Aims

Steroid injections are used for subacromial pain syndrome and can be administered via the anterolateral or posterior approach to the subacromial space. It is not currently known which approach is superior in terms of improving clinical symptoms and function. This is the protocol for a randomized controlled trial (RCT) to compare the clinical effectiveness of a steroid injection given via the anterolateral or the posterior approach to the subacromial space.

Aims

Frozen shoulder is a common, painful condition that results in impairment of function. Corticosteroid injections are commonly used for frozen shoulder and can be given as glenohumeral joint (GHJ) injection or suprascapular nerve block (SSNB). Both injection types have been shown to significantly improve shoulder pain and range of motion. It is not currently known which is superior in terms of relieving patients’ symptoms. This is the protocol for a randomized clinical trial to investigate the clinical effectiveness of corticosteroid injection given as either a GHJ injection or SSNB.

Abstract

Purposes of the study and background

Pain of lumbar facet-joint origin is a common cause of low back pain in adults, and may lead to chronic pain and disability. At present, there is no definitive research to support the use of targeted lumbar facet-joint injections to manage this pain.

The study's objective was to assess the feasibility of carrying out a definitive study to evaluate the clinical- and cost-effectiveness of lumbar facet-joint injections compared to a sham procedure.

Computer-aided surgical systems commonly use preoperative CT scans when performing pelvic osteotomies for intraoperative navigation. These systems have the potential to improve the safety and accuracy of pelvic osteotomies, however, exposing the patient to radiation is a significant drawback. In order to reduce radiation exposure, we propose a new smooth extrapolation method leveraging a partial pelvis CT and a statistical shape model (SSM) of the full pelvis in order to estimate a patient's complete pelvis. A SSM of normal, complete, female pelvis anatomy was created and evaluated from 42 subjects. A leave-one-out test was performed to characterise the inherent generalisation capability of the SSM. An additional leave-one-out test was conducted to measure performance of the smooth extrapolation method and an existing “cut-and-paste” extrapolation method. Unknown anatomy was simulated by keeping the axial slices of the patient's acetabulum intact and varying the amount of the superior iliac crest retained; from 0% to 15% of the total pelvis extent. The smooth technique showed an average improvement over the cut-and-paste method of 1.31 mm and 3.61 mm, in RMS and maximum surface error, respectively. With 5% of the iliac crest retained, the smoothly estimated surface had an RMS surface error of 2.21 mm, an improvement of 1.25 mm when retaining none of the iliac crest. This anatomical estimation method creates the possibility of a patient and surgeon benefiting from the use of a CAS system and simultaneously reducing the patient's radiation exposure.

Anterior Cruciate Ligament (ACL) rupture is one of the commonest injuries in sports medicine. However, the rates of the reported graft re-rupture range from 2–10%, leading to around 3000 to 10000 revision ACL reconstructions in United States per annum. Inaccurate tunnel positions are considered to be one of the commonest reasons leading to failure and subsequent revision surgery. Additionally, there remains no consensus of the optimal position for ACL reconstructions.

The positions of the bone tunnels in patients receiving ACL reconstruction are traditionally assessed using X-rays. It is well known that conventional X-ray is not a precise tool in assessing tunnel positions. Thus, there is a recent trend in using three-dimensional (3D) CT. However, routine CT carries a major disadvantage in terms of significant radiation hazard. In addition, it is both inconvenient and expensive to use CT as a regular assessment tools during the follow-up.

The goal of the present work is to develop a novel 2D-3D registration method using single X-ray image and a surface model. By performing such registration for two post-operative X-rays, we can further calculate the 3D tunnel positions after ACL reconstructions. Our framework consists of five parts: (1) a surface model of the knee, (2) a 2D-3D registration algorithm, (3) a 3D tunnel position calculation, (4) a graphic user interface (GUI), and (5) a semi-transparency rendering. Among them, the crucial part is our 2D-3D registration method that estimates the relative position of the knee model in the imaging coordinate system. Once registered, the 3D position of an ACL tunnel in the knee model is calculated from the imaging geometry. The only interaction required is to mark the ACL tunnels on the X-rays through the GUI.

We propose two 2D-3D registration methods. One is a contour-based method that uses pure geometric information. Most methods in this category accomplish the registration by extracting contours in X-rays, establishing their correspondences on the 3D model, and calculating the registration parameters. Unlike these methods, which need point-to-point correspondences, our method optimises the registration parameters in a statistical inference framework without giving or establishing point-to-point correspondences. Due to the use of the statistical inference, our method is robust to the spurs and broken contours that automatically extracted by the contour detector.

The second method takes into account both the geometric shape of the object and the intensity property (intensity changes) of the image, where the intensity changes can be detected via image gradients. The use of gradient is based on the interpretation that two images are considered similar, if intensity changes occur at the same locations. The angles between the image gradients and the projected surface normals were used as a distance measure. The summation of the measures for all projected model points gives us the gradient term, which we multiply the contour-based measurement. Multiplication is preferred over addition because addition of the terms would require both terms to be normalised.

