Martyn J. Parker

Bone remodeling at the endocortical surface of the human femoral neck: a mechanism for regional cortical thinning in cases of hip fracture.

Endocortical remodeling and wall thickness (W.Th.) were measured in femoral neck bone from 12 female fracture cases (81.3 ± 1.5 years) and 12 sex‐matched controls (81.9 ± 1.9 years). Regionally, osteoid and eroded surface were increased, whereas W.Th. was reduced. These processes likely contribute to cortical bone loss seen in hip fracture.

Early surgery for patients with a fracture of the hip decreases 30-day mortality

There has been extensive discussion about the effect of delay to surgery on mortality in patients sustaining a fracture of the hip. Despite the low level of evidence provided by many studies, a consensus has been accepted that delay of > 48 hours is detrimental to survival. The aim of this prospective observational study was to determine if early surgery confers a survival benefit at 30 days. Between 1989 and 2013, data were prospectively collected on patients sustaining a fracture of the hip at Peterborough City Hospital. They were divided into groups according to the time interval between admission and surgery. These thresholds ranged from < 6 hours to between 49 and 72 hours. The outcome which was assessed was the 30-day mortality. Adjustment for confounders was performed using multivariate binary logistic regression analysis. In all, 6638 patients aged > 60 years were included. Worsening American Society of Anaesthesiologists grade (p < 0.001), increased age (p < 0.001) and extracapsular fracture (p < 0.019) increased the risk of 30-day mortality. Increasing mobility score (p = 0.014), mini mental test score (p < 0.001) and female gender (p = 0.014) improved survival. After adjusting for these confounders, surgery before 12 hours improved survival compared with surgery after 12 hours (p = 0.013). Beyond this the increasing delay to surgery did not significantly affect the 30-day mortality.

Osteocyte Density in Aging Subjects Is Enhanced in Bone Adjacent to Remodeling Haversian Systems

The osteocyte is a candidate regulatory cell for bone remodeling. Previously, we demonstrated that there is a substantial (approximately 50%) loss of osteocytes from their lacunae in the cortex of the elderly femoral neck. Higher occupancy was evident in tissue exhibiting high remodeling and high porosity. The present study examines the distribution of osteocytes within individual osteonal systems at differing stages of the remodeling cycle. In 22 subjects, lacunar density, osteocyte density, and their quotient, the percent lacunar occupancy, was assessed up to a distance of 65 microm from the canal surface in six quiescent, resorbing, and forming osteons. In both forming (p = 0.024) and resorbing (p = 0.034) osteons, osteocyte densities were significantly higher in cases of hip fracture than controls. However, there were no significant between-group differences in lacunar occupancy. In both cases and controls, osteocyte density (p < 0.0001; mean difference +/-SEM: 157 +/- 34/mm2) and lacunar occupancy (p = 0.025; mean difference: 8.1 +/- 3.4%) were shown to be significantly higher in forming compared with quiescent osteons. Interestingly, resorbing systems also exhibited significantly elevated osteocyte density in both the fracture and the control group combined (mean difference 76 +/- 23/mm2; p = 0.003). Lacunar occupancy was also greater in resorbing compared with quiescent osteons (both groups combined: p = 0.022; mean difference: 5.7 +/- 2.3%). Elevated osteocyte density and lacunar occupancy in forming compared with quiescent systems was expected because of the likely effects of aging on quiescent osteons. However, the higher levels of these parameters in resorbing compared with quiescent systems was the opposite of what we expected and suggests that, in addition to their postulated mechanosensory role in the suppression of remodeling and bone loss, osteocytes might also contribute to processes initiating or maintaining bone resorption.

