We compared the incidence of pseudotumours after large head metal-on-metal (MoM) total hip arthroplasty (THA) with that after conventional metal-on-polyethylene (MoP) THA and assessed the predisposing factors to pseudotumour formation. . From a previous randomised controlled trial which compared large head (38 mm to 60 mm) cementless MoM THA with conventional head (28 mm) cementless MoP THA, 93 patients (96 THAs: 41 MoM (21 males, 20 females, mean age of 64 years, standard deviation (. sd. ) 4) and 55 MoP (25 males, 30 females, mean age of 65 years, . sd. 5) were recruited after a mean follow-up of 50 months (36 to 64). . The incidence of pseudotumours, measured using a standardised CT protocol was 22 (53.7%) after MoM THA and 12 (21.8%) after MoP THA. Women with a MoM THA were more likely to develop a pseudotumour than those with a MoP THA (15 vs 7, odds ratio (OR) = 13.4, p < 0.001). There was a similar incidence of pseudotumours in men with MoM THAs and those with MoP THAs (7 vs 5, OR = 2.1, p = 0.30). Elevated cobalt levels (≥ 5 microgram/L) were only associated with pseudotumours in women with a MoM THA. There was no difference in mean Oxford and Harris hip scores between patients with a pseudotumour and those without. . Contrary to popular belief, pseudotumours occur frequently around MoP THAs. Women with a MoM THA and an elevated cobalt level are at greatest risk. In this study, pseudotumours had no effect on the functional outcome after either large head MoM or conventional MoP THA. Cite this article: Bone Joint J 2015;97-B:1481–7

Aims

The primary aim of this study was to establish the cost-effectiveness of the early fixation of displaced midshaft clavicle fractures.

Aims. This is a prospective randomised study which compares the radiological and functional outcomes of ring and rail fixators in patients with an infected gap (> 3 cm) nonunion of the tibia. Patients and Methods. Between May 2008 and February 2013, 70 patients were treated at our Institute for a posttraumatic osseocutaneous defect of the tibia measuring at least 3 cm. These were randomised into two groups of 35 patients using the lottery method. Group I patients were treated with a ring fixator and group II patients with a rail fixator. The mean age was 33.2 years (18 to 64) in group I and 29.3 years (18 to 65) in group II. The mean bone gap was 5.84 cm in group I and 5.78 cm in group II. The mean followup was 33.8 months in group I and 32.6 months in group II. Bone and functional results were assessed using the classification of the Association for the Study and Application of the Method of Ilizarov (ASAMI). Functional results were also assessed at six months using the short musculoskeletal functional assessment (SMFA) score. Results. The bone result was excellent, good, fair and poor in 21, 12, 0 and 2 in group I; and 14, 15, 3, and 3 in group II, respectively. The functional results were excellent, good, fair, poor and failure in 16, 17, 1, 0 and 1 in group I; and 22, 10, 0, 3 and 0 in group II, respectively. Both fixator systems achieved comparable rates of union and functional outcomes. The rate of deep pintract infection was significantly higher in the rail fixator group but patients found it more comfortable. Conclusion. We recommend the use of a ring fixator in patients with a bone gap of more than 6 cm. Patients with a bone gap up to 6 cm can be managed with either a ring or rail fixator. Cite this article: Bone Joint J 2016;98B:1399–1405

Objectives

X-linked hypophosphataemic rickets (XLHR) is a disease of impaired bone mineralization characterized by hypophosphataemia caused by renal phosphate wasting. The main clinical manifestations of the disorder are O-shaped legs, X-shaped legs, delayed growth, and bone pain. XLHR is the most common inheritable form of rickets, with an incidence of 1/20 000 in humans. It accounts for approximately 80% of familial cases of hypophosphataemia and serves as the prototype of defective tubular phosphate (PO4³⁺) transport, due to extra renal defects resulting in unregulated FGF23 activity. XLHR is caused by loss-of-function mutations in the PHEX gene. The aim of this research was to identify the genetic defect responsible for familial hypophosphataemic rickets in a four-generation Chinese Han pedigree and to analyze the function of this mutation.

