Session 13: Foredragskonkurrence

Fredag den 23. oktober
13:30 – 15:00
Lokale: Stockholm/Copenhagen/Helsinki/Oslo
Chairmen: Anders Troelsen / Martin Lind

133. Double-Blinded Randomized Controlled Trial of Patellofemoral vs. Total Knee Arthroplasty for Isolated Patellofemoral Osteoarthritis
Anders Odgaard, Frank Madsen, Per Wagner Kristensen, Andreas Kappel, Jesper Fabrin
Dept. of Orthopaedics, Copenhagen University Hospital Gentofte

Background: Controversy exists over surgical treatment of patellofemoral osteoarthritis (PF-OA). Registers consistently show poor results of patellofemoral arthroplasty (PFA) compared to total knee arthroplasty (TKA), but case series show good results of PFA.
Purpose / Aim of Study: This study aims to compare the clinical and patient-reported outcomes of treatment with PFA and TKA.
Materials and Methods: A double-blinded (for the first year), multi-centre trial with intraoperative randomization between TKA and PFA was performed. Participating hospitals included 205 patients from 2007 until 2014. The inclusion criterion was bone-on-bone on the skyline view. Of the inclusions, 67 patients rejected participation, and a further 38 patients were excluded intraoperatively due to tibiofemoral lesions. The remaining 100 patients were operated in one of five hospitals, 50 received a PFA and 50 a TKA. Clinical, radiological and patient-reported data was collected. This paper reports the 1-7 year results.
Findings / Results: There were 76 females and 24 men. The OKS was 23.8/ 23.1 for the PFA/TKA groups at inclusion. For the PFA group, the OKS was 39.6, 39.0, 40.2 and 39.5 at 9 months, 1, 3 and 5 years, respectively, and for the TKA group, the OKS was 34.6, 36.3, 36.0 and 35.7 (p<0.01 for all time points before one year, n.s. thereafter). Similar results were found for other PROMs. The flexion range at two years was 130 degrees for the PFA group and 123 for the TKA group (p<0.05).
Conclusions: Patient-reported outcomes were significantly better for PFA compared to TKA for the first year. This difference between PFA and TKA results are also in favour of PFA for all later time points, although non-significant. Patients receiving a PFA had significantly better range of movement. There were more reoperations in the PFA group, but the number of implant revisions was identical.

134. Plate fixation compared with nonoperative treatment of displaced midshaft clavicular fractures. A randomized controlled trial.
Andreas Qvist, Carsten Moss, Michael Toft Væsel, Steen Lund Jensen
Orthopedics, Aalborg University Hospital

Background: Newer studies have questioned traditional nonoperative treatment of midshaft clavicular fractures, indicating superior results following operative treatment, including higher healing rates.
Purpose / Aim of Study: To compare the efficacy of osteosynthesis with that of nonoperative treatment regarding shoulder function, non-union rates, and sick leave in patients with a displaced midshaft clavicular fracture.
Materials and Methods: In a multicenter, prospective trial, 147 adult patients with an acute displaced fracture of the middle third clavicula were randomized to either osteosynthesis with a precontoured plate and locking screws (75) or nonoperative treatment with a sling (72). Outcome parameters included Disabilities of the Arm, Shoulder and Hand (DASH) Score, Constant Score, duration of sick leave, and radiographic union. Patients were followed for 1 year.
Findings / Results: At three months follow-up both DASH (median 1,7 vs. 8,3) and Constant Scores (97 vs. 90) were significant better in the operated group (p<0.05). After one year there was no difference in DASH (0.83 in both groups) or Constant Scores (98 vs. 97). The non-union rate was lower in the operated group (2 of 65 vs. 11 of 64 patients, p<0.02). Nine patients in the non-operated group were surgically treated for non-union. Plate removal was performed in sixteen patients after primary osteosynthesis. Ninety percent of surgically treated patients had returned to work after three months compared with seventy-four percent of conservatively treated patients (p<0.05).
Conclusions: Osteosynthesis of displaced midshaft clavicle fractures with precontoured plates and locking screws results in higher union rate and quicker return to work. There is, however, no difference in functional outcome after one year.

135. Autologous cartilage chip implantation improves cartilage repair tissue quality in osteochondral defects
Bjørn Borsøe Christensen, Casper Bindzus Foldager, Morten Lykke Olesen, Hede Kris Chadwick, Martin Lind
Department of orthopedic surgery, Orthopedic research laboratory, Aarhus University hospital; Orthopedic research laboratory, Aarhus University hospital; Department of orthopedic surgery, Aarhus University hospital

