Aims. With the ageing population, fragility fractures have become one of the most common conditions. The objective of this study was to investigate whether microbiological outcomes and fracture-healing in osteoporotic bone is worse than normal bone with fracture-related infection (FRI). Methods. A total of 120 six-month-old Sprague-Dawley (SD) rats were randomized to six groups: Sham, sham + infection (Sham-Inf), sham with infection + antibiotics (Sham-Inf-A), ovariectomized (OVX), OVX + infection (OVX-Inf), and OVX + infection + antibiotics (OVX-Inf-A). Open femoral diaphysis fractures with Kirschner wire fixation were performed. Staphylococcus aureus at 4 × 10. 4. colony-forming units (CFU)/ml was inoculated. Rats were euthanized at four and eight weeks post-surgery. Radiography, micro-CT, haematoxylin-eosin, mechanical testing, immunohistochemistry (IHC), gram staining, agar plating, crystal violet staining, and scanning electron microscopy were performed. Results. Agar plating analysis revealed a higher bacterial load in bone (p = 0.002), and gram staining showed higher cortical bone colonization (p = 0.039) in OVX-Inf compared to Sham-Inf. OVX-Inf showed significantly increased callus area (p = 0.013), but decreased high-density bone volume (p = 0.023) compared to Sham-Inf. IHC staining showed a significantly increased expression of TNF-α in OVX-Inf compared to OVX (p = 0.049). Significantly reduced bacterial load on bone (p = 0.001), enhanced ultimate load (p = 0.001), and energy to failure were observed in Sham-Inf-A compared to Sham-Inf (p = 0.028), but not in OVX-Inf-A compared to OVX-Inf. Conclusion. In osteoporotic bone with FRI, infection was more severe with more bone lysis and higher bacterial load, and fracture-healing was further delayed. Systemic antibiotics significantly reduced bacterial load and enhanced callus quality and strength in normal bone with FRI, but not in osteoporotic bone. Cite this article: Bone Joint Res 2022;11(2):49–60

1. The appearance of decalcified bone matrix in the electron microscope is described. 2. In the matrix two types of collagen fibril have been distinguished. Differences observed are in solubility, x-ray diffraction pattern and appearance. In infant bone the form which appears as fine fibrils predominates. In adult bone the form which appears as tubular fibrils of larger diameter predominates. 3. In bones from elderly subjects the chemical reaction employed to convert collagen into eucollagen sometimes hydrolyses fatty acid esters, and lines due to the free fatty acid are found on the x-ray diffraction patterns of the insoluble residue after citrate extraction. 4. In ancient bones and fossils the stable tubular form of collagen survives, but not the fine fibrils. 5. When decalcified, the matrix in osteoporotic bones loses its architecture and fibrillar form. Under conditions in which only a small fraction is dissolved from normal bone most of the collagen in osteoporotic bone disperses in citric acid. The insoluble residue then gives a modified x-ray diffraction pattern. 6. Evidence has been produced to suggest that the immediate cause of many forms of osteoporosis is some local factor affecting the osteocytes, rather than a general chemical effect

Intramedullary rods manufactured from polyacetal were used to fix diaphyseal fractures in osteoporotic bone. They are pliable and can be introduced without further damage to such bone. Their low elastic modulus induces abundant callus. They can be locked with cortical bone screws without the need of jigs or radiographic control. Nine femoral and five tibial fractures were fixed in 10 patients, all with osteoporosis; 13 united primarily; one required bone grafting. No implant broke; however, no ambulant patient weighed more than 75 kg. The rods offer a promising treatment for diaphyseal fractures in osteoporotic bone

