Norian SRS cement compared with conventional fixation in distal radial fractures. A randomized study

Is it possible to 3D bioprint load-bearing bone implants? A critical review

Rehabilitative capabilities of any tissue engineered scaffold rely primarily on the triad of (i) biomechanical properties such as mechanical properties and architecture, (ii) chemical behavior such as regulation of cytokine expression, and (iii) cellular response modulation (including their recruitment and differentiation). The closer the implant can mimic the native tissue, the better it can rehabilitate the damage therein. Among the available fabrication techniques, only 3D bioprinting (3DBP) can satisfactorily replicate the inherent heterogeneity of the host tissue. However, 3DBP scaffolds typically suffer from poor mechanical properties, thereby, driving the increased research interest in development of load-bearing 3DBP orthopedic scaffolds in recent years. Typically, these scaffolds involve multi-material 3D printing, comprising of at-least one bioink and a load-bearing ink; such that mechanical and biological requirements of the biomaterials are decoupled. Ensuring high cellular survivability and good mechanical properties are of key concerns in all these studies. 3DBP of such scaffolds is in early developmental stages, and research data from only a handful of preliminary animal studies are available, owing to limitations in print-capabilities and restrictive materials library. This article presents a topically focused review of the state-of-the-art, while highlighting aspects like available 3DBP techniques; biomaterials' printability; mechanical and degradation behavior; and their overall bone-tissue rehabilitative efficacy. This collection amalgamates and critically analyses the research aimed at 3DBP of load-bearing scaffolds for fulfilling demands of personalized-medicine. We highlight the recent-advances in 3DBP techniques employing thermoplastics and phosphate-cements for load-bearing applications. Finally, we provide an outlook for possible future perspectives of 3DBP for load-bearing orthopedic applications. Overall, the article creates ample foundation for future research, as it gathers the latest and ongoing research that scientists could utilize.

Rat model of an autologous cancellous bone graft

Autologous cancellous bone (ACB) grafting is the "gold standard" treatment for delayed bone union. However, small animal models for such grafts are lacking. Here, we developed an ACB graft rat model. Anatomical information regarding the iliac structure was recorded from five rat cadavers (10 ilia). Additionally, 5 and 25 rats were used as controls and ACB graft models, respectively. A defect was created in rat femurs and filled with ACB. Post-graft neo-osteogenic potential was assessed by radiographic evaluation and histological analysis. Iliac bone harvesting yielded the maximum amount of cancellous bone with minimal invasiveness, considering the position of parailiac nerves and vessels. The mean volume of cancellous bone per rat separated from the cortical bone was 73.8 ± 5.5 mm³. Bone union was evident in all ACB graft groups at 8 weeks, and new bone volume significantly increased every 2 weeks (P < 0.001). Histological analysis demonstrated the ability of ACB grafts to act as a scaffold and promote bone union in the defect. In conclusion, we established a stable rat model of ACB grafts by harvesting the iliac bone. This model can aid in investigating ACB grafts and development of novel therapies for bone injury.

An Assessment of Randomized Controlled Trial Quality in The Journal of Bone & Joint Surgery: Update from 2001 to 2013

BACKGROUND

The quality of reporting of randomized controlled trials (RCTs) published in The Journal of Bone & Joint Surgery (JBJS) from 1988 to 2000 was previously analyzed. The purpose of this current study was to analyze the quality of reporting of RCTs published in JBJS from 2001 to 2013 to identify trends over time and potential areas of improvement for future clinical trials.

METHODS

A manual search of the JBJS database identified RCTs published between January 2001 and December 2013. Quality assessments, using the Detsky quality-of-reporting index (Detsky score), a modified Cochrane risk-of-bias tool, and abstraction of relevant data identifying predictors of quality, were conducted.

RESULTS

A total of 5,780 publications were identified in JBJS from 2001 to 2013, with 285 RCTs (4.9%), representing an increase from the prior 13-year period. The overall mean transformed Detsky score (and standard error) increased significantly (p < 0.001) from 68.1% ± 1.67% to 76.24% ± 0.72%. The percentage of multicenter RCTs decreased from 67% to 31%. The percentage of positive trials also decreased from 80% to 50.5%, as did the mean sample size (212 to 166). Regression analysis indicated that trials with an epidemiologist as the first author and nonsurgical trials were significantly associated (p = 0.001) with a higher overall trial quality score. The categories of the lowest mean methodology scores were randomization and concealment, eligibility criteria, and reasons for patient exclusion, as identified with the Detsky score, and patient and assessor blinding, as identified with the risk-of-bias assessment.

CONCLUSIONS

The quantity and quality of published RCTs in JBJS have increased in the 2001 to 2013 time period compared with the previous time period. Although these improvements are encouraging, trends to smaller, single-center trials were also observed. To efficiently determine the efficacy of orthopaedic treatments and limit bias, high-quality randomized trials of appropriate sample size and rigorous design are needed.

Clinical impact of high-profile animal-based research reported in the UK national press

OBJECTIVES

We evaluated animal-based biomedical 'breakthroughs' reported in the UK national press in 1995 (25 years prior to the conclusion of this study). Based on evidence of overspeculative reporting of biomedical research in other areas (eg, press releases and scientific papers), we specifically examined animal research in the media, asking, 'In a given year, what proportion of animal research "breakthroughs"' published in the UK national press had translated, more than 20 years later, to approved interventions?'

METHODS

We searched the Nexis media database (LexisNexis.com) for animal-based biomedical reports in the UK national press. The only restrictions were that the intervention should be specific, such as a named drug, gene, biomedical pathway, to facilitate follow-up, and that there should be claims of some clinical promise.

MAIN OUTCOME MEASURES

Were any interventions approved for human use? If so, when and by which agency? If not, why, and how far did development proceed? Were any other, directly related interventions approved? Did any of the reports overstate human relevance?

RESULTS

Overspeculation and exaggeration of human relevance was evident in all the articles examined. Of 27 unique published 'breakthroughs', only one had clearly resulted in human benefit. Twenty were classified as failures, three were inconclusive and three were partially successful.

