Cartilage defects of the hip cause significant pain and may lead to arthritic changes that necessitate hip replacement. We propose the use of fresh osteochondral allografts as an option for the treatment of such defects in young patients. Here we present the results of fresh osteochondral allografts for cartilage defects in 17 patients in a prospective study. The underlying diagnoses for the cartilage defects were osteochondritis dissecans in eight and avascular necrosis in six. Two had Legg-Calve-Perthes and one a femoral head fracture. Pre-operatively, an MRI was used to determine the size of the cartilage defect and the femoral head diameter. All patients underwent surgical hip dislocation with a trochanteric slide osteotomy for placement of the allograft. The mean age at surgery was 25.9 years (17 to 44) and mean follow-up was 41.6 months (3 to 74). The mean Harris hip score was significantly better after surgery (p < 0.01) and 13 patients had fair to good outcomes. One patient required a repeat allograft, one patient underwent hip replacement and two patients are awaiting hip replacement. Fresh osteochondral allograft is a reasonable treatment option for hip cartilage defects in young patients.

Cite this article: Bone Joint J 2014;96-B(11 Supple A):11–16.

Our aim in this prospective study was to determine the best diagnostic method for discriminating between patients with and without osteochondral lesions of the talus, with special relevance to the value of MRI compared with the new technique of multidetector helical CT. We compared the diagnostic value of history, physical examination and standard radiography, a 4 cm heel-rise view, helical CT, MRI, and diagnostic arthroscopy for simultaneous detection or exclusion of osteochondral lesions of the talus. A consecutive series of 103 patients (104 ankles) with chronic ankle pain was included in this study. Of these, 29 with 35 osteochondral lesions were identified. Twenty-seven lesions were located in the talus.

Our findings showed that helical CT, MRI and diagnostic arthroscopy were significantly better than history, physical examination and standard radiography for detecting or excluding an osteochondral lesion. Also, MRI and diagnostic arthroscopy performed better than a mortise view with a 4 cm heel-rise. We did not find a statistically significant difference between helical CT and MRI. Diagnostic arthroscopy did not perform better than helical CT and MRI for detecting or excluding an osteochondral lesion.

We describe the application of a non-invasive extendible endoprosthetic replacement in skeletally-mature patients undergoing revision for failed joint replacement with resultant limb-length inequality after malignant or non-malignant disease. This prosthesis was developed for tumour surgery in skeletally-immature patients but has now been adapted for use in revision procedures to reconstruct the joint or facilitate an arthrodesis, replace bony defects and allow limb length to be restored gradually in the post-operative period.

We record the short-term results in nine patients who have had this procedure after multiple previous reconstructive operations. In six, the initial reconstruction had been performed with either allograft or endoprosthetic replacement for neoplastic disease and in three for non-neoplastic disease. The essential components of the prosthesis are a magnetic disc, a gearbox and a drive screw which allows painless lengthening of the prosthesis using the principle of electromagnetic induction. The mean age of the patients was 37 years (18 to 68) with a mean follow-up of 34 months (12 to 62). They had previously undergone a mean of six (2 to 14) open procedures on the affected limb before revision with the non-invasive extendible endoprosthesis.

The mean length gained was 56 mm (19 to 107) requiring a mean of nine (3 to 20) lengthening episodes performed in the outpatient department. There was one case of recurrent infection after revision of a previously infected implant and one fracture of the prosthesis after a fall. No amputations were performed. Planned exchange of the prosthesis was required in three patients after attainment of the maximum lengthening capacity of the implant. There was no failure of the lengthening mechanism. The Mean Musculoskeletal Tumour Society rating score was 22 of 30 available points (18 to 28).

The use of a non-invasive extendible endoprosthesis in this manner provided patients with good functional results and restoration of leg-length equality, without the need for multiple open lengthening procedures.

Bleeding is a major complication of revision total hip replacement. We report a case where the inflated balloon of a urinary catheter was used to temporarily control intrapelvic bleeding from the superior gluteal artery, while definitive measures for endovascular embolisation were made.

