Bilateral Proximal Tibia Research Articles

A Child with Severe Bilateral Tibia Vara: Treatment with Computer-Assisted Gradual Correction Utilizing Hexapod External Fixator

A 7-year-old obese boy presented to the Paediatric Orthopaedic clinic with a complaint of worsening bilateral knee bowing. He was initially seen for the same problem in another hospital at the age of 3. The bowing of the leg was associated with pain over the lateral aspect of both knees. He was able to walk but unable to run or participate in sports due to the deformity and knee pain. On examination, the child had a waddling gait and lateral thrust due to severe bilateral genu varus. The range of motion of bilateral knee joints was 0 to 110 degrees. The knee intercondylar distance was markedly increased and there was bilateral tibial torsion. No limb length discrepancy and neurovascular examination was normal. The radiograph revealed features of infantile tibia vara (Blount disease). Bilateral proximal tibia temporary hemiepiphysiodesis was attempted but no correction of the deformity was achieved due to implant failure. His parents were then counseled to let him undergo gradual deformity correction surgery using a ring external fixator (hexapod system). The bilateral varus deformity was corrected after 4 months, and the patient was able to walk normally.

A Girl with Limp and Rash on the Palms and Soles.

A Girl with Limp and Rash on the Palms and Soles.

Bilateral Tibia Stress Fractures: Case Report and Review of the Literature

Background: Tibia stress fractures are microscopic fractures of the tibia that are often the result of repetitive microtrauma as commonly seen in military recruits and intense athletics. Tibia stress fractures are more commonly unilateral and are usually in the diaphyseal portion of the tibia. We describe a case of bilateral medial proximal tibia occult fractures along the epiphyseal scar following blunt trauma. Case description: A 41-year-old bipolar male presented to the clinic one-week following a pedestrian versus motor vehicle accident. He subsequently developed low back pain and bilateral knee pain. The diagnosis of bilateral proximal tibia fractures was made using repeat plain X-ray films two-weeks after initial presentation. Operative treatment with bilateral medial tibia internal fixation was elected and the patient was discharged full weight-bearing. Literature review: There have been two case reports which explored the treatment options for bilateral proximal tibia fractures. Neither case elected to treat with internal fixation. Clinical relevance: Because the incidence of bilateral tibia stress fractures is low and operative treatment with bilateral internal fixation has not been reported, our case examines the viability of operatively treating bilateral tibia stress fractures with internal fixation. Our case demonstrates the successful treatment of bilateral medial proximal tibia occult fractures with internal fixation.

A new strategy to enhance artificial ligament graft osseointegration in the bone tunnel using hydroxypropylcellulose

The aim of this study was to determine whether hydroxypropylcellulose (HPC) coating of polyethylene terephthalate (PET) artificial ligaments enhances graft osseointegration in the bone tunnel. Thirty New Zealand white rabbits underwent artificial ligament graft transplantation in the bilateral proximal tibia tunnels. One limb was implanted with an HPC-coated PET graft, and the contralateral limb was implanted with a non-HPC-coated PET graft as a control. The rabbits were then randomly sacrificed at weeks four and eight after surgery for biomechanical testing, histological examination, and histomorphometric and real-time polymerase chain reaction analysis. At week four after surgery, there were no statistically significant differences in the load to failure or stiffness values between the experimental and control limbs (P = 0.328 and P = 0.128, respectively). At week eight after surgery, the mean load to failure and stiffness value of the experimental limbs was higher than that of the control limbs (P < 0.001 and P = 0.018, respectively). At week eight after surgery, some protruding new bone tissue from the host bone to the graft was found in the HPC-coated group, while a thick fibrous tissue band was observed at the interface between the graft and the host bone in the control group. Histomorphometric analysis showed that the graft-bone interface width in the HPC-coated group was significantly narrower than that in the control group at week eight after surgery (P < 0.001). At weeks four and eight after surgery, the mRNA expression level of bone morphogenetic protein-2 in the HPC group was higher than that in the control group (P = 0.001 and P = 0.010, respectively). The mRNA expression level of osteopontin in the HPC group was higher than that in the control group only at week four after surgery (P = 0.032). Our data show that an HPC coating on the surface of PET artificial ligament grafts may induce artificial ligament graft osseointegration in the bone tunnel.

Hydroxyapatite coating enhances polyethylene terephthalate artificial ligament graft osseointegration in the bone tunnel

The purpose of this study was to investigate whether hydroxyapatite (HAp) coating could induce polyethylene terephthalate (PET) artificial ligament graft osseointegration in the bone tunnel. Twenty-four New Zealand white rabbits underwent artificial ligament graft transplantation in bilateral proximal tibia tunnels. One limb was implanted with HAp-coated PET graft, and the contralateral limb was implanted with non-HAp-coated PET graft as control. The rabbits were randomly sacrificed at four and eight weeks after surgery. The loads to failure of the experimental group at eight weeks were significantly higher than those of the control group (p = 0.0057). Histologically, application of HAp coating induced new bone formation between graft and bone at eight weeks compared with the controls. Real-time polymerase chain reaction examination revealed significantly elevated messenger ribonucleic acid expression levels of osteopontin and collagen I in the grafts of the HAp group compared with the controls at four weeks (p < 0.05). The study has shown that HAp coating on the PET artificial ligament surface has a positive effect in the induction of artificial ligament osseointegration within the bone tunnel.

Distribution of bone mineral density in the proximal tibia in mid-teens.

The distribution of bone mineral density (BMD) in the proximal tibia was studied in 94 knees from 47 mid-teens. The subjects were healthy high school freshmen (19 male; 28 female) who engaged in daily physical exercise. We measured BMD at six regions of interest (ROI) at the bilateral proximal tibia (three immediately above and three immediately be-low the physeal line) using dual-energy X-ray absorptiometry (QDR-2000; Hologic, Waltham, MA, USA). Subjects were supine during the measurements, with the knee extended and the foot fixed in a special holding device, ensuring correct rotational alignment of the knee. Measurements were performed using the forearm array scan mode. The precision of this method (coefficient of variation) was 1.1%-4.9% (mean 2.5%) for six ROIs. The BMD of the medial side was higher than that of the lateral side, and the BMD at the center of the metaphysis was higher than that of the epiphysis. The subjects in the present study did not show any misalignment of the knee joints. These findings indicate that the medial side of the proximal tibia already has higher BMD than the lateral side in teenagers with normal alignment of the knee joint, and that the increase in epiphyseal BMD may be slower than that of metaphyseal BMD. It is suggested that this phenomenon should be life-long and may play a role in the progression of osteoarthritis of the knee.