CONCLUSIONS

The results of animal-based preclinical research studies are commonly overstated in media reports, to prematurely imply often-imminent 'breakthroughs' relevant to human medicine.

Evaluating the necessity of bone augmentation for distal radius fracture fixed with a volar locking plate: a retrospective study

Background

Multiple approaches for fixation of distal radius fractures exist; nonetheless, there is no consensus on the optimal treatment for these injuries. Although using volar locking plates has become increasingly common as a surgical intervention, the usefulness of bone augmentation remains debatable. Therefore, this study aimed to evaluate the necessity of bone augmentation for distal radius fractures fixed with a volar locking plate.

Methods

This retrospective study enrolled patients with a single distal radius fracture treated with a volar locking plate between January 2014 and December 2016. Overall, 105 fractures were included and divided into two groups (non-bone augmentation: group 1, n = 88; bone augmentation: group 2, n = 17). Images were reviewed, and dorsal cortex collapse, volar tilting, and radial height and inclination were measured immediately after surgery and at the 6-month follow-up.

Results

Both groups exhibited significant differences in dorsal collapse (p < 0.001 and p = 0.001, respectively) and radial height shortening (p < 0.001 and p = 0.039, respectively); volar tilting and radial inclination did not differ significantly. There was no difference in the degree of dorsal collapse (p = 0.715) and radial height shortening (p = 0.651) between the two groups. Of the 105 fractures, 54 were identified as comminuted type according to the AO classification (A3, C2, and C3), and similar radiographic outcomes were noted.

Conclusions

Volar locking plates for the treatment of distal radius fractures with or without bone augmentation do not affect the radiographic outcomes. In comminuted fractures, additional bone augmentation is unnecessary if intraoperative anatomical reduction and fixation are performed when possible.

Bone Grafts, Bone Substitutes, and Orthobiologics: Applications in Plastic Surgery

As reconstructive needs often extend past the soft tissue alone, a plastic surgeon must also be well versed in the methods of bony reconstruction. Understanding of the basic science of fracture healing and the biochemical mechanisms of the different bone grafts, bone substitutes, and orthobiologics is essential to selecting among the many different options available to the modern plastic surgeon. This review provides a broad overview of these different options and the specific applications for plastic surgeons based on anatomic location.

Autograft, Allograft, and Bone Graft Substitutes: Clinical Evidence and Indications for Use in the Setting of Orthopaedic Trauma Surgery

Bone grafts are the second most common tissue transplanted in the United States, and they are an essential treatment tool in the field of acute and reconstructive traumatic orthopaedic surgery. Available in cancellous, cortical, or bone marrow aspirate form, autogenous bone graft is regarded as the gold standard in the treatment of posttraumatic conditions such as fracture, delayed union, and nonunion. However, drawbacks including donor-site morbidity and limited quantity of graft available for harvest make autograft a less-than-ideal option for certain patient populations. Advancements in allograft and bone graft substitutes in the past decade have created viable alternatives that circumvent some of the weak points of autografts. Allograft is a favorable alternative for its convenience, abundance, and lack of procurement-related patient morbidity. Options include structural, particulate, and demineralized bone matrix form. Commonly used bone graft substitutes include calcium phosphate and calcium sulfate synthetics-these grafts provide their own benefits in structural support and availability. In addition, different growth factors including bone morphogenic proteins can augment the healing process of bony defects treated with grafts. Autograft, allograft, and bone graft substitutes all possess their own varying degrees of osteogenic, osteoconductive, and osteoinductive properties that make them better suited for different procedures. It is the purpose of this review to characterize these properties and present clinical evidence supporting their indications for use in the hopes of better elucidating treatment options for patients requiring bone grafting in an orthopaedic trauma setting.

Treatment of radius or ulna fractures in the elderly: A systematic review covering effectiveness, safety, economic aspects and current practice

Background

The objective of the present study was to evaluate effectiveness, complications and cost-effectiveness of any surgical or non-surgical treatment for radius or ulna fractures in elderly patients. Secondary objectives were to analyze present treatment traditions of distal radius fractures (DRF) in Sweden and to calculate resource usage for its treatment.

Methods and findings

The assessment contains a systematic review of clinical and health economic studies comparing treatment options for radius or ulna fractures. The results regarding the effectiveness of the treatments are summarized in meta-analyses. In addition, the assessment contains a cost analysis for different treatment options commonly used for DRF care, and an analysis of registry data on the incidence and treatment of DRF. In total 31 randomized controlled trials were included in meta-analyses. When comparing functional outcome for plate fixation versus non-surgical treatment for DRF, there were no clinically important differences at one-year follow-up (mean difference [MD], -3.29, 95% CI, -7.03; 0.44). Similar results were found when comparing plating and percutaneous methods with respect to functional outcome (standardized mean difference [SMD], -0.07, 95% CI, -0.21; 0.07) and grip strength (MD, -3.47, 95% CI, -11.21; 4.28). There were no differences for minor complications, (risk difference [RD], -0.01, 95% CI, -0.07; 0.05) whereas major complications were less common for the percutaneous group, (RD, 0.02, 95% CI, 0.02; 0.03). Given the low number of studies, the evidence above was rated as moderate certainty. The cost for plate fixation versus plaster cast was estimated to 1698 compared to 137 US dollars. For DRF, plate fixation increased in Sweden between 2005 and 2013, and was the most common surgical method in 2013.

Conclusions

Surgical treatment of moderately displaced distal radius fractures in elderly patients offers no clear benefit compared to non-surgical treatment. Plating procedures have become more common during the second millennium and involve higher costs and higher risk of major complications than percutaneous options.

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.

