Objectives. To evaluate the neck strength of school-aged rugby players, and to define the relationship with proxy physical measures with a view to predicting neck strength. Methods. Cross-sectional cohort study involving 382 rugby playing schoolchildren at three Scottish schools (all male, aged between 12 and 18 years). Outcome measures included maximal isometric neck extension, weight, height, grip strength, cervical range of movement and neck circumference. Results. Mean neck extension strength increased with age (p = 0.001), although a wide inter-age range variation was evident, with the result that some of the oldest children presented with the same neck strength as the mean of the youngest group. Grip strength explained the most variation in neck strength (R. 2. = 0.53), while cervical range of movement and neck girth demonstrated no relationship. Multivariable analysis demonstrated the independent effects of age, weight and grip strength, and the resultant model explained 62.1% of the variance in neck strength. This model predicted actual neck strength well for the majority of players, although there was a tendency towards overestimation at the lowest range and underestimation at the highest. Conclusion. A wide variation was evident in neck strength across the range of the schoolchild-playing population, with a surprisingly large number of senior players demonstrating the same mean strength as the 12-year-old mean value. This may suggest that current training regimes address limb strength but not neck strength, which may be significant for future neck injury prevention strategies. Age, weight and grip strength can predict around two thirds of the variation in neck strength, however specific assessment is required if precise data is sought

Purpose. Even though various factors have been associated with neck pain, skeletal muscle mechanical properties have been cited among the leading causes of neck pain. Changes in skeletal muscle stiffness may be related to chronic neck pain and these changes may be associated with the severity of pain and disability in patients with chronic neck pain. The purpose of the present study was to investigate differences in neck muscle stiffness between patients with chronic neck pain and asymptomatic control group. Another purpose of the study was to investigate the relationship of muscle stiffness with the severity of physical disability and pain in patients with chronic neck pain. Methods. A cross-sectional case-control study with 86 participants (43 patients with chronic neck pain and 43 age-matched asymptomatic controls) was designed. The present study included patients with a pain intensity level of 20 or more based on the Numerical Rating Scale (NRS) and a total disability level of 10 or more based on the Neck Disability Index (NDI). Ultrasonic evaluation of upper trapezius, splenius capitis, and sternocleidomastoid muscle performed with the ACUSON S3000 Ultrasonography Device using Siemens 9L4 (4–9 MHz) linear-array ultrasound probe. Shear Wave Velocity (SWV) of selected muscles was obtained using customized software, Virtual Touch Imaging and Quantification® (Siemens Medical Solution, Mountain View, CA, USA). Results. SWV of splenius capitis was similar in both groups (p=0.979); however, SWV of upper trapezius (p<0.001) and sternocleidomastoid (p=0.003) of the patients with chronic neck pain were higher compared to the asymptomatic controls groups. NRS score did not correlate with SWV of upper trapezius (r=−0.27, p=0.085), sternocleidomastoid (r=−0.02, p=0.879) and splenius capitis (r=0.01, p= 0.990). Similarly, NDI score did not correlate with SWV of upper trapezius (r=−0,09 p=0.567), sternocleidomastoid (r=0.15, p=0.345) and splenius capitis (r=0.18, p= 0.274). Conclusions. SWV of splenius capitis muscle stiffness was found similar in both groups, but SWV of upper trapezius and sternocleidomastoid muscle were found increased in patients with neck pain compared to asymptomatic controls groups. In addition, severity of pain and disability did not relate to stiffness of these muscles in patient with chronic neck pain

