Vasiliki C Panagiotopoulou1,2, Stewart K Tucker3, Robert K Whittaker4, Harry S Hothi4, Johann Henckel4,5, Julian J H Leong4,5, Thomas Ember3,6, John A Skinner4,5, Alister J Hart4,5. 1. Institute of Orthopaedics and Musculoskeletal Science, Royal National Orthopaedic Hospital, University College London, Brockley Hill, Stanmore, Middlesex, HA7 4LP, UK. v.panagiotopoulou@ucl.ac.uk. 2. The Royal National Orthopaedic Hospital, Stanmore, UK. v.panagiotopoulou@ucl.ac.uk. 3. Great Ormond Street Hospital for Children, London, UK. 4. Institute of Orthopaedics and Musculoskeletal Science, Royal National Orthopaedic Hospital, University College London, Brockley Hill, Stanmore, Middlesex, HA7 4LP, UK. 5. The Royal National Orthopaedic Hospital, Stanmore, UK. 6. Guy's and St Thomas NHS Foundation Trust, London, UK.
Abstract
PURPOSE: We aim to describe a mechanism of failure in magnetically controlled growth rods which are used for the correction of the early onset scoliosis. METHODS: This retrieval study involved nine magnetically controlled growth rods, of a single design, revised from five patients for metal staining, progression of scoliosis, swelling, fractured actuator pin, and final fusion. All the retrieved rods were radiographed and assessed macroscopically and microscopically for material loss. Two implants were further analysed using micro-CT scanning and then sectioned to allow examination of the internal mechanism. No funding was obtained to analyse these implants. There were no potential conflicts interests. RESULTS: Plain radiographs revealed that three out of nine retrieved rods had a fractured pin. All had evidence of surface degradation on the extendable telescopic rod. There was considerable corrosion along the internal mechanism. CONCLUSIONS: We found that a third of the retrieved magnetically controlled growth rods had failed due to pin fracture secondary to corrosion of the internal mechanism. We recommend that surgeons consider that any inability of magnetically controlled growth rods to distract may be due to corrosive debris building up inside the mechanism, thereby preventing normal function.
PURPOSE: We aim to describe a mechanism of failure in magnetically controlled growth rods which are used for the correction of the early onset scoliosis. METHODS: This retrieval study involved nine magnetically controlled growth rods, of a single design, revised from five patients for metal staining, progression of scoliosis, swelling, fractured actuator pin, and final fusion. All the retrieved rods were radiographed and assessed macroscopically and microscopically for material loss. Two implants were further analysed using micro-CT scanning and then sectioned to allow examination of the internal mechanism. No funding was obtained to analyse these implants. There were no potential conflicts interests. RESULTS: Plain radiographs revealed that three out of nine retrieved rods had a fracturedpin. All had evidence of surface degradation on the extendable telescopic rod. There was considerable corrosion along the internal mechanism. CONCLUSIONS: We found that a third of the retrieved magnetically controlled growth rods had failed due to pinfracture secondary to corrosion of the internal mechanism. We recommend that surgeons consider that any inability of magnetically controlled growth rods to distract may be due to corrosive debris building up inside the mechanism, thereby preventing normal function.
Authors: Oliver M Stokes; Elizabeth J O'Donovan; Dino Samartzis; Cora H Bow; Keith D K Luk; Kenneth M C Cheung Journal: Spine J Date: 2014-01-31 Impact factor: 4.166
Authors: Shay Bess; Behrooz A Akbarnia; George H Thompson; Paul D Sponseller; Suken A Shah; Hazem El Sebaie; Oheneba Boachie-Adjei; Lawrence I Karlin; Sarah Canale; Connie Poe-Kochert; David L Skaggs Journal: J Bone Joint Surg Am Date: 2010-10-01 Impact factor: 5.284
Authors: C J Goldberg; I Gillic; O Connaughton; D P Moore; E E Fogarty; G J Canny; F E Dowling Journal: Spine (Phila Pa 1976) Date: 2003-10-15 Impact factor: 3.468
Authors: Kar Hao Teoh; Daniel M G Winson; Stuart H James; Alwyn Jones; John Howes; Paul R Davies; Sashin Ahuja Journal: Spine J Date: 2016-02-01 Impact factor: 4.166
Authors: Martina Tognini; Harry Hothi; Elisabetta Dal Gal; Masood Shafafy; Colin Nnadi; Stewart Tucker; Johann Henckel; Alister Hart Journal: Eur Spine J Date: 2021-03-05 Impact factor: 3.134
Authors: K A Lüders; L Braunschweig; A Zioła-Frankowska; A Stojek; D Jakkielska; A Wichmann; G H Dihazi; F Streit; S E Güsewell; T C Trüe; S Lüders; J Schlie; K Tsaknakis; H M Lorenz; M Frankowski; A K Hell Journal: Sci Rep Date: 2022-06-25 Impact factor: 4.996
Authors: V C Panagiotopoulou; K Davda; H S Hothi; J Henckel; A Cerquiglini; W D Goodier; J Skinner; A Hart; P R Calder Journal: Bone Joint Res Date: 2018-08-04 Impact factor: 5.853
Authors: Alastair Beaven; Adrian C Gardner; David S Marks; Jwalant S Mehta; Matthew Newton-Ede; Jonathan B Spilsbury Journal: Asian Spine J Date: 2018-09-10
Authors: Jack Z Wei; Harry S Hothi; Holly Morganti; Sean Bergiers; Elisabetta Dal Gal; Doris Likcani; Johann Henckel; Alister J Hart Journal: BMC Musculoskelet Disord Date: 2020-08-05 Impact factor: 2.362