Novel adhesives for distal radius fixation: A biomechanical analysis

Wrist fractures can be difficult to treat due to advanced age of the patient, medical co-morbidities, and comminution of the bone. This study examines the effectiveness of two injectable glass polyalkenoate cements (GPCs), derived from two different glasses (A and B), as minimally invasive treatments for distal radius fractures. Twenty-seven fresh cadaveric radial pairs were tested either in compressive fatigue or to quasi-static compressive failure. The radii tested to failure had one pair fixated with a GPC while the other was left intact. The radii tested under fatigue had one pair fixated with a GPC and the other with a volar locking plate. A wedge osteotomy was used to simulate a severely comminuted fracture. When loaded to failure, the radii fixated with a GPC made from glass A or B were found to be, respectively, at least 57% and 62% as strong as their intact biological pair (95% Confidence Interval, Lower). Using a paired t-test, the radii fixated with either adhesive were found to be significantly stiffer than their biological pairs fixated with a volar locking plate for all cycles of fatigue loading. The adhesives under investigation demonstrate promise as treatment for distal radius fractures. In vivo investigations are warranted to determine the effect that the adhesives have on the bone remodelling process.

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.

Increased differentiation and production of extracellular matrix components of primary human osteoblasts after cocultivation with endothelial cells: A quantitative proteomics approach

Coculturing of bone-forming and blood vessel-forming cells is a strategy aimed at increasing vascularity of implanted bone constructs in tissue-engineering applications. We previously described that the coculture of primary human osteoblasts (hOBs) and human umbilical vein endothelial cells (HUVECs) improves the differentiation of both cell types, leading to the formation of functional blood vessels and enhanced bone regeneration. The objective of this study was to further delineate the multifaceted interactions between both cell types. To investigate the proteome of hOBs after cocultivation with HUVECs we used stable isotope labeling by amino acids in cell culture, revealing 49 significantly upregulated, and 54 significantly downregulated proteins. Amongst the highest regulated proteins, we found the proteins important for osteoblast differentiation, cellular adhesion, and extracellular matrix function, notably: connective tissue growth factor, desmoplakin, galectin-3, and cyclin-dependent kinase 6. The findings were confirmed by enzyme-linked immunosorbent assays. We also investigated whether the mRNA transcripts correlate with the changes in protein levels by quantitative real-time reverse transcription polymerase chain reaction. In addition, the data was compared to our previous microarray analysis of hOB transcriptome. Taken together, this in-depth analysis delivers reliable data suggesting the importance of coculturing of hOBs and HUVECs in tissue engineering.

Bone Graft Options in Upper-Extremity Surgery

Bone grafting in the upper extremity is an important consideration in patients with injuries or conditions resulting in missing bone stock. A variety of indications can necessitate bone grafting in the upper extremity, including fractures with acute bone loss, nonunions, malunions, bony lesions, and bone loss after osteomyelitis. Selecting the appropriate bone graft option for the specific consideration is important to ensure optimal patient outcomes. Considerations such as donor site morbidity and the amount and characteristics of bone graft needed all weigh in the decision making regarding which type of bone graft to use. This article reviews the options available for bone grafting in the upper extremity.

Definition of infection after fracture fixation: A systematic review of randomized controlled trials to evaluate current practice

INTRODUCTION

One of the most challenging musculoskeletal complications in modern trauma surgery is infection after fracture fixation (IAFF). Although infections are clinically obvious in many cases, a clear definition of the term IAFF is crucial, not only for the evaluation of published research data but also for the establishment of uniform treatment concepts. The aim of this systematic review was to identify the definitions used in the scientific literature to describe infectious complications after internal fixation of fractures. The hypothesis of this study was that the majority of fracture-related literature do not define IAFF.

MATERIAL AND METHODS

A comprehensive search was performed in Embase, Cochrane, Google Scholar, Medline (OvidSP), PubMed publisher and Web-of-Science for randomized controlled trials (RCTs) on fracture fixation. Data were collected on the definition of infectious complications after fracture fixation used in each study. Study selection was accomplished through two phases. During the first phase, titles and abstracts were reviewed for relevance, and the full texts of relevant articles were obtained. During the second phase, full-text articles were reviewed. All definitions were literally extracted and collected in a database. Then, a classification was designed to rate the quality of the description of IAFF.

RESULTS

A total of 100 RCT's were identified in the search. Of 100 studies, only two (2%) cited a validated definition to describe IAFF. In 28 (28%) RCTs, the authors used a self-designed definition. In the other 70 RCTs, (70%) there was no description of a definition in the Methods section, although all of the articles described infections as an outcome parameter in the Results section.

CONCLUSION

This systematic review shows that IAFF is not defined in a large majority of the fracture-related literature. To our knowledge, this is the first study conducted with the objective to explore this important issue. The lack of a consensus definition remains a problem in current orthopedic trauma research and treatment and this void should be addressed in the near future.

Role for cementoplasty in intra-articular distal radius fractures: Cadaver study and application to arthroscopy

BACKGROUND

Die-punch intra-articular fractures of the distal radius raise surgical challenges. The residual articular step-off must be less than 1mm to prevent the development of radio-carpal osteoarthritis. The objectives of this cadaver study were to evaluate whether cementoplasty was effective in reducing die-punch fractures and to determine whether this technique was feasible as an arthroscopic procedure.

HYPOTHESIS

Cementoplasty performed as an arthroscopic procedure is effective in treating die-punch fractures.

MATERIAL AND METHODS

Eleven cadaver forearms collected at a laboratory were studied. In each, a depressed fracture of the lunate fossa of the radial articular surface was created using a Tinius Olsen H25K-S compression test machine. A Kyphon XPander^® balloon (Medtronic) was used to lift the depressed area, and calcium-phosphate cement was then injected to stabilise the reduction. Cementoplasty under arthroscopic guidance was performed on an additional forearm.

RESULTS

Computed tomography of the wrists after fracture induction showed a mean depression of 4.66mm (range, 4.01-5.25mm). Arthroscopic cementoplasty proved feasible with the arthroscope inserted through the 3-4 radio-carpal portal. Positioning the balloon under the depressed area ensured satisfactory reduction and allowed the injection of cement.

