Session 13: DOS Best Papers

Torsdag d. 27. oktober
15:30 – 17:00
Lokale: Stockholm/Copenhagen/Helsinki/Oslo
Chairmen: Ole Rahbek / Jeannette Penny

86. Comparison of soft tissue and bone graft fixation for reconstruction of the medial patellofemoral ligament. A randomized controlled trial.
Martin Lind, Peter Faunø, Ole Gade Sørensen, Bjarne Mygind-Klavsen, Lene MIller, Thorsten Nielsen
Orthopedics, Århus University Hospital; Orthopedics, Århus University Hospital; Orthopedics, Århus University Hospital; Orthopedics, Århus University Hospital; Orthopedics, Århus University Hospital; Orthopedics, Århus University Hospital


Background: Medial patellofemoral ligament reconstruction (MPFL-R) has recently been accepted as the primary surgical treatment for patella instability. Limited knowledge exists concerning which reconstruction technique that gives the best clinical outcome and the least surgical morbidity.
Purpose / Aim of Study: The present study compares clinical outcome and surgical morbidity after MPFL- R with either bone (standard technique) or soft tissue femoral graft fixation in a randomized controlled study.
Materials and Methods: 60 patients were randomized to two MPFL- R techniques: Bone or soft tissue fixation of the graft at the femoral condyle. Patients were operated between 2010 and 2015. Indication for surgery was two or more patella dislocations. Surgical technique bone fixation: Gracilis tendon fixed in a bone tunnel with interference screw. Surgical technique soft tissue fixation. Gracilis tendon was looped around the adductor magnus tendon. Both techniques had patella graft fixation with drillholes in the medial patella edge. Clinical outcome were evaluated with Kujala, KOOS and NRS pain scores preoperatively and at 1-year follow-up. Surgical morbidity was evaluated by pain at palpation along the reconstruction.
Findings / Results: Kujala score was 83 and 84 for bone and soft tissue MPFL-R respectively with no difference between groups. No differences on KOOS and pain scores were found. Surgical morbidity analysis demonstrated that 13 and 12 % had significant palpable pain at the reconstruction for bone and soft tissue MPFL-R respectively. There were no patella redislocations in both groups.
Conclusions: MPFL-R with soft tissue femoral fixation results in similar subjective clinical outcome, patella stability and pain levels as bone fixation. Surgical morbidity was also similar between soft tissue and bone fixation MPFL-R.

87. Alarmingly high failure rate after Medial Patellofemoral Ligament reconstructions. A retrospective nationwide epidemiological study with a 10 year follow up on surgical intervention and 2.572 Medial Patellofemoral Ligament reconstruction surgeries
Kasper Skriver Gravesen, Anders Troelsen, Lars Blønd, Kristoffer Weisskirchner Barfod
Dept. of Orthopedic Surgery, Clinical Orthopedic Research Hvidovre (CORH), Copenhagen University Hospital Hvidovre; Dept. of Orthopedic Surgery, Clinical Orthopedic Research Hvidovre (CORH), Copenhagen University Hospital Hvidovre; Dept. of Orthopedic Surgery, Zealand University Hospital Køge and Aleris-Hamlet Parken; Dept. of Orthopedic Surgery, Clinical Orthopedic Research Hvidovre (CORH), Copenhagen University Hospital Hvidovre


