A Prospective Randomized Controlled Trial of a Bioresorbable Calcium Phosphate Paste (α-BSM) in Treatment of Displaced Intra-Articular Calcaneal Fractures

An evaluation of the efficacy of percutaneous reduction and screw fixation without bone grafting in Sanders Type-II and Type-III displaced intra-articular calcaneal fractures

BACKGROUND

The aim of this retrospective monocentric study was to investigate the clinical efficacy of percutaneous reduction and screw fixation without bone grafting in Sanders Type-II and Type-III displaced intra-articular calcaneal fractures (DIACFs).

METHODS

The medical records of calcaneal fractures patients who were admitted to our department from January 2018 to January 2020 were retrospectively reviewed, and those meeting the inclusion criteria were fnally included for analysis. All patients were treated with percutaneous reduction and screw fixation, and no patients received bone grafting. The radiologic parameters evaluated included the BÖhler angle and the calcaneal height. In addition, the American Orthopaedic Foot and Ankle Society (AOFAS) hindfoot scores, Maryland Foot Score (MFS), and visual analog scale (VAS) score were determined.

RESULTS

Thirty-eight patients with Sanders Type-II and Type-III DIACFs were finally included, including 30 males and 8 females aged 21 to 61 years [(42.6 ± 9.6) years]. According to the Essex-Lopresti classification, 27 of the fractures were the tongue type, and 11 were the joint compression type. According to the Sanders classification, 27 of the fractures were type II, and 11 were type III. Immediately postoperatively, the calcaneal height had recovered to 39.8 ± 2.1 mm, the BÖhler angle had recovered from 4.2° ± 13.6° preoperatively to 27.2° ± 3.4° (P = 0.000). All patients were followed up for 18-42 months [(25.2 ± 9.5) months]. All fractures healed. No differences were found in the outcome measures six-months postoperatively (BÖhler angle, p = 0.24; calcaneal height, p = 0.82) or at final follow-up (BÖhler angle, p = 0.33; calcaneal height, p = 0.28) compared to the immediately postoperative values. At the final follow-up, the AOFAS score was 91.7 ± 7.4 points, with an excellent and good rate of 92.1%; the MFS was 90.3 ± 7.8 points, with an excellent and good rate of 92.1%; and the VAS score was 2.2 ± 1.5 points. None of the patients had incision complications, and one patient developed traumatic arthritis.

CONCLUSION

Percutaneous reduction and screw fixation without bone grafting in Sanders Type-II and Type-III DIACFs can achieve good recovery and maintenance of the BÖhler angle and calcaneal height. Moreover, it has the advantage of a low complication rate.

Determining the Correlation Between Lateral Radiograph Morphology and the Outcome Following Surgically Treated Intra-Articular Calcaneal Fractures

Purpose. It is currently still common practice to obtain conventional radiographs in the follow-up of surgically treated displaced intra-articular calcaneal fractures at regular intervals. There is, however, insufficient evidence that these radiographs can be used to predict functional outcome. The aim of the current study was to evaluate the correlation between the most commonly used angles on lateral radiographs and disease-specific patient-reported outcome measures (PROMs). Methods. Two available databases, containing a total of 233 patients, were used in this study. Eleven angles on the lateral images of the preoperative and at 1-year follow-up radiographs were measured. The 6 most commonly used angles were also measured immediately postoperatively. These 6 most commonly used angles were correlated with PROMs (American Orthopaedic Foot and Ankle Society hindfoot score, Foot Function Index) by a Spearman's rho analysis. After a Bonferroni correction was applied, a P value of <.0042 was considered to be statistically significant. Results. After exclusion of bilateral fractures, primary arthrodesis, open fractures, wound infections, other wound complications, nonavailable radiographs, and nonresponders, 86 patients remained. No significant correlations were found between the measured angles on the preoperative and at 1-year follow-up radiographs and the PROMs. Conclusion. No apparent correlation between lateral radiograph morphology and outcome was detected. Therefore, long-term follow-up radiographs after confirmed healing may be restricted to patients with persistent complaints on indication.Levels of Evidence: Prognostic, Level IV: Retrospective.

A Mouse Femoral Ostectomy Model to Assess Bone Graft Substitutes

The shortcomings of autografts and allografts in bone defect healing have prompted researchers to develop suitable alternatives. Numerous biomaterials have been developed as bone graft substitutes each with their own advantages and disadvantages. However, in order to test if these biomaterials provide an adequate replacement of the clinical standard, a clinically representative animal model is needed to test their efficacy. In this chapter, we describe a mouse model that establishes a critical sized defect in the mid-diaphysis of the femur to evaluate the performance of bone graft substitutes. This is achieved by performing a femoral ostectomy and stabilization utilizing a femoral plate and titanium screws. The resulting defect enables the bone regenerative potential of bone graft substitutes to be investigated. Lastly, we provide instruction on assessing the torsional strength of the healed femurs to quantitatively evaluate the degree of healing as a primary outcome measure.

