Session 11: Hip
19. November
13:30 - 15:00
Lokale: 01+02
Chairmen: Claus Varnum & Stig S Jakobsen
Karen Dyreborg, Mikkel R. Andersen, Nikolaj Winther, Søren Solgaard, Gunnar Flivik, Michael Mørk Petersen
Rigshospitalet, Department of Orthopaedic Surgery, Copenhagen, Denmark; Herlev-Gentofte Hospital, Department of Hip and Knee Surgery, Hellerup, Denmark; Lund University and Skåne University Hospital, Department of Orthopedics, Lund, Sweden
Background: Despite the good results after total hip arthroplasty (THA), new implants are continuously being developed to improve the durability. The Echo Bi- Metric (EBM) THA stem is the successor to the Bi- Metric (BM) THA stem. The EBM stem includes many of the features of the BM stem, but minor changes in the design might improve the clinical performance.
Aim: We compared the migration behavior with radiostereometric analysis (RSA) of the EBM stem and the BM stem at 24 months and evaluated the clinical outcome.
Materials and Methods: We randomized 62 patients with osteoarthritis (mean age=64 years, Female/Male=28/34) scheduled for an uncemented THA to receive either an EBM or a BM THA stem. We performed RSA within 1 week after surgery and at 3, 6, 12, and 24 months. The clinical outcome was evaluated using Harris Hip Score (HHS) and Oxford Hip Score (OHS).
Results: At 24 months, we found no statistically significant differences in migration between the two implants. During the first 3 months both the EBM and the BM stems showed visible subsidence (-2.5 mm and -2.2 mm respectively), and retroversion (2.5° and 2.2° respectively), but after 3 months this stabilized. The expected increase in HHS and OHS was similar between the groups.
Interpretation / Conclusion: The EBM stem shows a migration at 24 months not different from the BM stem, and both stems display satisfying clinical results.
Rigshospitalet, Department of Orthopaedic Surgery, Copenhagen, Denmark; Herlev-Gentofte Hospital, Department of Hip and Knee Surgery, Hellerup, Denmark; Lund University and Skåne University Hospital, Department of Orthopedics, Lund, Sweden
Background: Despite the good results after total hip arthroplasty (THA), new implants are continuously being developed to improve the durability. The Echo Bi- Metric (EBM) THA stem is the successor to the Bi- Metric (BM) THA stem. The EBM stem includes many of the features of the BM stem, but minor changes in the design might improve the clinical performance.
Aim: We compared the migration behavior with radiostereometric analysis (RSA) of the EBM stem and the BM stem at 24 months and evaluated the clinical outcome.
Materials and Methods: We randomized 62 patients with osteoarthritis (mean age=64 years, Female/Male=28/34) scheduled for an uncemented THA to receive either an EBM or a BM THA stem. We performed RSA within 1 week after surgery and at 3, 6, 12, and 24 months. The clinical outcome was evaluated using Harris Hip Score (HHS) and Oxford Hip Score (OHS).
Results: At 24 months, we found no statistically significant differences in migration between the two implants. During the first 3 months both the EBM and the BM stems showed visible subsidence (-2.5 mm and -2.2 mm respectively), and retroversion (2.5° and 2.2° respectively), but after 3 months this stabilized. The expected increase in HHS and OHS was similar between the groups.
Interpretation / Conclusion: The EBM stem shows a migration at 24 months not different from the BM stem, and both stems display satisfying clinical results.
Lars Lykke Hermansen, Bjarke Viberg, Søren Overgaard
Department of Orthopaedics, Hospital of South West Jutland, Esbjerg, and The Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Odense; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Odense and Department of Orthopedic Surgery and Traumatology, Lillebaelt Hospital, University hospital of Southern Denmark; Department of Orthopedic Surgery and Traumatology, Bispebjerg Hospital og Institute of Clinical Medicine, Copenhagen University
Background: It is well-known that there is substantial risk of re-dislocation and eventually revision after the first dislocation following primary THA, but knowledge about patient-reported outcomes (PRO) after dislocation and closed reduction is lacking.
Aim: Our aim was to report on health- and hip- related quality of life (QoL) in patients with dislocation following primary THA due to osteoarthritis.
Materials and Methods: We conducted a cross-sectional, matched case-control study involving patients registered in the Danish Hip Arthroplasty Register between 2010 and 2014. Dislocations were captured in the Danish National Patient Register using a validated algorithm. We matched patients with dislocation 1:2 upon age, sex, date and hospital of primary surgery to patients without dislocation. They received two PRO questionnaires (EQ- 5D, HOOS) and three patient satisfaction items. Results are presented as means with 95% confidence intervals and analyzed with multiple linear regression.
Results: We identified 1010 living patients with dislocation. The response rate was 70.1%. Mean follow-up was 7.2 years from index surgery and 4.9 years from the latest dislocation. Patients without dislocation reported a higher EQ-5D VAS score of 75.6 (74.5-76.7) compared to 67.8 (65.9-69.7) in the dislocation group (p<0.01). Regarding hip-related QoL, patients with dislocation reported a lower HOOS-QoL domain score of 62.8 (60.2- 65.4) compared to 82.9 (81.7-84.1) in the control group (p<0.01). Even after five years from the latest dislocation, the HOOS-QoL score was still low, demonstrated by 65.6 (62.0-69.2) points. The other HOOS domains were consistently 8-10 points worse after dislocation. Regarding satisfaction, only 59% reported either an “excellent” or a “very good” overall result after experiencing dislocations, as opposed to 85% for the controls.
Interpretation / Conclusion: This is the first national case-control study on PRO after hip dislocation. The study showed that both health- and hip-related QoL is markedly and persistently reduced compared to a control group even 2-5 years after the latest dislocation. The most important aspect must be to avoid the first episode of dislocation, since the full relieving potential for this THA is never achieved.
Department of Orthopaedics, Hospital of South West Jutland, Esbjerg, and The Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Odense; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Odense and Department of Orthopedic Surgery and Traumatology, Lillebaelt Hospital, University hospital of Southern Denmark; Department of Orthopedic Surgery and Traumatology, Bispebjerg Hospital og Institute of Clinical Medicine, Copenhagen University
Background: It is well-known that there is substantial risk of re-dislocation and eventually revision after the first dislocation following primary THA, but knowledge about patient-reported outcomes (PRO) after dislocation and closed reduction is lacking.