We investigated several factors which affect the stability of cortical screws in osteoporotic bone using 18 femora from cadavers of women aged between 45 and 96 years (mean 76). We performed bone densitometry to measure the bone mineral density of the cortical and cancellous bone of the shaft and head of the femur, respectively. The thickness and overall bone mass of the cortical layer of the shaft of the femur were measured using a microCT scanner. The force required to pull-out a 3.5 mm titanium cortical bone screw was determined after standardised insertion into specimens of the cortex of the femoral shaft. A significant correlation was found between the pull-out strength and the overall bone mass of the cortical layer (r. 2. = 0.867, p < 0.01) and also between its thickness (r. 2. = 0.826, p < 0.01) and bone mineral density (r. 2. = 0.861, p < 0.01). There was no statistically significant correlation between the age of the donor and the pull-out force (p = 0.246), the cortical thickness (p = 0.199), the bone mineral density (p = 0.697) or the level of osteoporosis (p = 0.378). We conclude that the overall bone mass, the thickness and the bone mineral density of the cortical layer, are the main factors which affect the stability of a screw in human female osteoporotic cortical bone

Introduction. The objective of this study was to determine if a synthetic bone substitute would provide results similar to bone from osteoporotic femoral heads during in vitro testing with orthopaedic implants. If the synthetic material could produce results similar to those of the osteoporotic bone, it could reduce or eliminate the need for testing of implants on bone. Methods. Pushout studies were performed with the dynamic hip screw (DHS) and the DHS Blade in both cadaveric femoral heads and artificial bone substitutes in the form of polyurethane foam blocks of different density. The pushout studies were performed as a means of comparing the force displacement curves produced by each implant within each material. Results. The results demonstrated that test material with a density of 0.16 g/cm. 3. (block A) produced qualitatively similar force displacement curves for the DHS and qualitatively and quantitatively similar force displacement curves for the DHS Blade, whereas the test material with a density of 0.08 g/cm. 3. (block B) did not produce results that were predictive of those recorded within the osteoporotic cadaveric femoral heads. Conclusion. This study demonstrates that synthetic material with a density of 0.16 g/cm. 3. can provide a good substitute for cadaveric osteoporotic femoral heads in the testing of implants. However we do recognise that no synthetic material can be considered as a definitive substitute for bone, therefore studies performed with artificial bone substrates may need to be validated by further testing with a small bone sample in order to produce conclusive results

We implanted nails made of titanium (Ti6Al4V) and of two types of glass ceramic material (RKKP and AP40) into healthy and osteopenic rats. After two months, a histomorphometric analysis was performed and the affinity index calculated. In addition, osteoblasts from normal and osteopenic bone were cultured and the biomaterials were evaluated in vitro.

In normal bone the rate of osseointegration was similar for all materials tested (p > 0.5) while in osteopenic bone AP40 did not osseointegrate (p > 0.0005).

In vitro, no differences were observed for all biomaterials when cultured in normal bone-derived cells whereas in osteopenic-bone-derived cells there was a significant difference in some of the tested parameters when using AP40.

Our findings suggest that osteopenic models may be used in vivo in the preclinical evaluation of orthopaedic biomaterials. We suggest that primary cell cultures from pathological models could be used as an experimental model in vitro.

Despite being one of the most common injuries around the elbow, the optimal treatment of olecranon fractures is far from established and stimulates debate among both general orthopaedic trauma surgeons and upper limb specialists. It is almost universally accepted that stable non-displaced fractures can be safely treated nonoperatively with minimal specialist input. Internal fixation is recommended for the vast majority of displaced fractures, with a range of techniques and implants to choose from. However, there is concern regarding the complication rates, largely related to symptomatic metalwork resulting in high rates of implant removal. As the number of elderly patients sustaining these injuries increases, we are becoming more aware of the issues associated with fixation in osteoporotic bone and the often fragile soft-tissue envelope in this group. Given this, there is evidence to support an increasing role for nonoperative management in this high-risk demographic group, even in those presenting with displaced and/or multifragmentary fracture patterns. This review summarizes the available literature to date, focusing predominantly on the management techniques and available implants for stable fractures of the olecranon. It also offers some insights into the potential avenues for future research, in the hope of addressing some of the pertinent questions that remain unanswered. Cite this article: Bone Joint J 2023;105-B(2):112–123