Biomineralization-Inspired Material Design for Bone Regeneration

Synthetic substitutes of bone grafts, such as calcium phosphate-based ceramics, have shown some good clinical successes in the regeneration of large bone defects and are currently extensively used. In the past decade, the field of biomineralization has delivered important new fundamental knowledge and techniques to better understand this fascinating phenomenon. This knowledge is also applied in the field of biomaterials, with the aim of bringing the composition and structure, and hence the performance, of synthetic bone graft substitutes even closer to those of the extracellular matrix of bone. The purpose of this progress report is to critically review advances in mimicking the extracellular matrix of bone as a strategy for development of new materials for bone regeneration. Lab-made biomimicking or bioinspired materials are discussed against the background of the natural extracellular matrix, starting from basic organic and inorganic components, and progressing into the building block of bone, the mineralized collagen fibril, and finally larger, 2D and 3D constructs. Moreover, bioactivity studies on state-of-the-art biomimicking materials are discussed. By addressing these different topics, an overview is given of how far the field has advanced toward a true bone-mimicking material, and some suggestions are offered for bridging current knowledge and technical gaps.

Is Use of Bone Cement for Treatment of Second Metatarsal Stress Fractures Safe? A Case Report

Metatarsal stress fractures are common injuries of the foot and can be a source of chronic pain without appropriate management. Conservative management is first line, but surgery may be indicated in athletes, cases of nonunion, and fractures of the fifth metatarsal. We report a case of a 34-year-old female who presented to clinic for intractable pain of the left foot secondary to a stress fracture of the left second metatarsal, which had been previously treated with injectable acrylic bone cement. Calcium sulfate hydroxyapatite cement has a multitude of applications in orthopedic surgery, but to our knowledge no studies have documented its use in the treatment of metatarsal stress fractures. Our findings suggest that injectable calcium sulfate hydroxyapatite cement is not a suitable stand-alone treatment in fractures of the second metatarsal.

Effect of age on biomaterial-mediated in situ bone tissue regeneration

Emerging studies show the potential application of synthetic biomaterials that are intrinsically osteoconductive and osteoinductive as bone grafts to treat critical bone defects. Here, the biomaterial not only assists recruitment of endogenous cells, but also supports cellular activities relevant to bone tissue formation and function. While such biomaterial-mediated in situ tissue engineering is highly attractive, success of such an approach relies largely on the regenerative potential of the recruited cells, which is anticipated to vary with age. In this study, we investigated the effect of the age of the host on mineralized biomaterial-mediated bone tissue repair using critical-sized cranial defects as a model system. Mice of varying ages, 1-month-old (juvenile), 2-month-old (young-adult), 6-month-old (middle-aged), and 14-month-old (elderly), were used as recipients. Our results show that the bio-mineralized scaffolds support bone tissue formation by recruiting endogenous cells for all groups albeit with differences in an age-related manner. Analyses of bone tissue formation after 2 and 8 weeks post-treatment show low mineral deposition and reduced number of osteocalcin and tartrate-resistant acid phosphatase (TRAP)-expressing cells in elderly mice.

STATEMENT OF SIGNIFICANCE

Tissue engineering strategies that promote tissue repair through recruitment of endogenous cells will have a significant impact in regenerative medicine. Previous studies from our group have shown that biomineralized materials containing calcium phosphate minerals can contribute to neo-bone tissue through recruitment and activation of endogenous cells. In this study, we investigated the effect of age of the recipient on biomaterial-mediated bone tissue repair. Our results show that the age of the recipient mouse had a significant impact on the quality and quantity of the engineered neo-bone tissues, in which delayed/compromised bone tissue formation was observed in older mice. These findings are in agreement with the clinical observations that age of patients is a key factor in bone repair.

Is calcium phosphate augmentation a viable option for osteoporotic hip fractures?

The use of calcium phosphate bone cement has been described to allow for retention of reduction. Therefore, we evaluated whether augmentation with resorbable calcium phosphate could improve fracture stability in osteoporotic hip fractures. The results showed that augmentation with calcium phosphate cement significantly improved the stability of intertrochanteric fractures.

INTRODUCTION

The aim with this study was to measure whether augmentation with resorbable calcium phosphate cement could improve fracture stability in osteoporotic hip fractures.

METHODS

We retrospectively reviewed 82 patients who underwent closed reduction and internal fixation with proximal femoral nail (PFN) for unstable intertrochanteric fractures between 2014 and 2017. In 42 of 82 patients, patients were treated with a PFN alone (group I). These patients were compared with 40 patients for whom the same device combined with calcium phosphate cement for augmentation was used (group II). Questionnaire surveys or telephone interviews were conducted and patients completed a self-report Harris hip score (HHS) and visual analog scale (VAS) scores. Radiographic outcomes including mean sliding distance of screw, femoral shortening, and varus collapse were compared. Postoperative complications were compared.

