BACKGROUND: A novel imageless measurement algorithm to assess leg length (LL) and offset (OS) changes during total hip arthroplasty (THA) has been established, the purpose of this study was to describe the process and establish whether or not it is accurate. METHODS: THA was performed on 17 cadaver hip specimens. LL and OS changes were determined intra-operatively, using an imageless navigation system. Pre- and postoperatively, all specimens had a computed tomography scan (CT) and the LL and OS changes were analysed by two blinded investigators. RESULTS: With mean differences of less than 1 mm (LL, 0.74; SD, 2.4 mm; OS, 0.89; SD, 1.8 mm) supported by substantial significant correlations [r = 0.83 (LL) and r = 0.92 (OS)] imageless navigation values demonstrated a high accuracy when compared to CT measurements. CONCLUSIONS: Intra-operative LL and OS measures are reliable and accurate when using an imageless calculation algorithm which stores the position of the femoral reference frame in relation to the pelvic coordinate system before and after reconstruction.
BACKGROUND: A novel imageless measurement algorithm to assess leg length (LL) and offset (OS) changes during total hip arthroplasty (THA) has been established, the purpose of this study was to describe the process and establish whether or not it is accurate. METHODS: THA was performed on 17 cadaver hip specimens. LL and OS changes were determined intra-operatively, using an imageless navigation system. Pre- and postoperatively, all specimens had a computed tomography scan (CT) and the LL and OS changes were analysed by two blinded investigators. RESULTS: With mean differences of less than 1 mm (LL, 0.74; SD, 2.4 mm; OS, 0.89; SD, 1.8 mm) supported by substantial significant correlations [r = 0.83 (LL) and r = 0.92 (OS)] imageless navigation values demonstrated a high accuracy when compared to CT measurements. CONCLUSIONS: Intra-operative LL and OS measures are reliable and accurate when using an imageless calculation algorithm which stores the position of the femoral reference frame in relation to the pelvic coordinate system before and after reconstruction.
Authors: Tobias Renkawitz; Tibor Schuster; Joachim Grifka; Thomas Kalteis; Ernst Sendtner Journal: Clin Orthop Relat Res Date: 2009-09-19 Impact factor: 4.176
Authors: Alfonso Manzotti; Pietro Cerveri; Elena De Momi; Chris Pullen; Norberto Confalonieri Journal: Int Orthop Date: 2009-11-11 Impact factor: 3.075
Authors: Tobias Renkawitz; Martin Haimerl; Lars Dohmen; Sabine Gneiting; Melanie Wegner; Nicole Ehret; Claudia Buchele; Mario Schubert; Philipp Lechler; Michael Woerner; Ernst Sendtner; Tibor Schuster; Kurt Ulm; Robert Springorum; Joachim Grifka Journal: BMC Musculoskelet Disord Date: 2011-08-19 Impact factor: 2.362