A lack of consensus in the assessment of fracture healing among orthopaedic surgeons

Development of the radiographic union score for tibial fractures for the assessment of tibial fracture healing after intramedullary fixation

BACKGROUND

: The objective was to evaluate the newly developed Radiographic Union Score for Tibial fractures (RUST). Because there is no "gold standard," it was hypothesized that the RUST score would provide substantial improvements compared with previous scores presented in the literature.

METHODS

: Forty-five sets of X-rays of tibial shaft fractures treated with intramedullary fixation were selected. Seven orthopedic reviewers independently scored bony union using RUST. Radiographs were reassessed at 9 weeks. Intraclass correlation coefficients (ICC) with 95% confidence intervals (CI) measured agreement.

RESULTS

: Overall agreement was substantial (ICC, 0.86; 95% CI, 0.79-0.91). There was improved reliability among traumatologists compared with others (ICC = 0.86, 0.81, and 0.83, respectively). Overall intraobserver reliability was also substantial (ICC, 0.88; 95% CI, 0.80-0.96).

CONCLUSIONS

: The RUST score exhibits substantial improvements in reliability from previously published scores and produces equally reproducible results among a variety of orthopedic specialties and experience levels. Because no "gold standards" currently exist against which RUST can be compared, this study provides only the initial step in the score's full validation for use in a clinical context.

Open interlocking nailing and bone grafting for neglected femoral shaft fractures

PURPOSE

To review the treatment outcome of patients with neglected femoral shaft fractures.

METHODS

Records of 22 men and 3 women aged 20 to 55 (mean, 36) years who underwent open interlocking nailing and bone grafting for neglected (2-month-old or more) closed femoral shaft fractures were reviewed. 21 had nonunion and 4 had malunion. All patients had deformed, shortened, and wasted lower limbs, with knee stiffness. The mean delay in presentation was 3 (range, 2-7) months.

RESULTS

Patients were followed up for a mean of 18 (range, 14-30) months. The mean time for radiological union was 5 (range, 4-7) months. Three patients had delayed union (6 months or more) and underwent secondary procedures (dynamisation or bone marrow injection). None had non-union. All had some degree of shortening; in 3 it was >2 cm. None had neurological injury following acute gain in length. None had deep infections; 2 had superficial wound infections and 6 had pin tract infections. Mean knee flexion improved 50 (from 70 to 120) degrees and the mean extensor lag decreased 7 (from 15 to 8) degrees. After a mean of 18 weeks, 23 of the patients were able to return to their work.

CONCLUSION

Open interlocking nailing and bone grafting coupled with aggressive rehabilitation can achieve acceptable results for patients with neglected femoral shaft fractures.

Outcomes assessment in fracture healing trials: a primer

The measurement of clinical outcomes in trauma research is often problematic in that it is subjective and currently no feasible gold standard evaluation is available. Consequently, observed trial results are partly dependent on which outcome measure is used. Precise and useful estimates of treatment effects can only be obtained when using reliable, valid, and responsive instruments for measuring fracture healing. This overview outlines the concept of the validation of outcome measures and provides a summary of available and frequently used instruments in orthopaedic clinical trials. Outcome instruments can be divided into assessments by the clinician and assessments by the patient. Clinician-assessed measures are frequently used in routine practice but have often not been validated before their use in research. They include clinical and radiographic assessments. In contrast, patient-assessed measures have been designed specifically for investigational purposes and measure health on various domains. Some of them have been validated extensively. Critically evaluating established clinician-based assessments and integrating those found to be valid with patient-assessed outcomes into a composite measure of fracture healing constitute major future challenges.

The radiographic union scale in tibial fractures: reliability and validity

Radiographic assessment of tibial fracture healing continues to pose significant challenges to both routine fracture care and clinical research. Orthopaedic surgeons fail to achieve sufficient agreement on fracture healing when using conventional radiographic measures such as their general impression or the number of cortices bridged by callus. Moreover, the extent to which radiographic assessment of healing corresponds to patient-important outcomes is largely unknown. In an attempt to improve the former (ie, reliability) and inform the latter (ie, validity), recent studies have explored a novel radiographic assessment for tibial shaft fractures, the Radiographic Union Scale for Tibial fractures (RUST). The RUST score assesses the presence of bridging callus and that of a fracture line on each of 4 cortices seen on 2 orthogonal radiographic views. A recent study has found that RUST scores have greater inter-rater reliability when compared with surgeon's general impression or the number of cortices bridged by callus. This may increase the utility of radiographs as a standardized measure of treatment efficacy in the follow-up of tibial fractures.

Locked plating of distal femur fractures leads to inconsistent and asymmetric callus formation

OBJECTIVES

Locked plating constructs may be too stiff to reliably promote secondary bone healing. This study used a novel imaging technique to quantify periosteal callus formation of distal femur fractures stabilized with locking plates. It investigated the effects of cortex-to-plate distance, bridging span, and implant material on periosteal callus formation.