The “Universal Protocol” (UP) was launched as a regulatory compliance standard by the Joint Commission on 1st July 1 2004, with the primary intent of reducing the occurrence of wrong-site and wrong-patient surgery. As we’re heading into the tenth year of the UP implementation in the United States, it is time for critical assessment of the protocol’s impact on patient safety related to the incidence of preventable never-events. This article opens the debate on the potential shortcomings and pitfalls of the UP, and provides recommendations on how to circumvent specific inherent vulnerabilities of this widely established patient safety protocol.

The aim of this study was to establish the natural course of unrevised asymptomatic pseudotumours after metal-on-metal (MoM) hip resurfacing during a six- to 12-month follow-up period. We used repeated metal artefact reduction sequence (MARS)-magnetic resonance imaging (MRI), serum metal ion analysis and clinical examination to study 14 unrevised hips (mean patient age 52.7 years, 46 to 68, 5 female, 7 male) with a pseudotumour and 23 hips (mean patient age 52.8 years, 38 to 69, 7 female, 16 male) without a pseudotumour. The mean post-operative time to the first MARS-MRI scan was 4.3 years (2.2 to 8.3), and mean time between the first and second MARS-MRI scan was eight months (6 to 12). At the second MRI scan, the grade of severity of the pseudotumour had not changed in 35 hips. One new pseudotumour (Anderson C2 score, moderate) was observed, and one pseudotumour was downgraded from C2 (moderate) to C1 (mild). In general, the characteristics of the pseudotumours hardly changed.

Repeated MARS-MRI scans within one year in patients with asymptomatic pseudotumours after MoM hip resurfacing showed little or no variation. In 23 patients without pseudotumour, one new asymptomatic pseudotumour was detected.

This is the first longitudinal study on the natural history of pseudotumours using MARS-MRI scans in hip resurfacing, and mirrors recent results for 28 mm diameter MoM total hip replacement.

Cite this article: Bone Joint J 2013;95-B:1626–31.

Objectives

An experimental piglet model induces avascular necrosis (AVN) and deformation of the femoral head but its secondary effects on the developing acetabulum have not been studied. The aim of this study was to assess the development of secondary acetabular deformation following femoral head ischemia.

Our aims were to map the tibial footprint of the posterior cruciate ligament (PCL) using MRI in patients undergoing PCL-preserving total knee replacement, and to document the disruption of this footprint as a result of the tibial cut. In 26 consecutive patients plain radiography and MRI of the knee were performed pre-operatively, and plain radiography post-operatively.

The lower margin of the PCL footprint was located a mean of 1 mm (−10 to 8) above the upper aspect of the fibular head. The mean surface area was 83 mm² (49 to 142). One-third of patients (8 of 22) had tibial cuts made below the lowest aspect of the PCL footprint (complete removal) and one-third (9 of 22) had cuts extending into the footprint (partial removal). The remaining patients (5 of 22) had footprints unaffected by the cuts, keeping them intact.

Our study highlights the wide variation in the location of the tibial PCL footprint when referenced against the fibula. Proximal tibial cuts using conventional jigs resulted in the removal of a significant portion, if not all of the PCL footprint in most of the patients in our study. Our findings suggest that when performing PCL-retaining total knee replacement the tibial attachment of the PCL is often removed.

We investigated the effect of stimulation with a pulsed electromagnetic field on the osseointegration of hydroxyapatite in cortical bone in rabbits. Implants were inserted into femoral cortical bone and were stimulated for six hours per day for three weeks.

Electromagnetic stimulation improved osseointegration of hydroxyapatite compared with animals which did not receive this treatment in terms of direct contact with the bone, the maturity of the bone and mechanical fixation. The highest values of maximum push-out force (F_max) and ultimate shear strength (σ_u) were observed in the treated group and differed significantly from those of the control group at three weeks (F_max; p < 0.0001; σ_u, p < 0.0005).