DISCUSSION

Cementoplasty may be useful for the treatment of die-punch fractures. Additional indications may be other types of distal radius fractures with articular surface depression.

LEVEL OF EVIDENCE

IV, cadaver study.

Treatment of thoracic or lumbar burst fractures with Balloon Assisted Endplate Reduction using Tricalcium Phosphate cement: histological and radiological evaluation

Background

Short-segment pedicle-screw instrumentation is frequently used to stabilize thoracolumbar burst fractures. A recognized disadvantage of this procedure is recurrent kyphosis from intervertebral disc creep into the fractured central endplate. Balloon Assisted Endplate Reduction (BAER) using Tricalcium Phosphate bone cement (TCP) enables elevation of the centrally depressed endplate. Our objective was to evaluate the bone-tissue response to TCP and to analyse whether BAER using TCP can prevent recurrent kyphosis after removal of the instrumentation.

Methods

Fourteen patients with traumatic thoracolumbar burst fractures were operated with BAER using TCP in combination with short-segment instrumentation. Nine months after surgery, instrumentation was removed and transpedicular biopsies were taken for histological and histochemical analysis. Roentgenograms pre- and postoperatively and at latest follow-up after removal of the instrumentation were evaluated.

Results

Average follow-up was 2.6 years. Analysis of the biopsies showed a variable degree of bone remodelling with incorporation of TCP into newly formed bone matrix. No extensive foreign body reactions, inflammation, granulomatous responses or tissue necrosis were observed. Wedge-angle, kyphosis-angle and both the anterior-posterior and central-posterior vertebral body height ratios improved significant postoperatively (p < 0.001). After removal of the instrumentation no significant differences in wedge-angle or height ratios were seen (p = 0.12). The kyphosis-angle increased four degrees (p = 0.01).

Conclusion

TCP showed good histological osseointegration with no adverse events. TCP can therefore be safely used and could be beneficial in treatment of thoracolumbar burst fractures. BAER with TCP in combination with short-segment instrumentation might reduce recurrence of deformity even after removal of the instrumentation in comparison to short-segment instrumentation alone.

Trial registration

This study is registered at the at the Dutch Trial Registry (NTR3498).

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

Evaluating augmentation with calcium phosphate cement (chronOS Inject) for bone defects after internal fixation of proximal tibial fractures: A prospective, multicenter, observational study

INTRODUCTION

Managing subchondral bone defects in proximal tibia fractures after plateau reduction is an important consideration. ChronOS Inject is a recently developed calcium phosphate bone substitute that shows relatively fast osteointegration.

HYPOTHESIS

Using chronOS Inject during internal fixation of proximal tibial fractures provides a satisfactory treatment option that is both clinically and radiologically safe.

PATIENTS AND METHODS

Patients enrolled in this study were treated with chronOS Inject bone void filler, during internal fixation of proximal tibial fractures. Patients were evaluated preoperatively and at 6 weeks, 6 and 12 months postoperative. Radiographic union was assessed using plain films supplemented by CT scans. Pain, function and adverse events were collected at all visits. A total of 36 patients were enrolled in the study and treated according to a predetermined protocol. Seven of the 36 patients (19.4%) were lost to follow-up.

RESULTS

Successful radiographic union was achieved in 27/29 (93.1%) of patients at final follow-up. Articular subsidence of>2mm only occurred in one patient. Statistical analysis showed significant improvements both in leg pain and knee function. Progress in knee function was observed in 93.1% (27/29) of patients from 6 weeks to 12 months. No product-related complications were reported.

CONCLUSIONS

Successful union was achieved based on radiographic criteria as well as clinical outcomes. When managing bone defects after internal fixation of proximal tibial fractures, the use of chronOS Inject resulted in significant improvement of knee function and reduction of leg pain.

LEVEL OF EVIDENCE

Level IV, prospective observational study.

Dorsal Plating of Unstable Distal Radius Fractures Using a Bio-Absorbable Plating System and Bone Substitute

This study reports the results of open reduction and internal fixation of 26 unstable, intraarticular, dorsally displaced fractures of the distal radius using a bio-absorbable dorsal distal radius (Reunite) plate and calcium phosphate (Biobon) bone substitute. The bio-absorbable plate has the advantage of being low profile, easily contourable and angularly stable. In the majority of cases, this plate produces functional results comparable with metal plates. The Gartland and Werley score was excellent or good in 21 patients. The theoretical advantage over metal plates is in eliminating the need to remove the plate and hence the need for a second operation if implant-related extensor tenosynovitis occurs. Inflammatory tissue reaction to the degradation products of the plate is a potential concern, although the co-polymer ratio used in this plate appears to have reduced the severity of this reaction, which was seen in two patients in this series. The reduction was lost in five patients with severe dorsal comminution. Following this experience, we do not recommend this plating system for fractures with a metaphyseal gap of greater than 7 mm following reduction.

Open Reduction and Palmar Plate-Osteosynthesis in Combination with a Nanocrystalline Hydroxyapatite Spacer in the Treatment of Comminuted Fractures of the Distal Radius

In a prospective study, we used the nanocrystalline hydroxyapatite paste Ostim (Osartis, Obernburg, Germany) in combination with a palmar plate to treat comminuted radius fractures with a metaphyseal and articular component in order to examine the clinical use of Ostim as a bone substitute. Twenty-one patients with 22 radius fractures of AO types C2 and C3 were included in the study. The measurements, taken 10.2±1.3 months after the initial treatment, revealed a dorsopalmar tilt of 8.8±3.7°, a radioulnar inclination of 18.8±2.8° and an ulnar variance of 0.8±1.8 mm. According to the Gartland and Werley evaluation, eight of the treated fractures attained an excellent, 11 a good and the remaining three a fair result. The study demonstrates that Ostim, in combination with angularly stable osteosynthesis, can be used as an acceptable bone substitute for the treatment of type C2 and C3 radial fractures.

Patient-Reported Outcome Measures for Hand and Wrist Trauma: Is There Sufficient Evidence of Reliability, Validity, and Responsiveness?