To evaluate the feasibility of our methods, a simulation study was conducted using Digitally Reconstructed Radiographs (DRR) of a sawbone underwent a single-bundle ACL reconstruction performed by an experienced orthopedic surgeon. The real position of the bone tunnel entry point was obtained using the CT images, which were acquired using a custom-made well-calibrated cone-beam CT. The knee model was built by downsampling and smoothing the high-resolution CT reconstructions. It is important in our experiments to make the model different from the original reconstruction since this simulates the condition in which patient's CT is unavailable. Two DRRs generated from approximately anteroposterior and lateral viewpoints were used. For each DRR, 50 trials of 2D-3D registration were carried out for the femoral part using 50 different initialisations, which were randomly selected from the values independently and uniformly distributed within ±10 degrees and ±10 mm of the ground-truth.

Compared with the ground-truth established using the CT images, our single image contour-based method achieved accurate estimations in rotations and in-plane translations, which were (−0.67±1.38, −0.98±0.84, −0.42±0.71) degrees and (0.11±0.26, −0.06±1.20) mm for the anteroposterior image, and (−0.78±0.76, −0.37±0.87, 0.70±0.88) degrees and (−0.14±0.22, 0.31±0.71) mm for the lateral one, respectively. The same experiments were also performed using the second method. However, it did not produce desirable results in our experiments. The tunnel entry point was then calculated using the averaged registration result of our contour-based method. The entry point of the tunnel was obtained with high accuracy of 1.25 mm distance error from the real position of the entry point.

For the 2D-3D registration, the estimated off-plane translations showed relatively low accuracy. It is well known that the depth can be difficult to be accurately estimated using one single image. As the result showed, the accuracy in rotations and in-plane translations is more important for ACL tunnel position estimation in our framework. As for the image gradient, it is too sensitive to the small perturbation caused by image noises. A more robust way of integrating the gradient information into our contour-based method is required. We propose a novel approach for estimating the 3D position of bone tunnels in ACL reconstruction using two post-operative X-rays. It was tested in a sawbone study using DRRs. The most significant advantage of our approach is to potentially eliminate the necessity of acquiring a patient's CT. The success in developing and validating the proposed workflow will allow convenient and precise assessment of tunnel positions in ACL reconstruction with minimal risk of radiation hazard.

Introduction: Giant cell tumour of bone (GCTB) is an expansile osteolytic tumour of bone which contains numerous osteoclast-like giant cells. GCTB is a locally aggressive tumour which can cause extensive bone destruction that can be difficult to control surgically, up to 35% of cases recurring after simple curettage. Bisphosphonates are anti-resorptive agents that have proved effective in the treatment of a number of osteolytic conditions.

Methods: This study reports results from four European centres where bisphosphonates are being used to treat problematic GCTBs. Details of treatment with bisphosphonates of 25 cases of primary, recurrent and metastatic GCTBs was assessed clinically and radiologically.

Results: Most primary/recurrent tumours did not exhibit progressive enlargement and, in some cases, both primary and metastatic GCTBs showed a degree of radiological improvement following treatment. Some patients also noted relief of pain following treatment. In a few cases, no apparent treatment effect was noted and there was disease progression. Several inoperable large spinal/pelvic GCTBs remained stable in size following treatment.

Discussion: Our findings provide preliminary evidence for the use of bisphosphonates to inhibit the progressive osteolysis associated with GCTB. These agents had a beneficial clinical and/or radiological effect in most cases. This study reports results from four European centres and highlights the fact that these centres are all employing different clinical indications and different regimes of bisphosphonate treatment. Bisphosphonates have significant side effects and indications for treatment and standardisation of drug type and dosage regimes (and measurement of agreed outcome measures to determine treatment efficacy) should be established for the use of these agents to control GCTB tumour growth and osteolysis.

Giant cell tumour of bone (GCTB) is an expansile osteolytic tumour of bone which contains numerous osteoclast-like giant cells. GCTB is a locally aggressive tumour which can cause extensive bone destruction that can be difficult to control surgically, up to 35% of cases recurring after simple curettage. Bisphosphonates are anti-resorptive agents that have proved effective in the treatment of a number of osteolytic conditions.

In keeping with its known effect on osteoclasts, we found that the aminobisphosphonate zoledronate abolished in vitro lacunar resorption in cultures of osteoclasts isolated from GCTB. The effect of zoledronate and other bisphosphonates on 15 cases of recurrent primary GCTB, four of which had metastasised to the lung, was assessed clinically. Most recurrent tumours did not exhibit progressive enlargement and, in some cases, both primary and metastatic GCTBs showed a degree of radiological improvement following treatment However, tumours did not diminish in size and, in some cases, no apparent treatment effect was noted.