Aims. To compare the gait of unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) patients with healthy controls, using a machine-learning approach. Patients and Methods. 145 participants (121 healthy controls, 12 patients with cruciate-retaining TKA, and 12 with mobile-bearing medial UKA) were recruited. The TKA and UKA patients were a minimum of 12 months post-operative, and matched for pattern and severity of arthrosis, age, and body mass index. . Participants walked on an instrumented treadmill until their maximum walking speed was reached. Temporospatial gait parameters, and vertical ground reaction force data, were captured at each speed. Oxford knee scores (OKS) were also collected. An ensemble of trees algorithm was used to analyse the data: 27 gait variables were used to train classification trees for each speed, with a binary output prediction of whether these variables were derived from a UKA or TKA patient. Healthy control gait data was then tested by the decision trees at each speed and a final classification (UKA or TKA) reached for each subject in a majority voting manner over all gait cycles and speeds. Top walking speed was also recorded. Results. 92% of the healthy controls were classified by the decision tree as a UKA, 5% as a TKA, and 3% were unclassified. There was no significant difference in OKS between the UKA and TKA patients (p = 0.077). Top walking speed in TKA patients (1.6 m/s; 1.3 to 2.1) was significantly lower than that of both the UKA group (2.2 m/s; 1.8 to 2.7) and healthy controls (2.2 m/s; 1.5 to 2.7; p < 0.001). . Conclusion. UKA results in a more physiological gait compared with TKA, and a higher top walking speed. This difference in function was not detected by the OKS. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):16–21

Aims. Cubitus varus is the most common late complication of a supracondylar fracture of the humerus in children. Correction can be performed using one of a number of techniques of osteotomy but each has disadvantages. We describe a new technique for correcting post-traumatic cubitus varus using a lateral closing wedge isosceles triangular osteotomy. Patients and Methods. A lateral closing wedge isosceles triangular osteotomy was performed in 25 patients (15 male and ten female with a mean age of 9.5 years (6 to 12)) between May 2010 and April 2013. All patients had cubitus varus secondary to malunion of a supracondylar fracture, with good function of the elbow and a full range of movement. The osteotomy lines were marked on the bone with an isosceles triangular template made before surgery, after which the osteotomy was performed leaving the medial cortex intact. Fixation was performed using two lateral 2 mm Kirschner (K)-wires and patients were immobilised in an above-elbow plaster. By six to eight weeks callus was present and the wires and cast were removed. Patients were reviewed at four and six weeks, three, six and 12 months and then every two years until skeletal maturity. Clinical and radiographic outcomes were categorised as excellent, good or poor. Results. A total of 23 patients had an excellent and two had a good outcome at a mean final follow-up of 3.4 years (two to four). The mean post-operative carrying angle in the corrected elbow was 11.7° (7° to 18°). One patient fell, displacing the osteotomy, and needed revision of the fixation. No patient had a nerve injury. Conclusion. A lateral isosceles triangular osteotomy and with K-wire fixation is a practical, effective, reliable, safe and simple method of correcting post-traumatic cubitus varus in children. It has inherent stability and excellent cosmesis without prominence of the lateral condyle. . Cite this article: Bone Joint J 2016;98-B:1521–5

Aims. We compared the outcome of total hip arthroplasty (THA) in obese patients who previously underwent bariatric surgery and those who did not, in a matched cohort study. Patients and Methods. There were 47 THAs in the bariatric group (42 patients), and 94 THAs in the comparison group (92 patients). The mean age of the patients was 57 years in both groups (24 to 79) and 57% of the patients in both groups were women. The mean time between bariatric surgery and THA was five years (four months to 12 years) in the bariatric group. The mean follow-up after THA was three years (2 to 9). . Results. The mean BMI improved from 49.7 kg/m. 2. (35 to 75) prior to bariatric surgery to 35.3 kg/m. 2 . (21 to 49) at the time of THA (p < 0.001). Patients in the comparison group had an increased risk of re-operation (Hazard Ratio (HR) 3.2; 95% confidence intervals (CI) 1.3 to 9.5, p = 0.01) and revision (HR 5.4; 95% CI 1.5 to 34.5, p = 0.01) when compared with the bariatric group. Conclusion. Patients had a dramatic improvement in BMI after bariatric surgery and those with prior bariatric surgery had a lower risk of re-operation and revision in the short- and mid-term after a subsequent THA. Larger prospective studies are required before it can be concluded that this extra surgery should be advised in these patients. Cite this article: Bone Joint J 2016;98-B:1180–4

Objectives

Preclinical data showed poly(methyl methacrylate) (PMMA) loaded with microsilver to be effective against a variety of bacteria. The purpose of this study was to assess patient safety of PMMA spacers with microsilver in prosthetic hip infections in a prospective cohort study.