A delay in establishing the diagnosis of an occult fracture of the hip that remains unrecognised after plain radiography can result in more complex treatment such as an arthroplasty being required. This might be avoided by earlier diagnosis using MRI. The aim of this study was to investigate the best MR imaging sequence for diagnosing such fractures. From a consecutive cohort of 771 patients admitted between 2003 and 2011 with a clinically suspected fracture of the hip, we retrospectively reviewed the MRI scans of the 35 patients who had no evidence of a fracture on their plain radiographs. In eight of these patients MR scanning excluded a fracture but the remaining 27 patients had an abnormal scan: one with a fracture of the pubic ramus, and in the other 26 a T₁-weighted coronal MRI showed a hip fracture with 100% sensitivity. T₂-weighted imaging was undertaken in 25 patients, in whom the diagnosis could not be established with this scanning sequence alone, giving a sensitivity of 84.0% for T₂-weighted imaging.

If there is a clinical suspicion of a hip fracture with normal radiographs, T₁-weighted coronal MRI is the best sequence of images for identifying a fracture.

We used three-dimensional movement analysis by computer modelling of knee flexion from 0° to 50° in 14 knees in 12 patients with recurrent patellar dislocation and in 15 knees in ten normal control subjects to compare the in vivo three-dimensional movement of the patella. Flexion, tilt and spin of the patella were described in terms of rotation angles from 0°. The location of the patella and the tibial tubercle were evaluated using parameters expressed as percentage patellar shift and percentage tubercle shift. Patellar inclination to the femur was also measured and patellofemoral contact was qualitatively and quantitatively analysed.

The patients had greater values of spin from 20° to 50°, while there were no statistically significant differences in flexion and tilt. The patients also had greater percentage patellar shift from 0° to 50°, percentage tubercle shift at 0° and 10° and patellar inclination from 0° to 50° with a smaller oval-shaped contact area from 20° to 50° moving downwards on the lateral facet.

Patellar movement analysis using a three-dimensional computer model is useful to clearly demonstrate differences between patients with recurrent dislocation of the patella and normal control subjects.

Advanced MRI cartilage imaging such as T₁-rho (T1ρ) for the diagnosis of early cartilage degradation prior to morpholgic radiological changes may provide prognostic information in the management of joint disease. This study aimed first to determine the normal T1ρ profile of cartilage within the hip, and secondly to identify any differences in T1ρ profile between the normal and symptomatic femoroacetabular impingement (FAI) hip. Ten patients with cam-type FAI (seven male and three female, mean age 35.9 years (28 to 48)) and ten control patients (four male and six female, mean age 30.6 years (22 to 35)) underwent 1.5T T1ρ MRI of a single hip. Mean T1ρ relaxation times for full thickness and each of the three equal cartilage thickness layers were calculated and compared between the groups. The mean T1ρ relaxation times for full cartilage thickness of control and FAI hips were similar (37.17 ms (sd 9.95) and 36.71 ms (sd 6.72), respectively). The control group demonstrated a T1ρ value trend, increasing from deep to superficial cartilage layers, with the middle third having significantly greater T1ρ relaxation values than the deepest third (p = 0.008). The FAI group demonstrated loss of this trend. The deepest third in the FAI group demonstrated greater T1ρ relaxation values than controls (p = 0.028).

These results suggest that 1.5T T1ρ MRI can detect acetabular hyaline cartilage changes in patients with FAI.

The identification of the extent of neural damage in patients with acute or chronic spinal cord injury is imperative for the accurate prediction of neurological recovery. The changes in signal intensity shown on routine MRI sequences are of limited value for predicting functional outcome. Diffusion tensor imaging (DTI) is a novel radiological imaging technique which has the potential to identify intact nerve fibre tracts, and has been used to image the brain for a variety of conditions. DTI imaging of the spinal cord is currently only a research tool, but preliminary studies have shown that it holds considerable promise in predicting the severity of spinal cord injury.