Aims. To propose a new method for evaluating paediatric radial neck fractures and improve the accuracy of fracture angulation measurement, particularly in younger children, and thereby facilitate planning treatment in this population. Methods. Clinical data of 117 children with radial neck fractures in our hospital from August 2014 to March 2023 were collected. A total of 50 children (26 males, 24 females, mean age 7.6 years (2 to 13)) met the inclusion criteria and were analyzed. Cases were excluded for the following reasons: Judet grade I and Judet grade IVb (> 85° angulation) classification; poor radiograph image quality; incomplete clinical information; sagittal plane angulation; severe displacement of the ulna fracture; and Monteggia fractures. For each patient, standard elbow anteroposterior (AP) view radiographs and corresponding CT images were acquired. On radiographs, Angle P (complementary to the angle between the long axis of the radial head and the line perpendicular to the physis), Angle S (complementary to the angle between the long axis of the radial head and the midline through the proximal radial shaft), and Angle U (between the long axis of the radial head and the straight line from the distal tip of the capitellum to the coronoid process) were identified as candidates approximating the true coronal plane angulation of radial neck fractures. On the coronal plane of the CT scan, the angulation of radial neck fractures (CTa) was measured and served as the reference standard for measurement. Inter- and intraobserver reliabilities were assessed by Kappa statistics and intraclass correlation coefficient (ICC). Results. Angle U showed the strongest correlation with CTa (p < 0.001). In the analysis of inter- and intraobserver reliability, Kappa values were significantly higher for Angles S and U compared with Angle P. ICC values were excellent among the three groups. Conclusion. Angle U on AP view was the best substitute for CTa when evaluating radial neck fractures in children. Further studies are required to validate this method. Cite this article: Bone Joint J 2024;106-B(9):964–969

Aims. In computer simulations, the shape of the range of motion (ROM) of a stem with a cylindrical neck design will be a perfect cone. However, many modern stems have rectangular/oval-shaped necks. We hypothesized that the rectangular/oval stem neck will affect the shape of the ROM and the prosthetic impingement. Methods. Total hip arthroplasty (THA) motion while standing and sitting was simulated using a MATLAB model (one stem with a cylindrical neck and one stem with a rectangular neck). The primary predictor was the geometry of the neck (cylindrical vs rectangular) and the main outcome was the shape of ROM based on the prosthetic impingement between the neck and the liner. The secondary outcome was the difference in the ROM provided by each neck geometry and the effect of the pelvic tilt on this ROM. Multiple regression was used to analyze the data. Results. The stem with a rectangular neck has increased internal and external rotation with a quatrefoil cross-section compared to a cone in a cylindrical neck. Modification of the cup orientation and pelvic tilt affected the direction of projection of the cone or quatrefoil shape. The mean increase in internal rotation with a rectangular neck was 3.4° (0° to 7.9°; p < 0.001); for external rotation, it was 2.8° (0.5° to 7.8°; p < 0.001). Conclusion. Our study shows the importance of attention to femoral implant design for the assessment of prosthetic impingement. Any universal mathematical model or computer simulation that ignores each stem’s unique neck geometry will provide inaccurate predictions of prosthetic impingement. Cite this article: Bone Joint Res 2021;10(12):780–789

Background: Sensorimotor mechanisms that control activation of neck and trunk muscles are important in preventing injury to spinal tissues. People with back pain often show delayed reflex activation of trunk muscles, and such impairment increases the risk of future back pain. The aim of this study was to investigate whether sensorimotor impairment is evident in patients with neck pain. Methods: Measures of sensorimotor function were assessed in fourteen patients with chronic, non-traumatic neck pain and forty healthy controls. Position sense was evaluated using the Fastrak electromagnetic tracking device to assess angular errors during head repositioning tasks. Movement sense was assessed using a KinCom dynamometer to determine the time taken to detect head motion at 1°s-1 and 10°s-1. Reflex responses were assessed using surface electromyography to determine the onset of muscle activation (reflex latency) in trapezius and sternocleidomastoid muscles, following perturbations of the head. Results: Neck pain patients showed increased angular errors in reproducing upright postures, compared to controls (2.24±1.21° vs 1.85±1.06° respectively; p=0.01), and faster movement detection times (385±98ms vs 540±182ms respectively; p=0.0052). Reflex activation of trapezius was delayed in patients, indicated by a 20ms increase in reflex latency (89±19ms vs 69±21ms in controls; p=0.0039). Conclusions: Sensorimotor function is altered in patients with neck pain. Enhanced movement detection suggests some afferents become hypersensitive in response to pain. However, impaired position sense and reflex activation suggest that some proprioceptors, including muscle spindles, develop a reduced sensitivity to mechanical stimuli. These changes may impair reflexive muscle protection and expose the cervical spine to repetitive minor injuries. Conflicts of Interest: None. Source of Funding: BBSRC (Biotechnology and Biological Sciences Research Council, U.K.)