Background: No reliable epidemiological data was found in both trends in patellar stabilizing surgery and in the risk of recurrent patellar dislocation.
Purpose / Aim of Study: To evaluate the trends in treatment of patellar dislocations in the Danish population as a whole from 1996 to 2014.
Materials and Methods: This descriptive epidemiological study was performed by retrospectively searching the Danish National Patients Registry from 1996 to 2014. The study investigated the trends in surgery performed on patients with patellar dislocations and the risk of recurrent dislocation with a 10 year follow up. National population data were collected at the services of Statistics Denmark. Risk estimates were calculated by cox proportional hazard models, all analysis was done in R 3.2.2.
Findings / Results: The 10-year overall risk of recurrent dislocation after a Medial Patellofemoral Ligament (MPFL) reconstruction was 21% when investigating 2.572 MPFL- reconstructions performed from 2005 until 2014. The conservatively treated patients had a 31% risk and patients treated with other patellar stabilizing surgery had 36%. From 1996 until 2013 the amount of patellar stabilizing surgery was stable but with a rise in MPFL-reconstruction surgeries from 2005. In 2013 MPFL-reconstruction surgery constituted 75% of all patella stabilizing surgery and was performed on almost 10% of patients with patellar dislocation.
Conclusions: A rapid rise in MPFL-reconstruction was found over time with little effect on risk of recurrent dislocation. The overall risk of recurrent dislocation after MPFL- reconstruction was 21% compared to 31% after conservative treatment and 36% after other stabilizing surgery. These findings could indicate that the underlying pathomorphology for the patella dislocation have to be examined and corrected concomitant to reconstructions of the MPFL.

88. Gait Function Before and After Total Knee Arthroplasty A Randomized Study of Fixed Bearing versus Mobile Bearing Articulation
Michael Tjørnild, Uwe Kersting, Kjeld Søballe, Poul Mogensen, Maiken Stilling
Ortopædkirurgisk Afdeling E, Aarhus Universitetshospital; Center for Sensory-Motor Interaction, Aalborg University; Ortopædkirurgisk afdeling E, Aarhus Universitetshospital; Neurologisk afdeling, Aalborg Universitetshospital; Ortopædkirurgisk afdeling, Regionshospitalet Holstebro, Hospitalsenheden Vest


Background: Total knee arthroplasty (TKA) is the standard treatment at the terminal stadium of knee arthritis. Good results are achieved based on assessment of pain relief, misalignment correction and improved function.
Purpose / Aim of Study: The purpose of this study was to compare two TKA articulation designs frequently used in the Nordic countries (P.F.C. Sigma fixed bearing (FB) and mobile bearing (MB) design) in an RCT investigating new aspects of gait function and restored function following TKA. The focus points were 1) to compare the FB to MB patients regarding level walking and surface electromyography (EMG) pre-operatively, at 6, and 12 months post-surgical follow-up; and 2) to compare the patients’ level walking to a healthy and BMI, gender and age-matched group. Finally we aimed at complementing the objective gait analysis with 3) patient reported outcome measurements.
Materials and Methods: In a prospective, randomized clinical trial we compared 51 osteoarthritis patients operated either with a FB or a MB TKA. Assessments were made using three-dimensional gait analysis, EMG and knee-scores prior to surgery, and at 6 and 12- months follow-up. A reference data set of body mass index, gender and age-matched controls was included in this study.
Findings / Results: Both intervention groups increased their walking speed at 12-months follow-up and decreased asymmetry in single support times. Regarding kinematics and kinetics both intervention groups reached the control group conficence interval. EMG results indicate less co-contraction after 12 months in both groups and knee scores improved with both articulation designs (p<0.01).
Conclusions: Both articulation designs demonstrated improved knee scores and favourable changes towards a more normal gait pattern, but neither of the two significantly outperformed the other.

89. Collagenase clostridium histolyticum (Xiapex®) versus percutaneous needle fasciotomy for Dupuytren’s contracture in proximal interphalangeal joints. An independent, open-label, randomized controlled trial
Simon Toftgaard Skov, Therkel Bisgaard, Per Søndergaard, Jeppe Lange
Center for planned surgery, Regional Hospital Silkeborg; Center for planned surgery, Regional Hospital Silkeborg; Center for planned surgery, Regional Hospital Silkeborg; Center for planned surgery, Regional Hospital Silkeborg