Aim: Our aim was to report on health- and hip- related quality of life (QoL) in patients with dislocation following primary THA due to osteoarthritis.
Materials and Methods: We conducted a cross-sectional, matched case-control study involving patients registered in the Danish Hip Arthroplasty Register between 2010 and 2014. Dislocations were captured in the Danish National Patient Register using a validated algorithm. We matched patients with dislocation 1:2 upon age, sex, date and hospital of primary surgery to patients without dislocation. They received two PRO questionnaires (EQ- 5D, HOOS) and three patient satisfaction items. Results are presented as means with 95% confidence intervals and analyzed with multiple linear regression.
Results: We identified 1010 living patients with dislocation. The response rate was 70.1%. Mean follow-up was 7.2 years from index surgery and 4.9 years from the latest dislocation. Patients without dislocation reported a higher EQ-5D VAS score of 75.6 (74.5-76.7) compared to 67.8 (65.9-69.7) in the dislocation group (p<0.01). Regarding hip-related QoL, patients with dislocation reported a lower HOOS-QoL domain score of 62.8 (60.2- 65.4) compared to 82.9 (81.7-84.1) in the control group (p<0.01). Even after five years from the latest dislocation, the HOOS-QoL score was still low, demonstrated by 65.6 (62.0-69.2) points. The other HOOS domains were consistently 8-10 points worse after dislocation. Regarding satisfaction, only 59% reported either an “excellent” or a “very good” overall result after experiencing dislocations, as opposed to 85% for the controls.
Interpretation / Conclusion: This is the first national case-control study on PRO after hip dislocation. The study showed that both health- and hip-related QoL is markedly and persistently reduced compared to a control group even 2-5 years after the latest dislocation. The most important aspect must be to avoid the first episode of dislocation, since the full relieving potential for this THA is never achieved.
Kristian Kjærgaard, Claus Varnum, Ming Ding, Søren Overgaard
Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, J.B.Winsløws Vej 4, DK-5000 Odense C. Department of Clinical Research, University of Southern Denmark, Campusvej 55, DK-5230 Odense S; Department of Orthopaedic Surgery, Lillebaelt Hospital – Vejle, Beriderbakken 4, DK-7100 Vejle. Department of Regional Health Research, University of Southern Denmark, Winsløwparken 19,3, DK-5000 Odense C; Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, J.B.Winsløws Vej 4, DK-5000 Odense C. Department of Clinical Research, University of Southern Denmark, Campusvej 55, DK-5230 Odense S; Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, J.B.Winsløws Vej 4, DK-5000 Odense C. Department of Clinical Research, University of Southern Denmark, Campusvej 55, DK-5230 Odense S. Bispebjerg og Frederiksberg Hospital, Ortopædkirurgisk afdeling M, Nielsine Nielsens Vej 5, opgang 6, 2. sal, 2400 København NV. Københavns Universitet, Sundhedsvidenskabelige Fakultet, Institut for Klinisk Medicin
Background: The main long-term revision cause for total hip arthroplasty (THA) is aseptic loosening. This is associated with polyethylene wear and a lower wear would, in theory, reduce the rate of revision due to aseptic loosening. Vitamin E doped polyethylene liners have been designed to reduce wear, but the material is rather new and needs post marked surveillance analysis in large register studies.
Aim: The aim of this nationwide population-based study was to investigate 1) the risk of polyethylene-related endpoints (aseptic loosening, wear, granuloma, or osteolysis) from 12 months after THA with vitamin E-doped polyethylene (VEPE) liners compared to THA with cross-linked annealed or remelted polyethylene (XLPE) liners and 2) the risk of any and specific revision causes.
Materials and Methods: We included THAs from The Danish Hip Arthroplasty Register from January 1, 2008 to June 30, 2019, with uncemented cup, VEPE or XLPE liner, and metal or ceramic head. The outcome was polyethylene-related endpoints from 12 months and onwards, and further outcomes were any and specific revision causes. Risk of revision was estimated using Cox regression.
Results: A total of 110,803 THAs were assessed for eligibility and 63,892 THAs (55,230 patients) were included in the study, 5,885 (9.2%) THAs with a VEPE liner and 58,007 (91.8%) with a XLPE liner. Median observation time was 5.35 (inter-quartile range (IQR) [3.62, 7.09]) years for VEPE and 4.78 (IQR [2.64, 7.68]) for XLPE. We found a lower risk of revision for polyethylene-related endpoints from 12 months for VEPE compared to XLPE (hazard ratio (HR) 0.51 [0.31, 0.84]). THAs with VEPE liners were associated with increased risk of any revision within the first 3 months (HR 1.57 [1.33, 1.86]), revision recorded as aseptic loosening within 3 months (4.15 [2.19, 7.87]), fracture within 3 months (HR 2.58 [1.99, 3.34]), and other revision at any time (1.35 [1.00, 1.81]).
Interpretation / Conclusion: VEPE liners had a lower revision rate due to polyethylene-related endpoints from 12 months compared to XLPE liners. No difference in other specific reasons was shown. Regarding safety, we found one cracked liner in VEPE while thirteen cracked liners were reported for XLPE.
Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, J.B.Winsløws Vej 4, DK-5000 Odense C. Department of Clinical Research, University of Southern Denmark, Campusvej 55, DK-5230 Odense S; Department of Orthopaedic Surgery, Lillebaelt Hospital – Vejle, Beriderbakken 4, DK-7100 Vejle. Department of Regional Health Research, University of Southern Denmark, Winsløwparken 19,3, DK-5000 Odense C; Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, J.B.Winsløws Vej 4, DK-5000 Odense C. Department of Clinical Research, University of Southern Denmark, Campusvej 55, DK-5230 Odense S; Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, J.B.Winsløws Vej 4, DK-5000 Odense C. Department of Clinical Research, University of Southern Denmark, Campusvej 55, DK-5230 Odense S. Bispebjerg og Frederiksberg Hospital, Ortopædkirurgisk afdeling M, Nielsine Nielsens Vej 5, opgang 6, 2. sal, 2400 København NV. Københavns Universitet, Sundhedsvidenskabelige Fakultet, Institut for Klinisk Medicin
Background: The main long-term revision cause for total hip arthroplasty (THA) is aseptic loosening. This is associated with polyethylene wear and a lower wear would, in theory, reduce the rate of revision due to aseptic loosening. Vitamin E doped polyethylene liners have been designed to reduce wear, but the material is rather new and needs post marked surveillance analysis in large register studies.