DESIGN

Retrospective cohort study.

SETTING

One Level I and one Level II trauma center.

PATIENTS

Sixty-four consecutive patients with distal femur fractures (AO types 32A, 33A-C) stabilized with periarticular locking plates.

INTERVENTION

Osteosynthesis using indirect reduction and bridge plating with periarticular locking plates.

MAIN OUTCOME MEASUREMENT

Periosteal callus size on lateral and anteroposterior radiographs.

RESULTS

Callus size varied from 0 to 650 mm2. Deficient callus (20 mm2 or less) formed in 52%, 47%, and 37% of fractures at 6, 12, and 24 weeks postsurgery, respectively. Callus formation was asymmetric, whereby the medial cortex had on average 64% more callus (P=0.001) than the anterior or posterior cortices. A longer bridge span correlated minimally with an increased callus size at Week 6 (P=0.02), but no correlation was found at Weeks 12 and 24 postsurgery. Compared with stainless steel plates, titanium plates had 76%, 71%, and 56% more callus at Week 6 (P=0.04), Week 12 (P=0.03), and Week 24 (P=0.09), respectively.

CONCLUSIONS

Stabilization of distal femur fractures with periarticular locking plates can cause inconsistent and asymmetric formation of periosteal callus. A larger bridge span only minimally improves callus formation. The more flexible titanium plates enhanced callus formation compared with stainless steel plates.

When is a fracture healed? Radiographic and clinical criteria revisited

Selecting the most appropriate outcome measures can be especially burdensome in trials studying fracture healing, because the process of fracture healing is subjective and without a gold standard. Although a wide variety of radiographic modalities are available, plain radiography remains the most common approach for healing assessment. Radiographic criteria, however, do not correlate well with fracture strength and stiffness. Additional challenges include a lack of consensus in what radiographic measures are most appropriate in the assessment of healing. In this article, we provide an overview of the most commonly used radiographic and clinical criteria for defining fracture healing. The validity and reliability of alternative approaches is also discussed.

Are large fracture trials possible?

Reliable clinical orthopaedic trauma research is important and necessary to guide orthopaedic surgeons and their patients to best practices and expected outcomes. Currently, most fracture care is guided by suboptimal clinical research. To address this need, large fracture trials are necessary to deliver Level I evidence and direct the orthopaedic trauma surgeon in the best treatments. Although trials of this nature have been rare, they have been completed successfully. Although each fracture trial comes with its own set of obstacles, the trial can be successful with proper expertise, study planning, and study design. The purpose of this article is to present the rationale, methodology, and implementation strategies to successfully complete a large fracture trial.

Ultrasound for fracture healing: current evidence

Low-intensity pulsed ultrasound (LIPUS) is a relatively new technique for the acceleration of fracture healing in fresh fractures and nonunions. It has a frequency of 1.5 MHz, a signal burst width of 200 micros, a signal repetition frequency of 1 kHz, and an intensity of 30 mW/cm2. In 1994 and 1997, two milestone double-blind randomized controlled trials revealed the benefits of LIPUS for the acceleration of fracture healing in the tibia and radius. They showed that LIPUS accelerated the fracture healing rate from 24% to 42% for fresh fractures. Some literature, however, has shown no positive effects. The beneficial effect of acceleration of fracture healing by LIPUS is considered to be larger in the group of patients or fractures with potentially negative factors for fracture healing. The incidence of delayed union and nonunion is 5% to 10% of all fractures. For delayed union and nonunion, the overall success rate of LIPUS therapy is approximately 67% (humerus), 90% (radius/radius-ulna), 82% (femur), and 87% (tibia/tibia-fibula). LIPUS likely has the ability to enhance maturation of the callus in distraction osteogenesis and reduce the healing index. The critical role of LIPUS for fracture healing is still unknown because of the heterogeneity of results in clinical trials for fresh fractures and the lack of controlled trials for delayed unions and nonunions.

Risk factors for femoral nonunion after femoral shaft fracture

The purpose of this study was to evaluate risk factors for nonunion after femoral nailing of femoral shaft fractures. A case-control study with two to one matching was conducted. Forty-five patients with 46 femoral nonunions (cases) and 92 patients with healed femoral shaft fractures (controls) were identified from our orthopedic trauma registry. All cases and controls were initially managed with reamed, statically locked femoral nails. The characteristics that were significantly different between the two groups were open fracture, delay to weight bearing, and tobacco use. Fracture classification, gender, direction of nail insertion (antegrade vs. retrograde), and Injury Severity Score were not predictive of nonunion. We conclude that open fracture, tobacco use, and delayed weight bearing are risk factors for femoral nonunion after intramedullary nailing for diaphyseal femur fractures.