RESULTS

Clinical outcomes at 6 months after surgery were equivalent in both groups. Screw sliding, femoral shortening, and varus collapse were all significantly reduced in the cemented group at the last follow-up (p < 0.001, p = 0.005, p < 0.001, respectively). A total of 9 (21%) complications occurred in group I. In contrast, 2 (5%) complications were seen in group II (p = 0.029).

CONCLUSIONS

Augmentation with calcium phosphate cement significantly improved the stability of intertrochanteric fractures fixed with a PFN and reduced overall failure rates. We believe augmentation with resorbable calcium phosphate cement for osteoporotic hip fractures is a reasonable option in selected patients.

The effect of time to post-operative weightbearing on functional and clinical outcomes in adults with a displaced intra-articular calcaneal fracture; A systematic review and pooled analysis

BACKGROUND

Post-operative weightbearing guidelines for displaced intra-articular calcaneal fractures (DIACF) have been pragmatically developed in the past, however hardly adapted to current health care insights. A period of six to nine weeks of non-weightbearing is usually recommended. It is unknown whether an earlier start of weightbearing is advisable.

OBJECTIVES

The primary aim was to evaluate the effect of time to post-operative weightbearing on Böhler's angle. Secondary aims were to determine the effect on functional outcome (e.g., The American Orthopedic Foot and Ankle Society Scale), post-operative pain score, complications (e.g., infections, nonunion, implant removal), and revision surgeries. Finally, the effect of bone void filling on these outcomes was investigated.

DATA SOURCE

A literature search was performed on January 24, 2017 in the Cochrane Library, Medline Ovid, Embase, Web of Science, Google Scholar, and CINAHL.

LITERATURE SELECTION

Studies reporting on operatively treated patients with a DIACF and time to weightbearing were eligible for inclusion. Studies were excluded when not reporting primary data, solely reporting on open fractures, bilateral fractures, or polytrauma patients. Based upon the time to starting partial weightbearing, patient cohorts were stratified into very early (0-4 weeks), early (4-6 weeks), intermediate (6-8 weeks), or late (8-12 weeks) start of partial weightbearing.

DATA EXTRACTION

Two investigators extracted data independently using a predefined data sheet.

RESULTS

After applying exclusion criteria, 72 studies remained eligible for analysis. Böhler's and Gissane's angles, calcaneal height, AOFAS, pain scores, and complications had overlapping confidence intervals in all weightbearing groups.

CONCLUSION

The adverse sequelae which are assumed to be associated with starting partial weightbearing already within six weeks after internal fixation of calcaneal fractures, is not supported by literature data. This systematic review suggests that early weightbearing does not result in impaired outcomes compared with more conservative weightbearing regimes.

Minimally invasive opening wedge tibia outpatient osteotomy, using screw-to-plate locking technique and a calcium phosphate cement

Medial knee osteoarthritis on angular varus deformity of a lower limb is very common. Open-wedge high tibial osteotomy is a treatment of choice if cartilage is not excessively worn (Allback 1 or 2). The technique based on a plate fixation and the bone defect filled with calcium phosphate cement is thoroughly described. Data at 1, 3, 6 months and 1 year of a 19 cases continuous and prospective series are collected and analysed. Mean age at the time of operation was 55 years. The average preoperative varus deformity was 5° and corrected to an average postoperative valgus of 4° (range 3°-6°). Each control includes the collection of eventual complications, the measurement of health status (quality of life and functional scores) and antero-posterior and lateral X-rays. All osteotomies were considered healed at 6 weeks without any correction loss except one, probably result of a technical error. There was no difference in clinical and functional results between the group and the literature, but the final result occurred earlier in the treatment when the bone defect was filled with either calcium phosphate cement. Faster recovery involved no specific complication and enabled outpatient treatment in a majority of patients.

Open Reduction Assisted With an External Fixator and Internal Fixation With Calcaneal Locking Plate for Intra-articular Calcaneal Fractures

BACKGROUND

The extensile lateral approach (ELA) has been considered to be a standard approach for displaced intra-articular calcaneal fractures (DICF) because it provides excellent exposure and allows direct reduction of the depressed posterior facet fragment. But continuous retraction during surgery needs sufficient manpower and may cause ischemia. Failure of rigid fixation of DICF will not allow for early weight bearing and may lead to a loss of reduction. To avoid these disadvantages, this study presents open reduction assisted with an external fixator and internal fixation with a calcaneal locking plate.