Aim: The aim of this nationwide population-based study was to investigate 1) the risk of polyethylene-related endpoints (aseptic loosening, wear, granuloma, or osteolysis) from 12 months after THA with vitamin E-doped polyethylene (VEPE) liners compared to THA with cross-linked annealed or remelted polyethylene (XLPE) liners and 2) the risk of any and specific revision causes.
Materials and Methods: We included THAs from The Danish Hip Arthroplasty Register from January 1, 2008 to June 30, 2019, with uncemented cup, VEPE or XLPE liner, and metal or ceramic head. The outcome was polyethylene-related endpoints from 12 months and onwards, and further outcomes were any and specific revision causes. Risk of revision was estimated using Cox regression.
Results: A total of 110,803 THAs were assessed for eligibility and 63,892 THAs (55,230 patients) were included in the study, 5,885 (9.2%) THAs with a VEPE liner and 58,007 (91.8%) with a XLPE liner. Median observation time was 5.35 (inter-quartile range (IQR) [3.62, 7.09]) years for VEPE and 4.78 (IQR [2.64, 7.68]) for XLPE. We found a lower risk of revision for polyethylene-related endpoints from 12 months for VEPE compared to XLPE (hazard ratio (HR) 0.51 [0.31, 0.84]). THAs with VEPE liners were associated with increased risk of any revision within the first 3 months (HR 1.57 [1.33, 1.86]), revision recorded as aseptic loosening within 3 months (4.15 [2.19, 7.87]), fracture within 3 months (HR 2.58 [1.99, 3.34]), and other revision at any time (1.35 [1.00, 1.81]).
Interpretation / Conclusion: VEPE liners had a lower revision rate due to polyethylene-related endpoints from 12 months compared to XLPE liners. No difference in other specific reasons was shown. Regarding safety, we found one cracked liner in VEPE while thirteen cracked liners were reported for XLPE.
Marie Bagger Bohn, Bent Lund, Kasper Spoorendonk, Jeppe Lange
H-HiP, Department of Orthopedic Surgery, Horsens Regional Hospital, 8700 Horsens, Denmark, Department of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark; H-HiP, Department of Orthopedic Surgery, Horsens Regional Hospital, 8700 Horsens, Denmark;H-Hip, Department of Physio and Occupational Therapy, Horsens Regional Hospital, Denmark; H-HiP, Department of Orthopedic Surgery, Horsens Regional Hospital, 8700 Horsens, Denmark, Department of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark
Background: Awareness of Gluteus medius (GM) and/or minimus tendon tears as the cause of lateral hip pain (LHP) has been growing over the past two decades. It is estimated that GM tears may be present in as many as 25% of late middle-aged women and 10% of middle-aged men. Tears that impart significant functional impairment to patients and may be a source of debilitating and chronic LHP. Unfortunately, these tears are often misdiagnosed and, thus, treated insufficiently. In recent years, surgical repair has shown promising results.
Aim: To report one-year outcomes of our initial 40 cases of surgical repair of GM tendon tears.
Materials and Methods: Data were prospectively collected between September 2017 and October 2020. Inclusion criteria for the study were patients undergoing surgical GM repair who had completed a one- year follow-up. MRI was pre-operatively used to visualize the GM tears and select patients deemed suitable for surgery. Pre- and 12-months post-operative testing included pain (at rest, during activity and worst pain (NRS 0-10)), patient reported outcome measures (Copenhagen hip and groin score (HAGOS), Oxford Hip score (OHS), EQ-VAS and Global rating of Change (GROC)), and maximal voluntary isometric contraction of hip abduction (MVC) measured with a handheld dynamometer.
Results: The cohort included 40 patients (36 women) with a median age of 55 years (range 18-81). From pre- to 12-months post-operative, pain at rest, during activity and worst pain decreased from 4.7 to 1.6, 6.3 to 2.5, and 8.6 to 4.5 (p>0.001), respectively. All HAGOS sub scores, OHS and EQ-VAS improved (HAGOS; pain: 35 to 67, Symptom: 43 to 71, ADL: 34 to 65, Sport/Rec: 21 to 53, PA: 16 to 44 , QOL: 23 to 52 (p>0.001), OHS; 22 to 33 (p>0.001) and EQ-VAS: 61 to 72 (p=0.0107)). At follow-up the success rate of GROC (”moderately better” to ”very much better”) was 61.1%. MVC of the operated and non-operated hip increased by 0.09 Nm/kg (95% CI 0.007;0.17) and 0.03 Nm/kg (95%CI -0.04;0.11).
Interpretation / Conclusion: This study indicates that surgical repair may be an effective treatment of MRI verified gluteus medius tears. At one-year follow-up, the patients experience less pain, and subjective outcome measures and hip abductor strength improve.
H-HiP, Department of Orthopedic Surgery, Horsens Regional Hospital, 8700 Horsens, Denmark, Department of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark; H-HiP, Department of Orthopedic Surgery, Horsens Regional Hospital, 8700 Horsens, Denmark;H-Hip, Department of Physio and Occupational Therapy, Horsens Regional Hospital, Denmark; H-HiP, Department of Orthopedic Surgery, Horsens Regional Hospital, 8700 Horsens, Denmark, Department of Clinical Medicine, Aarhus University, 8200 Aarhus N, Denmark
Background: Awareness of Gluteus medius (GM) and/or minimus tendon tears as the cause of lateral hip pain (LHP) has been growing over the past two decades. It is estimated that GM tears may be present in as many as 25% of late middle-aged women and 10% of middle-aged men. Tears that impart significant functional impairment to patients and may be a source of debilitating and chronic LHP. Unfortunately, these tears are often misdiagnosed and, thus, treated insufficiently. In recent years, surgical repair has shown promising results.
Aim: To report one-year outcomes of our initial 40 cases of surgical repair of GM tendon tears.
