Findings / Results: We found no difference between PA and LA after 12 months in HOOS-PS (mean difference between LA and PA: -3.3 point, 95% confidence interval: -8.73 to 2.13; p=0.23). Also; no significant differences were found in any of the secondary outcome measures.
Conclusions: The PA group did not improve more in physical function, pain or quality of life than the LA group within the first postoperative year. Both groups improved significantly from pre- to post-surgery in all PROMs. When surgical approach has no influence on PROM, other factors like risk of dislocation or risk of revision may play a role when selecting approach for the patient.
Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Institute of Clinical Research, University of Southern Denmark and Køge
Background: The posterior approach (PA) and the lateral approach (LA) are commonly used worldwide in total hip arthroplasty (THA), but the impact on both subjective and objective outcome is widely debated. The LA may be associated with reduced patient reported outcomes whereas PA may be associated with increased risk of dislocation. However, the effect of surgical approach on patient reported outcome measures (PROM) has not been investigated with 12 month follow-up in a randomized controlled trail.
Purpose / Aim of Study: The primary aim was to investigate the effect of PA versus LA on patient reported physical function after 12 months. Secondary to investigate the effect of approach on patient reported pain and quality of life.
Materials and Methods: Eighty patients with unilateral primary hip osteoarthritis scheduled for THA surgery were randomized to operation with either PA or modified direct LA. The primary outcome was patient reported physical function measured with HOOS-physical function-Short Form (HOOS-PS) (0=extreme symptoms; 100=no symptoms). Secondary outcomes were HOOS-Pain, HOOS-QOL, EQ-5D- index and EQ5D-VAS. All outcomes were measured pre-operatively 3, 6 and 12 months after surgery.
Findings / Results: We found no difference between PA and LA after 12 months in HOOS-PS (mean difference between LA and PA: -3.3 point, 95% confidence interval: -8.73 to 2.13; p=0.23). Also; no significant differences were found in any of the secondary outcome measures.
Conclusions: The PA group did not improve more in physical function, pain or quality of life than the LA group within the first postoperative year. Both groups improved significantly from pre- to post-surgery in all PROMs. When surgical approach has no influence on PROM, other factors like risk of dislocation or risk of revision may play a role when selecting approach for the patient.
Stig Storgaard Jakobsen, Charlotte Hartig-Andreasen, Lone Rømer, Kjeld Søballe
Department of Orthopaedics, Aarhus University Hospital; Department of Radiology, Aarhus University Hospital
Background: Hip dysplasia becomes symptomatic due to labral pathology and secondary muscular pain. A CE angle < 25 is considered pathologic and defined as dysplasia in PAO centres in Denmark. However, it is debated whether a CE angle between 20 and 25 is borderline.
Purpose / Aim of Study: We aimed to investigate the degree of labral pathology in symptomatic patients with CE between 20 and 25 compared with patients with CE < 20.
Materials and Methods: Ninety-nine patients (104 hips) with a mean age 34.1 years (range 14.5- 58.9 years) consecutively scheduled for PAO due to symptomatic DDH were enrolled in the study. Five patients were excluded from the study and four patients failed to show up at follow- up, hence 90 patients were evaluated. Indication for PAO were persisting hip pain, a center-edge angle of Wiberg <25, pelvic bone maturity, internal rotation >15, hip flexion <110 and Tönnis grade of osteoarthritis 0 or 1. All patients had a magnetic resonance arthrography (MRA) performed. The MRA was assessed for labral pathology in terms of degeneration, hypertrophic changes, tears and paralabral cysts. Labral lesions were graded according to the Czerny classification.
Findings / Results: In the group with CE angle between 20 and 25 (n=41) 80% had labral pathology (Czerny 1A:2, 1B:1, 2A:7, 2B:3, 3A:15, 3B:5), whereas in the the group with CE angle < 20 (n=54) 92% had labral pathology (Czerny 1A:1, 1B:1, 2A:7, 2B:0, 3A:29, 3B:12) (P=0.12, Fisher’s exact test).
Conclusions: We present evidence that the majority of symptomatic hips with a CE angle between 20 and 25 have labral pathology, and therefore a CE angle between 20 and 25 should be considered pathological. Since the labral pathology is non-traumatic and caused by the dysplastic condition we believe that the osseous abnormality should be treated with redirection of the acetabulum (PAO) before considering hip arthroscopy.
Department of Orthopaedics, Aarhus University Hospital; Department of Radiology, Aarhus University Hospital
Background: Hip dysplasia becomes symptomatic due to labral pathology and secondary muscular pain. A CE angle < 25 is considered pathologic and defined as dysplasia in PAO centres in Denmark. However, it is debated whether a CE angle between 20 and 25 is borderline.
Purpose / Aim of Study: We aimed to investigate the degree of labral pathology in symptomatic patients with CE between 20 and 25 compared with patients with CE < 20.
Materials and Methods: Ninety-nine patients (104 hips) with a mean age 34.1 years (range 14.5- 58.9 years) consecutively scheduled for PAO due to symptomatic DDH were enrolled in the study. Five patients were excluded from the study and four patients failed to show up at follow- up, hence 90 patients were evaluated. Indication for PAO were persisting hip pain, a center-edge angle of Wiberg <25, pelvic bone maturity, internal rotation >15, hip flexion <110 and Tönnis grade of osteoarthritis 0 or 1. All patients had a magnetic resonance arthrography (MRA) performed. The MRA was assessed for labral pathology in terms of degeneration, hypertrophic changes, tears and paralabral cysts. Labral lesions were graded according to the Czerny classification.
Findings / Results: In the group with CE angle between 20 and 25 (n=41) 80% had labral pathology (Czerny 1A:2, 1B:1, 2A:7, 2B:3, 3A:15, 3B:5), whereas in the the group with CE angle < 20 (n=54) 92% had labral pathology (Czerny 1A:1, 1B:1, 2A:7, 2B:0, 3A:29, 3B:12) (P=0.12, Fisher’s exact test).
Conclusions: We present evidence that the majority of symptomatic hips with a CE angle between 20 and 25 have labral pathology, and therefore a CE angle between 20 and 25 should be considered pathological. Since the labral pathology is non-traumatic and caused by the dysplastic condition we believe that the osseous abnormality should be treated with redirection of the acetabulum (PAO) before considering hip arthroscopy.