METHODS

A series of 58 patients with 62 DICFs were treated over a period of 49 months. All patients were clinically and radiologically followed up with a mean follow-up of 35 (range 29-42) months. Clinical follow-up included visual analog scale (VAS), the American Orthopaedic Foot & Ankle Society (AOFAS) hindfoot score, and ability to work. Radiologic follow-up included axial and lateral radiographs and measurements of the Bohler angle and Gissane angle.

RESULTS

At the final follow-up, all fractures had healed. The mean VAS score was 2.9 (range 0 to 8, SD 1.9) and the average AOFAS score was 71 (range 55-85, SD 8.1). The mean postoperative Bohler angle immediately after the surgery was 28.3 degrees (range 13.0-44.6, SD 7.0), which decreased to 27.5 degrees (range 12.2-43.3, SD 7.0) at the final follow-up, and the mean postoperative Gissane angle after the surgery was 116.3 degrees (range 94.9-131.5, SD 9.0) which finally increased to 118.4 degrees (range 94.5-135.8, SD 9.3). No statistically significant differences regarding Bohler and Gissane angles were found between different Sanders fracture types ( P>.05).

CONCLUSION

The presented operative technique was found to provide comparable reduction of Sanders type II-IV injuries.

LEVEL OF EVIDENCE

Level III, case control study.

The role of orthobiologics in foot and ankle surgery: Allogenic bone grafts and bone graft substitutes

Orthobiologics are biological substances that are used therapeutically for their positive effects on healing skeletal and soft-tissue injuries. The array of orthobiological products currently available to the foot and ankle surgeon is wide, and includes bone allografts, bone substitutes, growth factors, and chondral scaffolds. Nonetheless, despite the surge in interest and usage of orthobiologics, there remains a relative paucity of research addressing their specific applications in foot and ankle surgery. In this review, we attempt to provide an overview of the literature on commonly available allogenic bone grafts and bone substitutes.

There is Level II, III and IV evidence addressing allogenic bone grafts in primary arthrodesis and osteotomy procedures in foot and ankle surgery, which compares favourably with autogenic bone grafts in terms of fusion rates and clinical outcomes (often with fewer complications), and supports a Grade B recommendation for its use.

Pertaining to bone substitutes, the multiplicity of products, coupled with a lack of large prospective clinical trials, makes firm recommendations difficult. Level II and IV studies of calcium phosphate and calcium sulphate products in displaced intra-articular calcaneal fractures have found favourable results in addressing bone voids, maintaining reduction and promoting union, meriting a Grade B recommendation. Evidence for TCP is limited to level IV studies reporting similarly good outcomes in intra-articular calcaneal fractures, warranting a Grade C recommendation. The use of demineralised bone matrix products in hindfoot and ankle fusions has been described in Level II and III studies, with favourable results in achieving fusion and good clinical outcomes, supporting a Grade B recommendation for these indications.

Overall, despite the general lack of high-level evidence in foot and ankle surgery, allogenic bone grafts and bone substitutes continue to hold front-line roles in treating the bone defects encountered in trauma, tumour, and deformity correction surgery. However, more investigation is required before firm recommendations can be made.

Cite this article: EFORT Open Rev 2017;2:272–280. DOI: 10.1302/2058-5241.2.160044

Patient-reported health-related quality of life after a displaced intra-articular calcaneal fracture: a systematic review

BACKGROUND

A displaced intra-articular calcaneal fracture (DIACF) is known for having a negative influence on the daily activities of patients. A health-related quality of life (HRQoL) outcome instrument is used to quantify the impact of DIACF. It seems that these studies used restrictive inclusion criteria and observe specific patient groups; consequently, an increased risk of bias that results in incorrect estimation of the impact. Therefore, we will systematically review the current literature.

MATERIALS AND METHODS

A systematic search was performed in PubMed, Embase and Cochrane library. Inclusion criteria were studies reporting DIACF and HRQoL, measured with SF-36, SF-36v2, EQ-5D or EQ-6D. The identified articles were critically appraised for their relevance and validity. The overall risk of bias was determined. The studies with a low to medium risk of bias were used for data extraction.

RESULTS

32 articles were available for the critical appraisal. 13 articles had a medium risk of bias. All studies reported the SF-36 and two studies also reported the EQ-5D.

CONCLUSIONS

This systematic review indicates that DIACF is a life-changing event for most patients. The HRQoL is substantially lower in comparison to the period before the trauma and to the general population, in particular the subdomains related to the physical domain are affected. In addition, this review reveals that the identified studies have a medium to high risk of bias. Consequently, it is challenging to make reliable and valid conclusions. Therefore, we provided recommendations to decrease the risk of bias in order to improve future research.

Posterior Facet Settling and Changes in Bohler's Angle in Operatively and Nonoperatively Treated Calcaneus Fractures

BACKGROUND

Patients with calcaneus fractures often exhibit settling of the posterior facet with a corresponding decrease in Bohler's angle (BA) following either operative or nonoperative treatment. Both injury BA and postoperative BA have been shown to be prognostic for outcomes; however, the demographic and surgeon-specific factors that may contribute to settling have not been critically examined in the literature. The purpose of this study was to identify these causative factors.

