We released the infraspinatus tendons of six sheep, allowed retraction of the musculotendinous unit over a period of 40 weeks and then performed a repair. We studied retraction of the musculotendinous unit 35 weeks later using CT, MRI and macroscopic dissection.

The tendon was retracted by a mean of 4.7 cm (3.8 to 5.1) 40 weeks after release and remained at a mean of 4.2 cm (3.3 to 4.7) 35 weeks after the repair. Retraction of the muscle was only a mean of 2.7 cm (2.0 to 3.3) and 1.7 cm (1.1 to 2.2) respectively at these two points. Thus, the musculotendinous junction had shifted distally by a mean of 2.5 cm (2.0 to 2.8) relative to the tendon. Sheep muscle showed an ability to compensate for approximately 60% of the tendon retraction in a hitherto unknown fashion. Such retraction may not be a quantitatively reliable indicator of retraction of the muscle and may overestimate the need for elongation of the musculotendinous unit during repair.

We undertook this retrospective study to determine the rate of recurrence and functional outcome after intralesional curettage for chondroblastoma of bone. The factors associated with aggressive behaviour of the tumour were also analysed. We reviewed 53 patients with histologically-proven chondroblastoma who were treated by intralesional curettage in our unit between 1974 and 2000. They were followed up for at least two years to a maximum of 27 years.

Seven (13.2%) had a histologically-proven local recurrence. Three underwent a second intralesional curettage and had no further recurrence. Two had endoprosthetic replacement of the proximal humerus and two underwent below-knee amputation after aggressive local recurrence. One patient had the rare malignant metastatic chondroblastoma and eventually died. The mean Musculoskeletal Tumour Society functional score of the survivors was 94.2%.

We conclude that meticulous intralesional curettage alone can achieve low rates of local recurrence and excellent long-term function.

The treatment of osteochondral lesions of the talus has evolved with the development of improved imaging and arthroscopic techniques. However, the outcome of treatment for large cystic type-V lesions is poor, using conventional grafting, debridement or microfracture techniques.

This retrospective study examined the outcomes of 50 patients with a cystic talar defect who were treated with arthroscopically harvested, cored osteochondral graft taken from the ipsilateral knee.

Of the 50 patients, 45 (90%) had a mean good to excellent score of 80.3 (52 to 90) in the Karlsson-Peterson Ankle Score, at a mean follow-up of 36 months (24 to 83). A malleolar osteotomy for exposure was needed in 26 patients and there were no malleolar mal- or nonunions. One patient had symptoms at the donor site three months after surgery; these resolved after arthroscopic release of scar tissue.

This technique is demanding with or without a malleolar osteotomy, but if properly performed has a high likelihood of success.

Femoroacetabular cam impingement is thought to be a cause of premature osteoarthritis of the hip.

The presence of cam malformation was determined in 2803 standardised anteroposterior (AP) pelvic radiographs from the Copenhagen Osteoarthritis Study by measuring the alpha (α) angle and the triangular index, a new measure of asphericity of the femoral head. In addition, the α-angle and the triangular index were assessed on the AP and lateral hip radiographs of 82 men and 82 women randomly selected from patients scheduled for total hip replacement (THR). The influence of varying femoral rotation on the α angle and the triangular index was also determined in femoral specimens under experimental conditions.

From the 2803 radiographs the mean AP α-angle was 55° (30° to 100°) in men and 45° (34° to 108°) in women. Approximately 6% of men and 2% of women had cam malformation. The α-angle and triangular index were highly inter-related. Of those patients scheduled for THR, 36 men (44%) and 28 women (35%) had cam malformation identifiable on the AP radiographs. The triangular index proved to be more reliable in detecting cam malformation when the hip was held in varying degrees of rotation.

The combination of the α-angle and the triangular index will allow examination of historical radiographs for epidemiological purposes in following the natural history of the cam deformity.

The purpose of this study was to describe the anatomical distribution and incidence of fatigue injuries of the femur in physically-active young adults, based upon MRI studies. During a period of 70 months, 1857 patients with exercise-induced pain in the femur underwent MRI of the pelvis, hips, femora, and/or knees.

Of these, 170 patients had a total of 185 fatigue injuries, giving an incidence of 199 per 100 000 person-years. Bilateral injuries occurred in 9% of patients. The three most common sites affected were the femoral neck (50%), the condylar area (24%) and the proximal shaft (18%). A fatigue reaction was seen in 57%, and a fracture line in 22%. There was a statistical correlation between the severity of the fatigue injury and the duration of pain (p = 0.001). The location of the pain was normally at the site of the fatigue injury. Fatigue injuries of the femur appear to be relatively common in physically-active patients.

New developments in osteotomy techniques and methods of fixation have caused a revival of interest of osteotomies around the knee. The current consensus on the indications, patient selection and the factors influencing the outcome after high tibial osteotomy is presented. This paper highlights recent research aimed at joint pressure redistribution, fixation stability and bone healing that has led to improved surgical techniques and a decrease of post-operative time to full weight-bearing.

Low back injuries account for the greatest loss of playing time for professional fast bowlers in cricket. Previous radiological studies have shown a high prevalence of degeneration of the lumbar discs and stress injuries of the pars interarticularis in elite junior fast bowlers. We have examined MRI appearance of the lumbar spines of 36 asymptomatic professional fast bowlers and 17 active control subjects. The fast bowlers had a relatively high prevalence of multi-level degeneration of the lumbar discs and a unique pattern of stress lesions of the pars interarticularis on the non-dominant side. The systems which have been used to classify the MR appearance of the lumbar discs and pars were found to be reliable. However, the relationship between the radiological findings, pain and dysfunction remains unclear.