Background: Osteochondral injuries in the knee have a poor endogenous healing potential and no gold standard treatment has been established. Recently, the use of cartilage chips has been emerging in the literature with promising short-term clinical results.
Purpose / Aim of Study: The aim of this study was to investigate the repair response of cartilage chips in a Göttingen minipig (GMP) osteochondral defect model. The hypothesis was that the presence of cartilage chips would improve the quality of the cartilage repair tissue in osteochondral defects.
Materials and Methods: Twelve GMP’s received two 6 mm deep osteochondral defects in each knee. The defects were randomized to autologous bone graft combined with autologous cartilage chips (Autologous dual-tissue transplantation, ADTT) or autologous bone graft alone (ABG). Six GMP’s were euthanized at six months and six GMP’s at 12 months. Evaluation of repair was performed by histomorphometry.
Findings / Results: The presence of cartilage chips in the defects resulted in significantly more hyaline cartilage in the ADTT group compared with the ABG group at both six months (25.8% vs. 12.8%) and at 12 months (20.1% vs. 4.8%). There was significantly more fibrocartilage in the ADTT group compared with ABG alone at both time-points (44% vs. 27.5% and 60.8% vs. 41%, respectively) and there was significantly less fibrous tissue in the ADTT group compared with the ABG group at both time-points (27.6% vs. 57.7% and 16% vs. 48.3% respectively).
Conclusions: The presence of cartilage chips in an osteochondral defect facilitated the formation of fibrocartilage as opposed to fibrous tissue at both six- and 12- months follow-up. This study confirms the chondrogenic effect of cartilage chips on cartilage repair tissue in osteochondral defects.

136. Combined Intra-articular and Intravenous Tranexamic Acid Significantly reduce Blood Loss in Knee Arthroplasty
Christian Skovgaard Nielsen, Oejvind Jans, Nicolai Bang Foss, Tue Ørsnes, Anders Troelsen, Henrik Husted
Department of Orthopaedic Surgery , Hvidovre University Hospital, Denmark; Lundbeck Foundation Centre for Fast-track Hip and Knee Arthroplasty, Rigshospitalet, Copenhagen, Denmark; Department of Anaesthesia, Hvidovre University Hospital, Denmark

Background: In total knee arthroplasty (TKA) both systemic and topical administration of tranexamic acid (TXA) has been proven to reduce blood loss in several RCT´s though routine use of systemic TXA is considerably more common. However, additional benefit of topical TXA in addition to systemic TXA has not previously been investigated.
Purpose / Aim of Study: The aim was to evaluate if combined topical and systemic TXA administration reduced total blood loss compared to systemic TXA alone.
Materials and Methods: In this randomized, double-blind, placebo- controlled, trial 60 patients scheduled for TKA were assigned to receive either 1) combined TXA administration 1 g intravenously (IV) preoperatively + intra-articular (3 g TXA diluted in 100 ml saline) prior to wound closure (TXA IA + IV) or 2) 1 g TXA IV alone + 100 mL saline intra- articular (TXA IV + placebo). IA TXA was administrated through a puncture needle. Primary outcome was 24 h calculated blood loss. Secondary outcomes were blood loss on 2nd postoperative day, thromboembolic complications and transfusion rate. Blood loss was calculated by hemoglobin differences.
Findings / Results: Data on primary outcome was available for all 60 included patients. 24 h blood loss was 466 (SD±313) mL in the TXA IV + IA vs. 743 (SD±358) mL in the TXA IV + placebo group, treatment effect 277 (95% CI 103 – 451; p = 0.002) mL. 2nd day blood loss was 644 (SD±382) mL in the TXA IV + IA vs. 1017 (±519) mL in the TXA IV + placebo group, treatment effect 373 (95% CI 132 – 614; p = 0.003) mL. No thrombo- embolic complications were observed within 90 days postoperatively.
Conclusions: The combined administration of systemic and intra- articular TXA resulted in a clinically relevant reduction in blood loss of 37% both 24 h and 2nd day after surgery compared to intravenous TXA alone. No thromboembolic events were observed.

137. Splinting versus Extension Block Pinning Technique in the Treatment of Mallet Finger Fracture. - A Randomized Controlled Trial.
Janni Kjærgaard Thillemann, Theis Muncholm Thillemann, Anders Ditlev Foldager-Jensen, Bo Munk
Department of Handsurgery, Aarhus Universitetshospital; , Aarhus Universitetshospital

Background: Treatment of mallet finger fractures with a bony fragment of more than one third of the articulating surface is controversial. Surgery is commonly recommended, but conservative treatment has been proposed regardless the size of the bony fragment.
Purpose / Aim of Study: This study aimed to compare the outcomes after conservative treatment with splinting and surgical extension block pinning (EBP) of mallet finger fractures.
Materials and Methods: Based on sample size calculation we included thirty patients in this study. The inclusion criteria’s were acute mallet finger fracture with a bony fragment of at least one third of the articulating surface and no subluxation. Patients were randomized to a 6 weeks of splinting or surgical EBP. Patients were followed up at 3 and 6 months. The primary outcome was degrees of extension lag. Secondary outcomes were range of motion and finger pulp-distal crease distance. At final follow up patients reported pain intensity on a Numeric Rating Scale (0-10), DASH score was filled in and complications were recorded.
Findings / Results: At 3 months follow up the extension lag was 10° (95% CI; 6-15) in the splinting group and 9° (95% CI; 4-15) in the surgical EBP group (p=0.84). Range of motion was 54° (95% CI; 48-59) in the splinting group and 35° (CI; 25-46) in the surgical EBP group (p<0.05). The finger pulp-distal crease distance were 0 centimeter (range 0-1) and 1.5 (range 0-5) in the splinting and surgical EBP group, respectively (p< 0.05). The complete six months results will be ready for presentation at the DOS conference 2015.
Conclusions: To our knowledge this is the first randomized controlled trial comparing splinting and surgical treatment with EBP in mallet finger fractures. Based on results from this study we recommend splinting in the treatment of mallet finger fractures without subluxation.

