Objective: The number of hip prostheses replacement surgeries particularly in elder people with osteoporosis, has been increasing every year; given this scenario, treatment of postoperative periprosthetic femoral fracture has become a critical problem. Osteosynthesis is generally selected as the procedure of choice for the surgical treatment of fractures, provided the stem prostheses do not show loosening. Stable fixation of periprosthetic femoral fracture is difficult in the elderly because they have osteoporotic bone and most of the intramedullary space is occupied by the metal stem implanted in the proximal femoral shaft. With a view to solving this problem, we developed a new surgical treatment for postoperative periprosthetic femoral fracture; this procedure use a trimming intramedullary nail, which we have termed “docking nail.” [Materials] The subjects were 3 patients (81, 75 and 76 years old) who had suffered a femoral shaft fracture around the femoral prosthesis after total hip replacement; in all 3 patients, there was no apparent sign of loosening of the stem prosthesis. The implanted stem was cemented in one patient and uncemented in the other two.

Method: Using information on the size and shape of the stem prosthesis as well as information from the pre-operative radiographs, we cut the docking nail till the proper length was achieved and trimmed it to suit the cutting site in order to ensure that it was compatible with tip of the stem. We then performed osteosynthesis using instruments of an ordinary supracondylar type intramedullary nail. In cases where it was difficult to reposition or where it was necessary to remove excessive cement and bone from around the tip of stem and graft a free bone in the bony defect, we exposed the fracture site as minimally as possible. The major difference between our procedure and the conventional procedure is that in our procedure, the docking nail is connected to the tip of the implanted stem to ensure proper alignment. Postoperative immobilization was not used in any of the patients except for the 81-year-old patient, for whom partial weight-bearing was allowed at 4 weeks, and full weight bearing at 12 weeks. The mean follow up period was 22 months (range, 6–48 months).

Result: Within 3 months, bony union with good alignment was achieved in all 3 patients without malunion or infection. The clinical and radiographic examinations conducted during the follow-up period showed good results.

Conclusion: The advantages of this method are that it is less invasive and simple compared to the conventional methods. Its only disadvantage is that it requires considerable, preoperative planning and minor trimming of the nail. Although this series is small, we think that this new treatment can be recommended and will be beneficial for treating periprosthetic femoral fractures without a loose stem. However, these preliminary findings need to be confirmed by further investigations.

Lumbar spondylolysis can heal with conservative treatment, but few attempts have been made to identify factors which may affect union of the defects in the pars. We have evaluated, retrospectively, the effects of prognostic variables on bony union of pars defects in 134 young patients less than 18 years of age with 239 defects of the pars who had been treated conservatively. All patients were evaluated by CT scans when first seen and more than six months later at follow-up.

The results showed that the spinal level and the stage of the defects were the predominant factors. The site of the defects in the pars, the presence or development of spondylolisthesis, the condition of the contralateral pars, the degree of lumbar lordosis and the degree of lumbar inclination all significantly affected union.

We reviewed retrospectively the MRI examinations of 108 knees of 80 children to identify the prevalence of a high signal in the menisci of those without symptoms. There were 51 boys and 29 girls with a mean age of 12.2 years (8 to 15).

The prevalence of a high signal within the menisci was 66%, significantly higher than that in an adult group (29%). The prevalence decreased with age: grade-2 and grade-3 changes were observed in 80% of menisci at ten years of age, in 65% at 13 years and in 35% at 15 years. The prevalence of high signals also decreased with increased skeletal maturity at the knee.

We emphasise the importance of awareness of the high prevalence of a high signal intensity in the menisci of children, especially in early adolescence.

We have reviewed 37 patients under the age of 18 years with lesions of the lumbar posterior end plate. All but one were active in sport, and most were seen because of low back pain. An abnormality was commonly found at the inferior rim of the body of L4 and at the superior rim of the sacrum. All adjacent intervertebral discs showed a decrease of signal intensity on the T2-weighted MRI. In 12 patients there was no interposed tissue at the posterior end-plate lesions. When disc material had migrated posteriorly none protruded beyond the posterior margin of the end plate, the dissociated portion of which was the main element compressing neural tissue. The posterior end-plate lesion should be regarded as a vertebral non-articular osteochondrosis.

We investigated 185 adolescents under the age of 19 years with spondylolysis. All but five were active in sport. The pars defect was classified into early, progressive and terminal stages. Of the 346 pars defects in 185 patients, 39.6% were early, 29.5% progressive and 30.9% in the terminal stages. Conservative management produced healing in 73.0% of the early, 38.5% of the progressive and none of the terminal defects. These results suggest that spondylolysis is caused by repetitive microtrauma during growth and can be successfully treated conservatively if treatment is started in the early stage. There was elongation of the pars interarticularis as the pars defect progressed, and this is likely to be a consequence of the defect rather than a contributing cause.