Aims. Surgical treatment of young femoral neck fractures often requires an open approach to achieve an anatomical reduction. The application of a calcar plate has recently been described to aid in femoral neck fracture reduction and to augment fixation. However, application of a plate may potentially compromise the regional vascularity of the femoral head and neck. The purpose of this study was to investigate the effect of calcar femoral neck plating on the vascularity of the femoral head and neck. Methods. A Hueter approach and capsulotomy were performed bilaterally in six cadaveric hips. In the experimental group, a one-third tubular plate was secured to the inferomedial femoral neck at 6:00 on the clockface. The contralateral hip served as a control with surgical approach and capsulotomy without fixation. Pre- and post-contrast MRI was then performed to quantify signal intensity in the femoral head and neck. Qualitative assessment of the terminal arterial branches to the femoral head, specifically the inferior retinacular artery (IRA), was also performed. Results. Quantitative MRI revealed a mean reduction of 1.8% (SD 3.1%) of arterial contribution in the femoral head and a mean reduction of 7.1% (SD 10.6%) in the femoral neck in the plating group compared to non-plated controls. Based on femoral head quadrant analysis, the largest mean decrease in arterial contribution was in the inferomedial quadrant (4.0%, SD 6.6%). No significant differences were found between control and experimental hips for any femoral neck or femoral head regions. The inferior retinaculum of Weitbrecht (containing the IRA) was directly visualized in six of 12 specimens. Qualitative MRI assessment confirmed IRA integrity in all specimens. Conclusion. Calcar femoral neck plating at the 6:00 position on the clockface resulted in minimal decrease in femoral head and neck vascularity, and therefore it may be considered as an adjunct to laterally-based fixation for reduction and fixation of femoral neck fractures, especially in younger patients. Cite this article: Bone Jt Open 2021;2(8):611–617

Background. BANDAIDE aka Back and Neck Discomfort relief with Altered behaviour, Intelligent Postures, Dynamic movement and Exercises (ISBN - 0995676933) is a concise self-help booklet containing strengthening exercises and illustrated information to enable patients self-manage their back and neck pain. The aim of this preliminary audit was to determine patient opinion on BANDAIDE. Institutional audit approval was obtained – No. 8429. Methods and Results. BANDAIDE was distributed to 40 patients, who were asked to evaluate the booklet using the Usefulness Scale for Patient Information Material (USE). USE consists of nine positive statements which are subdivided into three sub-domains; cognition, emotional and behavioural. The cognition sub-domain assesses the knowledge obtained from the material, the emotional sub-domain evaluates the effects of the material on an individual's ability to cope with the illness and the behavioural sub-domain assesses ability to self-manage. Responders were required to rate the extent to which they agreed with each of the nine statements on a scale of 0 to 10, where 0 denotes ‘completely disagree’ and 10 denotes ‘completely agree’. Each subsection is on a scale of 0–30, with a higher score suggesting better usefulness. 23 participants provided their opinions of BANDAIDE through the USE. For the three sub-domains, the mean ratings for cognition, emotional and behavioural were 27.2, 24.7, and 26.4 respectively. Conclusions. This preliminary audit suggests that BANDAIDE provides coherent advice that enables a patient to self-manage their back and neck pain. Nevertheless, the opinions of a larger cohort should be pursued to obtain more robust conclusions. Conflict of Interest: George Ampat sells the BANDAIDE booklet online through Amazon and other platforms. S Rhodes and J Sims are employed by Talita Cumi Ltd, of which Bandaide is a trading name. Shantanu Kundu is a medical student and has no conflict of interest. Sources of funding: No funding was obtained