Background: Collagenase clostridium histolyticum injection (CI), a new minimal invasive procedure for Dupuytren’s contracture (DC), emerged in 2009-2011 with promising results. Head-to-head comparison with other active treatments has not been performed as of today. We hypothesized that CI would show better long-term results.
Purpose / Aim of Study: To compare percutaneous needle fasciotomy (PNF) to CI with Xiapex®.
Materials and Methods: The study was performed as a single- center, independent, open-label, Randomized Controlled Trial. 50 patients with isolated proximal interphalangeal (PIP) joint DC (≥20 degrees) were enrolled. Patients received either CI according to the manufacturer guideline or our center standardized PNF treatment. Patients were followed for 2 years. Primary outcome was clinical improvement, defined as a reduction in contracture by 50% or more relative to baseline. Several secondary outcomes were evaluated, including change in PIP-joint passive extension deficit (PED), patient satisfaction and Disability of Arm, Shoulder and Hand questionnaire score.
Findings / Results: Clinical improvement was achieved in 8% in the CI-group and 32% in the PNF-group at 2 year follow-up (p=0.05). Secondary clinical outcome parameters and DASH-scores did not differ significantly. Patient satisfaction at 2 years was poorer in the CI group with a median numerical rating scale score (0 worst, 10 best) of 1 vs. 7 in the PNF group (p=0.04). A higher complication rate was found in the CI group.
Conclusions: We conclude that CI offers no advantages over PNF in isolated PIP-joint DC. This is the first head-to-head comparison and the first independent RCT of CI to another active treatment procedure. Confirmation from other independent studies are needed.

90. Achilles Tendon Length, ATRS and Functional Outcomes 5 Years After Acute Achilles Tendon Rupture Treated Conservatively
Rasmus Kastoft, Jesper Bencke, Kristoffer Barfod, Merete Speedtsberg, Rasmus M. Søndergaard, Jeannette Ø. Penny
Dep of Orthopedic Surgery, Copenhagen University Hospital -Hvidovre; Laboratory of Human Movement Analysis, Dep of Orthopaedic Surgery, Copenhagen University Hospital -Hvidovre; Dep of Orthopedic Surgery, Epworth HealthCare, Melbourne - Australia; Laboratory of Human Movement Analysis, Dep of Orthopaedic Surgery, Copenhagen University Hospital -Hvidovre; Laboratory of Human Movement Analysis, Dep of Orthopaedic Surgery, Copenhagen University Hospital -Hvidovre; Dep of Orthopedic Surgery, Copenhagen University Hospital -Hvidovre


Background: Achilles tendon rupture (ATR) may lead to significant functional deficits, which mechanisms are poorly understood.
Purpose / Aim of Study: Primary aim was to investigate if the Achilles tendon (AT) was longer, muscles weaker in the injured leg 4- 5 years post injury. Secondary, to measure foot pressure and to compare functional outcomes with patient reported Achilles Tendon Total Rupture Score (ATRS).
Materials and Methods: We invited all participants from a RCT, of conservatively treated ATR with or without early weight bearing (E-WB, N-WB). Of the original 56, 37 patients participated - 19 from E-WB (1 re- rupture (RR)), and 18 from N-WB (2 RR). Time from injury to follow up was 4.5 years (4.1 to 5.1). AT length was measured using ultrasound. Heel raise work was measured on a 10 degree inclining platform, and the method validated. Foot pressure mapping was measured barefoot, using an EMED platform (novel, DE). T-tests for limb comparisons and linear regression for ATRS correlations were applied.
Findings / Results: We found no differences in any of the variables between the E-WB and N-WB groups. Including RR in the sample did not impact the results. Compared to the healthy limb, the AT was an average of 1,8 (1,2-2,3) cm longer on the injured limb, which produced 40% less work. A smaller calf circumference (p<0,001), larger dorsiflextion (p=0,001), AT resting angle (p<0.001) and delayed heel lift off (p=0,02) was found on the injured limb. Lower mean medial forefoot peak pressure in the injured limb was approaching significance (p=0,08). ATRS could not be linked to AT length or total work using linear regression.
Conclusions: Conservatively treated ATR were approximately 1,8 cm longer than control limb. The injured limb was persistently weaker, and had delayed heel lift. ATRS does not appear to correlate directly with AT length or loss of total work.

