BACKGROUNDFor partial-thickness tears of the rotator cuff, double-row fixation and transtendon single-row fixation restore insertion site anatomy, with excellent results. We compared the biomechanical properties of double-row and transtendon single-row suture anchor techniques for repair of grade III partial articular-sided rotator cuff tears.

METHODSIn 10 matched pairs of fresh-frozen sheep shoulders, the infraspinatus tendon from 1 shoulder was repaired with a double-row suture anchor technique. This comprised placement of 2 medial anchors with horizontal mattress sutures at an angle of ≤ 45° into the medial margin of the infraspinatus footprint, just lateral to the articular surface, and 2 lateral anchors with horizontal mattress sutures. Standardized, 50% partial, articular-sided infraspinatus lesions were created in the contralateral shoulder. The infraspinatus tendon from the contralateral shoulder was repaired using two anchors with transtendon single-row mattress sutures. Each specimen underwent cyclic loading from 10 to 100 N for 50 cycles, followed by tensile testing to failure. Gap formation and strain over the footprint area were measured using a motion capture system; stiffness and failure load were determined from testing data.

RESULTSGap formation for the transtendon single-row repair was significantly smaller (P < 0.05) when compared with the double-row repair for the first cycle ((1.74 ± 0.38) mm vs. (2.86 ± 0.46) mm, respectively) and the last cycle ((3.77 ± 0.45) mm vs. (5.89 ± 0.61) mm, respectively). The strain over the footprint area for the transtendon single-row repair was significantly smaller (P < 0.05) when compared with the double-row repair. Also, it had a higher mean ultimate tensile load and stiffness.

CONCLUSIONSFor grade III partial articular-sided rotator cuff tears, transtendon single-row fixation exhibited superior biomechanical properties when compared with double-row fixation.

Fracture Fixation, Internal ; Fractures, Bone ; surgery ; Humans ; Minimally Invasive Surgical Procedures ; methods ; Orthopedic Procedures ; methods

The innovative research on the platform of the guided-navigating surgery of bone and joints consists of four basic function modules and three technical-related systems. Through this research the functional modules will be constructed by orthopedic specialists and software experts who have made jointly efforts based on the transitional medicine to develop a new software for guided-navigating surgery of bone and joints suitable for people in Asia and for its application in medical treatment.
Equipment Design ; Humans ; Orthopedic Procedures ; instrumentation ; methods ; Software ; Surgery, Computer-Assisted ; instrumentation ; methods

Orthopaedic implant technology is heavily based on the development and use of biomaterials. These are non-living materials (e.g. metals, polymers and ceramics) that are introduced into the human body as constituents of implants that fulfill or replace some important function. Examples would be prosthetic joint replacements and fracture fixation implants. For orthopaedic biomaterials to succeed in their desired functions and outcomes in the body, a number of factors need to be considered. The most obvious mechanical properties of the implants are that they need to suit their intended function, and various classes and types of biomaterials have been developed and characterised for use in different implant components depending on their demands. Less well understood but no less important are the interactions that occur between the constituent biomaterials and the living cells and tissues, both of the human host as well as pathogens such as bacteria. Biomaterials used for orthopaedic applications are generally considered to be biocompatible. However, adverse effects arising from interactions at the implant interface can result in various modes of implant failure, such as aseptic loosening and implant infection. This review paper uses the illustrative example of total hip replacement (which has been called the operation of the century) to highlight key points in the evolution of orthopaedic biomaterials. It will also examine research strategies that seek to address some of the major problems that orthopaedic implant surgery are facing today.
Absorbable Implants ; Arthroplasty, Replacement, Hip ; instrumentation ; methods ; Biocompatible Materials ; Humans ; Orthopedic Procedures ; instrumentation ; methods ; trends ; Osteoblasts

In the past decades,a dramatic development of navigation technology in orthopaedic surgery has been witnessed. By assisting the localization of surgical region,verification of target bony structure,preoperative planning of fixation,intraoperative identification of planned entry point and direction of instruments or even automated insertion of implants,its ability and potential to reduce operation time,intraoperative radiation,surgical trauma,and improve accuracy has been proved. However,in contrast to the widespread use of navigation technology in arthroplasty,orthopaedic tumor,and spine surgery,its application in orthopaedic trauma is relatively less. In this manuscript,the main purpose is to introduce the technical principles of navigation devices,outline the current clinical application of navigation systems in orthopaedic trauma,analyze the current challenges confronting its further application in clinical practice and its prospect in the future.
Humans ; Orthopedics ; Surgery, Computer-Assisted/methods* ; Orthopedic Procedures/methods* ; Operative Time