The vast majority of total-joint-replacement components utilized are modular to some degree. Modularity increases the surgeon’s options in both primary and revision THA. Modular prostheses allow the surgeon intra-operative versatility, allowing adjustment of leg length, offset, neck length, and version. This is particularly helpful in CHD, posttraumatic arthritis and in hip revision. Modularity may be applied also to the neck, enlarging the range of choice for difficult cases. Howeverusing of a modular interface increases risk of fretting, wear debris, and dissociation and mismatching of components. A series of 87 revision THA performed between 1997 and 2003 using modular neck was reviewed. The pros-theses are AnCA-Fit with a cementless titanium anatomical stem and Profemur with a tapered revision titanium stem. Both provided with a modular neck inserted by morse taper and a hemispheric press-fitted cup. All the implants have a ceramic-ceramic coupling. Four cases were performed due to recurrent dislocation and 83 for implant loosening. Retrieved necks were studied searching for corrosion. No cases of disassembly or fracture of the neck were observed. Two cases of dislocation were treated with brace. Analysis of retrieved necks confirmed the absence of corrosion. Leg length discrepancy decreased from 57.7% to 22%. One post-operative infection was successfully treated with debridment. Modular neck system allows to correct intraoperatively leg length and offset, choosing between five interchangeable necks available in two lengths: straight, varus-valgus, ante-retroverted. Restoration of hip biomechanics prevents instability. Removal of the neck allows a better surgical exposure when femoral stem is retained. Moreover it allows to maintain ceramic-ceramic coupling. Modular prosthesis has some problems related to risk of corrosion, fretting, fracture or dislocation of components. We observed no cases of disassembly of components or fracture and comparative analysis between retrieved necks and those experimentally studied confirmed absence of corrosion

Modular femoral stems for total hip arthroplasty (THA) were introduced to allow additional options for surgeons in controlling leg lengths, offset, and implant stability. This option is widely used in Region Emilia Romagna, Italy, where the study was conducted, having a modular neck stem nearly 35% of primary THA in 2013. Great majority of modular neck is made of Titanium alloy. The study was designed as a retrospective descriptive case series of 67 hips in patients who underwent revision of a THA. All had a Titanium modular neck. In 44 cases revision was due to breakage of the neck, in the remaining 23 it was due to different reasons unrelated to modular neck such as bone fracture, breakage of a ceramic component, cup loosening. Mean follow up was 3.5 yrs. For all patients excised capsule and surrounding tissue were graded for presence of necrosis, inflammatory exudate, lymphocytes, and wear particles using light microscopy of routine paraffin sections stained with hematoxylin and eosin. The retrieved modular neck-body and head-neck junctions were examined for evidence of fretting and corrosion. For some patient dosage of circulating Titanium was obtained. Approval was obtained from institutional review board. It resulted that a variable amount of wear was observed in the first group of patients, with no evidence of lymphocytic reaction, but with variable notes of necrosis. Broken necks showed different patterns of damage, with different degree of corrosion, beside the fatigue fracture. In the second group wear was less evident or absent and negativity of lymphocyte reaction was substantially confirmed. Circulating Titanium ions were one order of magnitude higher in first group (mean 35 micrograms /litre). It can be concluded that fracture of Titanium modular necks occurs progressively, wear does not induce lymphocytic reaction and circulating ions increase. Level of Evidence. III retrospective, comparative study. Acknowledgments. The research was funded by Ministry of Health, grant ‘Early diagnosis of pending failure…’RF 20091472961

The author's experience is with a specific type of femoral stem and modular neck both fabricated from Ti alloy. Fracture of this Ti-Ti modular neck is associated with heavy weight, heavy activity, long modular necks and corrosion at the junction of the neck to the stem. Instruments have been designed that can remove the distal fragment of the fractured modular neck in most cases. After the neck is removed, the clinician is faced with the decision to remove the stem or to place another modular neck. At present MicroPort (formerly Wright Medical Technology) the company whose modular neck forms the data for this presentation, suggests that the female part of the taper (that is the part at the top of the stem) should not be reused if a modular neck (fractured or intact) has been removed. Thus the recommendation from the company is that the stem be removed. This recommendation is true across all modular neck – femoral stem combinations particularly for those that have been recalled by the manufacturer. There is no question that the female taper is changed by having had the modular neck implanted. In most cases of fracture there is severe corrosion at the junction of the neck to stem. Thus, reuse of the taper could have problems and it is understandable that the company does not sanction its reuse. On the other hand, removal of a well-fixed ingrown stem is not without morbidity. In several cases, with patient informed consent, I have left the stem and implanted a new modular neck (either CoCr or Ti alloy) in the damaged taper. We are following these patients closely and it is too soon to make recommendations as to the wisdom of this practice. My strong recommendation is to remove the stem and place a new one

