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

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

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

OBJECTIVETo determine the initial stability of a novel construct in cadaveric cervical spine in comparison with a conventional method.

METHODSTwelve specimens of fresh human cadaveric cervical spines (C(3)-C(7)) were randomly divided into the test group and control group. In the former group, one-level corpectomy of C(5) and three cortical iliac step-cut grafting with absorbable screw fixation was performed, and one-level corpectomy of C(5) and three cortical iliac strut grafting with anterior plate fixation in the control group. Flexibility test and graft push of strength test were carried out before and after grafting and fixation to determine the range of motion (ROM), neutral zone (NZ) and graft push out strength (POS).

RESULTSThe cervical spines of the two groups all had increased initial stability in all 6 rotational degrees of freedom with also enhanced graft POS after fixation. Compared with the control group, the test group had higher stability in extension and comparable stability in flexion and axial rotation, but lower stability in lateral bending. The graft POS after fixation in the test group, however, was lowered in comparison with the control group.

CONCLUSIONStep-cut grafting and absorbable screw fixation provides sufficient stability potential for the cervical spine in vitro and allows optimum biomechanical and biological environments to enhance graft fusion and reduce complications.

Absorbable Implants ; Biomechanical Phenomena ; Bone Screws ; Bone Transplantation ; methods ; Cadaver ; Cervical Vertebrae ; physiopathology ; surgery ; Humans ; Joint Instability ; physiopathology ; prevention & control ; Orthopedic Procedures ; instrumentation ; methods ; Spinal Fusion ; instrumentation ; methods

Anterior Cruciate Ligament ; surgery ; Anterior Cruciate Ligament Injuries ; Arthroscopy ; Biomedical Research ; methods ; trends ; Humans ; Minimally Invasive Surgical Procedures ; Orthopedic Procedures ; instrumentation ; methods ; Reconstructive Surgical Procedures ; instrumentation ; methods ; Tendons ; transplantation ; Transplantation, Autologous ; Transplantation, Homologous

Increasing incidence of musculoskeletal injuries coupled with limitations in the current treatment options have necessitated tissue engineering and regenerative medicine- based approaches. Moving forward from engineering isolated musculoskeletal tissues, research strategies are now being increasingly focused on repairing and regenerating the interfaces between dissimilar musculoskeletal tissues with the aim to achieve seamless integration of engineered musculoskeletal tissues. This article reviews the state-of-the-art in the tissue engineering of musculoskeletal tissue interfaces with a focus on Singapore's contribution in this emerging field. Various biomimetic scaffold and cellbased strategies, the use of growth factors, gene therapy and mechanical loading, as well as animal models for functional validation of the tissue engineering strategies are discussed.
Cell- and Tissue-Based Therapy ; Genetic Therapy ; Humans ; Intercellular Signaling Peptides and Proteins ; Musculoskeletal Diseases ; rehabilitation ; therapy ; Orthopedic Procedures ; instrumentation ; methods ; Osteogenesis ; Regenerative Medicine ; instrumentation ; methods ; Singapore ; Stem Cells ; Stress, Mechanical ; Tissue Engineering ; instrumentation ; methods ; Tissue Scaffolds ; Weight-Bearing

OBJECTIVETo evaluate the short-term outcomes of patients receiving orthopedic surgery with posterior pedicle screw fixation for degenerative lumbar scoliosis.

METHODSBetween March, 2006 and August, 2009, 36 patients with degenerative lumbar scoliosis (19 males and 17 females) underwent procedures of decompression, bone implantation and pedicle screw fixation. Fifteen patients were also treated by PLIF and 21 cases received posterior-lateral fusion. The JOA scores, Oswestry disability index (ODI), and Cobb angle were recorded before and after the operation, and the surgical complications were also observed.

RESULTSThe JOA scores increased significantly by 83.3% after the operation (P<0.05). The procedures resulted in significantly lowered ODI from (67.1∓11.4)% before the operation to (32.1∓10.8)% after the operation (P<0.01). A significant improvement of the coronal Cobb's angle was achieved after the operation (26.7° preoperatively vs 12.3° postoperatively, P<0.01), and the lordosis angle was improved from 10.7° to 36.6° after the operation (P<0.01). All the patients were followed up for 12 to 50 months (mean 38 months), and no implant loosening, displacement or fragmentation, or pseudarthrosis was found at the final follow-up.

CONCLUSIONPosterior pedicle screw fixation shows good short-term therapeutic effect in treatment of degenerative lumbar scoliosis. Individualized surgical plans and adequate preoperative evaluation are keys to successful operations.

