Introduction

The incidence of osteochondral lesions following ankle fractures varies in the literature between 17-70%. They are commonly associated with chronic pain and swelling in patients diagnosed with such pathology. There is less evidence about the relationship between OCL and the development of post-traumatic osteoarthritis, the most common type of ankle arthritis.

Lateral patellar dislocation is a common cause of acute traumatic haemarthrosis in young active patients, usually occurring during sporting activites. Patients can often be unaware it has occurred. Often magnetic resonance imaging offers the first diagnosis. Most patellar dislocations are treated conservatively with an emphasis on early return to movement.

We report on a series of 80 consecutive patients who were diagnosed as having had a transient patellar dislocation by MRI from November 2001 to April 2008 as evidenced by the characteristic countercoup pattern of bone bruising seen on the lateral femoral condyle. In addition to the patellar findings, the images were reviewed with specific reference to the medial collateral ligament, a heretofore undescribed concomitant injury.

During the study period, 80 patients (66 males, 14 females) were diagnosed on MRI as having had transient patellar dislocation. The mean age (mean +/− standard deviation) of the cohort was 23.9+/−7.5 years (range:11–60 years). In all but two cases, normal anatomical alignment had been restored. In addition to multiple patellar chondral findings, the condition of the MCL was commented upon in 77 cases (96.3%). Of these, 40 (51.9%) had documented damage to the MCL. These injuries were classified as grade 1 (n=20), grade 1/2 (n=2), grade 2 (n=13), grade 2/3 (n=2) and grade 3 (n=3). Male patients were more likely to have had MCL damage 54.5% vs. 28.6% (p=0.07, Chi-Square).

These results serve to highlight the co-existence of MCL injuries with patellar dislocation to a relatively high incidence. This injury should be suspected and examined for in the case of prolonged symptoms after dislocation especially in male patients.

Lateral patellar dislocation is a common cause of acute traumatic haemarthrosis in young active patients, usually occurring during sporting activites. However, patellar dislocation is usually transient with patients often unaware it has occurred. Often magnetic resonance imaging (MRI) offers the first diagnosis. Most patellar dislocations are treated conservatively with an emphasis on early return to movement.

We report on a series of 30 patients who were diagnosed as having had a transient patellar dislocation by MRI from December 2001 to October 2007 as evidenced by the characteristic countercoup pattern of bone bruising seen on the lateral femoral condyle. In addition to the patellar findings, the images were reviewed with specific reference to the medial collateral ligament, a heretofore undescribed concomitant injury.

During the study period, 30 patients (26 males, 4 females) were diagnosed on MRI as having had transient patellar dislocation. The mean age (mean +/− standard deviation) of the cohort was 23.1+/−6.1 years (range:14 – 36 years). In all but one case, normal anatomical alignment had been restored. In addition to multiple patellar chondral findings, the condition of the MCL was commented upon in 29 cases (97%). Of these, 12 (41%) had documented damage to the MCL. These injuries were classified as grade 1 (n=7), grade 2 (n=3) and grade 2/3 as defined by incomplete detachment of the MCL from the medial femoral condyle (n=2).

These results serve to highlight the co-existence of MCL injuries with patellar dislocation to a relatively high incidence. This injury should be suspected and examined for in the case of prolonged symptoms after dislocation. In addition, the current vogue for early rehabilitation needs to be regarded with some circumspection.

Bertolotti’s syndrome is characterised by anomalous enlargement of the transverse process(es) of the most caudal lumbar vertebra which may articulate or fuse with the sacrum or ilium and cause isolated L4/5 disc disease.

We analysed the elective MR scans of the lumbosacral spine of 769 consecutive patients with low back pain taken between July 2003 and November 2004. Of these 568 showed disc degeneration. Bertolotti’s syndrome was present in 35 patients with a mean age of 32.7 years (15 to 60). This was a younger age than that of patients with multiple disc degeneration, single-level disease and isolated disc degeneration at the L4/5 level (p ≤ 0.05). The overall incidence of Bertolotti’s syndrome in our study was 4.6% (35 of 769). It was present in 11.4% (20 patients) of the under-30 age group.