Fracture of the Ti-Ti modular neck is associated with heavy weight, heavy activity, long modular necks and corrosion of the junction of the neck to the stem. Instruments have been designed that can remove the distal fragment of the fractured modular neck in most cases. These instruments will be demonstrated in this video. After the neck is removed, the clinician is faced with the decision to remove the stem or to place another modular neck. At present MicroPort (formerly Wright Medical Technology) the company whose modular neck I used, suggests that the female part of the taper (that is the part at the top of the stem) should not be reused if a modular neck (fractured or intact) has been removed. There is no question that the female taper is changed by having had the modular neck implanted. In most cases of fracture there is severe corrosion at the junction of the neck to stem. Thus, reuse of the taper could have problems and it is understandable that the company does not sanction its reuse. On the other hand, removal of a well-fixed ingrown stem is not without morbidity. In several cases, with patient informed consent, I have left the stem and implanted a new modular neck (either CoCr and Ti alloy) in the damaged taper. We are following these patients closely and it is too soon to make recommendations as to the wisdom of this practice. My strong recommendation is to remove the stem and place a new one

Neck modularity has been proposed to improve THA accuracy, thanks to the close restoration of anatomy, however it has been associated with issues like early breakages or corrosion. Our Hospital has been using neck modularity since the 90s, so we analyzed retrospectively implants performed between January 2000 and December 2014. The minimum follow up was 1Y. The cohort was composed of 1,033 THAs or 951 patients (82 bilateral), of which 643 females and 390 males. Average patient age was 67.7Y. THA indications were primary Osteoarthritis (80.9%), Fracture (9.0%), Congenital Dysplasia or Congenital Luxation (4.2%), Osteonecrosis (3.2%), other causes (2,7%). The stems used were all cementless, 381 anatomically shaped (36.9%), 635 straight (61.5%), 17 short MIS (1.6%). All necks used were made of Titanium alloy. 419 implants (40.5%) were manufactured by Wright Medical, while 614 (59.5%) were produced by Adler Ortho. A total of 37 revisions has been reported, mainly due to periprosthetic fractures (32.4%), luxation (24.3%), implant mobilization (18.9%) and implant breakage (16.2%). We have recorded 3 modular neck breakages. 4 patients required re-revisions, because of luxations (3) and neck breakage (1). The overall survival rate was 96.4%. We did not observe any component corrosion, probably thanks to the exclusive use of Titanium necks. We had a neck breakages rate of 0.29% and a luxation rate of 0.87%, lower than normally reported in the literature. In conclusion, our experience suggests as neck modularity could be a safe and effective way to reconstruct the proximal femur in THA patients

Trauma & Orthopaedic Department, Bronglais Hospital & Hywel Dda University Health Board, Aberystwyth, UK. Auto-CAD study is done to observe the effects of head neck ratio (HNR) in joint replacements. Total hip replacement joints were reconstructed on CAD with increasing diameter of the head keeping neck diameter constant in 1997. Simulation was done and Range of Movement (ROM), impingement and stability of the hip joint was noted. A graph was plotted with HNR on X-axis and ROM on Y-axis. It was observed that as the HNR increases the ROM of the joint is increased, impingement is reduced and stability is also increased. It is also observed that diameter of the head and neck is more important than considering only head diameter of the hip joint. The graphical analysis confirms that different diameters of the head may have same HNR depending on the neck diameter. So even in smaller diameter head the HNR may be more due to smaller diameter neck and may be more advantages than larger diameter head with bigger neck having smaller HNR. We conclude that HNR is more important than the head diameter alone in hip replacements