BACKGROUND

Patient-reported outcome measures (PROMs) are important tools for assessing outcomes following injuries to the hand and wrist. Many commonly used PROMs have no evidence of reliability, validity, and responsiveness in a hand and wrist trauma population. This systematic review examines the PROMs used in the assessment of hand and wrist trauma patients, and the evidence for reliability, validity, and responsiveness of each measure in this population.

METHODS

A systematic review of Pubmed, Medline, and CINAHL searching for randomized controlled trials of patients with traumatic injuries to the hand and wrist was carried out to identify the PROMs. For each identified PROM, evidence of reliability, validity, and responsiveness was identified using a further systematic review of the Pubmed, Medline, CINAHL, and reverse citation trail audit procedure.

RESULTS

The PROM used most often was the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire; the Patient-Rated Wrist Evaluation (PRWE), Gartland and Werley score, Michigan Hand Outcomes score, Mayo Wrist Score, and Short Form 36 were also commonly used. Only the DASH and PRWE have evidence of reliability, validity, and responsiveness in patients with traumatic injuries to the hand and wrist; other measures either have incomplete evidence or evidence gathered in a nontraumatic population.

CONCLUSIONS

The DASH and PRWE both have evidence of reliability, validity, and responsiveness in a hand and wrist trauma population. Other PROMs used to assess hand and wrist trauma patients do not. This should be considered when selecting a PROM for patients with traumatic hand and wrist pathology.

Stabilisation of distal radius fractures: Lessons learned and future directions

Our understanding of the diagnosis and management of distal radius fractures has been a long developed over centuries. There has been a shift in treatment of these very common injuries from closed reduction and casting to internal fixation. The answer to the best method of treatment has yet to be found. Today, we have a multitude of treatment options available with varying degrees of evidence to support their use. This review helps to illustrate the lessons we have learned and future directions for treatment.

Balloon-assisted reduction, pin fixation and tricalcium phosphate augmentation for calcanear fracture

Two-thirds of hindfoot fractures involve the calcaneus. The best treatment for intraarticular fractures is still debated. The goal of treatment has been focussed for years on the anatomical reduction of the articular surface. Open reduction and internal fixation enables the surgeon to view the articular surface directly, but it is associated with a high rate of wound breakdown and infection. Therefore, length, width and angular replacement of the great tuberosity are actually the main parameters to consider when treating this type of fracture. This is a report of our experience of 20 patients treated with a minimally invasive technique of reduction using an inflatable bone tamp filled with tricalcium phosphate, with a mean follow-up of 12.25 months (range 7-26 months). Percutaneous K-wires were used to help reduction and to direct balloon inflation. Surgical goals were restoration of the mechanical stability for earlier full weight-bearing and patient mobilisation.

Accelerated rehabilitation compared with a standard protocol after distal radial fractures treated with volar open reduction and internal fixation: a prospective, randomized, controlled study

BACKGROUND

There are relatively few studies in the literature that specifically evaluate accelerated rehabilitation protocols for distal radial fractures treated with open reduction and internal fixation (ORIF). The purpose of this study was to compare the early postoperative outcomes (at zero to twelve weeks postoperatively) of patients enrolled in an accelerated rehabilitation protocol with those of patients enrolled in a standard rehabilitation protocol following ORIF for a distal radial fracture. We hypothesized that patients with accelerated rehabilitation after volar ORIF for a distal radial fracture would have an earlier return to function compared with patients who followed a standard protocol.

METHODS

From November 2007 to November 2010, eighty-one patients with an unstable distal radial fracture were prospectively randomized to follow either an accelerated or a standard rehabilitation protocol after undergoing ORIF with a volar plate for a distal radial fracture. Both groups began with gentle active range of motion at three to five days postoperatively. At two weeks, the accelerated group initiated wrist/forearm passive range of motion and strengthening exercises, whereas the standard group initiated passive range of motion and strengthening at six weeks postoperatively. Patients were assessed at three to five days, two weeks, three weeks, four weeks, six weeks, eight weeks, twelve weeks, and six months postoperatively. Outcomes included Disabilities of the Arm, Shoulder and Hand (DASH) scores (primary outcome) and measurements of wrist flexion/extension, supination, pronation, grip strength, and palmar pinch.

RESULTS

The patients in the accelerated group had better mobility, strength, and DASH scores at the early postoperative time points (zero to eight weeks postoperatively) compared with the patients in the standard rehabilitation group. The difference between the groups was both clinically relevant and statistically significant.

CONCLUSIONS

Patients who follow an accelerated rehabilitation protocol that emphasizes motion immediately postoperatively and initiates strengthening at two weeks after volar ORIF of a distal radial fracture have an earlier return to function than patients who follow a more standard rehabilitation protocol.

LEVEL OF EVIDENCE

Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Controversies in the management of distal radius fractures

Controversies span the entire spectrum of management of distal radius fractures-fracture assessment, diagnosis, treatment, and evaluation of outcomes. The utility of multiple radiographic views described in the literature has not been validated. Likewise, the several classification systems that exist have yet to demonstrate substantial interobserver and intraobserver reliability. Nonsurgical controversies involve fracture reduction, use of anesthesia, type of fracture immobilization, and forearm position during healing. Surgical controversies include surgical indications, need for release of carpal tunnel, fracture fixation method, and the need for augmentation (ie, bone graft). Postoperatively, rehabilitation, medication, and physical therapy also remain highly controversial. The best outcome measure has yet to be established. A strong need remains for high-level, prospective studies to determine the most effective way to assess, diagnose, treat, and measure outcomes in patients with distal radius fractures.