Our findings suggest that Bertolotti’s syndrome must form part of a list of differential diagnoses in the investigation of low back pain in young people.

Introduction: Total knee replacement (TKR) is an established and successful treatment option for symptomatic osteoarthritis of the knee. Arthroplasty surgeons, however, continue to debate the merits of posterior cruciate ligament (PCL) preservation or resection. Published literature on this subject has not demonstrated a significant clinical difference in outcome in matched subjects. Deliberate PCL resection during non-posterior stabilised TKR has also been shown to have similar outcomes.

The aims of this study were to map the tibial PCL footplate using MRI in patients undergoing TKR and more importantly, to document the percentage disruption of this footplate as a result of the tibial cut.

Patients and Methods: Patients awaiting TKR were prospectively enrolled into this study. Plain radiographs and an MRI scan of the knee were performed. Using coronal and sagittal images and the available software, the cross sectional area of the tibial PCL footplate was determined along with its location relative to the tip of the fibular head. Plain x-rays of the knee were performed postoperatively. Using a number of pre-determined markers we estimated the impact of the operative tibial cut on the PCL footplate.

Results: Twenty-five patients were enrolled into this study. There were 7 male and 18 female patients, mean age: 69 years. The vast majority of implants were AMK (80%), with a mean posterior slope cut of 3.6 degrees (range 0–7) and mean spacer height 11.4 mm (range 8–16).

From MRI analysis, the tibial PCL footplate had a mean surface area of 83 mm² (range: 49 – 142), and there was a significant difference between male and female patients [Male: 104 mm²versus Females: 75 mm²; t-test, p < 0.005]. The inferior most aspect of the PCL footplate was located on average 1 mm above the superior most aspect of the fibular head (range: 10 mm below to 7 mm above).

Analysis of post-operative radiographs showed that the average tibial cut extended to 4 mm above the tip of the fibular head (range 2 mm below to 14 mm above). Over one third of patients had tibial cuts extending below the inferior most aspect of their PCL footplate (complete removal) and a further one third had cuts which extended into their PCL footplate (partial removal).

Conclusions We have found a wide variation in the size and location of the tibial PCL footplate when referenced against the fibular head.

Proximal tibial cuts using conventional jigs resulted in the removal of a significant portion if not all of the PCL footplate in the majority of patients.

Our findings suggest that when performing PCL retaining TKR’s, we commonly do not actually preserve the PCL.

Bertolotti’s syndrome, first described in 1917, is characterised by the presence of an anomaly of unilateral or bilateral enlargement of the transverse process of the most caudal vertebra that may articulate or fuse with the sacrum or ilium. This gives rise to low back pain. Although described, relevant literature is sparse and in particular, no evidence exists as to its incidence specifically in young people.

This study analysed all MRI scans of the lumbosacral spine performed on patients between July 2003 and November 2004 inclusive. MRI scans for all indications were included in the study.

Out of a total of 818 MRI scans of the lumbosacral spine, 627 showed disc disease. Of these, 35 had radiological signs of Bertolotti’s syndrome (7 bilateral, 28 unilateral). There were 22 males and 17 females in this group. The average age of the Bertolotti group was 31.8+/−12.0 years (range: 15–60). This was less than those with multiple disc disease whose average age was 44.0+/−15.6 years (p< 0.0002, ANOVA), those with isolated disc disease (41.1+/−16.0 years, p=0.013, ANOVA) and those with isolated disc disease at the L4/5 level (46.0+/−11.3 years, p=0.003, ANOVA). The overall incidence of Bertolotti’s syndrome in this study was 5.6%. However, 18 of the patients in the Bertolotti group were under 30 years of age giving an overall incidence in this age group of 8.9%.

Bertolotti’s syndrome is a frequently occurring pathology in the lumbosacral spine. It occurs in significantly younger patients than either multi-level disc disease or isolated disc disease including at the L4/5 level. In the under 30 group its incidence of 8.9% mandates that it must form part of a differential list in the investigation of low back pain in young people.

Introduction and Aims: The aim of this study was to evaluate the role of Whole Body MR (WBMR) in the staging of Musculo Skeletal (MSK) tumors, on a premise that a single study might present an alternative to the traditional imaging.