Modular femoral stems for total hip arthroplasty (THA) were introduced to allow additional options for surgeons in controlling leg lengths, offset and implant stability. This option is widely used in our Region, where the study was conducted, having a modular neck stem nearly 35% of primary THA in 2013. Great majority of modular neck is made of Titanium alloy. The study was designed as a retrospective descriptive case series of 67 hips in patients who underwent revision of a THA. All had a Titanium modular neck. In 44 cases revision was due to breakage of the neck, in the remaining 23 it was due to different reasons unrelated to modular neck such as bone fracture, breakage of a ceramic component, cup loosening. Mean follow up was 3.5 yrs. For all patients excised capsule and surrounding tissue were graded for presence of necrosis, inflammatory exudate, lymphocytes, and wear particles using light microscopy of routine paraffin sections stained with hematoxylin and eosin. The retrieved modular neck-body and head-neck junctions were examined for evidence of fretting and corrosion. For some patient dosage of circulating Titanium was obtained. Approval was obtained from institutional review board. It resulted that a variable amount of wear was observed in the first group of patients, with no evidence of lymphocytic reaction, but with variable notes of necrosis. Broken necks showed different patterns of damage, with different degree of corrosion, beside the fatigue fracture. In the second group wear was less evident or absent and negativity of lymphocyte reaction was substantially confirmed. Circulating Titanium ions were one order of magnitude higher in first group (mean 35 micrograms /liter). It can be concluded that fracture of Titanium modular necks occurs progressively, wear does not induce lymphocytic reaction and circulating ions increase

Auto-CAD study is done to observe effects of head neck ratio (HNR) in hip replacements. Total hip replacement joints were reconstructed on CAD with increasing diameter of the head keeping neck diameter constant in 1997. Simulation was done and Range of Movement (ROM), impingement and stability of the hip joint was noted. A graph was plotted with Head Neck Ratio (HNR) on X-axis and ROM on Y-axis. It was observed that as the HNR increases the ROM of the joint is increased, impingement is reduced and stability is also increased. It is also observed that diameter of the head and neck is more important than considering only head diameter of the hip joint. The graphical analysis confirms that different diameters of the head may have same HNR depending on the neck diameter. So even in smaller diameter head the HNR may be more due to smaller diameter neck and may be more advantages than larger diameter head with bigger neck having smaller HNR. We conclude that HNR is more important than the head diameter alone in hip replacements

Introduction: Metal on metal hip resurfacing arthroplasty(MoMHRA) is an alternative option to THR in the treatment of young adults with OA. A recognised MoMHRA complication is the development of an inflammatory pseudotumour(IP). Diagnosis is made with the aid of US and/or MRI. To-date, no radiographic indication of the presence of IP has been identified. Neck thinning is a recognised phenomenon in MoMHRA hips not associated with any adverse clinical events. Its pathogenesis is considered multi-factorial. Our aim was to establish whether excessive neck narrowing is associated with the presence of a pseudotumour. Methods: Twenty-seven hips (26 patients) with IP confirmed clinically, radiologically, intra-operatively and histologically were matched for sex, age, pre-operative diagnosis, component size and follow-up with an asymptomatic MoMHRA cohort (Control n=60). For all patients, prosthesis-neck-ratio(PNR) was measured on plain AP pelvic radiographs post-operatively and at follow-up as previously described and validated. Results: All IP patients (4M:23F) and all (12M:48F) but two controls had a posterior approach at the time of MoMHRA. Post-operatively, there was no difference in the PNR between the two groups (p=0.19). At an average follow up of 3.5 years (range:0.7–8.3), IP patients(mean 1.26, 1.10–1.79) had a significantly higher (p< 0.0001) PNR in comparison to their controls(mean 1.14, 1.03–1.35). Greater neck narrowing occurred in both genders. IP necks had narrowed by an average of 8% (range:3–23). The degree of neck narrowing was correlated with length of survival of implant (p=0.001). Discussion: This study shows a strong association between IP and neck narrowing. Processes such as impingement and increased wear are considered to be involved in the pathogenesis of both IP and neck narrowing. Furthermore, the presence of an IP, could lead to altered vascularity via a mass effect and further contribute to neck narrowing. Neck narrowing in symptomatic MOMHRA patients should alert surgeons of the possible presence of IP