METHODS

234 patients with intra-articular calcaneus fractures were analyzed. All patients had preoperative plain radiographs, at least 5 months of orthopedic follow-up, and computed tomography scanning performed. BA was measured on the injury radiographs for all patients. For operatively treated patients, BA was measured on the immediate postoperative radiographs and compared with the last available radiograph. For nonoperatively treated patients, BA was measured on the last available radiograph. All patients were fully weightbearing at the time of final follow-up but not on initial radiographs due to their recent injury. Demographic data including age, gender, energy of injury mechanism, tobacco use, diabetes, osteoporosis, rheumatoid arthritis, and substance/alcohol abuse were retrospectively collected. Fractures were classified using the Essex-Lopresti and Sanders classifications. Time to full weightbearing was documented, as were any reports of noncompliance with weightbearing restrictions. For patients treated operatively, type of fixation (calcaneal-specific perimeter plate, nonperimeter plate, screw fixation), use of locking screws, use of bone graft or graft substitutes, and the number of screws supporting the posterior facet were documented.

RESULTS

There was a statistically significant amount of settling within the operative and nonoperative groups, but there was no statistically significant difference in settling of BA between the groups. The average settling of BA for the operative and nonoperative group was 8 degrees. Age greater than 50 years, diabetes, and alcohol abuse were all statistically significant and independent predictors of BA settling irrespective of treatment.

CONCLUSION

The amount of BA settling between the operative and nonoperative group was not significant and showed an average decrease of 8 degrees in each group. However, the amount of settling that we found, irrespective of treatment, increased with patient age, alcohol abuse, and diabetes.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Predicting loss of height in surgically treated displaced intra-articular fractures of the calcaneus

PURPOSE

The goal of calcaneal fracture surgery is to restore its anatomy and good foot function. However, loss of height of the subtalar joint can occur post-operatively, as expressed by a decrease in Böhler's angle (BA). The aim of this study was to identify potential factors associated with a post-operative decrease in BA.

METHODS

All consecutive adult patients treated with open reduction and internal fixation (ORIF) by an extended lateral approach (ELA) between 2000 and 2013 were retrospectively included. Primary outcome was the occurrence of a calcaneal collapse, defined as a postoperative decrease of ≥10° in BA. The BA was measured pre-operatively, directly following surgery and at one year follow-up. Patient characteristics (body mass index, diabetes mellitus, smoking/alcohol/substance abuse, American Society of Anaesthesiologist classification), fracture classification and treatment characteristics: per-operative increase in BA and occurrence of post-operative wound infection (POWI) were collected.

RESULTS

A total of 262 patients with 276 calcaneal fractures were included. A calcaneal collapse occurred in 46 cases (17%). The median preoperative BA, per-operative increase in BA and post-operative decrease in BA were, respectively, 2°, 27° and 4°. A calcaneal collapse was seen more often following a per-operative increase of >25° in BA, but no significant association was found (p = 0.056). Uni- and multivariate analysis showed that patients with substance abuse and those with POWI had significantly more calcaneal collapse (p < 0.05). No association was found between substance abuse and the occurrence of POWI (p = 0.293).

CONCLUSIONS

In nearly one in six patients with an intra-articular calcaneal fracture treated with ORIF by an ELA, a post-operative collapse of ≥10° was found during follow-up. Calcaneal collapse was correlated with the occurrence of a POWI and substance abuse.

Patient-important outcome for the assessment of fracture repair

Current evidence indicates that fracture healing assessment is limited to the use of one or two domains (such as pain, range of motion or mobility) in any single study. Functional outcome measures, which include physician-rated or observer-based impairment ratings and patient self-reported or observer-based activity limitation measures, better position the effectiveness of a given intervention towards patient-important outcomes. Health status measures, for example, cover a wide-range of physical, emotional, and social health dimensions. In this paper, we will examine the utility of metrics to assess fracture healing that are important to both the patient and provider, with selected examples from the recent literature. We recommend outcome measures with established and verified reliability and validity. Policy-makers and other stakeholders need to have an accurate assessment of treatment outcome that includes changes in function over time-adequate measures, should be re-applied at periodic intervals.

A biomechanical comparison of fixed angle locking compression plate osteosynthesis and cement augmented screw osteosynthesis in the management of intra articular calcaneal fractures

PURPOSE

The purpose of this study was to investigate whether cement-augmented screw osteosynthesis results in stability comparable to conventional fixed-angle locking plate osteosynthesis using cadaveric bones to model a Sanders type 2B fracture.