Method: Forty-two patients were referred for MR evaluation for primary bone or soft tissue sarcomas. These studies were done between October 2001 and April 2003. Each patient had a WBMR, Localised MR, CXR and CT Thorax, and bone scan.

Results: In 42 patients screened, 32 had a primary malignant musculo skeletal tumor. There were 14 primary bone tumors and 18 soft tissue sarcomas. Of the 32 patients concordance between WBMR imaging and the other staging modalities was identified in 27 patients. Discordance was identified in five patients. Two lesions were identified on WBMR and not seen on other imaging modalities. Two lesions not identified by WBMR, subsequently seen on CT thorax. One lesion was not seen on WBMR but seen on localised MR. Eight of the 32 patients had pulmonary metastases. In these patients concordance between the WBMR and CT Thorax was identified in five of eight patients and discordance was identified in three of eight patients where nodules were identified on CT Thorax and not on WBMR. Four patients were noted to have osseous metastases, all seen on WBMR. One bone scan failed to pick up metastasis seen on WBMR. One patient was identified as having a soft tissue metastasis on Whole Body MR, which was not identified on the conventional CT Thorax.

Case studies:

Case 1: Metastatic Leiomyosarcoma

Case 2: Metastatic Ewings sarcoma

Case 3: Metastatic Epithelioid sarcoma

Conclusion: Whole body MR Scanning techniques allow whole body imaging in as little as eight minutes. It is a useful technique in staging and assessing total tumor burden, but still should be performed in conjunction with a CT Thorax.

Percutaneous Radiofrequency Ablation (RFA) has become the method of choice in the treatment of a wide spectrum of disorders. It was introduced for the treatment of Trigeminal Neuralgia and has since been used both extensively and successfully in the treatment of this disorder. Over the past two decades it has been advocated in the treatment of hepatic metastases, lung tumours and cerebral tumours. In 1992 Rosenthal et al reported using this procedure for the treatment of Osteoid Osteomas with good outcome. Further case series have supported this modality of treatment. However, the biomechanical effects of RFA on cortical bone have not been reported to date.

The study comprised of 16 large white land-raised male pigs. All were between 70–80kg in weight at the time of treatment. RFA was performed on the femur, tibia and humerus of each animal 24 hours, 1 week and 4 weeks before euthanisation. RFA was carried out via a percutaneous technique under fluoroscopic guidance. The fibula was not treated in each case and used as an intrinsic control to account for inter-group variability. The Modulus of Rigidity, Maximum Torsional Strength of all bones were determined and compared.

There were three pathological fractures, all occurring in the hemerii and all occurring at 4 weeks post treatment. The Modulus of Rigidity and Maximum Torsional strength were significantly reduced at 24 hours and 1 week when compared with the control. However in the 4 weeks group the biomechanical strength of cortical bone was not significantly different and had almost returned to normal which is contradictory to the clinical setting. There was no significant difference at 24 hours and 1 week.

RFA has become well established as the method of choice for the treatment of Osteoid Osteomas, however the biomechanical consequences of this procedure have not been reported to date. The torsional strength of RF ablated cortical bone is severely attenuated after 1 week, 40% reduction in torsional strength when compared with the control group. This study demonstrated that RFA of cortical bone is an effective treatment for cortical lesions however the biomechanical weakness promotes the need for weight-bearing restrictions when managing these patients postoperatively.

Introduction: The Ganz periacetabular osteotomy aims to improve femoral head coverage in dysplastic hips. It is joint preserving procedure and therefore is ideally preformed before significant articular cartilage degeneration. One proposed advantage of this procedure is that it partially preserves the posterior column and does not disrupt the vascular supply of the main fragment. This study aims to 1) assess the role of MR imaging in the perioperative evaluation of articular cartilage and labrial tissues prior to Ganz osteotomies and 2) to document any alteration in the vascularity of the acetabular fragment post operatively.