Introduction. One of the objectives of total hip arthroplasty is to restore femoral and acetabular combined anteversion. It is desirable to reproduce both femoral and acetabular antevesions to maximize the acetabular cup fixation coverage and hip joint stability. Studies investigated the resultant of implanted femoral stem anteversion in western populations showed that the implanted femoral stems had only a small portion can meet the desirable femoral anteversion angle. 1. , and anteversion angle increases after the implantation of an anatomical femoral stem with anteverted stem neck comparing to anatomical femoral neck. 2. The purpose of this study was to anatomically measure the anteversion angular difference between metaphyseal long axis and femoral neck in normal Chinese population. The metaphyseal long axis represents the coronal fixation plane of modern cementless medial-lateral cortical fitting taper stem. This angular difference or torsion Δ angle provides the estimation of how much the neck antevertion angle of femoral stem would be needed to match for desirable anatomical femoral neck version. Methods. 140 (77 male and 63 female) anonymous normal adult Chinese CT data with average age of 54.6 (male 54.6, female 54.5, P=0.95) were segmented and reconstructed to 3D models in Trauson Orthopeadic Modeling and Analytics (TOMA) program. Femoral head center, femoral neck axis and center point of diaphyseal canal 100mm bellow calcar formed the femoral neck plane. The metaphyseal stem implantation plane was determined by the center point of medial calcar, proximal canal central axis formed by femoral neck plane and the center point of diaphyseal canal 100mm bellow calcar. [Fig. 1] The angle between two planes was the torsion Δ angle between femoral placement plane and anatomical femoral neck. [Fig. 2] The torsion Δ angles were measured for all 140 cases. The traditional anteversion angle for anatomical femoral neck was also measured by Murphy's method. Student T test was perform to compare the angles for male and female. The 98% confidence level was assumed. Results. The average torsion Δ angle for whole population was 4.9°(0.04°-15.6°), SD=3.52°, male: 4.6° (0.42°-13.9°), SD=3.09°; female: 5.3° (0.04°-15.6°), SD=3.98°. There was no statistical significant difference between genders. P=0.28. All metaphyseal stem placement planes were less anteverted than anatomical femoral neck plane. [Fig. 3] The average anatomical femoral neck anteversion angle for total population was 18.6° (0.27°-42.6°), SD=7.54°; male: 18.6° (0.27°-32.9°), SD=7.37°; female: 18.7° (1.74°-42.6°), SD=7.81°. There was no statistical significance between male and female P=0.92. Only 26% of study population or 37 cases with unadjusted implant neck version had normal anteversion angle of 10°-15° (Tönnis). Discussion. The study suggested femoral stem neck anteversion angle adjustments up to 11° was necessary to match anatomical femoral neck for 94% of cases in Chinese population. And the adjustments of 0°-7° represented the 76% majority of population. This finding was in agreement with the published data in western population. 2. . Significance. Variable femoral stem neck anteversion angles up to 11° are necessary to reproduce the anatomical anteversions for 94% of normal Chinese population. For any figures or tables, please contact the authors directly

In conventional DXA (Dual-energy X-ray Absorptiometry) analysis, pixel bone mineral density (BMD) is often averaged at the femoral neck. Neck BMD constitutes the basis for osteoporosis diagnosis and fracture risk assessment. This data averaging, however, limits our understanding of localised spatial BMD patterns that could potentially enhance fracture prediction. DXA region free analysis (RFA) is a validated toolkit for pixel-level BMD analysis. We have previously deployed this toolkit to develop a spatio-temporal atlas of BMD ageing in the femur. This study aims first to introduce bone age to reflect the overall bone structural evolution with ageing, and second to quantify fracture-specific patterns in the femur. The study dataset comprised 4933 femoral DXA scans from White British women aged 75 years or older. The total number of fractures was 684, of which 178 were reported at the hip within a follow-up period of five years. BMD maps were computed using the RFA toolkit. For each BMD map, bone age was defined as the age for which the L2-norm between the map and the median atlas at that age is minimised. Next, bone maps were normalised for the estimated bone age. A t-test followed by false discovery rate (FDR) analysis was applied to compare between fracture and non-fracture groups. Excluding the ageing effect revealed subtle localised patterns of loss in BMD oriented in the same direction as principal tensile curves. A new score called f-score was defined by averaging the normalised pixel BMD values over the region with FDR q-value less than 1e–6. The area under the curve (AUC) was 0.731 (95% confidence interval (CI)=0.689–0.761) and 0.736 (95% CI=0.694–0.769) for neck BMD and f-score. Combining bone age and f-score improved the AUC significantly by 3% (AUC=0.761, 95% CI=0.756–0.768) over the neck BMD alone (AUC=0.731, 95% CI=0.726–0.737). This technique shows promise in characterizing spatially-complex BMD changes, for which the conventional region-based technique is insensitive. DXA RFA shows promise to further improve fracture prediction using spatial BMD distribution

