Michael Hackl1, Nicolai Heinze2, Kilian Wegmann3, Sebastian Lappen3, Tim Leschinger3, Klaus Josef Burkhart4, Martin Scaal5, Lars Peter Müller3. 1. Institute of Anatomy I, University of Cologne, Cologne, Germany; Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany; Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany. Electronic address: michael.hackl@uk-koeln.de. 2. Institute for Medical Engineering, University of Magdeburg, Magdeburg, Germany. 3. Center for Orthopedic and Trauma Surgery, University Medical Center, Cologne, Germany; Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany. 4. Clinic for Shoulder Surgery, Bad Neustadt a.d.Saale, Germany. 5. Cologne Center for Musculoskeletal Biomechanics, Medical Faculty, University of Cologne, Cologne, Germany; Institute of Anatomy II, University of Cologne, Cologne, Germany.
Abstract
BACKGROUND: Ligament reconstruction with a circumferential graft represents an innovative technique for treatment of multidirectional elbow instability. This biomechanical study compared the stability of the intact elbow joint with the circumferential graft technique and the conventional technique. METHODS: Seven fresh frozen cadaveric elbows were evaluated for stability against valgus and varus/posterolateral rotatory forces (3 Nm) over the full range of motion. Primary stability was determined for intact specimens, after sectioning of the collateral ligaments, after applying the circumferential graft technique (box-loop), and after conventional collateral ligament reconstruction. Cyclic loading (1000 cycles) was performed to assess joint stability and stiffness of the native ligaments and the tendon grafts. RESULTS: Primary stability of both reconstruction techniques was equal to the native specimens (P = .17-.91). Sectioning of the collateral ligaments significantly increased joint instability (P < .001). The reconstruction techniques provided equal stability after 1000 cycles (P = .78). Both were inferior to the intact specimens (P = .02). Cyclic loading caused a significantly lower increase in stiffness of the native ligaments compared with the tendon grafts of either reconstruction technique (P = .001-.008). Significantly better graft stiffness was retained with the circumferential graft technique compared with conventional reconstruction (P = .04). CONCLUSION: Neither reconstruction technique fully reproduces the biomechanical profile of the native collateral ligaments. The circumferential graft technique seems to resist cyclic loading slightly better than the conventional reconstruction technique, yet both reconstruction techniques provide comparable stability.
BACKGROUND: Ligament reconstruction with a circumferential graft represents an innovative technique for treatment of multidirectional elbow instability. This biomechanical study compared the stability of the intact elbow joint with the circumferential graft technique and the conventional technique. METHODS: Seven fresh frozen cadaveric elbows were evaluated for stability against valgus and varus/posterolateral rotatory forces (3 Nm) over the full range of motion. Primary stability was determined for intact specimens, after sectioning of the collateral ligaments, after applying the circumferential graft technique (box-loop), and after conventional collateral ligament reconstruction. Cyclic loading (1000 cycles) was performed to assess joint stability and stiffness of the native ligaments and the tendon grafts. RESULTS: Primary stability of both reconstruction techniques was equal to the native specimens (P = .17-.91). Sectioning of the collateral ligaments significantly increased joint instability (P < .001). The reconstruction techniques provided equal stability after 1000 cycles (P = .78). Both were inferior to the intact specimens (P = .02). Cyclic loading caused a significantly lower increase in stiffness of the native ligaments compared with the tendon grafts of either reconstruction technique (P = .001-.008). Significantly better graft stiffness was retained with the circumferential graft technique compared with conventional reconstruction (P = .04). CONCLUSION: Neither reconstruction technique fully reproduces the biomechanical profile of the native collateral ligaments. The circumferential graft technique seems to resist cyclic loading slightly better than the conventional reconstruction technique, yet both reconstruction techniques provide comparable stability.
Authors: Michael Hackl; Kilian Wegmann; Christian Ries; Sebastian Lappen; Martin Scaal; Lars Peter Müller Journal: Surg Radiol Anat Date: 2016-11-07 Impact factor: 1.246