Patient and Methods: Twenty patients (all female, average age 18.2 years) under consideration for peracetabular osteotomy for hip dysplasia and MR Studies of the pelvis as part of the perioperative assessment. Sixteen patients had follow-up imaging at 4, 12 and 26 weeks post surgery, at which time evidence of healing, oedema, vascularity and femoral head coverage were assessed.

Discussion: MR imaging has proven to be a reliable method of assessing articular cartilage health before considering pelvic osteotomy. Hopefully this will allow more appropriate selection of patients likely to benefit from this procedure. In addition MRI scanning allows clearer assessment of other articular elements, such as labium and ligamentum teres, that are difficult to visualize with plain radiographs and CT scans. A further benefit of MR scanning is that, as this study has shown the vast majority of patients who are potential candidates are female of childbearing age and it voids the use of ionizing radiation in this sensitive group of patients. This study has shown that despite some early alterations in osteotomy fragment vascularity the ultimate outcome is that vascularity is substantively unharmed by periacetabular osteotomy.

Conclusion: MR imaging is extremely useful in the perioperative workup and postoperative follow-up in patients undergoing Ganz periacetabular osteotomies.

Aims: To correlate clinical imaging and surgical finding in patients with knee arthritis. In an attempt to identify specific lesions that correlate with the location of clinical pain.

Methods: 26 patients and 32 knees were eligible for inclusion in the study. All patients had been admitted for total knee arthroplasty. In all patients an attempt was made to correlate symptoms with radiographic findings and then intraoperative findings. A senior orthopaedic registrar carried out standard knee scores and clinical examinations, radiographs and a radiologist blindly evaluated MRI scans. The integrity of the articular cartilage as well as the menisci and ligaments were all graded.

Results: At clinical examination all patients score 70 or higher on a visual analogue scale. In eighteen patients, the maximum site of clinical tenderness was referable to the medial joint line. In seven patients symptoms were on the lateral aspect. Pain was recorded on a line diagram of the knee for analysis. MR images confirmed advanced arthritis with meniscal derangement with extrusion and maceration. Note was made of osteophyte formation, medial collateral ligament laxity and oedema and discrete osteochondral defects. Bone marrow bruising and oedema was also recorded. In nine patients subchondral cysts were identified with extensive associated bone oedema. At surgery, meniscal degeneration was identified in fifteen of twenty-six, meniscal tears were identified in six; the menisci were normal in two patients.

Discussion: These results suggest that there is a direct correlation between clinical symptoms and meniscal derangement in severe osteoarthritis. Isolated articular defects and bone marrow oedema did not correlate well with location of pain. Presence of medial collateral oedema correlated well with severity of radiological arthritis and clinical findings.

In summary, this study suggests that patients with symptomatic knee arthritis are likely to have meniscal derangement and medial collateral oedema. A greater understanding of the origin of pain in the degenerate knee may assist in the choice of management options for these patients.

Aims: To investigate the prevalence and significance of a high-intensity zone in a group of patients asymptomatic for low back pain.

Methods: A prospective observational study of the prevalence of abnormal MR imaging in normal volunteers without a significant history of back pain. All volunteers underwent physical examination, psychometric testing, plain radiograph, magnetic resonance imaging, and dexa scanning. Films were blindly assessed for the prevalence of degenerative disc disease, osteoporosis, high intensity zone, disc prolapse and spinal stenosis.

Results: Following history, clinical examination and psychometric testing 13 of 63 (20%) patients were excluded from the study on the basis of previous back injury, leg pain or abnormal clinical findings. 50 volunteers were eligible for inclusion in the study. The presence of a high-intensity zone or annular disruption was determined by standardised criteria on T2-wieghted magnetic resonance images. The prevalence of a high-intensity zone in the patient population was 12 of 50 patients (24%). 32% of all disc prolapses were at the L4/5 level, 33% were at L5/S1 and 17% were at L3/4 the remainder were at various other levels.

Conclusions: The presence of a high-intensity zone does not reliably indicate the presence of symptomatic internal disc disruption. Magnetic resonance imaging is accurate in determining nuclear anatomy, however positive findings do not always correlate with history and clinical findings. The presence of abnormal imaging in asymptomatic patients reinforces the need for a detailed history and clinical examination in the evaluation of the lumbar spine.