Aims

Pelvic incidence (PI) is a position-independent spinopelvic parameter traditionally used by spinal surgeons to determine spinal alignment. Its relevance to the arthroplasty surgeon in assessing patient risk for total hip arthroplasty (THA) instability preoperatively is unclear. This study was undertaken to investigate the significance of PI relative to other spinopelvic parameter risk factors for instability to help guide its clinical application.

The three-dimensional (3D) correction of glenoid erosion is critical to the long-term success of total shoulder replacement (TSR). In order to characterise the 3D morphology of eroded glenoid surfaces, we looked for a set of morphological parameters useful for TSR planning. We defined a scapular coordinates system based on non-eroded bony landmarks. The maximum glenoid version was measured and specified in 3D by its orientation angle. Medialisation was considered relative to the spino-glenoid notch. We analysed regular CT scans of 19 normal (N) and 86 osteoarthritic (OA) scapulae. When the maximum version of OA shoulders was higher than 10°, the orientation was not only posterior, but extended in postero-superior (35%), postero-inferior (6%) and anterior sectors (4%). The medialisation of the glenoid was higher in OA than normal shoulders. The orientation angle of maximum version appeared as a critical parameter to specify the glenoid shape in 3D. It will be very useful in planning the best position for the glenoid in TSR.

Cite this article: Bone Joint J 2014;96-B:513–18.

We have evaluated the reliability of the measurement of radiological indicators in developmental dysplasia of the hip. Three observers each independently assessed 60 pelvic radiographs from infants aged from 3 to 36 months. Errors from the true value of a single measurement made by a single observer (E1), of the average of two measurements by a single observer (E2), and of the average of two single measurements by two different observers (E3) were established for the acetabular index of Hilgenreiner, for the assessment of superior and lateral femoral displacement and for indicators of pelvic alignment.

The errors for the assessment of the acetabular index were E1 ± 5°, E2 ± 5°, and E3 ± 3.5°. There was a significant correlation between the presence of an acetabular notch on the radiograph and an increased error in measurement (p = 0.01). Yamamuro’s measurement of lateral femoral displacement was more reliable than the Hilgenreiner distance. The errors of indicators of pelvic alignment showed a correlation with the age of the infant; the quotient of pelvic rotation was more reliable after seven months of age (p < 0.0001). The errors of the measurement of the symphysis os-ischium angle tended to increase with age and those of the measurement of the index of pelvic tilt decreased with skeletal maturation (p = 0.002).

We describe a technique for measuring the Stiffness of regenerate bone after leg lengthening. This allows early identification of slow healing by reference to normal patterns. We determined the time of removal of the fixator from clinical and radiological information independent of the stiffness result.

In a series of 30 leg lengthenings there were no refractures when the tibial stiffness had reached 15 Nm/° or the femoral stiffness 20 Nm/°. Three refractures occurred at lower stiffness values. The technique is simple to perform, will allow a reduction in plain radiography and is recommended for routine postoperative management.

Aims. Acetabular retroversion is a recognized cause of hip impingement and can be influenced by pelvic tilt (PT), which changes in different functional positions. Positional changes in PT have not previously been studied in patients with acetabular retroversion. Methods. Supine and standing anteroposterior (AP) pelvic radiographs were retrospectively analyzed in 69 patients treated for symptomatic acetabular retroversion. Measurements were made for acetabular index (AI), lateral centre-edge angle (LCEA), crossover index, ischial spine sign, and posterior wall sign. The change in the angle of PT was measured both by the sacro-femoral-pubic (SFP) angle and the pubic symphysis to sacroiliac (PS-SI) index. Results. In the supine position, the mean PT (by SFP) was 1.05° (SD 3.77°), which changed on standing to a PT of 8.64° (SD 5.34°). A significant increase in posterior PT from supine to standing of 7.59° (SD 4.5°; SFP angle) and 5.89° (SD 3.33°; PS-SI index) was calculated (p < 0.001). There was a good correlation in PT change between measurements using SFP angle and PS-SI index (0.901 in the preoperative group and 0.815 in the postoperative group). Signs of retroversion were significantly reduced in standing radiographs compared to supine: crossover index (0.16 (SD 0.16) vs 0.38 (SD 0.15); p < 0.001), crossover sign (19/28 hips vs 28/28 hips; p < 0.001), ischial spine sign (10/28 hips vs 26/28 hips; p < 0.001), and posterior wall sign (12/28 hips vs 24/28 hips; p < 0.001). Conclusion. Posterior PT increased from supine to standing in patients with symptomatic acetabular retroversion. The features of acetabular retroversion were less evident on standing radiographs. The low PT angle in the supine position is a factor in the increased appearance of acetabular retroversion. Patients presenting with symptoms of hip impingement should be assessed by supine and standing pelvic radiographs to highlight signs of acetabular retroversion, and to assist with optimizing acetabular correction at the time of surgery. Cite this article: Bone Joint J 2022;104-B(7):786–791

