Comparison of Different Bone Age Methods and Chronological Age in Prediction of Remaining Growth Around the Knee.

Background: Bone age (BA) has been shown to be superior to chronological age (CA) when predicting remaining growth. However, it is not known whether the calculations are more accurate when BA is assessed by the Greulich and Pyle (GP) or the Sauvegrain (SG) methods. The aim of our study was to identify the method which gives an estimate closest to actual growth in the lower extremities.

A comparison of 3 different methods for assessment of skeletal age when treating leg-length discrepancies: an inter- and intra-observer study.

Background and purpose - Skeletal maturity is a crucial parameter when calculating remaining growth in children. We compared 3 different methods, 2 manual and 1 automated, in the radiological assessment of bone age with respect to precision and systematic difference. Material and methods - 66 simultaneous examinations of the left hand and left elbow from children treated for leg-length discrepancies were randomly selected for skeletal age assessment.

Limb lengthening and deformity correction with externally controlled motorized intramedullary nails: evaluation of 50 consecutive lengthenings.

Background and purpose - Limb lengthening with an intramedullary motorized nail is a relatively new method. We investigated if lengthening nails are reliable constructs for limb lengthening and deformity correction in the femur and the tibia. Patients and methods - 50 lengthenings (34 Precice and 16 Fitbone devices) in 47 patients (mean age 23 years [11-61]) with ≥12 months follow-up are included in this study.

Low rate of clinically important avascular necrosis of the femoral head after Ludloff's procedure.

Introduction: Ludloff's procedure for open reduction of congenital dislocation of the hip (CDH) is recommended for its minimal tissue damage, but is criticised for the risk of late avascular necrosis (AVN) of the femoral head. The aim of present study was primarily to assess the risk of late AVN of the femoral head and secondly the range of motion (ROM) of the hip and the quality of life in children following Ludloff's procedure.

Methods And Materials: 13 hips in 11 children after Ludloff's procedure due to CDH were included retrospectively from 1997 to 2005 at Aarhus University Hospital.

Limb lengthening and deformity correction of congenital and acquired deformities in children using the Taylor Spatial Frame.

Background and purpose - Hexapod ring fixators such as the Taylor Spatial Frame (TSF) have shown good outcomes. However, there have only been a few studies comparing the use of TSF with various etiologies of the deformity. We compared the use of TSF in congenital and acquired deformities in children.

The biology of bone lengthening.

Distraction osteogenesis biologically resembles fracture healing with distinctive characteristics notably in the distraction phase of osteogenesis. In the latency phase of bone lengthening, like in the inflammatory phase of fracture repair, interleukines are released and act with growth factors released from platelets in the local haematoma, leading to attraction, proliferation and differentiation of mesenchymal stem cells into osteoblasts and other differentiated mesenchymal cells. These in turn produce matrix, collagen fibers and growth factors.

Hemiepiphysiodesis: similar treatment time for tension-band plating and for stapling: a randomized clinical trial on guided growth for idiopathic genu valgum.

Background: In children with angulating deformities of the lower limbs, hemiepiphysiodesis can be used to guide growth to achieve better alignment at skeletal maturity. Traditionally, this has been performed with staples. The tension-band plating technique is new and it has been advocated because it is believed to reduce the risk of premature closure of the growth plate compared to stapling.

Three-dimensional microarchitecture of adolescent cancellous bone.

This study investigated microarchitectural, mechanical, collagen and mineral properties of normal adolescent cancellous bone, and compared them with adult and aging cancellous bone, to obtain more insight into the subchondral bone adaptations during development and growth. Twenty-three human proximal tibiae were harvested and divided into 3 groups according to their ages: adolescence (9 to 17 years, n=6), young adult (18 to 24 years, n=9), and adult (25 to 30 years, n=8). Twelve cubic cancellous bone samples with dimensions of 8×8×8 mm(3) were produced from each tibia, 6 from each medial and lateral condyle.

Parathyroid hormone PTH(1-34) increases the volume, mineral content, and mechanical properties of regenerated mineralizing tissue after distraction osteogenesis in rabbits.

Background And Purpose: Parathyroid hormone (PTH) has attracted considerable interest as a bone anabolic agent. Recently, it has been suggested that PTH can also enhance bone repair after fracture and distraction osteogenesis. We analyzed bone density and strength of the newly regenerated mineralized tissue after intermittent treatment with PTH in rabbits, which undergo Haversian bone remodeling similar to that in humans.

Calcium phosphate cement enhances primary stability of open-wedge high-tibial osteotomies.

We investigated if injectable calcium phosphate cement improves primary stability in open-wedge high-tibial osteotomy. A 10 mm open-wedge osteotomy was performed on eight pairs of preserved cadaver tibiae and seven pairs of composite (Sawbone) left tibiae. Osteosynthesis was performed with the Dynafix plate system.

