The purpose of this study was to investigate the development of the osseous acetabular index (OAI) and cartilaginous acetabular index (CAI) using MRI. The OAI and CAI were measured on the coronal MR images of the hip in 81 children with developmental dysplasia of the hip (DDH), with a mean age of 19.6 months (3 to 70), and 241 normal control children with a mean age of 5.1 years (1 month to 12.5 years). Additionally the developmental patterns of the OAI and CAI in normal children were determined by age-based cross-sectional analysis.

Unlike the OAI, the normal CAI decreased rapidly from a mean of 10.17° (sd 1.60) to a mean of 8.25° (sd 1.90) within the first two years of life, and then remained constant at a mean of 8.04° (sd 1.65) until adolescence. Although no difference in OAI was found between the uninvolved hips in children with unilateral DDH and normal hips (p = 0.639), the CAI was significantly different between them both (p < 0.001). The normal CAI has fully formed at birth, and is maintained constantly throughout childhood. The CAI in the unaffected hips in children with unilateral DDH is also mildly dysplastic.

Incomplete avulsion of the proximal hamstrings can be a severely debilitating injury that causes weakness, pain while sitting and inability to run. The results of the surgical treatment of 23 consecutive patients with such injuries at least two years after surgery are described. The surgery consisted of the repair of the hamstrings directly onto the ischial tuberosity. At review, using a visual analogue scale (VAS, 0 to 100), pain while sitting improved from a mean of 40 (0 to 100) to 64 (0 to 100) (p = 0.024), weakness from a mean of 39 (0 to 90) to 76 (7 to 100) (p = 0.0001) and the ability to run from a mean of 24 (0 to 88) to 64 (0 to 95) (p = 0.0001). According to a VAS, satisfaction was rated at a mean of 81 (0 to 100) and 20 patients (87%) would have the same procedure again. Hamstring strength measured pre- and post-operatively had improved significantly from a mean of 64% (0% to 95%) to 88% (50% to 114%) compared with the normal side.

Most of these patients with symptomatic incomplete hamstring avulsions unresponsive to conservative treatment had an improved outcome after surgical repair.

The April 2012 Shoulder & Elbow Roundup³⁶⁰ looks at katakori in Japan, frozen shoulder, if shoulder impingement actually exists, shoulder arthroscopy and suprascapular nerve blocks, why shoulder replacements fail, the infected elbow replacement, the four-part fracture, the acromion index, and arm transplantation

We present the electromyographic (EMG) results ten years after open decompression of the median nerve at the wrist and compare them with the clinical and functional outcomes as judged by Levine’s Questionnaire. This retrospective study evaluated 115 patients who had undergone carpal tunnel decompression at a mean of 10.47 years (9.24 to 11.36) previously. A positive EMG diagnosis was found in 77 patients (67%), including those who were asymptomatic at ten years.

It is necessary to include both clinical and functional results as well as electromyographic testing in the long-term evaluation of patients who have undergone carpal tunnel decompression particularly in those in whom revision surgery is being considered. In doubtful cases or when there are differing outcomes, self-administered scales such as Levine’s Questionnaire should prevail over EMG results when deciding on the need for revision surgery.

We carried out a prospective, continuous study on 529 patients who underwent primary total knee replacement between January 2006 and December 2007 at a major teaching hospital. The aim was to investigate weight change and the functional and clinical outcome in non-obese and obese groups at 12 months post-operatively. The patients were grouped according to their pre-operative body mass index (BMI) as follows: non-obese (BMI < 30 kg/m²), obese (BMI ³ 30 to 39 kg/m²) and morbidly obese (BMI > 40 kg/m²). The clinical outcome data were available for all patients and functional outcome data for 521 (98.5%). Overall, 318 (60.1%) of the patients were obese or morbidly obese.

At 12 months, a clinically significant weight loss of ≥ 5% had occurred in 40 (12.6%) of the obese patients, but 107 (21%) gained weight. The change in the International Knee Society score was less in obese and morbidly obese compared with non-obese patients (p = 0.016). Adverse events occurred in 30 (14.2%) of the non-obese, 59 (22.6%) of the obese and 20 (35.1%) of the morbidly obese patients (p = 0.001).