Objectives. We aimed to further evaluate the biomechanical characteristics of two locking screws versus three standard bicortical screws in synthetic models of normal and osteoporotic bone. Methods. Synthetic tubular bone models representing normal bone density and osteoporotic bone density were used. Artificial fracture gaps of 1 cm were created in each specimen before fixation with one of two constructs: 1) two locking screws using a five-hole locking compression plate (LCP) plate; or 2) three non-locking screws with a seven-hole LCP plate across each side of the fracture gap. The stiffness, maximum displacement, mode of failure and number of cycles to failure were recorded under progressive cyclic torsional and eccentric axial loading. Results. Locking plates in normal bone survived 10% fewer cycles to failure during cyclic axial loading, but there was no significant difference in maximum displacement or failure load. Locking plates in osteoporotic bone showed less displacement (p = 0.02), but no significant difference in number of cycles to failure or failure load during cyclic axial loading (p = 0.46 and p = 0.25, respectively). Locking plates in normal bone had lower stiffness and torque during torsion testing (both p = 0.03), but there was no significant difference in rotation (angular displacement) (p = 0.84). Locking plates in osteoporotic bone showed lower torque and rotation (p = 0.008), but there was no significant difference in stiffness during torsion testing (p = 0.69). Conclusions. The mechanical performance of locking plate constructs, using only two screws, is comparable to three non-locking screw constructs in osteoporotic bone. Normal bone loaded with either an axial or torsional moment showed slightly better performance with the non-locking construct

Objectives. Fractures of the proximal femur are a common clinical problem, and a number of orthopaedic devices are available for the treatment of such fractures. The objective of this study was to assess the rotational stability, a common failure predictor, of three different rotational control design philosophies: a screw, a helical blade and a deployable crucifix. Methods. Devices were compared in terms of the mechanical work (W) required to rotate the implant by 6° in a bone substitute material. The substitute material used was Sawbones polyurethane foam of three different densities (0.08 g/cm. 3. , 0.16 g/cm. 3. and 0.24 g/cm. 3. ). Each torsion test comprised a steady ramp of 1°/minute up to an angular displacement of 10°. Results. The deployable crucifix design (X-Bolt), was more torsionally stable, compared to both the dynamic hip screw (DHS, p = 0.008) and helical blade (DHS Blade, p= 0.008) designs in bone substitute material representative of osteoporotic bone (0.16 g/cm. 3. polyurethane foam). In 0.08 g/cm. 3. density substrate, the crucifix design (X-Bolt) had a higher resistance to torsion than the screw (DHS, p = 0.008). There were no significant differences (p = 0.101) between the implants in 0.24 g/cm. 3. density bone substitute. Conclusions. Our findings indicate that the clinical standard proximal fracture fixator design, the screw (DHS), was the least effective at resisting torsional load, and a novel crucifix design (X-Bolt), was the most effective design in resisting torsional load in bone substitute material with density representative of osteoporotic bone. At other densities the torsional stability was also higher for the X-Bolt, although not consistently significant by statistical analysis. Cite this article: J. D. Gosiewski, T. P. Holsgrove, H. S. Gill. The efficacy of rotational control designs in promoting torsional stability of hip fracture fixation. Bone Joint Res 2017;6:270–276. DOI: 10.1302/2046-3758.65.BJR-2017-0287.R1

Aims. The aim of this study is to report the results of a case series of olecranon fractures and olecranon osteotomies treated with two bicortical screws. Methods. Data was collected retrospectively for all olecranon fractures and osteotomies fixed with two bicortical screws between January 2008 and December 2019 at our institution. The following outcome measures were assessed; re-operation, complications, radiological loss of reduction, and elbow range of flexion-extension. Results. Bicortical screw fixation was used to treat 17 olecranon fractures and ten osteotomies. The mean age of patients being treated for olecranon fracture and osteotomy were 48.6 years and 52.7 years respectively. Overall, 18% of olecranon fractures were classified as Mayo type I, 71% type II, and 12% type III. No cases of fracture or osteotomy required operative re-intervention. There were two cases of loss of fracture reduction which occurred in female patients ≥ 75 years of age with osteoporotic bone. In both cases, active extension and a functional range of movement was maintained and so the loss of reduction was managed non-operatively. For the fracture fixation cohort, at final follow-up mean elbow extension and flexion were -5. °. ± 5. °. and 136. °. ± 7. °. , with a mean arc of motion of 131. °. ± 11. °. . Conclusion. This series has shown that patients regain near full range of elbow flexion-extension and complication rates are low following bicortical screw fixation of olecranon fractures and osteotomy. Cite this article: Bone Joint Open 2020;1-7:376–382