The effects of bone remodeling inhibition by alendronate on three-dimensional microarchitecture of subchondral bone tissues in guinea pig primary osteoarthrosis.

We assessed whether increase of subchondral bone density enhances cartilage stress during impact loading, leading to progressive cartilage degeneration and accelerated osteoarthrosis (OA) progression. Sixty-six male guinea pigs were randomly divided into six groups. During a 9-week treatment period, four groups received twice-weekly subcutaneous injections of alendronate (ALN) in two doses: two groups received 10 microg/kg and two groups received 50 microg/kg.

Effects of parathyroid hormone on newly regenerated bone during distraction osteogenesis in a rabbit tibial lengthening model. A pilot study.

Objective: The overall purpose of the study is to determine the effects of parathyroid hormone (PTH) (1-34) on bone formation in regenerated and surrounding bone of distracted callus during limb lengthening in rabbits. Additionally the aim of the pilot study is to titrate the optimal dose of PTH for distraction osteogenesis treatment in rabbits' tibial lengthening model.

Materials And Methods: A total of 18 rabbits underwent right tibia lengthening by callus distraction.

Surgery in hemophilia. The general view: patient selection, timing, and preoperative assessment.

Although often overlooked, the life of the patient with severe hemophilia is characterized by both intermittent and chronic pain. Bleeds into joints and muscles cause extensive pressure on sensory nerves and, following recurrent bleeds, joint destruction, and synovial reaction is accompanied by constant pains that are frequently mistaken for further bleeding. The orthopedic surgeon may break the vicious cycle of chronic synovitis by excising inflamed and hypertrophic synovium or severely damaged cartilage and adjacent bone ends, and implanting an artificial joint.

Mid-tibial distraction osteogenesis redistributes bone blood flow: a microsphere study in rabbits.

Background: Distraction osteogenesis can be used for the treatment of osteomyelitis and nonunion, conditions thought to benefit from increased blood flow in the bone tissue of the distracted limb. We have questioned whether such an increase occurs, and investigated the spatial distribution of bone blood flow after distraction osteogenesis.

Methods: The tibiae of 8 rabbits were lengthened 10 mm by a standard midtibial distraction osteogenesis procedure.

Effects of hyaluronan on three-dimensional microarchitecture of subchondral bone tissues in guinea pig primary osteoarthrosis.

Hyaluronan (HA) has received increasing interest as a potential agent in therapeutic intervention in osteoarthrosis (OA). HA has been shown to reduce arthritic lesions in experimental animal models of articular cartilage injury. This study was to investigate the effects of high molecular weight HA intra-articular injection on subchondral bone tissues.

Recombinant human bone morphogenetic protein 2 enhances bone healing in an experimental model of fractures at risk of non-union.

Introduction: Identification of patients at risk of developing non-union and institution of procedures preventing non-union could be attractive in routine fracture management. We investigated whether recombinant human bone morphogenetic protein (rhBMP-2) delivered in a hyaluronic acid carrier could prevent non-union development in an experimental non-union model, which simulates the clinical situation of open mid-tibial fractures.

Methods: Sixteen rabbits underwent a standard non-union operation comprising mid-tibial osteotomy, excision of periosteum and endosteum, and plate fixation.

Parathyroid hormone--possible future drug for orthopedic surgery.

Parathyroid hormone naturally secreted by the parathyroid glands is a potent anabolic agent for bone. Parathyroid hormone is primarily thought of as a catabolic protein involved in the physiologic release of calcium from bone. Whereas during recent years, a number of animal studies and clinical trials have demonstrated that intermittent parathyroid hormone administration induces anabolic effects on both cancellous and cortical bone, enhances bone mass and increases mechanical strength of the bones.

Effects of locally applied vascular endothelial growth factor (VEGF) and VEGF-inhibitor to the rabbit tibia during distraction osteogenesis.

Introduction: Therapeutic angiogenesis, a novel concept in tissue engineering, is neo-formation of blood vessels in a tissue upon delivery of an angiogenic growth factor to the tissue. We hypothesised that therapeutic angiogenesis could enhance bone formation and challenged the hypothesis in an experimental model of distraction osteogenesis.

Methods: Rabbits, divided into three equal groups of 12, had their right tibia lengthened by distraction osteogenesis.

Mutual associations among microstructural, physical and mechanical properties of human cancellous bone.

Previous studies have shown that low-density, rod-like trabecular structures develop in regions of low stress, whereas high-density, plate-like trabecular structures are found in regions of high stress. This phenomenon suggests that there may be a close relationship between the type of trabecular structure and mechanical properties. In this study, 160 cancellous bone specimens were produced from 40 normal human tibiae aged from 16 to 85 years at post-mortem.