Distal neck modularity places a modular connection at a mechanically critical location which is also the location that confers perhaps the greatest clinical utility. Assessment of femoral anteversion in 342 of our total hip replacement (THR) patients by CT showed a range from −24 to 61 degrees. The use of monoblock stems in some of these deformed femurs therefore must result in a failure to appropriately reconstruct the hip and have increased risks of impingement, instability, accelerated bearing wear or fracture, and adverse local tissue reaction (ALTR). However, the risks of failing to properly reconstruct the hip without neck modularity must be weighed against the additional risks introduced by neck modularity. There are several critical design, material, and technique variables that are directly associated with higher or lower incidences of problems associated with modular neck femoral components. Unfortunately, in vitro testing of the fatigue strength of these constructs has failed to predict their behavior in vivo. Designs predicted to tolerate loads that far exceed those experienced in vivo still fail at unacceptably high rates. Titanium alloy neck components subjected to the stresses at the neck-stem junction continue to fail at an unacceptable incidence. CoCr alloy neck components, while theoretically stronger, still fracture and are further compromised by mechanically assisted crevice corrosion, metal hypersensitivity, and rarely, adverse tissue reaction. Designs that have proven clinical strength and utility universally have larger, more robust junctions that extend into the metaphysis of the femur. While these designs are primarily designed for revision THR, they are occasionally indicated for primary THR. Overall, however, while design options at the neck-stem junction have unmatched clinical utility, no design that does not extend into the metaphysis has proven to be universally reliable. While routine use for primary THR does not appear clinically indicated based on current evidence, modular designs with proven successful proximal junctions appear to be indicated for extreme version or anatomical circumstances

Talar neck fractures are associated with high complication rates with significant associated morbidity. Adequate exposure and stable internal fixation remains challenging. We investigated the anterior extensile approach for exposure of these fractures and their fixation by screws introduced through the talo-navicular articulation. We also compared the quality and quantity of exposure of the talar neck obtained by this approach, with the classically described medial/lateral approaches. An anterior approach to the talus between the tibialis anterior and the extensor hallucis tendons protecting both the superficial and deep peroneal nerves was performed on 5 fresh frozen cadaveric ankles . The surface area of talar neck accessible was measured using an Immersion Digital Microscribe and analysed with Rhinoceros 3D graphics package. Standard antero-medial and antero –lateral approaches were also carried out on the same ankles, and similar measurements taken. Seven talar neck fractures underwent operative fixation using the anterior approach with parallel cannulated screws inserted through the talo-navicular joint. 3D mapping demonstrated that the talar surface area visible by the anterior approach (mean 1200sqmm) is consistently superior to that visible by either the medial or lateral approaches in isolation or in combination. Medial malleolar osteotomy does not offer any additional visualisation of the talar neck. 3D reconstruction of the area visualised by the three approaches confirms that the anterior approach provides superior access to the entirety of the talar neck. 5 male and 2 female patients were reviewed. All had anatomical articular restoration, and no wound problems. None developed non union or AVN. The anterior extensile approach offers superior visualisation of the talar neck in comparison to other approaches for anatomical articular restoration. We argue that this approach is safe, adequate and causes less vascular disruption