Materials and Methods: Data were prospectively collected between September 2017 and October 2020. Inclusion criteria for the study were patients undergoing surgical GM repair who had completed a one- year follow-up. MRI was pre-operatively used to visualize the GM tears and select patients deemed suitable for surgery. Pre- and 12-months post-operative testing included pain (at rest, during activity and worst pain (NRS 0-10)), patient reported outcome measures (Copenhagen hip and groin score (HAGOS), Oxford Hip score (OHS), EQ-VAS and Global rating of Change (GROC)), and maximal voluntary isometric contraction of hip abduction (MVC) measured with a handheld dynamometer.
Results: The cohort included 40 patients (36 women) with a median age of 55 years (range 18-81). From pre- to 12-months post-operative, pain at rest, during activity and worst pain decreased from 4.7 to 1.6, 6.3 to 2.5, and 8.6 to 4.5 (p>0.001), respectively. All HAGOS sub scores, OHS and EQ-VAS improved (HAGOS; pain: 35 to 67, Symptom: 43 to 71, ADL: 34 to 65, Sport/Rec: 21 to 53, PA: 16 to 44 , QOL: 23 to 52 (p>0.001), OHS; 22 to 33 (p>0.001) and EQ-VAS: 61 to 72 (p=0.0107)). At follow-up the success rate of GROC (”moderately better” to ”very much better”) was 61.1%. MVC of the operated and non-operated hip increased by 0.09 Nm/kg (95% CI 0.007;0.17) and 0.03 Nm/kg (95%CI -0.04;0.11).
Interpretation / Conclusion: This study indicates that surgical repair may be an effective treatment of MRI verified gluteus medius tears. At one-year follow-up, the patients experience less pain, and subjective outcome measures and hip abductor strength improve.
Rasmus Tyrsted Mikkelsen, Søren Overgaard, Alma Becic Pedersen, Johan Kärrholm, Ola Rolfson, Anne Marie Fenstad, Ove Furnes, Geir Hallan, Keijo Mäkelä, Antti Eskelinen, Claus Varnum
Rasmus Tyrsted Mikkelsen Department of Orthopedic Surgery, Lillebaelt Hospital - Vejle, University Hospital of Southern Denmark, Denmark; Department of Regional Health Research, Faculty of Health Science, University of Southern Denmark Søren Overgaard Department of Orthopaedic Surgery and Traumatology, Copenhagen University Hospital, Bispebjerg, Denmark; University of Copenhagen, Department of Clinical Medicine, Faculty of Health and Medical Sciences, Denmark; The Danish Hip Arthroplasty Register; Department of Clinical Research, University of Southern Denmark; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital Alma Becic Pedersen Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark Johan Kärrholm Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; The Swedish Arthroplasty Register, Gothenburg, Sweden Ola Rolfson Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; The Swedish Arthroplasty Register, Gothenburg, Sweden Anne Marie Fenstad The Norwegian Arthroplasty Register, Department of Orthopedic Surgery, Haukeland University Hospital, Bergen, Norway Ove Furnes Orthopedic Clinic, Haukeland University Hospital, Bergen, Norway; The Norwegian Arthroplasty Register, Department of Orthopedic Surgery, Haukeland University Hospital, Bergen, Norway Geir Hallan Orthopedic Clinic, Haukeland University Hospital, Bergen, Norway; The Norwegian Arthroplasty Register, Department of Orthopedic Surgery, Haukeland University Hospital, Bergen, Norway Keijo Mäkelä Department of Orthopaedics and Traumatology, Turku University Hospital, Turku; The Finnish Arthroplasty Registry, Helsinki, Finland Antti Eskelinen The Finnish Arthroplasty Registry, Helsinki, Finland; Coxa Hospital for Joint Replacement, Tampere, Finland Claus Varnum Department of Orthopedic Surgery, Lillebaelt Hospital - Vejle, University Hospital of Southern Denmark, Denmark; Department of Regional Health Research, Faculty of Health Science, University of Southern Denmark; The Danish Hip Arthroplasty Register
Background: Young patients risk undergoing multiple revisions of their total hip arthroplasty (THA) leading to poorer clinical outcome. Different bearings have been introduced to improve the survival of the THA. However, long-term results of these bearings in young patients are unknown.
Aim: Our aim was to compare the survival and risk of revision of primary stemmed cementless THA with metal-on-metal (MoM) and ceramic- on-ceramic (CoC) to that of metal-on-highly- crosslinked-polyethylene (MoXLP) bearings in patients between 20-54 years with primary osteoarthritis or childhood hip disorders.
Materials and Methods: The study population was identified from the Nordic Arthroplasty Register Association dataset and consisted of 2,246 MoM, 4,227 CoC and 10,433 MoXLP THA operated between 1995-2017. We used the Kaplan-Meier estimator for calculation of THA survivorship and Cox regression to estimate the hazard ratio (HR) of revision (including 95% confidence intervals) due to any and specific causes adjusted for sex, age, diagnosis, year of primary surgery and femoral head size. MoXLP was used as reference. The hazard ratios were given in 0-2, 2-7 and 7-15 years to meet the assumption of proportional hazards.
Results: The median follow-up was 10.3 years for MoM, 6.6 years for CoC and 4.8 years for MoXLP. 15 years postoperatively the Kaplan-Meier survival estimates were 80% (78-83%) for MoM, 92% (91-93%) for CoC and 94% (93-95%) for MoXLP bearings. The 0-2, 2-7 and 7-15 years adjusted HRs of revision by any cause were 1.4 (0.9-2.3), 3.3 (2.1-5.1) and 4.5 (2.3-8.8) for MoM and 1.1 (0.8-1.4), 1.0 (0.7-1.4) and 2.3 (1.2-4.3) for CoC bearings. After 7-15 years follow- up, the unadjusted cause specific HR of revision due to aseptic loosening was 6.4 (1.5-28) for MoM and 4.2 (0.9-20) for CoC THA. MoM and CoC had a 7-15 years adjusted HR of revision due to ‘other’ causes of 6.3 (2.1-19) and 2.1 (0.8-6.0).
Interpretation / Conclusion: For patient between 20-54 years receiving a primary stemmed cementless THA MoXLP bearings have better survival than MoM and CoC bearings, mainly because of lower risk of revision due to aseptic loosening and ‘other’ causes.