This paper briefly reviews our current knowledge of this technique.

Plasma levels of cobalt and chromium ions and Metal Artefact Reduction Sequence (MARS)-MRI scans were performed on patients with 209 consecutive, unilateral, symptomatic metal-on-metal (MoM) hip arthroplasties. There was wide variation in plasma cobalt and chromium levels, and MARS-MRI scans were positive for adverse reaction to metal debris (ARMD) in 84 hips (40%). There was a significant difference in the median plasma cobalt and chromium levels between those with positive and negative MARS-MRI scans (p < 0.001). Compared with MARS-MRI as the potential reference standard for the diagnosis of ARMD, the sensitivity of metal ion analysis for cobalt or chromium with a cut-off of > 7 µg/l was 57%. The specificity was 65%, positive predictive value was 52% and the negative predictive value was 69% in symptomatic patients. A lowered threshold of > 3.5 µg/l for cobalt and chromium ion levels improved the sensitivity and negative predictive value to 86% and 74% but at the expense of specificity (27%) and positive predictive value (44%).

Metal ion analysis is not recommended as a sole indirect screening test in the surveillance of symptomatic patients with a MoM arthroplasty. The investigating clinicians should have a low threshold for obtaining cross-sectional imaging in these patients, even in the presence of low plasma metal ion levels.

In an interdisciplinary project involving electronic engineers and clinicians, a telemetric system was developed to measure the bending load in a titanium internal femoral fixator. As this was a new device, the main question posed was: what clinically relevant information could be drawn from its application? As a first clinical investigation, 27 patients (24 men, three women) with a mean age of 38.4 years (19 to 66) with femoral nonunions were treated using the system. The mean duration of the nonunion was 15.4 months (5 to 69). The elasticity of the plate-callus system was measured telemetrically until union. Conventional radiographs and a CT scan at 12 weeks were performed routinely, and healing was staged according to the CT scans. All nonunions healed at a mean of 21.5 weeks (13 to 37). Well before any radiological signs of healing could be detected, a substantial decrease in elasticity was recorded. The relative elasticity decreased to 50% at a mean of 7.8 weeks (3.5 to 13) and to 10% at a mean of 19.3 weeks (4.5 to 37). At 12 weeks the mean relative elasticity was 28.1% (0% to 56%). The relative elasticity was significantly different between the different healing stages as determined by the CT scans.

Incorporating load measuring electronics into implants is a promising option for the assessment of bone healing. Future application might lead to a reduction in the need for exposure to ionising radiation to monitor fracture healing.

Hip arthroscopy is particularly attractive in children as it confers advantages over arthrotomy or open surgery, such as shorter recovery time and earlier return to activity. Developments in surgical technique and arthroscopic instrumentation have enabled extension of arthroscopy of the hip to this age group. Potential challenges in paediatric and adolescent hip arthroscopy include variability in size, normal developmental change from childhood to adolescence, and conditions specific to children and adolescents and their various consequences. Treatable disorders include the sequelae of traumatic and sports-related hip joint injuries, Legg–Calve–Perthes’ disease and slipped capital femoral epiphysis, and the arthritic and septic hip. Intra-articular abnormalities are rarely isolated and are often associated with underlying morphological changes.

This review presents the current concepts of hip arthroscopy in the paediatric and adolescent patient, covering clinical assessment and investigation, indications and results of the experience to date, as well as technical challenges and future directions.

This review briefly summarises some of the definitive studies of articular cartilage by microscopic MRI (µMRI) that were conducted with the highest spatial resolutions. The article has four major sections. The first section introduces the cartilage tissue, MRI and µMRI, and the concept of image contrast in MRI. The second section describes the characteristic profiles of three relaxation times (T₁, T₂ and T_1ρ) and self-diffusion in healthy articular cartilage. The third section discusses several factors that can influence the visualisation of articular cartilage and the detection of cartilage lesion by MRI and µMRI. These factors include image resolution, image analysis strategies, visualisation of the total tissue, topographical variations of the tissue properties, surface fibril ambiguity, deformation of the articular cartilage, and cartilage lesion. The final section justifies the values of multidisciplinary imaging that correlates MRI with other technical modalities, such as optical imaging. Rather than an exhaustive review to capture all activities in the literature, the studies cited in this review are merely illustrative.