Setting time and formability of calcium phosphate cements prepared using modified dicalcium phosphate anhydrous powders

Calcium phosphate cements (CPCs) were prepared using Ca4(PO4)2O (TeCP) and modified CaHPO4 (DCPA) to evaluate the effects of the powder properties for DCPA particles on the setting time and formability of the resulting CPCs. Two types of modified DCPA were prepared by milling commercially available DCPA with ethanol (to produce E-DCPA) or distilled water (to produce W-DCPA). The E-DCPA samples consisted of well-dispersed, fine primary particles, while the W-DCPA samples contained agglomerated particles, and had a smaller specific surface area. The mean particle size decreased with increased milling time in both cases. The raw CPC powders prepared using W-DCPA had a higher packing density than those prepared using E-DCPA, regardless of the mean particle size. The setting time of the CPC paste after mixing with distilled water decreased with decreases in the mean particle size and specific surface area, for both types of DCPA. The CPCs prepared using W-DCPA showed larger plasticity values compared with those prepared using E-DCPA, which contributed to the superior formability of the W-DCPA samples. The CPCs prepared using W-DCPA showed a short setting time and large plasticity values, despite the fact that only a small amount of liquid was used for the mixing of the raw CPC powders (a liquid-to-powder ratio of 0.25 g g(-1) was used). It is likely that the higher packing density of the raw CPC powders prepared using W-DCPA was responsible for the higher performance of the resulting CPCs.

Minimally invasive plate osteosynthesis for distal radius fractures

BACKGROUND

Fractures of distal radius are common injury in all age groups. Cast treatment with or without close reduction is a viable option. However, the results are often unsatisfactory with restricted function. The open reduction and internal fixation often results in extensive soft tissue dissection and associated high rates of infect and delayed/nonunion. The distractor/external fixator have reported good functional and anatomical results but the incidence of pin traction infection nerve injury and cosmedic deformity are high. We introduced a modified operative technique for minimally invasive plate osteosynthesis (MIPO) for distal radial fracture and evaluated the functional outcomes and complications.

MATERIALS AND METHODS

22 distal radial fractures (10 left, 12 right) were treated using the MIPO technique and two small incisions with a palmar locking plate from August 2009 to August 2010. The wrist function was assessed according to Dienst wrist rating system, and postoperative complications were recorded.

RESULTS

According to Dienst wrist rating system, 13 patients showed excellent results, 6 cases showed good results and 3 patients had moderate results. No patient had poor results. Thus, the excellent and good rate was 86.4%. One patient had anesthesia in the thenar eminence and this symptom disappeared after 3 months. One patient had delayed healing in the proximal wrist crease. Two patients had mild pain on the ulnar side of the wrist and two patients had limited wrist joint function.

CONCLUSION

The MIPO technique by using two small palmar incisions is safe and effective for treatment of distal radial fractures.

An investigation of the effect of AlloMatrix bone graft in distal radial fracture: a prospective randomised controlled clinical trial

The osteoinductive properties of demineralised bone matrix have been demonstrated in animal studies. However, its therapeutic efficacy has yet to be proven in humans. The clinical properties of AlloMatrix, an injectable calcium-based demineralised bone matrix allograft, were studied in a prospective randomised study of 50 patients with an isolated unstable distal radial fracture treated by reduction and Kirschner (K-) wire fixation. A total of 24 patients were randomised to the graft group (13 men and 11 women, mean age 42.3 years (20 to 62)) and 26 to the no graft group (8 men and 18 women, mean age 45.0 years (17 to 69)). At one, three, six and nine weeks, and six and 12 months post-operatively, patients underwent radiological evaluation, assessments for range of movement, grip and pinch strength, and also completed the Disabilities of Arm, Shoulder and Hand questionnaire. At one and six weeks and one year post-operatively, bone mineral density evaluations of both wrists were performed. No significant difference in wrist function and speed of recovery, rate of union, complications or bone mineral density was found between the two groups. The operating time was significantly higher in the graft group (p = 0.004). Radiologically, the reduction parameters remained similar in the two groups and all AlloMatrix extraosseous leakages disappeared after nine weeks. This prospective randomised controlled trial did not demonstrate a beneficial effect of AlloMatrix demineralised bone matrix in the treatment of this category of distal radial fractures treated by K-wire fixation.

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.

RADIOLOGICAL ASSESSMENTS OF INJECTED CALCIUM SULFATE BONE CEMENTS IN THE TREATMENT OF DISTAL RADIAL FRACTURE

It has been reported in many literatures that different kinds of bone graft augmentations have been applied in the treatment of distal radial fractures with favorable results. The authors applied calcium sulfate cement in the treatment of distal radial fractures and evaluated the radiological outcomes of 33 patients. The radiological changes of cement statuses, implants, and radiological parameter of distal radius were analyzed. After closed reduction of the displacement, fractures were fixed by Kirschner pins and stabilized by percutaneous injection of premixed calcium sulfate bone cement. Periodic X-ray evaluations were obtained at immediate post-operation and at every month. A total of 28 patients completed the follow-up and the cement extravasations into wrist joint or into soft tissues had been seen in almost every patient. The gradual settling and losses of radial height, radial inclination angle, and volar tilting angles were significant even after removal of Kirschner pins after 8 weeks. Gradual absorptions of cured cement block inside and outside distal radial cortices were observed in every case and complete absorptions of intraosseous cements after 8 weeks happened in 53.6% (15/28) of patients. The extravasated cements took longer time to fade away. The radiological results of current study revealed negative results of calcium sulfate applied in the treatment of distal radial fracture in terms of reduction parameters and cement block longevity.

Calcium phosphate cement augmentation after volar locking plating of distal radius fracture significantly increases stability

PURPOSE

Distal radius fractures represent the most common fractures in adults. Volar locking plating to correct unstable fractures has become increasingly popular. Although reasonable primary reduction is possible in most cases, maintenance of reduction until the fracture is healed is often problematic in osteoporotic bone. To our knowledge, no biomechanical studies have compared the effect of enhancement with biomaterial on two different volar fixed-angle plates.