Rasmus Tyrsted Mikkelsen Department of Orthopedic Surgery, Lillebaelt Hospital - Vejle, University Hospital of Southern Denmark, Denmark; Department of Regional Health Research, Faculty of Health Science, University of Southern Denmark Søren Overgaard Department of Orthopaedic Surgery and Traumatology, Copenhagen University Hospital, Bispebjerg, Denmark; University of Copenhagen, Department of Clinical Medicine, Faculty of Health and Medical Sciences, Denmark; The Danish Hip Arthroplasty Register; Department of Clinical Research, University of Southern Denmark; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital Alma Becic Pedersen Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus, Denmark Johan Kärrholm Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; The Swedish Arthroplasty Register, Gothenburg, Sweden Ola Rolfson Department of Orthopaedics, Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden; The Swedish Arthroplasty Register, Gothenburg, Sweden Anne Marie Fenstad The Norwegian Arthroplasty Register, Department of Orthopedic Surgery, Haukeland University Hospital, Bergen, Norway Ove Furnes Orthopedic Clinic, Haukeland University Hospital, Bergen, Norway; The Norwegian Arthroplasty Register, Department of Orthopedic Surgery, Haukeland University Hospital, Bergen, Norway Geir Hallan Orthopedic Clinic, Haukeland University Hospital, Bergen, Norway; The Norwegian Arthroplasty Register, Department of Orthopedic Surgery, Haukeland University Hospital, Bergen, Norway Keijo Mäkelä Department of Orthopaedics and Traumatology, Turku University Hospital, Turku; The Finnish Arthroplasty Registry, Helsinki, Finland Antti Eskelinen The Finnish Arthroplasty Registry, Helsinki, Finland; Coxa Hospital for Joint Replacement, Tampere, Finland Claus Varnum Department of Orthopedic Surgery, Lillebaelt Hospital - Vejle, University Hospital of Southern Denmark, Denmark; Department of Regional Health Research, Faculty of Health Science, University of Southern Denmark; The Danish Hip Arthroplasty Register
Background: Young patients risk undergoing multiple revisions of their total hip arthroplasty (THA) leading to poorer clinical outcome. Different bearings have been introduced to improve the survival of the THA. However, long-term results of these bearings in young patients are unknown.
Aim: Our aim was to compare the survival and risk of revision of primary stemmed cementless THA with metal-on-metal (MoM) and ceramic- on-ceramic (CoC) to that of metal-on-highly- crosslinked-polyethylene (MoXLP) bearings in patients between 20-54 years with primary osteoarthritis or childhood hip disorders.
Materials and Methods: The study population was identified from the Nordic Arthroplasty Register Association dataset and consisted of 2,246 MoM, 4,227 CoC and 10,433 MoXLP THA operated between 1995-2017. We used the Kaplan-Meier estimator for calculation of THA survivorship and Cox regression to estimate the hazard ratio (HR) of revision (including 95% confidence intervals) due to any and specific causes adjusted for sex, age, diagnosis, year of primary surgery and femoral head size. MoXLP was used as reference. The hazard ratios were given in 0-2, 2-7 and 7-15 years to meet the assumption of proportional hazards.
Results: The median follow-up was 10.3 years for MoM, 6.6 years for CoC and 4.8 years for MoXLP. 15 years postoperatively the Kaplan-Meier survival estimates were 80% (78-83%) for MoM, 92% (91-93%) for CoC and 94% (93-95%) for MoXLP bearings. The 0-2, 2-7 and 7-15 years adjusted HRs of revision by any cause were 1.4 (0.9-2.3), 3.3 (2.1-5.1) and 4.5 (2.3-8.8) for MoM and 1.1 (0.8-1.4), 1.0 (0.7-1.4) and 2.3 (1.2-4.3) for CoC bearings. After 7-15 years follow- up, the unadjusted cause specific HR of revision due to aseptic loosening was 6.4 (1.5-28) for MoM and 4.2 (0.9-20) for CoC THA. MoM and CoC had a 7-15 years adjusted HR of revision due to ‘other’ causes of 6.3 (2.1-19) and 2.1 (0.8-6.0).
Interpretation / Conclusion: For patient between 20-54 years receiving a primary stemmed cementless THA MoXLP bearings have better survival than MoM and CoC bearings, mainly because of lower risk of revision due to aseptic loosening and ‘other’ causes.
Karen Dyreborg, Søren Solgaard, Michael Skettrup, Michael Mørk Petersen
Rigshospitalet, Department of Orthopedic Surgery; Herlev-Gentofte University Hospital, Department of Hip and Knee Surgery
Background: This study evaluates how 2 different total hip arthroplasty (THA) stems compares regarding adaptive bone remodelling. The stems are both proximally porous coated, aiming for proximal fixation, but with different dispersal of the coating. They are also differently designed regarding the distal tip of the stem.
Aim: We aimed to investigate if there is a difference in periprosthetic adaptive bone remodelling between two different designs.
Materials and Methods: From February 2016 to September 2017, we randomised 62 patients, 1:1 (mean age=64 years, Female/Male=28/34), scheduled for an uncemented THA to receive either an EBM or a BM THA stem. We performed dual-energy x-ray absorptiometry (DEXA) scans within a week after surgery and at 3, 6, 12 and 24 months with measurements of bone mineral density (BMD) in the 7 Gruen zones (region of interest (ROI) 1-7). Additionally, Oxford Hip Score and Harris Hip Score were collected at 6, 12 and 24 months.
Results: We found a decrease in BMD between the postoperative and the 24-months values in all ROIs for both stems. The greatest decrease over time was seen for both groups in the ROI1 (BM =-8.4%, p=0.044, and EBM=-6.5%, p=0.001) and ROI7 (BM =-7%, p=0.005, and EBM=-8.6%, p<0.0005). We found a tendency in ROI2-4 of a higher degree of bone loss in the EBM group. However, this difference only continued beyond 6 months in ROI4 (24 months: BM=-1.2% and EBM =-2.8%, p=0.001).
Interpretation / Conclusion: The stems show similar adaptive bone remodelling and are clinically performing well
Rigshospitalet, Department of Orthopedic Surgery; Herlev-Gentofte University Hospital, Department of Hip and Knee Surgery
Background: This study evaluates how 2 different total hip arthroplasty (THA) stems compares regarding adaptive bone remodelling. The stems are both proximally porous coated, aiming for proximal fixation, but with different dispersal of the coating. They are also differently designed regarding the distal tip of the stem.
