ABSTRACT
OBJECTIVE: To investigate the effect of hemicerclage suture on the occurrence of fractures during advancement of an elongated bi-directional hinged osteotomy (EBHO) for tibial tuberosity advancement (TTA) in dogs. STUDY DESIGN: Experimental ex vivo study. ANIMALS: Canine cadavers (n = 14) METHODS: A uniform EBHO was performed in 28 cadaveric hind limbs (n = 28) from 14 skeletally mature, medium-sized, mixed breed dogs. Paired limbs were randomly assigned with or without hemicerclage suture. The osteotomy was slowly spread (TTA) at a rate 1.5 mm every 15 seconds to a maximum distance of 24 mm or until a fracture was detected as an audible crack, visible propagation of the distal osteotomy or transverse fracture of the cortical bridge. The occurrence of fractures was compared between limbs with hemicerclage and without hemicerclage (control) suture using a chi-square analysis. The advancement distance at the time of fracture was compared using a paired t test. A P value <.05 was considered significant. RESULTS: The cumulative occurrence of intraoperative fracture was significantly greater without hemicerclage than with hemicerclage at advancements of 12, 15, 18, and 24 mm. The mean (SD) spreading distance at the time of fracture was significantly less without hemicerclage at 16.85 (4.10) mm with a range of 12-24 mm, than with hemicerclage at 20.62 (2.39) mm with a range of 18-24 mm (P = .029). CONCLUSION: The occurrence of immediate intraoperative fracture during advancement of an EBHO of the tibial tuberosity is less when a hemicerclage suture is placed.
Subject(s)
Dogs/surgery , Fractures, Bone/veterinary , Hindlimb/surgery , Osteotomy/veterinary , Polydioxanone , Sutures/veterinary , Animals , Cadaver , Fractures, Bone/etiology , Osteotomy/methods , Sutures/adverse effectsABSTRACT
INTRODUCTION: Scyon Orthopaedics AG developed a new mode of cementless fixation of the femoral component that provides immediate and permanent anchorage by monocortical locking screws. The aim of this study was to evaluate the stability of the Scyon total hip replacement (THR) stem in-vivo. METHODS: A total of 15 patients, with an average age of 50 years had surgery between 2008 and 2011. Each patient received a Scyon THR. Standard questionnaires were completed at each follow-up visit for evaluation of functional outcomes. RSA, patient reported outcomes, and plain radiographic follow-up were obtained at 6 months, 1 year, 2 years, and 5 years postoperatively. RESULTS: The median ± standard error (SE) stem subsidence (negative y-translation) was 0.07 ± 0.07 mm at 1 year, 0.05 ± 0.04 mm at 2 years and 0.04 ± 0.13 mm at 5 years. The median ± SE stem rotation (y-rotation) was 0.1 ± 0.21 degrees at 1 year, 0.51 ± 0.31 degrees at 2 years and 0.60 ± 0.37 degrees at 5 years. Plain radiographs showed bone on-growth onto medial aspect of the stem. Median HHS improved from 55 preoperatively to 93 at 1 year and 97 at 5 years. The median UCLA Activity Score improved from 4 preoperatively to 6 at 1 year and 5 years. CONCLUSIONS: RSA results indicate that the Scyon stem with its 5 monocortical locking screws is stable at 5 years. Immediate surgical fixation of the stem and bony on-growth onto the femoral component may ultimately decrease the rate of aseptic stem loosening in these THR patients.
Subject(s)
Arthroplasty, Replacement, Hip/methods , Hip Prosthesis , Prosthesis Design/methods , Radiostereometric Analysis/methods , Range of Motion, Articular/physiology , Adult , Arthroplasty, Replacement, Hip/adverse effects , Bone Cements , Bone Screws , Female , Follow-Up Studies , Humans , Male , Middle Aged , Osteoarthritis, Hip/diagnostic imaging , Osteoarthritis, Hip/surgery , Prosthesis Failure , Retrospective Studies , Risk Assessment , Suture Anchors , Time Factors , Treatment OutcomeABSTRACT
In 1997, the proximal femoral nail was introduced for treatment of peritrochanteric femoral fractures. Treatment results show a low complication rate. The most serious complication is cutout of the hip pin and femoral neck screw. Considerable load on the hip pin is thought to facilitate cutout. The biomechanical behavior of the hip pin and the femoral neck screw as part of the standard proximal femoral nail, and of an experimentally modified proximal femoral nail (in which the hole through the nail for the hip pin is modified to a slot) was studied. In the standard proximal femoral nail, the amount of the total load carried by the hip pin varies between 8% and 39% (mean, 21%). If the hip pin passes through a slot in the nail, it carries 2% to 8% (mean, 5%) of the load. The nonconstrained lateral end of the hip pin reduces the bending load applied to the implant. The slotted hole for the hip pin also allows the femur and the nail to medialize, even if the hip pin and femoral neck screw lose parallelism. The prevalence of cutout of the proximal femoral nail may be reduced by introduction of this mechanism.