Aims. Guided growth using eight-plates is commonly used for correction of angular limb deformities in growing children. The principle is of tethering at the physeal periphery while enabling growth in the rest of the physis. The method is also applied for epiphysiodesis to correct limb-length discrepancy (LLD). Concerns have been raised regarding the potential of this method to create an epiphyseal deformity. However, this has not been investigated. The purpose of this study was to detect and quantify the occurrence of deformities in the proximal tibial epiphysis following treatment with eight-plates. Patients and Methods. A retrospective study was performed including 42 children at a mean age of 10.8 years (3.7 to 15.7) undergoing eight-plate insertion in the proximal tibia for correction of coronal plane deformities or LLD between 2007 and 2015. A total of 64 plates were inserted; 48 plates (34 patients) were inserted to correct angular deformities and 16 plates (8 patients) for LLD. Medical records, Picture Archive and Communication System images, and conventional radiographs were reviewed. Measurements included interscrew angle, lateral and medial plateau slope angles measured between the plateau surface and the line between the ends of the physis, and tibial plateau roof angle defined as 180° minus the sum of both plateau angles. Measurements were compared between radiographs performed adjacent to surgery and those at latest follow-up, and between operated and non-operated plateaus. Statistical analysis was performed using BMDP Statistical Software. Results. Slope angle increased in 31 (49.2%) of operated epiphyses by a mean of 5° (1° to 23°) compared with 29 (31.9%) in non-operated epiphyses (p = 0.043). Roof angle decreased in 29 (46.0%) of operated tibias and in 25 (27.5%) of non-operated ones by a mean of 5° (1° to 18°) (p = 0.028). Slope angle change frequency was similar in patients with LLD, varus and valgus correction (p = 0.37) but roof angle changes were slightly more frequent in LLD (p = 0.059) and correlated with the change in inter screw angles (r = 0.74, p = 0.001). Conclusion. The use of eight-plates in the proximal tibia for deformity correction and limb-length equalization causes a change in the bony morphology of the tibial plateau in a significant number of patients and the effect is more pronounced in the correction of LLD. Cite this article: Bone Joint J 2018;100-B:1112–16

Aims. The aims of this study were to determine the proportion of patients with outlier varus or valgus alignment in kinematically aligned total knee arthroplasty (TKA), whether those with outlier varus or valgus alignment have higher forces in the medial or lateral compartments of the knee than those with in-range alignment and whether measurements of the alignment of the limb, knee and components predict compartment forces. Patients and Methods. The intra-operative forces in the medial and lateral compartments were measured with an instrumented tibial insert in 67 patients who underwent a kinematically aligned TKA during passive movement. The mean of the forces at full extension, 45° and 90° of flexion determined the force in the medial and lateral compartments. Measurements of the alignment of the limb and the components included the hip-knee-ankle (HKA) angle, proximal medial tibial angle (PMTA), and distal lateral femoral angle (DLFA). Measurements of the alignment of the knee and the components included the tibiofemoral angle (TFA), tibial component angle (TCA) and femoral component angle (FCA). Alignment was measured on post-operative, non-weight-bearing anteroposterior (AP) scanograms and categorised as varus or valgus outlier or in-range in relation to mechanically aligned criteria. Results. The proportion of patients with outlier varus or valgus alignment was 16%/24% for the HKA angle, 55%/0% for the PMTA, 0%/57% for the DLFA, 25%/12% for the TFA, 100%/0% for the TCA, and 0%/64% for the FCA. In general, the forces in the medial and lateral compartments of those with outlier alignment were not different from those with in-range alignment except for the TFA, in which patients with outlier varus alignment had a mean paradoxical force which was 6 lb higher in the lateral compartment than those with in-range alignment. None of the measurements of alignment of the limb, knee and components predicted the force in the medial or lateral compartment. Conclusion. Although kinematically aligned TKA has a high proportion of varus or valgus outliers using mechanically aligned criteria, the intra-operative forces in the medial and lateral compartments of patients with outlier alignment were comparable with those with in-range alignment, with no evidence of overload of the medial or lateral compartment of the knee. Cite this article: Bone Joint J 2017;99-B:1319–28