Aim: We aimed to investigate if there is a difference in periprosthetic adaptive bone remodelling between two different designs.
Materials and Methods: From February 2016 to September 2017, we randomised 62 patients, 1:1 (mean age=64 years, Female/Male=28/34), scheduled for an uncemented THA to receive either an EBM or a BM THA stem. We performed dual-energy x-ray absorptiometry (DEXA) scans within a week after surgery and at 3, 6, 12 and 24 months with measurements of bone mineral density (BMD) in the 7 Gruen zones (region of interest (ROI) 1-7). Additionally, Oxford Hip Score and Harris Hip Score were collected at 6, 12 and 24 months.
Results: We found a decrease in BMD between the postoperative and the 24-months values in all ROIs for both stems. The greatest decrease over time was seen for both groups in the ROI1 (BM =-8.4%, p=0.044, and EBM=-6.5%, p=0.001) and ROI7 (BM =-7%, p=0.005, and EBM=-8.6%, p<0.0005). We found a tendency in ROI2-4 of a higher degree of bone loss in the EBM group. However, this difference only continued beyond 6 months in ROI4 (24 months: BM=-1.2% and EBM =-2.8%, p=0.001).
Interpretation / Conclusion: The stems show similar adaptive bone remodelling and are clinically performing well
Lars Lykke Hermansen, Bjarke Viberg, Søren Overgaard
Department of Orthopaedics, Hospital of South West Jutland, Esbjerg, and The Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Odense; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Odense and Department of Orthopedic Surgery and Traumatology, Lillebaelt Hospital, University hospital of Southern Denmark; Department of Orthopedic Surgery and Traumatology, Bispebjerg Hospital og Institute of Clinical Medicine, Copenhagen University
Background: Persistent instability after hip revision due to dislocation is a serious problem. In order to lower the risk of this complication, it is essential to identify risk factors.
Aim: Our aim was to analyze surgery- (liner type, extent of revision, head size) and patient- (age, sex, Charlson comorbidity index (CCI)) related risk factors for both new dislocation and re-revision of any cause following a first-time revised hip due to dislocation.
Materials and Methods: We included patients with a primary THA due to osteoarthritis and a first-time revision due to dislocation registered in the Danish Hip Arthroplasty Register (DHR) from 1996-2016. Patients were followed from the day of the first revision to either Dec. 2018, re-revision, or death. We identified dislocations in the Danish National Patient Register based on a validated method and re-revisions in the DHR. Risk factors were analyzed by a Fine-Gray multiple regression analysis adjusting for the competing risk of death. Results are presented as sub-distribution hazard ratios (sHR) with 95% confidence intervals.
Results: We identified 1,678 first-time revisions due to dislocation and 22.4% of these had a new dislocation. 19.8% were re- revised for any reason. Median follow-up was 5.3 years. For new dislocations, the sHR was 0,36 (0.27-0.48) for those who had a constrained liner (CL) during revision and 0.21 (0.08-0.58) for dual mobility cups (DMC) meaning a lower risk of dislocations compared to regular liners. Changing only the head/liner increased the risk of dislocation (sHR=2.65 (2.05- 3.42)) compared to full cup revisions. Age, sex, CCI, and head size was not significant risk factors for new dislocations. Regarding risk of new re-revision, changing only head/liner resulted in an increased risk of re-revision (sHR=1.73 (1.34-2.23)). Patients <65 years had increased risk of re-revision compared to 65-75 years (sHR=1.36 (1.05-1.77)). Sex, CCI, head size and liner type were not significantly associated with re- revisions.
Interpretation / Conclusion: Patients revised with a DMC and CL were associated with a lower risk of dislocation after a first-time revision but not re-revision whereas only changing the head/liner was associated with higher risk of dislocation and re-revision.
Department of Orthopaedics, Hospital of South West Jutland, Esbjerg, and The Orthopaedic Research Unit, Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Odense; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Odense and Department of Orthopedic Surgery and Traumatology, Lillebaelt Hospital, University hospital of Southern Denmark; Department of Orthopedic Surgery and Traumatology, Bispebjerg Hospital og Institute of Clinical Medicine, Copenhagen University
Background: Persistent instability after hip revision due to dislocation is a serious problem. In order to lower the risk of this complication, it is essential to identify risk factors.
Aim: Our aim was to analyze surgery- (liner type, extent of revision, head size) and patient- (age, sex, Charlson comorbidity index (CCI)) related risk factors for both new dislocation and re-revision of any cause following a first-time revised hip due to dislocation.
Materials and Methods: We included patients with a primary THA due to osteoarthritis and a first-time revision due to dislocation registered in the Danish Hip Arthroplasty Register (DHR) from 1996-2016. Patients were followed from the day of the first revision to either Dec. 2018, re-revision, or death. We identified dislocations in the Danish National Patient Register based on a validated method and re-revisions in the DHR. Risk factors were analyzed by a Fine-Gray multiple regression analysis adjusting for the competing risk of death. Results are presented as sub-distribution hazard ratios (sHR) with 95% confidence intervals.
Results: We identified 1,678 first-time revisions due to dislocation and 22.4% of these had a new dislocation. 19.8% were re- revised for any reason. Median follow-up was 5.3 years. For new dislocations, the sHR was 0,36 (0.27-0.48) for those who had a constrained liner (CL) during revision and 0.21 (0.08-0.58) for dual mobility cups (DMC) meaning a lower risk of dislocations compared to regular liners. Changing only the head/liner increased the risk of dislocation (sHR=2.65 (2.05- 3.42)) compared to full cup revisions. Age, sex, CCI, and head size was not significant risk factors for new dislocations. Regarding risk of new re-revision, changing only head/liner resulted in an increased risk of re-revision (sHR=1.73 (1.34-2.23)). Patients <65 years had increased risk of re-revision compared to 65-75 years (sHR=1.36 (1.05-1.77)). Sex, CCI, head size and liner type were not significantly associated with re- revisions.
Interpretation / Conclusion: Patients revised with a DMC and CL were associated with a lower risk of dislocation after a first-time revision but not re-revision whereas only changing the head/liner was associated with higher risk of dislocation and re-revision.