Aims. Our aim was to investigate the outcomes of patients with a displaced fracture of the glenoid fossa who are treated conservatively. There is little information in the literature about the treatment of these rare injuries non-operatively. Patients and Methods. We reviewed 24 patients with a mean age of 52 years (19 to 81) at a mean of 5.6 years (11 months to 18 years) after the injury. Results. At final follow-up, the mean Constant and Murley score was 79 points (18 to 98); the mean Western Ontario Shoulder Instability Index score (WOSI) was 77% (12 to 100) and the mean Rowe score was 93 points (50 to 100). Fractures with little intra-articular displacement (≤ 3 mm) had an uneventful outcome. Those with intra-articular displacement of ≤ 3 mm had a significant better mean Constant and Murley score than those with displacement of ≥ 5 mm and/or a fracture gap of ≥ 5 mm. Poor clinical results such as nonunion and post-traumatic osteoarthritis were associated with displaced or angulated glenoid fragments and significant intra-articular displacement. Conclusion. Glenoid fossa fractures with displacement of ≥ 5 mm should be treated surgically if the patient’s condition allows. Displacement and angulation can lead to nonunion and a poor outcome if the degree of displacement results in a persistent fracture gap in the glenoid fossa or if the angulation of fragments leads to malunion. Cite this article: Bone Joint J 2016;98-B:1074–9

The most widely used classification system for acetabular fractures was developed by Judet, Judet and Letournel over 50 years ago primarily to aid surgical planning. As population demographics and injury mechanisms have altered over time, the fracture patterns also appear to be changing. We conducted a retrospective review of the imaging of 100 patients with a mean age of 54.9 years (19 to 94) and a male to female ratio of 69:31 seen between 2010 and 2013 with acetabular fractures in order to determine whether the current spectrum of injury patterns can be reliably classified using the original system. Three consultant pelvic and acetabular surgeons and one senior fellow analysed anonymous imaging. Inter-observer agreement for the classification of fractures that fitted into defined categories was substantial, (κ = 0.65, 95% confidence interval (CI) 0.51 to 0.76) with improvement to near perfect on inclusion of CT imaging (κ = 0.80, 95% CI 0.69 to 0.91). However, a high proportion of injuries (46%) were felt to be unclassifiable by more than one surgeon; there was moderate agreement on which these were (κ = 0.42 95% CI 0.31 to 0.54). Further review of the unclassifiable fractures in this cohort of 100 patients showed that they tended to occur in an older population (mean age 59.1 years; 22 to 94 vs 47.2 years; 19 to 94; p = 0.003) and within this group, there was a recurring pattern of anterior column and quadrilateral plate involvement, with or without an incomplete posterior element injury. . Cite this article: Bone Joint J 2015;97-B:1139–43

Aims

This study of patients with osteoarthritis (OA) of the hip aimed to: 1) characterize the contribution of the hip, spinopelvic complex, and lumbar spine when moving from the standing to the sitting position; 2) assess whether abnormal spinopelvic mobility is associated with worse symptoms; and 3) identify whether spinopelvic mobility can be predicted from static anatomical radiological parameters.

Aims. We undertook a prospective non-randomised radiological study to evaluate the preliminary results of using magnetically-controlled growing rods (MAGEC System, Ellipse technology) to treat children with early-onset scoliosis. Patients and Methods. Between January 2011 and January 2015, 19 children were treated with magnetically-controlled growing rods (MCGRs) and underwent distraction at three-monthly intervals. The mean age of our cohort was 9.1 years (4 to 14) and the mean follow-up 22.4 months (5.1 to 35.2). Of the 19 children, eight underwent conversion from traditional growing rods. Whole spine radiographs were carried out pre- and post-operatively: image intensification was used during each lengthening in the outpatient department. The measurements evaluated were Cobb angle, thoracic kyphosis, proximal junctional kyphosis and spinal growth from T1 to S1. Results. The mean pre-, post-operative and latest follow-up Cobb angles were 62° (37.4 to 95.8), 45.1° (16.6 to 96.2) and 43.2° (11.9 to 90.5), respectively (p < 0.05). The mean pre-, post-operative and latest follow-up T1-S1 lengths were 288.1 mm (223.2 to 351.7), 298.8 mm (251 to 355.7) and 331.1 mm (275 to 391.9), respectively (p < 0.05). In all, three patients developed proximal pull-out of their fixation and required revision surgery: there were no subsequent complications. There were no complications of outpatient distraction. Conclusions. Our study shows that MCGRs provide stable correction of the deformity in early-onset scoliosis in both primary and revision procedures. They have the potential to reduce the need for multiple operations and thereby minimise the potential complications associated with traditional growing rod systems. Cite this article: Bone Joint J 2016;98-B:1240–47