Our findings provide in vitro evidence for the use of bisphosphonates to inhibit the progressive osteolysis associated with GCTB. In vivo, these agents produced a degree of clinical and radiological improvement in some cases. This study reports results from three European centres where bisphosphonates are being used to treat recurrent GCTB and highlights the fact that these centres are all employing different clinical indications and different regimes of bisphosphonate treatment. Bisphosphonates have significant side effects and indications for treatment and standardisation of drug type and dosage regimes (and measurement of agreed outcome measures to determine treatment efficacy) should be established before these agents are included as part of a treatment protocol to control GCTB tumour growth and osteolysis.

Study design: To investigate the effects of muscle atrophy on back muscle fatigue:

Objective: To assess fibre type atrophy in patients undergoing surgery for pro-lapsed lumbar intervertebral disc, and to determine its effect upon EMG measures of fatigue.

Methods: Intra-operative biopsies were obtained from the erector spinae muscles of patients undergoing microdiscectomy. Mean fibre area of type I and II fibres were determined after myosin ATPase staining. Prior to surgery, EMG activity of the erector spinae muscles was recorded bilaterally at T10 and L3 whilst subjects performed the Biering-Sorensen fatigue test. Power spectral analysis indicated the initial median frequency and its rate of decline (median frequency gradient) at each recording site. Fibre type area was compared with the median frequency measures.

Subjects: 34 subjects (20 male) with intervertebral disc prolapse.

Results: Mean fibre area of type I and II fibres was 5890 ± 1947μm² and 3461 ± 1946μm² in men, and 5144 ± 1692μm² and 1945 ± 1039μm² in women, indicating marked type II fibre atrophy. Type II MFA was positively correlated with initial median frequency at L3 on the operated side (R=0.445) and negatively correlated with the maximum median frequency gradient of the four recording sites (R= −0.430).

Conclusion: Type II fibre atrophy influences EMG measures of fatigue. The decrease in initial median frequency with type II fibre atrophy probably reflects a reduced conduction velocity in these small fibres. The less negative median frequency gradient with decreased type II fibre size indicates a lower rate of fatigue which may be explained by an increased contribution to force generation from type I fibres which occupy a greater proportion of the muscle.

Introduction Twenty-one feet in fifteen patients underwent osteotomies of the calcaneus and one or more metatarsals for symptomatic cavo-varus foot deformity.

Methods Seven (nine feet) were male, and eight (12 feet) were female. The etiology included hereditary motor sensory neuropathy (HMSN) (15 feet), post-polio syndrome (two feet) sacral cord lipomeningicoccle (two feet), parietal lobe porencephalic cyst (one foot) and idiopathic peripheral neuropaty (one foot). Presenting complaints were metatarsalgia (15 feet), ankle instability (five feet and ulceration beneath the second metatarsal head (one foot). Eleven feet were assessed using the Maryland Foot Rating Score (MFRS).

Results MFRS improved from 72.1 (average) pre-operatively to 89.9 (average) post-operatively (follow-up 70.9 months average). Eight feet were assessed using the AOFAS ankle-hindfoot and midfoot scores. The AOFAS ankle-hindfoot score improved from 46.3 (average) pre-operatively to 89.1 (average) post-operatively and the AOFAS midfoot score improved from 40.9 (average) pre-operatively to 88.8 (average) post-operatively (follow-up 20.8 months average). Two patients were lost to follow-up and were not included in the study. Ankle, hindfoot and midfoot motion was maintained or improved in 16 feet. Complications included delyed union in two and non-union in three of 66 metatarsal osteotomies. While three patients required an AFO (ankle-foot orthosis) for ambulation pre-operatively, all patientrs were brace free post-operatively and expressed willingness to undergo the same procedure again if it were necessary. Weight bearing radiographs were available for 17 feet. Radiographic analysis revealed a decrease in forefoot adduction (9.6° average) and a reduction in both hindfoot (9.1° average) and forefoot cavus (10.6°) leading to an overall 13% reduction in the height of the longitudinal arch.

Conclusions Lateral sliding elevating calcaneal ostetomy combined with doso-lateral closing wedge osteotomies of one or more metatarsal bases in the severe symptomatic cavovarus foot can provide a pain free, plantigrade foot with a lowered longitudinal arch and a stable ankle without sacrificing motion.

In relation to the conduct of this study, one or more of the authors has received, or is likely to receive direct material benefits.

We have studied the influence of weight-bearing on the measurement of wear of the polyethylene acetabular component in total hip arthroplasty using two techniques. The measured vertical wear was significantly greater when radiographs were taken weight-bearing rather than with the patient supine (p = 0.001, method 1; p = 0.007, method 2). Calculations of rates of linear wear of the acetabular component were significantly underestimated (p < 0.05) when radiographs were taken supine. There are two reasons for this. First, a change in pelvic orientation when bearing weight ensures that the thinnest polyethylene is brought into relief, and secondly, the head of the femoral component assumes the position of maximal displacement along its wear path. Interpretation of previous studies on both linear and volumetric polyethylene wear in total hip arthroplasty should be reassessed in the light of these findings.