Nina M. Edwards, Claus Varnum, Søren Overgaard, Rob G. H. H. Nelissen, Alma B. Pedersen
Department of Clinical Epidemiology, Aarhus University Hospital, Denmark; Department of Orthopaedic Surgery, Lillebaelt Hospital - Vejle, Denmark and Department of Regional Health Research, University of Southern Denmark, Denmark; Danish Hip Arthroplasty Register; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Denmark, Department of Clinical Research, University of Southern Denmark, Denmark; Department of Orthopaedics, Leiden University Medical Center, Leiden, The Netherlands.
Background: In orthopaedic surgery, the quality of care and outcomes after surgery are correlated to socioeconomic status (SES). However, previous research concerning infection is limited by assessing SES only by a single marker, no distinction between infection causes, or area-based SES measurements.
Aim: We examined whether SES is associated with the risk of hospitalization due to infections after total hip arthroplasty (THA) within 30 and 90 days.
Materials and Methods: We obtained individual-based information on SES markers (cohabitation, education, income, and liquid assets) on 103,901 THA patients from Danish health registers (year 1995-2017). The outcome was readmission due to any infection, pneumonia, urinary tract infection (UTI), or periprosthetic joint infection (PJI). We calculated the cumulative incidences with death as competing risk, and we used the pseudo-observation method and generalized linear regression to estimate relative risks (RR) with 95 % confidence intervals (CI).
Results: The cumulative incidence of any infection at 90 days was highest among patients who lived alone (1.5% (CI 1.3-1.6)), had the lowest education (1.1% (CI 1.0-1.6)), had the lowest income (1.5% (CI 1.3-1.6)), and had lowest liquid assets (1.3% (CI 1.1-1.4)). The RRs for any infection within the first 30 days were 1.5 (CI 1.3-1.7) for patients living alone vs. cohabiting, 1.3 (CI 1.1-1.6) for medium income vs. high income, and 1.6 (CI 1.4-1.8) for low liquid assets vs. high liquid assets. Education was not associated with the risk of any infection, however, the RR for pneumonia was 8.0 (CI 2.2-30.0) for low education vs. high education. The RR for PJI were 1.2 (0.6-2.3) for patients living alone vs. cohabiting, 1.6 (0.8-3.3) for low liquid assets vs. high liquid assets. The same trends were seen within the first 90 days.
Interpretation / Conclusion: We found that living alone, low education, low income, and low liquid assets were all associated with higher risks of infections within the first 30 and 90 days after THA. Our findings highlight the socioeconomic disadvantage as a risk factor for developing infection after THA, emphasizing the importance of policy-, patient,- and surgeon practice when addressing inequalities in THA outcome.
Department of Clinical Epidemiology, Aarhus University Hospital, Denmark; Department of Orthopaedic Surgery, Lillebaelt Hospital - Vejle, Denmark and Department of Regional Health Research, University of Southern Denmark, Denmark; Danish Hip Arthroplasty Register; Department of Orthopaedic Surgery and Traumatology, Odense University Hospital, Denmark, Department of Clinical Research, University of Southern Denmark, Denmark; Department of Orthopaedics, Leiden University Medical Center, Leiden, The Netherlands.
Background: In orthopaedic surgery, the quality of care and outcomes after surgery are correlated to socioeconomic status (SES). However, previous research concerning infection is limited by assessing SES only by a single marker, no distinction between infection causes, or area-based SES measurements.
Aim: We examined whether SES is associated with the risk of hospitalization due to infections after total hip arthroplasty (THA) within 30 and 90 days.
Materials and Methods: We obtained individual-based information on SES markers (cohabitation, education, income, and liquid assets) on 103,901 THA patients from Danish health registers (year 1995-2017). The outcome was readmission due to any infection, pneumonia, urinary tract infection (UTI), or periprosthetic joint infection (PJI). We calculated the cumulative incidences with death as competing risk, and we used the pseudo-observation method and generalized linear regression to estimate relative risks (RR) with 95 % confidence intervals (CI).
Results: The cumulative incidence of any infection at 90 days was highest among patients who lived alone (1.5% (CI 1.3-1.6)), had the lowest education (1.1% (CI 1.0-1.6)), had the lowest income (1.5% (CI 1.3-1.6)), and had lowest liquid assets (1.3% (CI 1.1-1.4)). The RRs for any infection within the first 30 days were 1.5 (CI 1.3-1.7) for patients living alone vs. cohabiting, 1.3 (CI 1.1-1.6) for medium income vs. high income, and 1.6 (CI 1.4-1.8) for low liquid assets vs. high liquid assets. Education was not associated with the risk of any infection, however, the RR for pneumonia was 8.0 (CI 2.2-30.0) for low education vs. high education. The RR for PJI were 1.2 (0.6-2.3) for patients living alone vs. cohabiting, 1.6 (0.8-3.3) for low liquid assets vs. high liquid assets. The same trends were seen within the first 90 days.
Interpretation / Conclusion: We found that living alone, low education, low income, and low liquid assets were all associated with higher risks of infections within the first 30 and 90 days after THA. Our findings highlight the socioeconomic disadvantage as a risk factor for developing infection after THA, emphasizing the importance of policy-, patient,- and surgeon practice when addressing inequalities in THA outcome.
Katrine Hvidt, , Katrine Væsel Wade, Niels Harry Krarup, Marianne Toft Vestermark
Katrine Hvidt; Department of Orthopaedics, Aarhus University Hospital Katrine Væsel Wade; Department of Orthopaedics, Viborg Regional Hospital Marianne Toft Vestermark; Department of Orthopaedics, Viborg Regional Hospital Niels Harry Krarup; Department of Orthopaedics, Viborg Regional Hospital
Background: Dislocation is a well-known complication after total hip arthroplasty (THA). The dual mobility cup (DMC) has shown promising results in lowering the dislocation rate compared to conventional cups, but not many studies on long-term dislocation rate of DMC in a large cohort are available.
Aim: To determine the dislocation rate of DMC in primary THAs in a large cohort with up to ten years follow- up. Further, to elucidate factors that might affect the dislocation rate.
Materials and Methods: The Danish Hip Arthroplasty Registry (DHR) was used to identify primary THAs with DMC inserted at Viborg Regional Hospital since January 2001. 2711 were included, 1874 Saturne® cups and 837 Avantage™ cups. Events of dislocations, revisions and patient deaths were retrospectively identified by review of medical files. Information for subgroup analysis was collected from DHR.