Aims. After the initial correction of congenital talipes equinovarus (CTEV) using the Ponseti method, a subsequent dynamic deformity is often managed by transfer of the tendon of tibialis anterior (TATT) to the lateral cuneiform. Many surgeons believe the lateral cuneiform should be ossified before surgery is undertaken. This study quantifies the ossification process of the lateral cuneiform in children with CTEV between one and three years of age. . Patients and Methods. The length, width and height of the lateral cuneiform were measured in 43 consecutive patients with unilateral CTEV who had been treated using the Ponseti method. Measurements were taken by two independent observers on standardised anteroposterior and lateral radiographs of both feet taken at one, two and three years of age. Results. All dimensions of the lateral cuneiform on the affected side increased annually but remained smaller than the corresponding dimensions of the unaffected foot (p < 0.01). The lateral cuneiform resembled a 9 mm cube at two years and an 11 mm cube at three years. Conclusion. At one and two years, the ossification centre of the lateral cuneiform may not be large enough to accommodate a drill hole for tendon transfer. However, by three years, it has undergone sufficient ossification to do so. Cite this article: Bone Joint J 2017;99-B:1109–14

The ability to predict load-bearing capacity during the consolidation phase in distraction osteogenesis by non-invasive means would represent a significant advance in the management of patients undergoing such treatment. Measurements of stiffness have been suggested as a promising tool for this purpose. Although the multidimensional characteristics of bone loading in compression, bending and torsion are apparent, most previous experiments have analysed only the relationship between maximum load-bearing capacity and a single type of stiffness. We have studied how compressive, bending and torsional stiffness are related to the torsional load-bearing capacity of healing callus using a common set of samples of bone regenerate from 26 sheep treated by tibial distraction osteogenesis. Our findings showed that measurements of torsional, bending and compressive stiffness were all suitable as predictors of the load-bearing capacity of healing callus. Measurements of torsional stiffness performed slightly better than those of compressive and bending stiffness

Aims. Carpal malalignment after a distal radial fracture occurs due to loss of volar tilt. Several studies have shown that this has an adverse influence on function. We aimed to investigate the magnitude of dorsal tilt that leads to carpal malalignment, whether reduction of dorsal tilt will correct carpal malalignment, and which measure of carpal malalignment is the most useful. Methods. Radiographs of patients with a distal radial fracture were prospectively collected and reviewed. Measurements of carpal malalignment were recorded on the initial radiograph, the radiograph following reduction of the fracture, and after a further interval. Linear regression modelling was used to assess the relationship between dorsal tilt and carpal malalignment. Receiver operating characteristic (ROC) analysis was used to identify which values of dorsal tilt led to carpal malalignment. Results. A total of 250 consecutive patients with 252 distal radial fractures were identified. All measures of carpal alignment were significantly associated with dorsal tilt at each timepoint. This relationship persisted after adjustment for age, sex, and the position of the wrist. Capitate shift consistently had the strongest relationship with dorsal tilt and was the only parameter that was not influenced by age or the position of the wrist. ROC curve analysis identified that abnormal capitate shift was seen with > 9° of dorsal tilt. Conclusion. Carpal malalignment is related to dorsal tilt following a distal radial fracture. Reducing the fracture and improving dorsal tilt will reduce carpal malalignment. Capitate shift is easy to assess visually, unrelated to age and sex, and appears to be the most useful measure of carpal malalignment. The aim during reduction of a distal radial fracture should be to realign the capitate with the axis of the radius and prevent carpal malalignment. Cite this article: Bone Joint J 2020;102-B(1):137–143

Aims

In the UK, the agricultural, military, and construction sectors have stringent rules about the use of hearing protection due to the risk of noise-induced hearing loss. Orthopaedic staff may also be at risk due to the use of power tools. The UK Health and Safety Executive (HSE) have clear standards as to what are deemed acceptable occupational levels of noise on A-weighted and C-weighted scales. The aims of this review were to assess the current evidence on the testing of exposure to noise in orthopaedic operating theatres to see if it exceeds these regulations.

