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Bone & Joint Open
Vol. 5, Issue 1 | Pages 37 - 45
19 Jan 2024
Alm CE Karlsten A Madsen JE Nordsletten L Brattgjerd JE Pripp AH Frihagen F Röhrl SM

Aims

Despite limited clinical scientific backing, an additional trochanteric stabilizing plate (TSP) has been advocated when treating unstable trochanteric fractures with a sliding hip screw (SHS). We aimed to explore whether the TSP would result in less post operative fracture motion, compared to SHS alone.

Methods

Overall, 31 patients with AO/OTA 31-A2 trochanteric fractures were randomized to either a SHS alone or a SHS with an additional TSP. To compare postoperative fracture motion, radiostereometric analysis (RSA) was performed before and after weightbearing, and then at four, eight, 12, 26, and 52 weeks. With the “after weightbearing” images as baseline, we calculated translations and rotations, including shortening and medialization of the femoral shaft.


The Bone & Joint Journal
Vol. 104-B, Issue 10 | Pages 1132 - 1141
1 Oct 2022
Holm-Glad T Røkkum M Röhrl SM Roness S Godang K Reigstad O

Aims

To analyze the short-term outcome of two types of total wrist arthroplasty (TWA) in terms of wrist function, migration, and periprosthetic bone behaviour.

Methods

A total of 40 patients suffering from non-rheumatoid wrist arthritis were enrolled in a randomized controlled trial comparing the ReMotion and Motec TWAs. Patient-rated and functional outcomes, radiological changes, blood metal ion levels, migration measured by model-based radiostereometric analysis (RSA), bone mineral density (BMD) measured by dual-energy X-ray absorptiometry (DXA), complications, loosening, and revision rates at two years were compared.


Bone & Joint Open
Vol. 2, Issue 9 | Pages 737 - 744
1 Sep 2021
Øhrn F Lian ØB Tsukanaka M Röhrl SM

Aims

Medial pivot (MP) total knee arthroplasties (TKAs) were designed to mimic native knee kinematics with their deep medial congruent fitting of the tibia to the femur almost like a ball-on-socket, and a flat lateral part. GMK Sphere is a novel MP implant. Our primary aim was to study the migration pattern of the tibial tray of this TKA.

Methods

A total of 31 patients were recruited to this single-group radiostereometric analysis (RSA) study and received a medial pivot GMK Sphere TKA. The distributions of male patients versus female patients and right versus left knees were 21:10 and 17:14, respectively. Mean BMI was 29 kg/m2 (95% confidence interval (CI) 27 to 30) and mean age at surgery was 63 years (95% CI 61 to 66). Maximum total point motions (MTPMs), medial, proximal, and anterior translations and transversal, internal, and varus rotations were calculated at three, 12, and 24 months. Patient-reported outcome measure data were also retrieved.


Aims

Vitamin E-infused highly crosslinked polyethylene (VEPE) has been introduced into total hip arthroplasty (THA) with the aim of further improving the wear characteristics of moderately and highly crosslinked polyethylenes (ModXLPE and HXLPE). There are few studies analyzing the outcomes of vitamin E-infused components in cemented arthroplasty, though early acetabular component migration has been reported. The aim of this study was to measure five-year polyethylene wear and acetabular component stability of a cemented VEPE acetabular component compared with a ModXLPE cemented acetabular component.

Methods

In a prospective randomized controlled trial (RCT), we assessed polyethylene wear and acetabular component stability (primary outcome) with radiostereometric analysis (RSA) in 68 patients with reverse hybrid THA at five years follow-up. Patients were randomized to either a VEPE or a ModXLPE cemented acetabular component.


The Bone & Joint Journal
Vol. 97-B, Issue 6 | Pages 755 - 761
1 Jun 2015
Flatøy B Röhrl SM Rydinge J Dahl J Diep LM Nordsletten L

Cemented femoral stems with force closed fixation designs have shown good clinical results despite high early subsidence. A new triple-tapered stem in this category (C-stem AMT) was introduced in 2005. This study compares this new stem with an established stem of similar design (Exeter) in terms of migration (as measured using radiostereometric analysis), peri-prosthetic bone remodelling (measured using dual energy x-ray densitometry, DXA), Oxford Hip Score, and plain radiographs.

A total of 70 patients (70 hips) with a mean age of 66 years (53 to 78) were followed for two years. Owing to missing data of miscellaneous reasons, the final analysis represents data from 51 (RSA) and 65 (DXA) patients. Both stems showed a typical pattern of migration: Subsidence and retroversion that primarily occurred during the first three months. C-stem AMT subsided less during the first three months (p = 0.01), before stabilising at a subsidence rate similar to the Exeter stem from years one to two. The rate of migration into retroversion was slightly higher for C-stem AMT during the second year (p = 0.03). Whilst there were slight differences in movement patterns between the stems, the C-stem AMT exhibits good early clinical outcomes and displays a pattern of migration and bone remodelling that predicts good clinical performance.

Cite this article: Bone Joint J 2015;97-B:755–61.


Orthopaedic Proceedings
Vol. 92-B, Issue SUPP_III | Pages 392 - 392
1 Jul 2010
Dahl J Nivbrant B Søderlund P Nordsletten L Röhrl SM
Full Access

Introduction: Increased wear is associated with aseptic loosening and late dislocations. Hard on hard bearings may reduce wear but still have topics of concern such as free metal ions in metal on metal bearings and the risk for fracture in ceramic articulations. Ceramic heads against conventional polyethylene is also used with the intention to reduce wear. But this effect has not been conclusively documented in the literature and is still discussed. 87 patients were operated consecutively by the same surgeon with the same surgical technique. All patients received a cemented all poly cup sterilized with irradiation in inert atmosphere and a cemented stem. Head size was 28 mm in all patients. 40 patients received cobalt-chrome heads and 47 patients aluminiumoxid heads. The patients were followed with RSA for 10 years and analysed for wear.

Results: Mean (SEM) wear for the group with cobalt chrome heads was 0.93 mm (0.13) and for the group with aluminiumoxide was 0.43 mm (0.08) (p = 0.001).

Discussion: We found significantly less wear with aluminumoxide heads compared to cobalt-chrome heads. The wear results in the cobalt-chrome group correlate well to wear values in the literature for conventional polyethylene. Although the polyethylene in this study is partly cross-linked (3Mrad) it is not clear whether these results can be extrapolated directly to the use of highly cross-linked PE. If longer follow-ups confirm the mechanical stability of highly cross-linked PE, ceramic heads might contribute additionally to the reduction of wear.

In conclusion we found significantly reduced wear for aluminumoxide heads compared to cobalt chrome heads which could be beneficial for young and active patients.