Objectives

Prosthetic joint infection (PJI) is the most common cause of arthroplasty failure. However, infection is often difficult to detect by conventional bacterial cultures, for which false-negative rates are 23% to 35%. In contrast, 16S rRNA metagenomics has been shown to quantitatively detect unculturable, unsuspected, and unviable pathogens. In this study, we investigated the use of 16S rRNA metagenomics for detection of bacterial pathogens in synovial fluid (SF) from patients with hip or knee PJI.

Aims. The interest in unicompartmental knee arthroplasty (UKA) for medial osteoarthritis has increased rapidly but the long-term follow-up of the Oxford UKAs has yet to be analysed in non-designer centres. We have examined our ten- to 15-year clinical and radiological follow-up data for the Oxford Phase III UKAs. Patients and Methods. Between January 1999 and January 2005 a total of 138 consecutive Oxford Phase III arthroplasties were performed by a single surgeon in 129 patients for medial compartment osteoarthritis (71 right and 67 left knees, mean age 72.0 years (47 to 91), mean body mass index 28.2 (20.7 to 52.2)). Both clinical data and radiographs were prospectively recorded and obtained at intervals. Of the 129 patients, 32 patients (32 knees) died, ten patients (12 knees) were not able to take part in the final clinical and radiological assessment due to physical and mental conditions, but via telephone interview it was confirmed that none of these ten patients (12 knees) had a revision of the knee arthroplasty. One patient (two knees) was lost to follow-up. Results. The mean follow-up was 11.7 years (10 to 15). A total of 11 knees (8%) were revised. The survival at 15 years with revision for any reason as the endpoint was 90.6% (95% confidence interval (CI) 85.2 to 96.0) and revision related to the prosthesis was 99.3% (95% CI 97.9 to 100). The mean total Knee Society Score was 47 (0 to 80) pre-operatively and 81 (30 to 100) at latest follow-up. The mean Oxford Knee Score was 19 (12 to 40) pre-operatively and 42 (28 to 55) at final follow-up. Radiolucency beneath the tibial component occurred in 22 of 81 prostheses (27.2%) without evidence of loosening. Conclusion. This study supports the use of UKA in medial compartment osteoarthritis with excellent long-term functional and radiological outcomes with an excellent 15-year survival rate. Cite this article: Bone Joint J 2016;98-B(10 Suppl B):41–7

There is a high risk of the development of avascular necrosis of the femoral head and nonunion after the treatment of displaced subcapital fractures of the femoral neck in patients aged < 50 years. We retrospectively analysed the results following fixation with two cannulated compression screws and a vascularised iliac bone graft. We treated 18 women and 16 men with a mean age of 38.5 years (20 to 50) whose treatment included the use of an iliac bone graft based on the ascending branch of lateral femoral circumflex artery. There were 20 Garden grade III and 14 grade IV fractures. Clinical and radiological outcomes were evaluated. The mean follow-up was 5.4 years (2 to 10). In 30 hips (88%) union was achieved at a mean of 4.4 months (4 to 6). Nonunion occurred in four hips (12%) and these patients had a mean age of 46.5 years (42 to 50) and underwent revision to a hip replacement six months after operation. The time to union was dependent on age with younger patients achieving earlier union (p < 0.001). According to the Harris hip score which was available for 27 of the 30 hips with satisfactory union, excellent results were obtained in 15 (score ≥ 90 points), fair in ten (score 80 to 90 points), and poor in two hips (≤ 80 points). One patient aged 48 years developed avascular necrosis of femoral head six years after operation and underwent total hip replacement. The management of displaced subcapital fractures of the femoral neck, in patients aged <  50 years, with two cannulated compression screws and an iliac bone graft based on the ascending branch of lateral femoral circumflex artery, gives satisfactory results with a low rate of complication including avascular necrosis and nonunion. Cite this article: Bone Joint J 2014;96-B:1024–8