METHODS

Seven pairs of fresh frozen human calcanei and the corresponding tali were used. The specimens were assigned pairwise to two study groups in a randomised manner. In order to determine the initial quasi-static stiffness of the bone-implant construct, testing commenced with quasi-static compression ramp loading; subsequently, sinusoidal cyclic compression loading at 2 Hz was performed until construct failure occurred. Initial dynamic stiffness (cycle 1), range of motion (ROM), cycles to failure and load to failure were determined from the machine data during the cyclic test. In addition, at 250-cycle intervals, Böhler's angle and the critical angle of Gissane were determined on mediolateral X-rays shot with a triggered C-arm; 5° angle flattening was arbitrarily defined as a failure criterion.

RESULTS

Bone mineral density was normally distributed without significant differences between the groups. The augmented screw osteosynthesis resulted in higher stiffness values compared to the fixed-angle locking plate osteosynthesis. The fracture fragment motion in the locking plate group was significantly higher compared to the group with augmented screw osteosynthesis.

CONCLUSIONS

The results of this study indicate that in our selected test set-up augmented screw osteosynthesis was significantly superior to the conventional fixed-angle locking plate osteosynthesis with respect to primary stability and ROM during cyclic testing.

Calcium phosphate-bearing matrices induce osteogenic differentiation of stem cells through adenosine signaling

Synthetic matrices emulating the physicochemical properties of tissue-specific ECMs are being developed at a rapid pace to regulate stem cell fate. Biomaterials containing calcium phosphate (CaP) moieties have been shown to support osteogenic differentiation of stem and progenitor cells and bone tissue formation. By using a mineralized synthetic matrix mimicking a CaP-rich bone microenvironment, we examine a molecular mechanism through which CaP minerals induce osteogenesis of human mesenchymal stem cells with an emphasis on phosphate metabolism. Our studies show that extracellular phosphate uptake through solute carrier family 20 (phosphate transporter), member 1 (SLC20a1) supports osteogenic differentiation of human mesenchymal stem cells via adenosine, an ATP metabolite, which acts as an autocrine/paracrine signaling molecule through A2b adenosine receptor. Perturbation of SLC20a1 abrogates osteogenic differentiation by decreasing intramitochondrial phosphate and ATP synthesis. Collectively, this study offers the demonstration of a previously unknown mechanism for the beneficial role of CaP biomaterials in bone repair and the role of phosphate ions in bone physiology and regeneration. These findings also begin to shed light on the role of ATP metabolism in bone homeostasis, which may be exploited to treat bone metabolic diseases.

Self-setting calcium orthophosphate formulations

In early 1980s, researchers discovered self-setting calcium orthophosphate cements, which are bioactive and biodegradable grafting bioceramics in the form of a powder and a liquid. After mixing, both phases form pastes, which set and harden forming either a non-stoichiometric calcium deficient hydroxyapatite or brushite. Since both of them are remarkably biocompartible, bioresorbable and osteoconductive, self-setting calcium orthophosphate formulations appear to be promising bioceramics for bone grafting. Furthermore, such formulations possess excellent molding capabilities, easy manipulation and nearly perfect adaptation to the complex shapes of bone defects, followed by gradual bioresorption and new bone formation. In addition, reinforced formulations have been introduced, which might be described as calcium orthophosphate concretes. The discovery of self-setting properties opened up a new era in the medical application of calcium orthophosphates and many commercial trademarks have been introduced as a result. Currently such formulations are widely used as synthetic bone grafts, with several advantages, such as pourability and injectability. Moreover, their low-temperature setting reactions and intrinsic porosity allow loading by drugs, biomolecules and even cells for tissue engineering purposes. In this review, an insight into the self-setting calcium orthophosphate formulations, as excellent bioceramics suitable for both dental and bone grafting applications, has been provided.

Subjective and novel objective radiographic evaluation of inflatable bone tamp treatment of articular calcaneus, tibial plateau, tibial pilon and distal radius fractures

There is a growing need to develop tools that allow for better reductions of difficult to treat fractures in minimally disruptive ways. One such technique has been developed using the inflatable bone tamp and a fast setting calcium phosphate. KYPHON(®) XPANDER Inflatable Bone Tamp and the KYPHON(®) Osteo Introducer(®) System were used to reduce the articular fractures and a fast-setting calcium phosphate was introduced into those voids and metal hardware was applied as deemed necessary. Subjects were skeletally mature patients treated for articular fractures of the calcaneus, tibial plateau, tibial pilon, or distal radius. Post-operative day zero and week 12 radiographs were objectively and subjectively evaluated by three independent orthopaedic surgeons. Their objective scores were then translated into subjective categories based on the Heiney-Redfern scaled scoring (H-R score) system established herein. Overall, the thorough radiographic analysis by independent reviewers indicates that the technique is capable of obtaining and maintaining articular reductions in a good or adequate manner at 12-weeks post-operatively. Introduced is a potential novel evaluation scale scoring system for these articular fractures that evaluates the important anatomic considerations reproducibly in fracture reductions. There are many potential benefits that remain speculative to this type of tool within a procedure, and therefore this tool and technique warrants further research.