Randomised trial of blood transfusion versus a restrictive transfusion policy after hip fracture surgery

BACKGROUND Debate exists as to what should be the transfusion threshold for patients with anaemia after hip fracture surgery. METHODS A total of 200 patients aged 60 years and above with a haemoglobin level of between 8.0 and 9.5gdl(-1) after hip fracture surgery were randomised to receive a transfusion to raise the haemoglobin to at least 10.0gdl(-1) or not to have a transfusion unless definite symptoms of anaemia became apparent. Patients were followed up for 1 year. RESULTS There was no statistically significant difference in the outcomes of mortality, hospital stay, regain of mobility or complications between the two groups. CONCLUSIONS This study confirms other recent research studies which found that reducing the transfusion threshold to 8.0gdl(-1) appears to be a safe practice for this group of patients.

Osteoclastic cortical erosion as a determinant of subperiosteal osteoblastic bone formation in the femoral neck's response to BMU imbalance. Effects of stance-related loading and hip fracture.

Femoral neck fractures have previously been shown to be associated with increased cortical and endocortical remodeling, reduced wall thickness of endocortical packets and cortical porosity. Femoral neck width is associated positively with history of lifetime physical activity; so we hypothesized that exposure to mechanical loading may influence the subperiosteal osteoblastic response to the weakening effect of intracortical bone resorption. In 21 femoral neck biopsies from female subjects (13 with hip fracture), there was a positive association between osteoblastic periosteal alkaline phosphatase expression shown in frozen sections and the percentage of cortical canals internal to the subperiosteal surface showing evidence of osteoclastic erosion (Goldner’s stain; p =0.03). This was stronger in the plane of locomotor loading and particularly strong in the inferior (compression) cortex ( p =0.002). In 35 cases and 23 age/gender-matched postmortem controls, osteoid-bearing cortical canals (%) were significantly elevated in the fracture cases compared with the controls within the anterior region. There was also a significant correlation between cortical and endocortical %OS/BS (percentage osteoid surface to bone surface) (fracture, n =12; control, n =12) over the whole biopsy ( p =0.041). Generally, these associations of intracortical with endocortical remodeling were consistent with both envelopes being regulated by common processes. These results support the concept that the slow growth of femoral neck width by subperiosteal apposition of bone occurs directly or, otherwise, in response to the weakening of the cortex as it is “trabecularized” by imbalance of bone multicellular units (BMU). This process, in turn, depends on cortical thinning and enlargement of canals with the formation of giant, composite osteons, the whole being more marked in cases of future hip fracture.

Cemented Thompson hemiarthroplasty versus cemented Exeter Trauma Stem (ETS) hemiarthroplasty for intracapsular hip fractures: a randomised trial of 200 patients.

Numerous different designs of hemiarthroplasty are available but few have been compared within the context of a randomised controlled trial. Two-hundred patients presenting with a displaced intracapsular fracture of the hip were randomised to receive either a cemented Thompson hemiarthroplasty or a cemented smooth tapered stem hemiarthroplasty (Exeter Trauma Stem). All operations were undertaken or directly supervised by one surgeon using the same operative approach. Patients were followed up for 1 year from injury by a research nurse blinded to the treatment used. The smooth tapered stem was felt to present less operative difficulties compared to the Thompson prosthesis. There were no other statistically significant differences in outcomes between the two prostheses.

Orthopaedic injuries associated with hip fractures in those aged over 60 years: A study of patterns of injury and outcomes for 1971 patients