Aims. The aim of this study was to determine the influence of pelvic parameters on the tendency of patients with adolescent idiopathic scoliosis (AIS) to develop flatback deformity (thoracic hypokyphosis and lumbar hypolordosis) and its effect on quality-of-life outcomes. Patients and Methods. This was a radiological study of 265 patients recruited for Boston bracing between December 2008 and December 2013. Posteroanterior and lateral radiographs were obtained before, immediately after, and two-years after completion of bracing. Measurements of coronal and sagittal Cobb angles, coronal balance, sagittal vertical axis, and pelvic parameters were made. The refined 22-item Scoliosis Research Society (SRS-22r) questionnaire was recorded. Association between independent factors and outcomes of postbracing ≥ 6° kyphotic changes in the thoracic spine and ≥ 6° lordotic changes in the lumbar spine were tested using likelihood ratio chi-squared test and univariable logistic regression. Multivariable logistic regression models were then generated for both outcomes with odds ratios (ORs), and with SRS-22r scores. Results. Reduced T5-12 kyphosis (mean -4.3° (. sd. 8.2); p < 0.001), maximum thoracic kyphosis (mean -4.3° (. sd. 9.3); p < 0.001), and lumbar lordosis (mean -5.6° (. sd. 12.0); p < 0.001) were observed after bracing treatment. Increasing prebrace maximum kyphosis (OR 1.133) and lumbar lordosis (OR 0.92) was associated with postbracing hypokyphotic change. Prebrace sagittal vertical axis (OR 0.975), prebrace sacral slope (OR 1.127), prebrace pelvic tilt (OR 0.940), and change in maximum thoracic kyphosis (OR 0.878) were predictors for lumbar hypolordotic changes. There were no relationships between coronal deformity, thoracic kyphosis, or lumbar lordosis with SRS-22r scores. Conclusion. Brace treatment leads to flatback deformity with thoracic hypokyphosis and lumbar hypolordosis. Changes in the thoracic spine are associated with similar changes in the lumbar spine. Increased sacral slope, reduced pelvic tilt, and pelvic incidence are associated with reduced lordosis in the lumbar spine after bracing. Nevertheless, these sagittal parameter changes do not appear to be associated with worse quality of life. Cite this article: Bone Joint J 2019;101-B:1370–1378

Aims

The aim of this study is to evaluate whether acetabular retroversion (AR) represents a structural anatomical abnormality of the pelvis or is a functional phenomenon of pelvic positioning in the sagittal plane, and to what extent the changes that result from patient-specific functional position affect the extent of AR.

Aims

Spinopelvic pathology increases the risk for instability following total hip arthroplasty (THA), yet few studies have evaluated how pathology varies with age or sex. The aims of this study were: 1) to report differences in spinopelvic parameters with advancing age and between the sexes; and 2) to determine variation in the prevalence of THA instability risk factors with advancing age.

Aims

The aim of this study was to investigate the association between fracture displacement and survivorship of the native hip joint without conversion to a total hip arthroplasty (THA), and to determine predictors for conversion to THA in patients treated nonoperatively for acetabular fractures.

Aims

Total knee arthroplasty (TKA) may provoke ankle symptoms. The aim of this study was to validate the impact of the preoperative mechanical tibiofemoral angle (mTFA), the talar tilt (TT) on ankle symptoms after TKA, and assess changes in the range of motion (ROM) of the subtalar joint, foot posture, and ankle laxity.

Aims

Achieving accurate implant positioning and restoring native hip biomechanics are key surgeon-controlled technical objectives in total hip arthroplasty (THA). The primary objective of this study was to compare the reproducibility of the planned preoperative centre of hip rotation (COR) in patients undergoing robotic arm-assisted THA versus conventional THA.