91. Risk of revision and reasons for revision after shoulder replacement for acute fracture of the proximal humerus: a Nordic registry-based study of 6,756 cases
Stig Brorson, Björn Salomonsson, Steen Lund Jensen, Anne Marie Fenstad, Yilmaz Demir, Jeppe Vejlgaard Rasmussen
Department of Orthopaedic Surgery, Herlev University Hospital; Karolinska Institutet, Danderyds Sjukhus AB, Stockholm, Sweden; Department of Orthopaedic surgery, Aalborg University Hospital; Department of Orthopaedic surgery, Haukeland University Hospital, Bergen, Norway; Karolinska Institutet, Danderyds Sjukhus AB, Stockholm, Sweden; Department of Orthopaedic Surgery, Herlev University Hospital


Background: Stemmed shoulder hemiarthroplasty is a treatment option in comminuted and displaced fractures of the proximal humerus. Within the last decade reverse prostheses have been increasingly popular when fixation of the tuberosities is considered impossible. There is a lack of reporting of risk of revision and reasons for revision for hemiarthroplasty and particularly for reverse shoulder arthroplasty.
Purpose / Aim of Study: Our primary aim was to report revision rates and reasons for revision after shoulder replacement in acute fractures. Our secondary aim was to compare risk of revision, reasons for revision and risk of infection between hemiarthroplasty and reverse prostheses.
Materials and Methods: This study is based on a common data set established through collaboration between the shoulder arthroplasty registries in Denmark, Sweden, and Norway. It contains 6,756 shoulder replacements in acute fractures inserted between 2004 and 2013.
Findings / Results: Hemiarthroplasty was used in 90.4% of acute fractures compared to 8.4% reverse prostheses. A total of 3.3% prostheses were revised. Relative risk for revision of reverse shoulder arthroplasty compared to hemiarthroplasty was 1.07 (p=0.24). In both designs the most common reason for revision was infection. Relative risk for revision due to infection was 3.0 (p=0.001) in reverse shoulder arthroplasty compared to hemiarthroplasty. The relative risk of revision was 2.8 in patients younger than 75 years (p=0.001).
Conclusions: Reoperations after shoulder replacement in acute fractures are rare, but the number of clinical failures might be underestimated if measured by reoperations only. We found no significant difference in revision rate between hemiarthroplasty and reverse arthroplasty. Early infection was more common after reverse arthroplasty.

92. Early Mobilization after Volar Plate Osteosynthesis of Distal Radius Fractures - a Prospective Randomized Study.
Thomas Juul Sørensen, Kecia Ardensø, Gunnar H. Laier, Susanne Kristensen Mallet
Department of Orthopedic Surgery, Zealand University Hospital; Department of Occupational- and Physiotherapy, Zealand University Hospital; Production, Research and Innovation, Region Zealand; Department of Orthopedic Surgery, Zealand University Hospital


Background: Distal radius fracture is one of the most common fractures in people over 50. Volar locked plating has become the primary choice of treatment. Little is known about the postoperative regime and the influence on outcome and morbidity.
Purpose / Aim of Study: To investigate if early mobilization improved patient reported outcome and did not increase the risk of fracture displacement.
Materials and Methods: The study was performed as a prospective, randomized trial. 100 patients with distal radius fracture treated with volar locked plating were randomized 1:1 to either removable wrist lacer with mobilization from day one or cast for 14 days before mobilization. The primary outcome measure was the DASH-score after 1, 3, 6 and 12 months. The score range from 0 to 100 with 0 being the best possible score. Secondary outcome measure was fracture displacement at x-rays after 14 days. Statistical analysis was done using a repeated measurement ANOVA model of the square root transformed DASH scores. Overall difference between groups was assessed using a maximum likelihood ratio test.
Findings / Results: 83 patients were eligible for analysis after 12 months. The estimated median DASH score in the early mobilization group ⦋n = 41⦌ after 12 months was 7.46, 95% CI ⦋4.74, 10.78⦌ compared to 8.37 ⦋5.28, 12.17⦌ in the late mobilization group ⦋n = 42⦌, p = 0.69. One fracture dislocation occurred after 14 days in the early mobilization group, but can be explained by a wrong use of the volar locking plate.
Conclusions: The study did not find any statistical significant difference between groups though DASH scores at all follow ups were lower in the early mobilization group. Early mobilization with removable wrist lacer is a safe and equal postoperative treatment compared to regular casting.