Bone graft substitutes currently available in orthopaedic practice: the evidence for their use

We reviewed 59 bone graft substitutes marketed by 17 companies currently available for implantation in the United Kingdom, with the aim of assessing the peer-reviewed literature to facilitate informed decision-making regarding their use in clinical practice. After critical analysis of the literature, only 22 products (37%) had any clinical data. Norian SRS (Synthes), Vitoss (Orthovita), Cortoss (Orthovita) and Alpha-BSM (Etex) had Level I evidence. We question the need for so many different products, especially with limited published clinical evidence for their efficacy, and conclude that there is a considerable need for further prospective randomised trials to facilitate informed decision-making with regard to the use of current and future bone graft substitutes in clinical practice.

Extended lateral approach for intra-articular calcaneal fractures: an inverse relationship between surgeon experience and wound complications

The current reference standard for the treatment of displaced intra-articular calcaneal fractures is open reduction and internal fixation using an extended lateral approach. In the present retrospective study, we evaluated the results of a consecutive series of patients treated in the same fashion from June 2005 to September 2011 using a subcuticular single-layer closure technique. We also determined the risk factors for the development of wound complications and the rate of wound complications. Also, we assessed which patient, fracture, and surgical characteristics affected these complications. During the 75-month study period, we operated on 53 displaced intra-articular calcaneal fractures in 50 patients using the extended lateral approach. The incision was closed using the subcuticular technique in 49 cases (92.45%). In the subcuticular closure group 2 (4.1%) deep infections and 2 (4.1%) superficial wound complications (1 dehiscence and 1 infection) occurred. Wound edge or flap necrosis was not encountered. The use of bone-void filler and the experience of the surgical team were significantly (p < .001 and p = .026, respectively) associated with the occurrence of wound complications. The subcuticular single-layer suture technique is a suitable closure technique in the treatment of displaced intra-articular calcaneal fractures. It was associated with a low complication rate combined with the extended lateral approach. The effect of bone void fillers on the incidence of complications should receive more attention in future research. The association between wound complications and the experience level of the surgical team supports the need for centralization of this complex injury.

The fate of Böhler's angle in conservatively-treated displaced intra-articular calcaneal fractures

PURPOSE

Although the predictive value of Böhler's angle on outcome remains subject of debate, the initial angle at the time of trauma still guides treatment. Changes in Böhler's angle during follow-up are frequently reported following surgical treatment of displaced intra-articular calcaneal fractures (DIACF). The aim of the present study was to determine the changes in Böhler's angle as a measure of secondary fracture displacement following conservative management of DIACF.

METHODS

Thirty-eight patients with a total of 44 displaced intra-articular calcaneal fractures treated conservatively with a minimum of two lateral radiographs during follow-up were analysed. Böhler's angle at different follow-up times was measured by three observers. The change in angle was compared with the angle at trauma, and influence of trauma mechanism and common calcaneal fracture classifications were determined.

RESULTS

The results showed a significant decline over time of the Böhler's angle in conservatively-treated patients of more than 11° on average at a mean follow-up of 29.2 weeks. This decrease was not related to gender, the initial angle, or the Essex-Lopresti or Sanders classification. A statistically significantly higher decrease was detected in high energetic trauma compared with low energetic trauma.

CONCLUSION

The conservative treatment of displaced intra-articular calcaneal fractures is still a viable option, yet a significant secondary displacement in time should be taken into account, as reflected in a decrease of Böhler's angle of 11° up to one year following trauma.

Management of calcaneal fractures: what have we learnt over the years?

Calcaneal fractures result, in many cases, in, subtalar joint stiffness and severe disability. Diagnosis is usually made by X-ray, but more accurately by a computed tomography (CT) scan. In the last years, much has been known regarding its physiopathology and osteosynthesis. Although new developments in osteosynthesis materials have been made, calcaneus fractures still remains in dispute of those advocating non-operative treatment and those defending open reduction and internal fixation. Less invasive surgery, arthroscopy and three-dimensional (3D) fluoroscopy are very important for reduction accuracy and soft-tissue damage avoidance. In this article, the physiopathology, diagnosis, classification and treatment of calcaneus fractures are updated. Nevertheless, systematic reviews have shown no evidence about what treatment is better.