The August 2014 Trauma Roundup. 360 . looks at: On-table CT for calcaneal fractures; timing of femoral fracture surgery and outcomes; salvage arthroplasty for failed internal fixation of the femoral neck; screw insertion in osteoporotic bone; fibular intramedullary nailing on the ascendant; posterior wall acetabular fractures not all that innocent; bugs, plating and resistance and improving outcomes in olecranon tension band wiring

Objectives. Osteosynthesis of anterior pubic ramus fractures using one large-diameter screw can be challenging in terms of both surgical procedure and fixation stability. Small-fragment screws have the advantage of following the pelvic cortex and being more flexible. The aim of the present study was to biomechanically compare retrograde intramedullary fixation of the superior pubic ramus using either one large- or two small-diameter screws. Materials and Methods. A total of 12 human cadaveric hemipelvises were analysed in a matched pair study design. Bone mineral density of the specimens was 68 mgHA/cm. 3. (standard deviation (. sd). 52). The anterior pelvic ring fracture was fixed with either one 7.3 mm cannulated screw (Group 1) or two 3.5 mm pelvic cortex screws (Group 2). Progressively increasing cyclic axial loading was applied through the acetabulum. Relative movements in terms of interfragmentary displacement and gap angle at the fracture site were evaluated by means of optical movement tracking. The Wilcoxon signed-rank test was applied to identify significant differences between the groups. Results. Initial axial construct stiffness was not significantly different between the groups (p = 0.463). Interfragmentary displacement and gap angle at the fracture site were also not statistically significantly different between the groups throughout the evaluated cycles (p ⩾ 0.249). Similarly, cycles to failure were not statistically different between Group 1 (8438, . sd. 6968) and Group 2 (10 213, . sd. 10 334), p = 0.379. Failure mode in both groups was characterised by screw cutting through the cancellous bone. Conclusion. From a biomechanical point of view, pubic ramus stabilisation with either one large or two small fragment screw osteosynthesis is comparable in osteoporotic bone. However, the two-screw fixation technique is less demanding as the smaller screws deflect at the cortical margins. Cite this article: Y. P. Acklin, I. Zderic, S. Grechenig, R. G. Richards, P. Schmitz, B. Gueorguiev. Are two retrograde 3.5 mm screws superior to one 7.3 mm screw for anterior pelvic ring fixation in bones with low bone mineral density? Bone Joint Res 2017;6:8–13. DOI: 10.1302/2046-3758.61.BJR-2016-0261

The best method of managing a fracture of the distal humerus in a frail low-demand patient with osteoporotic bone remains controversial. Total elbow arthroplasty (TEA) has been recommended for patients in whom open reduction and internal fixation (ORIF) is not possible. Conservative methods of treatment, including the ‘bag of bones’ technique (acceptance of displacement of the bony fragments and early mobilisation), are now rarely considered as they are believed to give a poor functional result. We reviewed 40 elderly and low-demand patients (aged 50 to 93 years, 72% women) with a fracture of the distal humerus who had been treated conservatively at our hospital between March 2008 and December 2013, and assessed their short- and medium-term functional outcome. . In the short-term, the mean Broberg and Morrey score improved from 42 points (poor; 23 to 80) at six weeks after injury to 67 points (fair; 40 to 88) by three months. . In the medium-term, surviving patients (n = 20) had a mean Oxford elbow score of 30 points (7 to 48) at four years and a mean Disabilities of the Arm, Shoulder and Hand score of 38 points (0 to 75): 95% reported a functional range of elbow flexion. The cumulative rate of fracture union at one year was 53%. The mortality at five years approached 40%. . Conservative management of a fracture of the distal humerus in a low-demand patient only gives a modest functional result, but avoids the substantial surgical risks associated with primary ORIF or TEA. Cite this article: Bone Joint J 2015;97-B:1132–8