Aged ; Aged, 80 and over ; Bone Screws ; Decompression, Surgical ; methods ; Female ; Humans ; Lumbar Vertebrae ; pathology ; Male ; Middle Aged ; Orthopedic Procedures ; instrumentation ; methods ; Scoliosis ; pathology ; surgery ; Treatment Outcome

OBJECTIVETo evaluate and generalize the application of intermaxillary fixation screw in the jaw fracture.

METHODS41 cases of jaw fracture have been treated with intermaxillary fixation screw.

RESULTSBoth function and appearance have recuperated in 40 cases except 1 case has light malocclusion.

CONCLUSIONSApplication of intermaxillary fixation screw advanced the traditional therapy.

Adolescent ; Adult ; Bone Screws ; standards ; Female ; Humans ; Jaw Fractures ; surgery ; Male ; Maxillary Fractures ; surgery ; Middle Aged ; Orthopedic Fixation Devices ; standards ; Reconstructive Surgical Procedures ; instrumentation ; methods ; Treatment Outcome

OBJECTIVE: To review the experience with Wang procedure for treatment of pectus excavatum in young children. METHODS: The clinical data of 21 children with a mean age of 3.3 ± 1.1 years (ranging from 1.5-6 years) undergoing Wang procedure for pectus excavatum were analyzed. A longitudinal incision (1 to 2 cm) was made in the front of the xiphoid, and two tunnels were created using steel bars beneath the muscles on two sides of the chest wall. The fibrous tissue between the diaphragm and the sternum was dissociated, and the steel wires were sutured through the deformed chest wall. After the steel bar was placed in the tunnels, the wires were pulled and fixed in the middle of the bar, and the incision was sutured. RESULTS: All the operations were performed using 3 wires and 1 steel bar. The operation time was 25 to 51 (38.1 ± 9.6) min with an intraoperative bleeding volume of 5 to 10 (7.1±1.5) mL. The time of hospitalization of the patients ranged from 6 to 10 days (mean 8.1±1.3 days). In all the patients, the incision healed smoothly without serious pain or obvious complications. All the patients were followed up for 1 to 13 months after the operation. During the follow- up, no recess recurred and no such complications as bar displacement or transposition occurred. According to the evaluation criteria after pectus excavatum operation, 13 cases had a total score of 9, and 8 had a total score of 8. The overall effect was satisfactory, and there were no cases rated as basically satisfactory or unsatisfactory. CONCLUSIONS Wang procedure is a good option for treatment of pectus excavatum in young children.
Bone Wires ; Child ; Child, Preschool ; Diaphragm ; Funnel Chest ; surgery ; Humans ; Internal Fixators ; Operative Time ; Orthopedic Procedures ; instrumentation ; methods ; Retrospective Studies ; Thoracic Wall ; Treatment Outcome ; Xiphoid Bone ; surgery

BACKGROUND: Due to the anatomical nature of the radial nerve, dissection and attainment of an adequate operative field in mid to distal humerus fracture is dangerous and limited. We devised a combined anterolateral and lateral approach that ensures protection of the radial nerve. This is achieved by performing bimodal dissection of the proximal humerus anteriorly and the distal humerus laterally. METHODS: Thirty-five consecutive patients were treated using a combined anterolateral and lateral approach for a minimum follow-up period of 24 months. We analyzed time to bony union, time to return to daily work, range of motion, elbow joint function as assessed by the Mayo elbow performance index and complications. RESULTS: Radiologic bony union was observed at 11.2 weeks (range, 8 to 20 weeks) on average. Four cases of incomplete radial nerve palsy before surgery all recovered. Time to return to work was 10.2 weeks (range, 2 to 32 weeks) on average. The average range of motion of the elbow was 3.3degrees (range, 0degrees to 10degrees) of extension and 135.9degrees (range, 125degrees to 145degrees) of flexion. There were 21 cases of excellent and 13 cases of good or better recovery, comprising over 97.1% on the Mayo elbow performance index. There were no complications of radial nerve palsy, non-union, mal-union, or infection. CONCLUSIONS: Our a modified combined anterolateral and lateral approach is a clinically effective surgical method of achieving protection of the radial nerve and securing easy and firm internal fixation.
Adolescent ; Adult ; Aged ; Female ; Humans ; Humeral Fractures/radiography/*surgery ; Male ; Middle Aged ; Orthopedic Fixation Devices ; Orthopedic Procedures/adverse effects/instrumentation/*methods ; Pain, Postoperative ; Prospective Studies ; Range of Motion, Articular ; Return to Work ; Treatment Outcome