BACKGROUND: Several different surgical techniques have been described to address the coracoclavicular (CC) ligaments in acromioclavicular (AC) joint injuries. However, very few techniques focus on reconstructing the AC ligaments, despite its importance in providing stability. The purpose of our study was to compare the biomechanical properties of two free-tissue graft techniques that reconstruct both the AC and CC ligaments in cadaveric shoulders, one with an extramedullary AC reconstruction and the other with an intramedullary AC reconstruction. We hypothesized intramedullary AC reconstruction will provide greater anteroposterior translational stability and improved load to failure characteristics than an extramedullary technique. METHODS: Six matched cadaveric shoulders underwent translational testing at 10 N and 15 N in the anteroposterior and superoinferior directions, under AC joint compression loads of 10 N, 20 N, and 30 N. After the AC and CC ligaments were transected, one of the specimens was randomly assigned the intramedullary free-tissue graft reconstruction while its matched pair received the extramedullary graft reconstruction. Both reconstructed specimens then underwent repeat translational testing, followed by load to failure testing, via superior clavicle distraction, at a rate of 50 mm/min. RESULTS: Intramedullary reconstruction provided significantly greater translational stability in the anteroposterior direction than the extramedullary technique for four of six loading conditions (p < 0.05). There were no significant differences in translational stability in the superoinferior direction for any loading condition. The intramedullary reconstructed specimens demonstrated improved load to failure characteristics with the intramedullary reconstruction having a lower deformation at yield and a higher ultimate load than the extramedullary reconstruction (p < 0.05). CONCLUSIONS: Intramedullary reconstruction of the AC joint provides greater stability in the anteroposterior direction and improved load to failure characteristics than an extramedullary technique. Reconstruction of the injured AC joint with an intramedullary free tissue graft may provide greater strength and stability than other currently used techniques, allowing patients to have improved clinical outcomes.
Acromioclavicular Joint/physiology/*surgery ; Aged ; Biomechanical Phenomena ; Humans ; Male ; Middle Aged ; Orthopedic Procedures/*methods ; Reconstructive Surgical Procedures/*methods ; Transplants/*physiology

There is little consensus on how to optimally reconstruct the posterior cruciate ligament (PCL) and the natural history of injured PCL is also unclear. The graft material (autograft vs. allograft), the type of tibial fixation (tibial inlay vs. transtibial tunnel), the femoral tunnel position within the femoral footprint (isometric, central, or eccentric), and the number of bundles in the reconstruction (1 bundle vs. 2 bundles) are among the many decisions that a surgeon must make in a PCL reconstruction. In addition, there is a paucity of information on rehabilitation after reconstruction of the PCL and posterolateral structures. This article focused on the conflicting issues regarding the PCL, and the scientific rationales behind some critical points are discussed.
Biomechanical Phenomena ; Humans ; Knee Joint/*surgery ; Orthopedic Procedures/*methods ; Posterior Cruciate Ligament/*surgery ; Reconstructive Surgical Procedures/*methods ; Treatment Outcome

The pedicle is a power nucleus of the vertebra and offers a secure grip of all 3 columns. Pedicle screw instrumentation has advantages of rigid fixation with improved three-dimensional (3D) correction and it is accepted as a reliable method with a high margin of safety. Accurate placement of the pedicle screws is important to reduce possible irreversible complications. Many methods of screw insertion have been reported. The author has been using the K-wire method coupled with the intraoperative single posteroanterior and lateral radiographs, which is the most safe, accurate and fast method. Identification of the curve patterns and determining the fusion levels are very important. The ideal classification of adolescent idiopathic scoliosis should address the all patterns, predict the extent of accurate fusion and have good inter/intraobserver reliability. My classification system matches with the ideal classification system, and it is simple and easy to learn; and my classification system has only 4 structural curve patterns and each curve has 2 types. Scoliosis is a 3D deformity; the coronal and sagittal curves can be corrected with rod rotation, and rotational deformity has to be corrected with direct vertebral rotation (DVR). Rod derotation and DVR are true methods of 3D deformity correction with shorter fusion and improved correction of both the fused and unfused curves, and this is accomplished using pedicle screw fixation. The direction of DVR is very important and it should be opposite to the direction of the rotational deformity of the vertebra. A rigid rod has to be used to prevent rod bend-out during the derotation and DVR.
Adolescent ; *Bone Screws ; Humans ; Orthopedic Procedures/instrumentation/*methods ; Rotation ; Scoliosis/*surgery ; Spinal Fusion

BACKGROUNDWe aimed to use the animal model of dynamic fixation to examine the interaction of the pedicle screw surface with surrounding bone, and determine whether pedicle screws achieve good mechanical stability in the vertebrae.

METHODSTwenty-four goats aged 2-3 years had Cosmic ® pedicle screws implanted into both sides of the L2-L5 pedicles. Twelve goats in the bilateral dynamic fixation group had fixation rods implanted in L2-L3 and L4-L5. Twelve goats in the unilateral dynamic fixation group had fixation rods randomly fixed on one side of the lumbar spine. The side that was not implanted with fixation rods was used as a static control group.

RESULTSIn the static control group, new bone was formed around the pedicle screw and on the screw surface. In the unilateral and bilateral dynamic fixation groups, large amounts of connective tissue formed between and around the screw threads, with no new bone formation on the screw surface; the pedicle screws were loose after the fixed rods were removed. The bone mineral density and morphological parameters of the region of interest (ROI) in the unilateral and bilateral dynamic fixation group were not significantly different (P > 0.05), but were lower in the fixed groups than the static control group (P < 0.05). This showed the description bone of the ROI in the static control group was greater than in the fixation groups. Under loading conditions, the pedicle screw maximum pull force was not significantly different between the bilateral and unilateral dynamic fixation groups (P > 0.05); however the maximum pull force of the fixation groups was significantly less than the static control group (P < 0.01).

CONCLUSIONSFibrous connective tissue formed at the bone-screw interface under unilateral and bilateral pedicle dynamic fixation, and the pedicle screws lost mechanical stability in the vertebrae.

To evaluate the application of blood salvage techmque in spine orthopaedic operation. 26 cases of spine orthopaedic operations were divided into two groups. Group A received homologous blood transfusion. Group B received intraoperative blood salvage by cell saver in spine orthopaedic operations. No complications of transfusion and dysfunciton were found in all pateints. The results showed that blood salvage technique can decrease effectively the need of homologous blood transfusion in spine orthopaedic operation and can be used safely in clinical practice.
Adolescent ; Adult ; Blood Transfusion, Autologous ; methods ; Child ; Child, Preschool ; Female ; Humans ; Male ; Orthopedic Procedures ; Scoliosis ; surgery