Specimens of femoral cortical bone from normal subjects and from patients with osteoporosis were mechanically tested in tension to destruction. The osteoporotic bone showed less strength and less stiffness than the normal bone; these reductions are related to the increased cavity area in osteoporosis. Further, the osteoporotic bone is not able to absorb as much energy before fracture as the normal bone; but this difference is not related to changes in cavity area

Bone defects are frequently observed in anterior shoulder instability. Over the last decade, knowledge of the association of bone loss with increased failure rates of soft-tissue repair has shifted the surgical management of chronic shoulder instability. On the glenoid side, there is no controversy about the critical glenoid bone loss being 20%. However, poor outcomes have been described even with a subcritical glenoid bone defect as low as 13.5%. On the humeral side, the Hill-Sachs lesion should be evaluated concomitantly with the glenoid defect as the two sides of the same bipolar lesion which interact in the instability process, as described by the glenoid track concept. We advocate adding remplissage to every Bankart repair in patients with a Hill-Sachs lesion, regardless of the glenoid bone loss. When critical or subcritical glenoid bone loss occurs in active patients (> 15%) or bipolar off-track lesions, we should consider anterior glenoid bone reconstructions. The techniques have evolved significantly over the last two decades, moving from open procedures to arthroscopic, and from screw fixation to metal-free fixation. The new arthroscopic techniques of glenoid bone reconstruction procedures allow precise positioning of the graft, identification, and treatment of concomitant injuries with low morbidity and faster recovery. Given the problems associated with bone resorption and metal hardware protrusion, the new metal-free techniques for Latarjet or free bone block procedures seem a good solution to avoid these complications, although no long-term data are yet available.

Cite this article: Bone Joint J 2024;106-B(10):1100–1110.

Aims

Proximal humeral fractures are the third most common fracture among the elderly. Complications associated with fixation include screw perforation, varus collapse, and avascular necrosis of the humeral head. To address these challenges, various augmentation techniques to increase medial column support have been developed. There are currently no recent studies that definitively establish the superiority of augmented fixation over non-augmented implants in the surgical treatment of proximal humeral fractures. The aim of this systematic review and meta-analysis was to compare the outcomes of patients who underwent locking-plate fixation with cement augmentation or bone-graft augmentation versus those who underwent locking-plate fixation without augmentation for proximal humeral fractures.

Aims

The purpose of this study was to compare reoperation and revision rates of double plating (DP), single plating using a lateral locking plate (SP), or distal femoral arthroplasty (DFA) for the treatment of periprosthetic distal femur fractures (PDFFs).

1. It is well known that the administration of corticosteroids may result in necrosis and progressive destruction of the femoral head. Identical changes have been found in chronic alcoholics, in South African negroes suffering from iron-overload osteoporosis and in patients with arthritis of the hip treated with non-steroid anti-inflammatory and analgesic preparations. The term "drug-induced arthropathy" is used to describe the common pathological lesion. 2. Seventy-two patients with this complication have been investigated and forty-two femoral heads were available for detailed study. The characteristic change is subchondral fragmentation and osteonecrosis, followed later by reactive bone formation and the typical increased radiographic density. 3. The frequent occurrence of fat occupying the Haversian canals in the affected femoral heads has not been adequately explained and its relationship to the destructive arthropathy remains obscure. The findings presented here do not support the theory that fat emboli are responsible for the subchondral bone changes. 4. More credence is given to the theory of subchondral microfracture in osteoporotic bone. The destructive arthropathy invariably follows the administration of some anti-inflammatory or analgesic preparation. It is postulated that a state of diminished sensibility predisposes to microtrauma in osteoporotic bone resulting in subarticular collapse of the femoral head

Aims

This study aimed to establish the optimal fixation methods for calcaneal tuberosity avulsion fractures with different fragment thicknesses in a porcine model.