Open reduction and internal fixation of OTA type C2-C4 fractures of the calcaneus with a triple-plate technique

The purpose of this study was to present a surgical technique of open reduction and internal fixation of displaced intra-articular calcaneal fractures with 3 AO mini-fragment plates and to evaluate the clinical and radiological outcome of a consecutive group of patients after a mean follow-up of 41.7 months. A series of 54 patients (16 women and 38 men) with 62 calcaneal fractures were treated over a period of 6.5 years. Forty-five patients with 50 calcaneal fractures were completely clinically and radiologically followed up. Clinical follow-up included assessment of range of motion, pain according to a visual analogue scale, the American Orthopaedic Foot and Ankle Society hindfoot score, and the short-form 36 health survey. Radiological follow-up included plain axial and lateral radiographs and measurement of the Böhler's angle and Gissane's angle. Independent Student's t test and paired Student's t test were used alongside the chi-square test to compare clinical and radiological data and score values between different groups of patients. Eleven patients showed breakage of the osteosynthesis material during the healing process and 2 patients sustained deep wound infection requiring revision surgery. At the final follow-up all fractures had healed. The average range of motion was supination 26.4° (range 0° to 50°; SD 11.6°), pronation 15.4° (range 0° to 30°; SD 6.4°), dorsal extension 14.3° (range -10° to 30°; SD 8.0°), and plantarflexion 39.6° (range 20° to 65°; SD 11.7°). Patients with OTA type C4 fractures achieved significantly lower supination (p < .01) and plantarflexion (p < .01) compared with other fracture types. The mean visual analog scale pain score was 3.6 (range 0 to 8; SD 2.3) points, average American Orthopaedic Foot and Ankle Society hindfoot score was 70.8 (range 33 to 100; SD 17.1) points, and the mean short-form 36 score was 60.98 (range 22.9 to 93.0; SD 18.4) points. The mean postoperative Böhler's angle was 28.9° (range 8° to 38°; SD 7.1°), which decreased to 23.6° (range 4° to 34°; SD 8.7°) at the final follow-up, and the mean postoperative Gissane's angle was 108.6° (range 80° to 140°; SD 11.8°), which finally decreased to 102.4° (range 72° to 126°; SD 12.7°). No statistically significant differences regarding Böhler's and Gissane's angles were found between different OTA fracture types. In conclusion, the presented surgical technique was found to provide comparable and adequate reduction of OTA type C2-C4 injuries based on statistically insignificant differences in radiographic measures of postoperative fracture reduction. Greater limitation in subtalar motion was observed in OTA type C4 fractures in comparison with less severe fractures (p < .01).

Treatment of displaced intraarticular calcaneal fractures with or without bone grafts: A systematic review of the literature

BACKGROUND

The necessity of bone grafts in the treatment of intraarticular calcaneal fractures continues to be one of the most debated topics in foot and ankle surgery. The purpose of this study was to determine whether there are sufficient objective cumulative data in the literature to compare the two methods and if the bone graft was needed in surgical treatment of intraarticular calcaneal fractures.

MATERIALS AND METHODS

A comprehensive search of all relevant articles from 1990 to 2010 was conducted. Two reviewers evaluated each study to determine its suitability for inclusion and collected the data of interest. Meta-analytic pooling of group results across studies was performed for the two treatment methods.

RESULTS

The systematic review identified 32 primary studies with 1281 fractures, which contained 4 comparative studies, 13 with bone grafts, and 15 without bone grafts in treatment methods. The infection rate in bone graft group was higher through statistically insignificant than in non-graft group (8.3% vs. 6.3%) No significant difference was found between good reduction rate, postoperative osteoarthritis rate, and subtalar fusion rate. The average full weight-bearing time in bone graft group was significantly lower (5.4 months) than in non-graft group (10.5 months). The mean postoperative Böhler's angle was significantly higher in bone graft group (lose due to collapse was significancy less). For the efficacy outcomes, the bone graft group had a lower American Orthopaedic Foot and Ankle Society Score (AOFAS) (71.4 points vs. 80.5 points) but a higher Creighton score (89.9 points vs. 81.0 points) compared with non-graft group. Pooled mean results showed 35% of the patients in bone graft group had an excellent result, 40% had a good result, 21% had a fair result, and 4% had a poor result. In the non-graft group, the corresponding values were 34, 42, 14, and 10%, respectively.

CONCLUSIONS

The operative treatment of intraarticular calcaneal fractures with bone grafts could restore the Böhler's angle better and the patients could return to full weight bearing earlier. However, the functional and efficacy outcomes appear to be similar between the two treatment groups. There were more joint depression and comminuted fractures in the bone graft group, and the mean followup time was shorter. Large sample comparative studies are still needed.

Controversies in calcaneus fracture management: a systematic review of the literature

Despite the fact that the calcaneus is the commonest tarsal bone fractured, many controversies exist in the literature regarding the management options. This stems from the fact that the understanding of the fracture pattern has evolved only recently, surgical approaches have lately been standardized, surgical timing has become more clear, and newer implants are regularly being introduced. Despite the significant advances, complications and controversies related to this common fracture abound. The present paper looks at all aspects of modern management options of calcaneus fractures and tries to review the literature with regard to the controversial issues that still persist.