Intact abductors of the hip play a crucial role in preventing limping and are known to be damaged through the direct lateral approach. The extent of trauma to the abductors after revision total hip replacement (THR) is unknown. The aim of this prospective study was to compare the pre- and post-operative status of the gluteus medius muscle after revision THR. We prospectively compared changes in the muscle and limping in 30 patients who were awaiting aseptic revision THR and 15 patients undergoing primary THR. The direct lateral approach as described by Hardinge was used for all patients. MRI scans of the gluteus medius and functional analyses were recorded pre-operatively and six months post-operatively. The overall mean fatty degeneration of the gluteus medius increased from 35.8% (1.1 to 98.8) pre-operatively to 41% (1.5 to 99.8) after multiple revision THRs (p = 0.03). There was a similar pattern after primary THR, but with considerably less muscle damage (p = 0.001), indicating progressive muscle damage. Despite an increased incidence of a positive Trendelenburg sign following revision surgery (p = 0.03) there was no relationship between the cumulative fatty degeneration in the gluteus medius and a positive Trendelenburg sign (p = 0.26). The changes associated with other surgical approaches to the hip warrant investigation.

Cite this article: Bone Joint J 2014;96-B:1618–22.

Study Design: The lumbar spine of children an adolescents with suspected spondylolysis was assessed by magneting resonance imaging. Objectives: To evaluate the value of MRI in diagnosis and after nonoperative treatment of incipient spondylolysis in children and adolescents. Summary of Background Data: The diagnosis of incipient spondylolysis in children and adolescents is difficult. Radiographs have a low sensitivity and the use of bone scans, computer tomography and MRI controversial. Methods: The study is prospective. The lumbar spine was assessed by MR imaging in children (n=14, mean age 12.4 years) with unspecific low back pain for more than 3 weeks and normal plain radiographs at presentation. Six of the seven children were involved in moderate to severe sport activities. Incipient spondylolysis was diagnosed when on T1 sequences a hypointense area was found within the pars interarticularis of any lumbar vertebra while on T2 sequences a corresponding hyperintense zone was detected. Brace and activity restriction was recommended. Follow-up MRI studies were performed after treatment at 3 months interval. Results: Seven of 14 patients presented with pars edema (T1 hypointense, T2 hyperintense), six at L5 vertebra, one at L4 and L5 vertebra, respectively. After 3 months healing was demonstrated both clinically and by imaging in six children in another child healing was observed after 6 months. Conclusions: MRI showed promising results in detecting and monitoring the early onset of spondylolysis. In our cases early treatment prevented pars defects

A paper was presented two years ago reviewing evidence of absorption of the Bio Interference screw and tunnel widening at three, six and 12 months following anterior cruciate ligament reconstruction using double-stranded hamstrings. The femoral fixation was with an Endobutton with a double loop of Mercylene tape with a Bio Interference screw and an extra small staple for the distal fixation. This paper presents further magnet resonance imaging (MRI) studies at least two years after surgery on 10 of those patients to assess if there was any MRI evidence of absorption of the Bio Interference screw or tunnel widening (in particular ganglion formation) in the femoral or tibial tunnels. The results showed that at least two years after surgery there was little evidence of Bio Interference screw absorption. There was no evidence of tunnel widening