Results: The two-year dislocation rate for DMC was 2,21%, ten-year dislocation rate was 2,79%. The risk of dislocation was lowest in patients who had THA with DMC due to primary arthrosis with a ten-year dislocation rate of 1,4% and highest in patients treated for a displaced collum femoris fracture with a ten-year dislocation rate on 4,00%. No significant difference in risk of dislocation was found when comparing Saturne® and Avantage™ cups.
Interpretation / Conclusion: Our findings indicate a lower dislocation rate of DMC compared to conventional cups, especially in regard to long-term risk. Further studies on prosthesis survival of DMC are needed.
Katrine Hvidt; Department of Orthopaedics, Aarhus University Hospital Katrine Væsel Wade; Department of Orthopaedics, Viborg Regional Hospital Marianne Toft Vestermark; Department of Orthopaedics, Viborg Regional Hospital Niels Harry Krarup; Department of Orthopaedics, Viborg Regional Hospital
Background: Dislocation is a well-known complication after total hip arthroplasty (THA). The dual mobility cup (DMC) has shown promising results in lowering the dislocation rate compared to conventional cups, but not many studies on long-term dislocation rate of DMC in a large cohort are available.
Aim: To determine the dislocation rate of DMC in primary THAs in a large cohort with up to ten years follow- up. Further, to elucidate factors that might affect the dislocation rate.
Materials and Methods: The Danish Hip Arthroplasty Registry (DHR) was used to identify primary THAs with DMC inserted at Viborg Regional Hospital since January 2001. 2711 were included, 1874 Saturne® cups and 837 Avantage™ cups. Events of dislocations, revisions and patient deaths were retrospectively identified by review of medical files. Information for subgroup analysis was collected from DHR.
Results: The two-year dislocation rate for DMC was 2,21%, ten-year dislocation rate was 2,79%. The risk of dislocation was lowest in patients who had THA with DMC due to primary arthrosis with a ten-year dislocation rate of 1,4% and highest in patients treated for a displaced collum femoris fracture with a ten-year dislocation rate on 4,00%. No significant difference in risk of dislocation was found when comparing Saturne® and Avantage™ cups.
Interpretation / Conclusion: Our findings indicate a lower dislocation rate of DMC compared to conventional cups, especially in regard to long-term risk. Further studies on prosthesis survival of DMC are needed.
André Nis Klenø, Martin Bækgaard Stisen, Nina Mckinnon Edwards, Inger Mechlenburg, Alma Becic Pedersen
Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N Department of Orthopaedic Surgery, Aarhus University Hospital, Denmark Department of Clinical Medicine, Aarhus University, Denmark
Background: Hip osteoarthritis (OA) approximately affects 11% of people globally. When pharmacological and non- pharmacological treatment fail to provide adequate pain relief, total hip arthroplasty (THA) is recommended. Although THA is an effective and common procedure, persistent pain and use of analgesics up to two years after THA surgery are common.
Aim: We examined the trends in the utilization of analgesics before and after THA, overall, and in relation to markers of socioeconomic status (SES) in a population based cohort.
Materials and Methods: We used the Danish Hip Arthroplasty Registry to identify 103,209 patients who underwent THA between 1996 and 2018. Data on medication and SES markers were obtained from Danish medical databases. Proportions of redeemed prescriptions for analgesics with 95% confidence intervals (95%CI) were calculated for 4 quartiles before and 4 quartiles after THA for the entire THA population, and by three SES markers (education, cohabiting status and wealth).
Results: Overall, the proportion of analgesic use was 41.8% (95%CI 40.5;42.1) at 9-12 months and 58.8% (95%CI 58.5;59.1) at 0-3 months before THA. The proportion of analgesics reached its highest at 64.0% (95%CI 63.7;64.3) 0-3 months after THA, but declined to 27.0% (95%CI 26.8;27.3) at 9-12 months after THA. Low education, living alone and having low wealth (low SES) were associated with higher proportions of analgesic use both before and after THA. Use of analgesics decreased after THA regardless of SES, but the decrease was less pronounced among patients with low SES.
Interpretation / Conclusion: The use of analgesics decreased 9-12 months after THA, but remained relatively high. Our results suggest that clinicians should focus in the larger extent on patients with low SES when phasing out of opioid treatment and planning rehabilitation.
Department of Clinical Epidemiology, Aarhus University Hospital, Aarhus N Department of Orthopaedic Surgery, Aarhus University Hospital, Denmark Department of Clinical Medicine, Aarhus University, Denmark
Background: Hip osteoarthritis (OA) approximately affects 11% of people globally. When pharmacological and non- pharmacological treatment fail to provide adequate pain relief, total hip arthroplasty (THA) is recommended. Although THA is an effective and common procedure, persistent pain and use of analgesics up to two years after THA surgery are common.
Aim: We examined the trends in the utilization of analgesics before and after THA, overall, and in relation to markers of socioeconomic status (SES) in a population based cohort.
Materials and Methods: We used the Danish Hip Arthroplasty Registry to identify 103,209 patients who underwent THA between 1996 and 2018. Data on medication and SES markers were obtained from Danish medical databases. Proportions of redeemed prescriptions for analgesics with 95% confidence intervals (95%CI) were calculated for 4 quartiles before and 4 quartiles after THA for the entire THA population, and by three SES markers (education, cohabiting status and wealth).
Results: Overall, the proportion of analgesic use was 41.8% (95%CI 40.5;42.1) at 9-12 months and 58.8% (95%CI 58.5;59.1) at 0-3 months before THA. The proportion of analgesics reached its highest at 64.0% (95%CI 63.7;64.3) 0-3 months after THA, but declined to 27.0% (95%CI 26.8;27.3) at 9-12 months after THA. Low education, living alone and having low wealth (low SES) were associated with higher proportions of analgesic use both before and after THA. Use of analgesics decreased after THA regardless of SES, but the decrease was less pronounced among patients with low SES.
Interpretation / Conclusion: The use of analgesics decreased 9-12 months after THA, but remained relatively high. Our results suggest that clinicians should focus in the larger extent on patients with low SES when phasing out of opioid treatment and planning rehabilitation.