The June 2012 Shoulder & Elbow Roundup³⁶⁰ looks at: reverse shoulder replacement; torn rotator cuffs and platelet-rich fibrin; rotator cuff repair; frozen shoulder; whether an arthroscopic rotator cuff repair actually heals; the torn rotator cuff’s effect on activities of daily living; subacromial impingement; how to improve the reliability of the Constant-Murley score; and failure of the Neer modification of an open Bankart procedure.

Radiological assessment of total and unicompartmental knee replacement remains an essential part of routine care and follow-up. Appreciation of the various measurements that can be identified radiologically is important. It is likely that routine plain radiographs will continue to be used, although there has been a trend towards using newer technologies such as CT, especially in a failing knee, where it provides more detailed information, albeit with a higher radiation exposure.

The purpose of this paper is to outline the radiological parameters used to evaluate knee replacements, describe how these are measured or classified, and review the current literature to determine their efficacy where possible.

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.

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.

We describe a symptomatic, progressive restriction of knee flexion due to an accessory quadriceps femoris in a nine-year-old girl. There was no history or findings of post-injection fibrosis, nor any obvious swelling of the affected quadriceps. At arthroscopy no intra-articular pathology was found. An accessory ‘quinticeps femoris’ was diagnosed by ultrasonography and MRI. Following excision of the muscle and tendon full flexion of the knee was regained and there was no recurrence of the contracture.

Femoroacetabular impingement is a well-documented cause of hip pain. There is, however, increasing evidence for the presence of a previously unrecognised impingement-type condition around the hip – ischiofemoral impingement. This is caused by abnormal contact between the lesser trochanter of the femur and the ischium, and presents as atypical groin and/or posterior buttock pain. The symptoms are gradual in onset and may be similar to those of iliopsoas tendonitis, hamstring injury or bursitis. The presence of ischiofemoral impingement may be indicated by pain caused by a combination of hip extension, adduction and external rotation. Magnetic resonance imaging demonstrates inflammation and oedema in the ischiofemoral space and quadratus femoris, and is distinct from an acute tear. To date this has only appeared in the specialist orthopaedic literature as a problem that has developed after total hip replacement, not in the unreplaced joint.

Dislocation of the shoulder may occur during seizures in epileptics and other patients who have convulsions. Following the initial injury, recurrent instability is common owing to a tendency to develop large bony abnormalities of the humeral head and glenoid and a susceptibility to further seizures. Assessment is difficult and diagnosis may be missed, resulting in chronic locked dislocations with protracted morbidity. Many patients have medical comorbidities, and successful treatment requires a multidisciplinary approach addressing the underlying seizure disorder in addition to the shoulder pathology. The use of bony augmentation procedures may have improved the outcomes after surgical intervention, but currently there is no evidence-based consensus to guide treatment. This review outlines the epidemiology and pathoanatomy of seizure-related instability, summarising the currently-favoured options for treatment, and their results.

This review summarises the opinions and conclusions reached from a symposium on infected total knee replacement (TKR) held at the British Association of Surgery of the Knee (BASK) annual meeting in 2011. The National Joint Registry for England and Wales reported 5082 revision TKRs in 2010, of which 1157 (23%) were caused by infection. The diagnosis of infection beyond the acute post-operative stage relies on the identification of the causative organism by aspiration and analysis of material obtained at arthroscopy. Ideal treatment then involves a two-stage surgical procedure with extensive debridement and washout, followed by antibiotics. An articulating or non-articulating drug-eluting cement spacer is used prior to implantation of the revision prosthesis, guided by the serum level of inflammatory markers. The use of a single-stage revision is gaining popularity and we would advocate its use in certain patients where the causative organism is known, no sinuses are present, the patient is not immunocompromised, and there is no radiological evidence of component loosening or osteitis.

It is our opinion that single-stage revision produces high-quality reproducible results and will soon achieve the same widespread acceptance as it does in infected hip arthroplasty.