METHODS

Human fresh-frozen cadaver pairs of radii were used to simulate an AO/OTA 23-A3 fracture. In a total of four groups (n = 7 for each group), two volar fixed-angle plates (Aptus 2.5 mm locking fracture plate, Medartis, Switzerland and VA-LCP two-column distal radius plate 2.4, volar, Synthes, Switzerland) with or without an additional injection of a biomaterial (Hydroset Injectable HA Bone Substitute, Stryker, Switzerland) into the dorsal comminution zone were used to fix the distal metaphyseal fragment. Each specimen was tested load-controlled under cyclic loading with a servo-hydraulic material testing machine. Displacement, stiffness, dissipated work and failure mode were recorded.

RESULTS

Improved mechanical properties (decreased displacement, increased stiffness, decreased dissipated work) were found in both plates if the biomaterial was additionally injected. Improvement of mechanical parameters after biomaterial injection was more evident in the Synthes plate compared to the Aptus plate. Pushing out of the screws was noticed as a failure mode only in samples lacking supplementary biomaterial.

CONCLUSIONS

Injection of a biomaterial into the dorsal comminution zone increases stability after volar locking plating of distal radius fractures in vitro.

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.

Corrective osteotomy of the distal radius following failed internal fixation

INTRODUCTION

The purpose of this study was to quantify the clinical and radiographic outcomes after corrective osteotomy for malunions of the distal radius following failed internal fixation.

MATERIALS AND METHODS

Results of 18 patients (8 women, 10 men; mean age 41 years) are presented an average of 7 years after osteotomy of a malunited distal radius fracture. We assessed active range of motion, grip strength, radiographic alignment, pain and disability. Subjective and objective data were summarized using the modified Mayo Wrist Score and the point-score system of Fernandez.

RESULTS

Wrist motion, pain and deformity improved with the operation in all cases. The modified Mayo Wrist Score averaged 79 points. The scale of Fernandez indicated ten good, two fair and six poor results.

CONCLUSIONS

The results of this study suggest that the operative correction of a distal radius malunion following an unsuccessful internal fixation can be achieved with outcomes comparable to those reported after initial nonoperative treatment.

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.

Fixation of distal radius fractures in adults: a review

In patients for whom function is a priority, anatomic reduction and stable fixation are prerequisites for good outcomes. Several therapeutic options exist, including orthopedic treatment and internal fixation with pins (intra- and extrafocal), external fixation which may or may not bridge the wrist, and different internal fixation techniques with dorsal or palmar plates using or not, locking screws. Arthroscopy may be necessary in case of articular fracture. In the presence of significant metaphyseal bone defects, filling of the comminution with phosphocalcic cements provides better graft stability. The level of evidence is too low to allow recommending one type of fixation for one type of fracture; and different fixation options to achieve stable reduction exist, each with its own specific complications. With the new generations of palmar plate, secondary displacement is becoming a thing of the past.

Augmentation of implant fixation in osteoporotic bone

Osteoporosis presents a dilemma for the orthopedic surgeon. Screw fixation within the bone is crucial for mechanical stabilization, maintenance of reduction, and ultimately, fracture healing. For the patient, soft bones and physiological fragility usually benefit from immediate weight bearing and mobility to avoid further disuse osteoporosis, deconditioning, and immobility. For implant companies, traditional screws, plates, and nails function for simple fractures and compliant patients. Locked plating has improved screw purchase in osteoporotic bone and has expanded fracture fixation capabilities but is not the panacea for all fractures. For orthopedic surgeons, traditional surgical augmentation for osteoporosis consisting of dual plating, augmentation with polymethyl methacrylate, joint replacement, and now locked plating are beneficial. In order to advance orthopedic care in the expanding population of elderly osteoporotic patients, modern solutions utilizing the dual properties of secure fixation and relatively flexible implants are required. Endosteal substitution, extraosteal substitution, and combined nail/plate combinations are methods of utilizing traditional implants in a nontraditional way. Nonsurgical augmentation of fracture fixation is also paramount.

Bone graft substitutes

Replacement of missing bone stock is a reconstructive challenge to upper extremity surgeons and decision-making with regards to available choices remains difficult. Preference is often given to autograft in the form of cancellous, cortical, or corticocancellous grafts from donor sites. However, the available volume from such donor sites is limited and fraught with potential complications. Advances in surgical management and medical research have produced a wide array of potential substances that can be used for bone graft substitute. Considerations in selecting bone grafts and substitutes include characteristic capabilities, availability, patient morbidity, immunogenicity, potential disease transmission, and cost variability.

Future treatment and research directions in distal radius fracture

Whether or not they will have their lives dramatically extended in the next few decades, it is clear that people are living longer, healthier, and more active lives. The two peak incidences of distal radius fractures will remain within the pediatric and geriatric age groups, with the latter experiencing a substantial increase in the coming years. This article attempts to project future developments with regard to epidemiology, risk and prevention, fracture assessment, and treatment of distal radius fractures, and the ever increasing concern for the economic impact of this prevalent injury.

The use of bone grafts and substitutes in the treatment of distal radius fractures

The interest in developing biomaterials to augment fracture healing continues to grow. New products promise early return to function with minimal morbidity; however, indications to use these products remain unclear. An ideal bone graft material stimulates bone healing and provides structural stability while being biocompatible, bioresorbable, easy to use, and cost-effective. This article reviews the biology of bone grafts and the clinical evidence in the use of bone graft substitutes for the treatment of distal radius fractures.

Mechanical characterization of bone graft substitute ceramic cements

The aim of this laboratory work was to study the compressive and flexural characteristics of various commercially available bone graft substitute (BGS) ceramic cements, in their initial as-mixed condition, and compare them to polymethylmethacrylate (PMMA). The tested biomaterials were two different calcium phosphate cements, two different calcium sulphate cements, one nanocrystalline hydroxyapatite and one PMMA cement. All biomaterials were prepared according to manufacturers instructions and the methodology described in ISO 5833 (2002) for acrylic bone cement was followed, as the one closest approaching in vivo requirements. All BGS cements had a brittle behaviour and when subjected to mechanical stress they all failed under sudden crack propagations in their bulk. Both in compression and bending, all BGS cements failed under loads lower than those of PMMA. In compression, the calcium sulphate extra strength cement showed a strength value of approximately 60% of PMMA, the other cements following at a distance. In bending, all BGS cements showed strengths below 22% of PMMA. However, due to limited number and fragility of specimens, calculated bending strengths can only be considered as indicative figures with limited comparative value. The results of this in vitro study showed a varying mechanical performance between tested BGS ceramic cements, whilst all of them exhibited lower compression and bending strength than the selected PMMA. These findings, of course, cannot be directly extrapolated to surgical or clinical implications, since the adopted in vitro context does not necessarily reflect the actual in vivo conditions met by such biomaterials.