The direct anterior approach in total hip replacement anatomically offers the chance to minimise soft-tissue trauma because an intermuscular and internervous plane is explored. This motivated us to abandon our previously used transgluteal approach and to adopt the direct anterior approach for total hip replacement. Using MRI, we performed a retrospective comparative study of the direct anterior approach with the transgluteal approach. There were 25 patients in each group. At one year post-operatively all the patients underwent MRI of their replaced hips. A radiologist graded the changes in the soft-tissue signals in the abductor muscles. The groups were similar in terms of age, gender, body mass index, complexity of the reconstruction and absence of symptoms.

Detachment of the abductor insertion, partial tears and tendonitis of gluteus medius and minimus, the presence of peri-trochanteric bursal fluid and fatty atrophy of gluteus medius and minimus were significantly less pronounced and less frequent when the direct anterior approach was used. There was no significant difference in the findings regarding tensor fascia lata between the two approaches.

We conclude that use of the direct anterior approach results in a better soft-tissue response as assessed by MRI after total hip replacement. However, the impact on outcome needs to be evaluated further.

We undertook a study of the anti-tumour effects of hyperthermia, delivered via magnetite cationic liposomes (MCLs), on local tumours and lung metastases in a mouse model of osteosarcoma. MCLs were injected into subcutaneous osteosarcomas (LM8) and subjected to an alternating magnetic field which induced a heating effect in MCLs. A control group of mice with tumours received MCLs but were not exposed to an AMF. A further group of mice with tumours were exposed to an AMF but had not been treated with MCLs. The distribution of MCLs and local and lung metastases was evaluated histologically. The weight and volume of local tumours and the number of lung metastases were determined. Expression of heat shock protein 70 was evaluated immunohistologically. Hyperthermia using MCLs effectively heated the targeted tumour to 45°C. The mean weight of the local tumour was significantly suppressed in the hyperthermia group (p = 0.013). The mice subjected to hyperthermia had significantly fewer lung metastases than the control mice (p = 0.005). Heat shock protein 70 was expressed in tumours treated with hyperthermia, but was not found in those tumours not exposed to hyperthermia.

The results demonstrate a significant effect of hyperthermia on local tumours and reduces their potential to metastasise to the lung.

We describe the clinical outcome of a technique of surgical augmentation of chronic massive tears of the rotator cuff using a polyester ligament (Dacron) in 21 symptomatic patients (14 men, seven women) with a mean age of 66.5 years (55.0 to 85.0). All patients had MRI and arthroscopic evidence of chronic massive tears. The clinical outcome was assessed using the Constant and Murley and patient satisfaction scores at a mean follow-up of 36 months (30 to 46).

The polyester ligament (500 mm × 10 mm) was passed into the joint via the portal of Neviaser, medial to the tear through healthy cuff. The two ends of the ligament holding the cuff were passed through tunnels made in the proximal humerus at the footprint of the insertion of the cuff. The ligament was tied with a triple knot over the humeral cortex.

All the patients remained free from pain (p < 0.001) with improvement in function (p < 0.001) and range of movement (p < 0.001). The mean pre-operative and post-operative Constant scores were 46.7 (39.0 to 61.0) and 85.4 (52.0 to 96.0), respectively (p < 0.001). The mean patient satisfaction score was 90%. There were two failures, one due to a ruptured ligament after one year and the other due to deep-seated infection. The MR scan at the final follow-up confirmed intact and thickened bands in 15 of 17 patients.

This technique of augmentation gives consistent relief from pain with improved shoulder movement in patients with symptomatic massive tears of the rotator cuff.