A total of 159 patients (84 women and 75 men, mean age of 53 (20 to 87)) with subacromial impingement were randomised to treatment with subacromial injections using lidocaine with one of hyaluronic acid (51 patients), corticosteroid (53 patients) or placebo (55 patients). Patients were followed up for 26 weeks. The primary outcome was pain on a visual analogue score (VAS), and secondary outcomes included the Constant Murley score, shoulder pain score, functional mobility score, shoulder disability questionnaire and pain-specific disability score. The different outcome measures showed similar results. After three, six and 12 weeks corticosteroid injections were superior to hyaluronic acid injections and only at six weeks significantly better than placebo injections. The mean short-term reduction in pain on the VAS score at 12 weeks was 7% (sd 2.7; 97.5% confidence interval (CI) 0.207 to 1.55; p = 0.084) in the hyaluronic acid group, 28% (sd 2.8; 97.5% CI 1.86 to 3.65; p < 0.001) in the corticosteroid group and 23% (sd 3.23; 97.5% CI 1.25 to 3.26; p < 0.001) in the placebo group. At 26 weeks there was a reduction in pain in 63% (32 of 51) of patients in the hyaluronic acid group, 72% (38 of 53) of those in the corticosteroid group and 69% (38 of 55) of those in the placebo group.

We were not able to show a convincing benefit from hyaluronic acid injections compared with corticosteroid or placebo injections. Corticosteroid injections produced a significant reduction in pain in the short term (three to 12 weeks), but in the long term the placebo injection produced the best results.

Schwannomas are the most common tumours of the sheath of peripheral nerves. The clinical diagnosis is usually straightforward, but may be delayed for many years in a schwannoma of the posterior tibial nerve. The symptoms are often attributed to entrapment neuropathy or to lumbosacral radiculopathy.

We describe 25 patients with a schwannoma of the posterior tibial nerve. Only three were diagnosed within a year of presentation. The mean time to diagnosis was 86.5 months with a median of 48 months (2 to 360). All the patients complained of pain, which was felt specifically in the sole of the foot in 18. A Tinel sign was detected in all 25 patients. MRI confirmed the diagnosis in all the cases in which it had been undertaken. Surgical resection of the lesion abolished the neuropathic pain. In patients with a long history of neuropathic pain in the lower limb in whom lumbar and pelvic lesions have been excluded, a benign tumour of the sheath of a peripheral nerve may explain the symptoms. Surgical resection of the tumour is safe and effective.

Our aim in this prospective study was to evaluate the outcome of total shoulder replacement in the treatment of young and middle-aged active patients with primary glenohumeral osteoarthritis. We reviewed 21 patients (21 shoulders) with a mean age of 55 years (37 to 60). The mean follow-up was seven years (5 to 9). The same anatomical, third-generation, cemented implant had been used in all patients. All the patients were evaluated radiologically and clinically using the Constant and Murley score.

No patients required revision. In one a tear of the supraspinatus tendon occurred. Overall, 20 patients (95%) were either very satisfied (n = 18) or satisfied (n = 2) with the outcome. Significant differences (p < 0.0001) were found for all categories of the Constant and Murley score pre- and post-operatively. The mean Constant and Murley score increased from 24.1 points (10 to 45) to 64.5 points (39 to 93), and the relative score from 30.4% (11% to 50%) to 83% (54% to 116%). No clinical or radiological signs of loosening of the implant were seen.

For young and middle-aged patients with osteoarthritis, third-generation total shoulder replacement is a viable method of treatment with a low rate of complications and excellent results in the mid-term.

We reviewed 101 patients with injuries of the terminal branches of the infraclavicular brachial plexus sustained between 1997 and 2009. Four patterns of injury were identified: 1) anterior glenohumeral dislocation (n = 55), in which the axillary and ulnar nerves were most commonly injured, but the axillary nerve was ruptured in only two patients (3.6%); 2) axillary nerve injury, with or without injury to other nerves, in the absence of dislocation of the shoulder (n = 20): these had a similar pattern of nerve involvement to those with a known dislocation, but the axillary nerve was ruptured in 14 patients (70%); 3) displaced proximal humeral fracture (n = 15), in which nerve injury resulted from medial displacement of the humeral shaft: the fracture was surgically reduced in 13 patients; and 4) hyperextension of the arm (n = 11): these were characterised by disruption of the musculocutaneous nerve. There was variable involvement of the median and radial nerves with the ulnar nerve being least affected.

Surgical intervention is not needed in most cases of infraclavicular injury associated with dislocation of the shoulder. Early exploration of the nerves should be considered in patients with an axillary nerve palsy without dislocation of the shoulder and for musculocutaneous nerve palsy with median and/or radial nerve palsy. Urgent operation is needed in cases of nerve injury resulting from fracture of the humeral neck to relieve pressure on nerves.