Fixation of comminuted distal radius fractures with a mixture of calcium phosphate and calcium sulfate cement

Distal radius fracture alignment and stabilization can be a surgical challenge in the face of severe comminution and bone loss. We describe a technique using a calcium phosphate/sulfate bone cement, as an adjunct to internal fixation. This bone cement is biocompatible, osteoconductive, and sets quickly with an isothermic reaction. The use of bone cement eliminates the need for primary autologous bone grafting and allows for easier reduction and retention of reduction at the time of surgery. Bone cement is employed for the following purposes in comminuted fractures: (1) to fill a void due to lost or crushed cancellous bone, (2) to hold larger unstable fragments while hardware is placed, and (3) to retain fragments too small to take hardware. Available bone cements, studies involving the use of bone cement for distal radius fractures, indications, and surgical technique will be reviewed.

Injectable bone-graft substitutes: current products, their characteristics and indications, and new developments

More than a decade has passed since the first injectable bone substitutes were introduced for use in orthopaedic trauma, and over recent years the number of commercial products has increased dramatically. Despite the fact that these bone substitutes have been on the market for many years, knowledge amongst potential users on how and when they might be useful is still fairly limited. Most injectable bone substitutes belong to one of two major groups: by far the largest group contains products based on various calcium phosphate (CP) mixtures, whilst the smaller group consists of calcium sulphate (CS) compounds. Following mixing, the CP or CS paste can be injected into--for instance--a fracture space for augmentation as an alternative to bone graft, or around a screw for augmentation if the bone is weak. Within minutes an in situ process makes the substitute hard; the mechanical strength in compression resembles that of cancellous bone, whereas the strength in bending and shear is lower. Over time, CP products undergo remodelling through a cell-mediated process that seems to mimic the normal bone remodelling, whilst CS products are dissolved through a faster process that is not cell-mediated. For CP, a number of clinical studies have shown that it can be useful for augmentation of metaphyseal fractures when a space is present. Randomised studies have verified that CP works especially well in tibial plateau fractures when compared with conventional bone grafting. So far the number of clinical studies on CS products is very low. Development at present seems to be heading towards premixed or directly mixed products as well as new compounds that contain fibres or other components to enhance bending and shear strength. Products that are based on combinations of CP and CS are also being developed to combine the fast-dissolving CS with the stronger and more slowly remodelling CP. Injectable bone substitutes, and especially CS, have also been targeted as potentially good carriers for antibiotics and growth factors.

Bone graft substitutes for articular support and metaphyseal comminution: what are the options?

Subchondral and metaphyseal bone defects pose a great challenge for the Orthopaedic surgeon not only because the support for the articular surface has been lost but also because the mechanism for the nourishment of articular cartilage through the subchondral plate is distorted. A number of options are available to the surgeons, none of them perfect. Autografting has an appreciable high rate of harvest site morbidity, allograft is associated with infection transmission and host immunologic response. These realities have stimulated interest in supplying bone replacement materials (demineralised bone matrix, synthetic bone substitutes, bone morphogenic proteins). This paper presents the indications and applications of bone substitutes for metaphyseal defects and subchondral support in orthopaedic trauma.

Monostotic fibrous dysplasia of the distal radius metaphysis: case report

We report the case of a 56-year-old male with distal radius monostotic fibrous dysplasia that was detected when the patient suffered a pathologic fracture. This case is unusual because of the location of the tumor and the age of the patient.

In vitro elution of amikacin and ticarcillin from a resorbable, self-setting, fiber reinforced calcium phosphate cement

OBJECTIVE

To determine in vitro elution characteristics of amikacin and ticarcillin from fiber reinforced calcium phosphate beads (FRCP).

SAMPLE POPULATION

Experimental.

METHODS

FRCP beads with water (A), amikacin (B), ticarcillin/clavulanate (C), or both amikacin and ticarcillin/clavulanate (D) were bathed in mL phosphate-buffered saline (PBS) at 37°C, 5% CO(2) and 95% room air. PBS was sampled (eluent) and beads were placed in fresh PBS at time points 1 and 8 hours and 1, 2, 3, 4, 5, 6, 7, 10, 12, 14, 18, 21, 25, 28, 35, 42, 49, and 56 days. Antibiotic concentration and antimicrobial activity of eluent against Escherichia coli, Staphylococcus aureus, and Klebsiella pneumoniae were determined.

RESULTS

Both antibiotics eluted in a bimodal pattern. Beads with a single antibiotic eluted 20.8 ± 2.5% of amikacin and 29.5 ± 0.8% of ticarcillin over 56 days. Coelution of the antibiotics resulted in a lower proportion (AUC(0-∞) ) of antibiotics eluted for both amikacin (9.5 ± 0.2%) and ticarcillin (21.7 ± 0.09%). Bioassay of antimicrobial activity of the eluent (t = 1, 8, and 24 hours) established reduced antimicrobial activity of amikacin from combination beads (D).

CONCLUSIONS

FRCP beads with amikacin or ticarcillin/clavulanate, but not the combination, are suitable carriers for wound implantation.

CLINICAL RELEVANCE

Duration before complete resorption of FRCP beads in vivo should be determined before clinical use as a resorbable depot. The results of this study underscore the importance of testing drug combinations, despite success of the combination systemically, before their use in local applications.