INTRODUCTION There has been little research into the consequence of suffering a hip fracture and associated orthopaedic injures. The aim of this research paper is to describe the patient characteristics, patterns of injury and to define the effect on outcomes of orthopaedic injuries occurring simultaneously with hip fractures. PATIENTS AND METHODS Hip fracture data was collected prospectively. Patients under 60 years of age were excluded from the study. Between 2004 and 2010 we treated 1971 consecutive patients aged 60 years or older with a hip fracture. RESULTS 81 (4.1%) patients sustained a simultaneous fracture or dislocation. 90% (73/81) of these injuries were in the upper limb and 88% (71/81) were ipsilateral, with the wrist (34 cases) and the proximal humerus (21 cases) being the commonest site of injury. Median hospital stay was significantly longer for those with additional injures. Pubic rami fractures were not seen in association with a hip fracture. Those patients who sustained a concomitant wrist fracture tended to be slightly fitter than those without associated injuries whist those with an associated humeral fracture were slightly frailer. Mortality was increased for those with an associated proximal humeral fracture but was lower with an associated wrist fracture. DISCUSSION AND CONCLUSION Simultaneous injuries occurring with hip fractures are mainly seen in the ipsilateral upper limb. They present a greater challenge to the multidisciplinary team than a solitary hip fracture, experiencing a longer hospital stay and inevitably a higher financial cost. Those patients with wrist fractures have the best prognosis in terms of mortality, whereas a proximal humerus fracture may indicate a higher risk of mortality.

The Ratio of Osteocytic Incorporation to Bone Matrix Formation in Femoral Neck Cancellous Bone: An Enhanced Osteoblast Work Rate in the Vicinity of Hip Osteoarthritis

Recently it has been shown that an inactivating mutation in the TGFb-SMAD3 signaling pathway, which increases the conversion of osteoblasts to osteocytes, is accompanied by bone loss combined with increased osteocyte density. We hypothesized that increased matrix TGFb, known to occur in osteoarthritis, might cause the reverse of these effects in man. Because coxarthrosis (cOA) is associated with a reduced risk of femoral neck fracture, whole cross-section femoral neck biopsies were obtained from 11 patients with femoral neck fracture, 14 patients with cOA, and 22 age-and sex-matched controls. Lacunar density (Lc.mm2), osteocyte density (Ot.mm2), and cancellous wall width (Cn.W.Wi), were compared between cases of coxarthrosis, femoral neck fracture (FNF) and controls. In cOA, Lc.mm2 was reduced by 24% (P <0.001) while in FNF it was increased by 20% (P <0.001). Cn.W.Wi was increased in cOA by 22% (P <0.05) and in FNF was reduced by 27% (P <0.001). Lc.mm2 was inversely related to percentage cancellous bone area (adj. r2 = 0.373; P <0.01) and wall widths, r2 = 0.382, P <0.001. The reduction in osteocyte lacunar density coupled with increased wall width is consistant with a model of cOA effects on bone in which increased levels of matrix TGFb might prolong the effective lifespan or work rate of the osteoblast and delay its incorporation into the matrix as an osteocyte. One possible approach to strengthening bone in osteoporosis might be to enhance the effective lifespan of the osteoblast by modulating TGFb-related pathway activity in its local environment.

Osteocytic Expression of Constitutive NO Synthase Isoforms in the Femoral Neck Cortex: A Case-Control Study of Intracapsular Hip Fracture†

NO is an osteocytic signaling molecule that can inhibit osteoclasts. The NO synthases eNOS and nNOS were expressed by >50% of osteonal osteocytes in controls. Hip fracture cases showed +NOS osteocytes only in deep osteonal bone, and 25–35% reduced expression overall. These data are consistent with increased osteonal vulnerability to deep osteoclastic attack.

Lateral versus posterior approach for insertion of hemiarthroplasties for hip fractures: A randomised trial of 216 patients

Continued debate exists about the merits of the different surgical approaches for arthroplasty of the hip. For hemiarthroplasty to the hip the two most commonly used approaches are lateral and posterior. 216 patients with an intracapsular hip fracture being treated with a cemented hemiarthroplasty were randomised to surgery using either a lateral or posterior approach. Surviving patients were followed up for one year with pain and functional outcomes assessed by an assessor blinded to the treatment allocation. No statistically significant differences were observed for any of the outcome measures including mortality, degree of residual pain and regain of walking ability. A subjective assessment of the ease of surgery favoured the lateral approach. In conclusion both surgical approaches appear to produce comparable function outcomes.