George P. Ashcroft

A longitudinal MRI study of muscle atrophy during lower leg immobilization following ankle fracture.

To investigate MRI biomarkers of muscle atrophy during cast immobilization of the lower leg.

Levels of systemic metal ions in patients with intramedullary nails

Background It is being increasingly recognized that orthopedic implants are associated with adverse tissue responses, mediated by degradation products. Recent interest has been focused on the production of metal ions from hip arthroplasty. Few studies have reviewed fracture fixation devices and their metal ion production Methods 61 subjects were enlisted into the study, with 3 subgroups. 21 subjects had Russell-Taylor intramedullary tibial nails in situ for 26 (21–32) months (316LVm stainless steel), 20 subjects had TriGen intramedullary tibial nails in situ for 43 (35–51) months (Ti-6Al-4V titanium alloy), and the remaining 20 subjects did not have any implant in situ and served as controls. Blood samples were taken and serum chromium, molybdenum, titanium, aluminium, and vanadium concentrations were measured using inductively coupled plasma (ICP) techniques. Results The 3 groups were matched for age, sex, and BMI. The subjects with Russell-Taylor nails had elevated levels of chromium (0.10 µg/L) with median concentrations 2.5 times higher than those of the control group. The subjects with TriGen nails had less significantly elevated levels of titanium (6.5 µg/L). Interpretation Stainless steel implants show significant differences from titanium implants in the dissemination of metal ions. Although the levels of chromium were elevated, the overall levels were modest when compared to published data regarding metal ion release and hip arthroplasty. Intramedullary nails are, however, often used in younger patients. If not removed, they may result in prolonged exposure to metal ions.

A systematic review of Tranexamic acid in hip fracture surgery

AIM To systematically examine and quantify the efficacy and safety of tranexamic acid in hip fracture surgery. METHODS A systematic literature search was conducted using Medline, EMBASE, AMED, CiNAHL, and the Cochrane Central Registry of Controlled Trials. Two assessors independently screened search outputs for potentially relevant articles which met the eligibility criteria. The primary outcome measure was requirement of post-operative blood transfusion. Risk of bias assessment was performed using the Cochrane Collaborations risk of bias tool for randomized controlled trials (RCTs) and the ROBINS-I tool for observational studies. Meta-analysis was performed to estimate risk ratio (RR), risk difference (RD) and mean difference (MD) values for dichotomous and continuous data outcomes, respectively. The interpretation of each outcome was made using the GRADE approach. RESULTS Of 102 studies identified, seven met the inclusion criteria including a total of 770 participants (TXA: 341; Control: 429). On meta-analysis, intravenous TXA resulted in a 46% risk reduction in blood transfusion requirement compared to a placebo/control group (RR: 0.54; 95% CI: 0.35-0.85; I2 : 78%; Inconsistency (χ2 ) P = <0.0001; n = 750). There was also a significantly higher post-operative haemoglobin for TXA versus placebo/control (MD: 0.81; 95% CI: 0.45-1.18; I2 : 46%; Inconsistency (χ2 ) P = 0.10; n = 638). There was no increased risk of thromboembolic events (RD: 0.01; 95% CI: -0.03, 0.05; I2 : 68%; Inconsistency (χ2 ) P = 0.007, n = 683). CONCLUSION There is moderate quality evidence that TXA reduces blood transfusion in hip fracture surgery, with low quality evidence suggesting no increased risk of thrombotic events. These findings are consistent with TXA use in other orthopaedic procedures.

Distraction lengthening of the radius for radial longitudinal instability after distal radio-ulnar subluxation and excision of the radial head: a case report

The results of late surgery for symptomatic proximal migration of the radius after resection of the radial head for trauma are usually disappointing. Ulnar variance increases when the interosseous membrane is disrupted. Its integrity should be assessed to predict the results of further surgery. We describe a 29-year-old patient in whom distraction lengthening of the radius through an Ilizarov frame allowed him to regain pain-free function of the wrist and elbow after a complex Essex-Lopresti fracture dislocation and late symptoms of ulnar carpal impingement.The results of late surgery for symptomatic proximal migration of the radius after resection of the radial head for trauma are usually disappointing. Ulnar variance increases when the interosseous membrane is disrupted. Its integrity should be assessed to predict the results of further surgery. We describe a 29-year-old patient in whom distraction lengthening of the radius through an Ilizarov frame allowed him to regain pain-free function of the wrist and elbow after a complex Essex-Lopresti fracture dislocation and late symptoms of ulnar carpal impingement.

A longitudinal study of muscle rehabilitation in the lower leg after cast removal using magnetic resonance imaging and strength assessment

Magnetic resonance imaging (MRI) was used to investigate muscle rehabilitation following cast immobilization. The aim was to explore MRI as an imaging biomarker of muscle function. Sixteen patients completed an eight-week rehabilitation programme following six weeks of cast immobilization for an ankle fracture. MRI of the lower leg was performed at two-week intervals for 14 weeks. Total volume and anatomical cross-sectional areas at 70% of the distance from lateral malleolus to tibial tuberosity (ACSA) were measured for tibialis anterior (TA), medial and lateral gastrocnemius (GM and GL) and soleus (SOL). Pennation angle of muscle fascicules was measured at the same position in GM. Fractional fat/water contents and T2 relaxation times before and after exercise were calculated. Strength was measured as maximum isometric torque developed in plantar- and dorsi-flexion. Torque increased by (mean [SD]) 1.10 (0.32) N m day−1 in males, 0.74 (0.43) N m day−1 in females in plantar-flexion (0.9% of final strength per day), and 0.36 (0.15) N m day−1 in males, 0.28 (0.19) N m day−1 in females in dorsi-flexion (1.1% per day). Neither difference between males and females was significant. Volume and ACSA of muscles recovered by week 14 apart from SOL which was still 6.8% smaller (p = 0.006) than the contralateral leg. T2 peaked at the end of the cast period for TA and SOL, and at week 8 for GM before returning to baseline. Pennation angle recovered rapidly following cast removal. Quantitative MRI can generate markers of muscle biomechanics and indicates that many of these return to baseline within eight weeks of remobilization.

Impact of trochanteric heterotopic ossification on measurement of femoral bone density following cemented total hip replacement.

During a study of bone mineral density changes around cemented femoral implants, we recognized heterotopic ossification occurring regularly in a position anterior to the greater trochanter and proximal femur. The aim of this study was to describe the incidence, distribution, and effect of this ossification on periprosthetic DXA scans following primary cemented total hip replacement. One hundre eleven patients underwent postoperative DXA examinations measuring changes in bone mineral density with heterotopic ossification identified and localized on standard radiographs with confirmation using DXA subtraction imaging. Male gender and age within the male group were significantly associated with occurrence of heterotopic ossification (p = 0.003 and 0.046, respectively). Femoral stem type, weight, and body mass index had no significant effect (p = 0.525, 0.372, and 0.243, respectively). Examining the Gruen zones in all patients suggested a median (plus interquartile range) zone 1 density drop of 4% (−12% to +7%). When separated and analyzed for the effect of heterotopic ossification, the 45 patients with heterotopic ossification showed a 2‐year density gain of +6% (−5% to +15%), whereas those without heterotopic ossification showed a loss of 8% (−14% to 0%), a significant difference (p < 0.001). Zone 2 also showed a significant difference (p = 0.048). We therefore recommend that affected zones should be identified and excluded from analysis at all time points. Without this precaution, researchers risk underestimating periprosthetic bone loss in their studies and reporting misleading conclusions.