138. Migration and bone remodeling after uncemented TKA. A randomized RSA and DEXA study comparing monoblock and modular tibial component designs.
Mikkel Rathsach Andersen, Nikolaj Winther, Thomas Lind, Henrik Schrøder, Gunnar Flivik, Michael Mørk Petersen
Orthopaedic Department, Gentofte Hospital, University of Copenhagen, Denmark; Orthopaedic, Skåne University Hospital, Lund, Sweden

Background: Previous studies have shown very low migration rate of the uncemented Zimmer Nexgen Trabecular Metal Monoblock tibial component (A), but there are no data regarding the modular version (B) of the implant exists.
Purpose / Aim of Study: To investigate the effects of the 2 different uncemented tibia component designs on the migration of the implants and the changes in bone mineral density (BMD) of the proximal tibia.
Materials and Methods: 67 patients scheduled for an uncemented TKA (Zimmer NexGen Trabecular metal) were included in the study and block randomized to 2 groups of either monoblock (A) or modular (B) polyethylene design. We performed 2 year follow-up of 53 patients (mean age 62 (38-70) years, F/M=27/26, BMI 29.5) using radiostereometric analysis (RSA) and dual energy X-ray absorptiometry (DEXA). Statistics: Nonparametric tests (Wilcoxon signed rank-sum test and Mann–Whitney U-test).
Findings / Results: We found no significant difference in maximum total point migration (MTPM) between the groups at 3 months (p=0.16) or 6 months (p=0.10), but at 12 and 24 months of follow-up a difference in MTPM between groups of 0.36 mm (p=0.021) and 0.42 mm (p=0.017) was found with the highest total migration of 1.01 mm in group B. In group A We found a decrease in BMD of 15% and 13% in respectively the medial and lateral tibia condyle, whereas in group B BMD at 2 years was almost unchanged compared to the preoperative level. The differences in BMD change were statistically significant between the groups in both the medial (p=0.034) and lateral (p=0.016) ROI. In the distal ROI we found no significant change in BMD in either group.
Conclusions: We found a higher MTPM in group B, but a beneficial migration pattern was seen in both groups. A higher degree of bone loss was seen in group A.

139. Analgesic and sedative effects of perioperative gabapentin in total knee arthroplasty: A randomized, double-blind, placebo-controlled, dose-finding study
Troels Haxholdt Lunn, Henrik Husted, Mogens Berg Laursen, Lars Tambour Hansen, Henrik Kehlet
Department of Orthopedic Surgery and Department of Anesthesiology, Copenhagen University Hospital, Hvidovre and and The Lundbeck Centre for Fast-track Hip and Knee Art; Department of Orthopedic Surgery, Copenhagen University Hospital, Hvidovre and and The Lundbeck Centre for Fast-track Hip and Knee Art; Section of Surgical Pathophysiology, Copenhagen University Hospital, Rigshospitalet and The Lundbeck Centre for Fast-track Hip and Knee A

Background: The acute postoperative pain intensity is pronounced after TKA. Gabapentin has shown promising analgesic effects, but the optimal dose and procedure-specific benefits vs. harm have not been clarified.
Purpose / Aim of Study: We aimed to investigate the dose- related effect of gabapentin in patients undergoing TKA by conducting the largest, randomized, double-blind, placebo-controlled, dose-finding study.
Materials and Methods: The study was approved by relevant health authorities and followed GCP- standards. It was conducted at 3 high volume knee arthroplasty centers; Hvidovre, Farsø and Grindsted. 300 patients scheduled for unilateral TKA were randomized (1:1:1) to gabapentin 1300 mg/day (group A), gabapentin 900mg/day (group B) or placebo (group C) daily from 2 hours preoperatively to postoperative day 6. In addition, all patients received a standardized multimodal analgesic regime. The primary outcome was pain upon ambulation (walking 5 meters) 24 hours after surgery; the secondary outcome sedation 6 hours after surgery. Further, we evaluated pain, morphine use, side-effects and adverse reactions in detail during the entire study period.
Findings / Results: Pain upon ambulation [VAS, mean (95% CI)] 24 hours after surgery in group A vs. B vs. C was: 41 (37-46) vs. 41 (36-45) vs. 42 (37-47), p=0.93. Sedation [NRS, median (range)] 6 hours after surgery was: 3.2 (0-10) vs. 2.6 (0-9) vs. 2.3 (0-9), the mean difference A vs. C being 0.9 (0.2–1.7), p=0.046. Sleep quality was better during the first 2 nights in group A and B vs. C, but dizziness was more pronounced from day 2-6 in A vs. C. More severe adverse reactions were observed in group A vs. B and C. No other between-group differences were observed.
Conclusions: Gabapentin has limited if any role in acute postoperative pain management of TKA patients and should not be recommended as standard of care.