Nonunion of forearm shaft fractures in children after intramedullary nailing

The elastic stable intramedullary nailing (ESIN) is the current treatment of choice for unstable forearm shaft fractures in children. There is no large study on paediatric nonunion of forearm shaft fractures in children after intramedullary nailing. There are only sporadic reports on nonunions after ESIN in children. The aim of this study was to define predisposing factors of nonunions in paediatric forearm fractures. All children who had been treated for forearm fractures by ESIN in our hospital from 1990 to 2006, and all children treated elsewhere surgically and being followed up at our institution were included in the study. In these children, we identified all patients who did not show bony consolidation of the fracture after 6 months from ESIN. Over a period of 16 years, 537 patients were primarily treated in our hospital and 55 children had been initially treated in a different institution. Six children were identified to fulfill the criteria of having developed a pseudarthrosis. Of these six children, three patients had been primarily treated in another hospital and three were our original patients. The average age was 11.1 years (9-14 years). There were only pseudarthroses of the ulna to be observed. In five children, the pseudarthrosis was in the middle third and in one patient in the distal third of the ulna. There were five closed fractures and one first-degree open fracture. Five times an open reduction of the ulna had been performed because closed reduction and insertion of the ESIN was impossible, whereas the radius had been treated closed in five cases and open in one case for intramedullary stabilization. Three cases were refractures, in one child it was a second refracture. In one case, we identified a technical error as cause of the development of the pseudarthrosis. Four children needed a revision surgery. In these children, the ulna was plated. Two patients showed spontaneous healing of the pseudarthrosis. In five patients, there was a hypertrophic pseudarthrosis present and in one case was hypotrophic pseudarthrosis. The reintervention was necessary because of increasing deformity in four patients and implant failure in one case. In conclusion, Non-unions after forearm fractures are observed in children and adolescents mainly in the middle third of the ulna. With the need of initial open reduction or the presence of an open fracture in the first instance, the risk of developing a pseudarthrosis. It may also be higher in such cases, which represent a refracture. Despite the small risk of developing a pseudarthrosis after forearm fracture, the indication for ESIN is clear. The surgical trauma needs to be as minimal as possible in cases with open reduction with as little as possible compromise of the blood circulation of the affected bone.

Ability and limitation of radiographic assessment of fracture healing in rats

The purpose of the present study was to assess whether clinicians are actually able to evaluate the mechanical status of fracture healing from radiograms. Fifteen orthopaedic surgeons evaluated the radiograms of experimentally produced femur fractures in rats and predicted mechanical strength (%) of the affected side compared to the unaffected control side. Following this, actual mechanical strength of the affected and control side was determined by a three-point bending test. The median of the strength in the transverse fracture model predicted from radiograms was 33% (2 weeks), 72% (4 weeks), 88% (6 weeks), 84% (8 weeks), and 89% (12 weeks). The actual measured recovery ratio of mechanical strength (exp/control x 100) was 36%, 76%, 93%, 89%, and 106% in each observation period respectively. The tendency was almost the same in a comminuted fracture model. The mean recovery rate determined by interpretation of the surgeons correlated linearly to the actual measured mechanical strength determined by mechanical testing (R(2): 0.80 in transverse fracture, 0.60 in comminuted fracture). Clinicians demonstrated that a comparatively good evaluation of the mechanical status of fracture healing is possible from radiograms up to approximately 80% recovery. However, they tended to make less accurate, weaker assessments at the final stages. In conclusion, radiograms may be inadequate for evaluation of fracture healing completion.

Fracture healing and bone repair: an update

Bone healing represents a physiological process of repair and restoration of function. Recent advances in a variety of medical disciplines have enabled scientists and clinicians to characterise this phenomenon at the molecular level. A number of molecular mediators and cells interact utilising different pathways. Despite the involvement of many local and systemic factors failure of the naturally occurring mechanisms can occur leading to either delayed union or non-union. This review article is focused on the recent understanding of the mechanisms governing the bone repair process.

Outcome instruments: rationale for their use

The number of outcome instruments available for use in orthopaedic observational studies has increased dramatically in recent years. Properly developed and tested outcome instruments provide a very useful tool for orthopaedic research. Criteria have been proposed to assess the measurement properties and quality of health-status instruments. Unfortunately, not all instruments are developed with use of strict quality criteria. In this article, we discuss these quality criteria and provide the reader with a tool to help select the most appropriate instrument for use in an observational study. We also review the steps for future use of outcome instruments, including the standardization of their use in orthopaedic research.

Electrical stimulation: Nonunions

The current paper attempts to provide an overview on the currently available fundamental, preclinical, and clinical evidence on the biologic rationale and therapeutic efficacy of electrical stimulation devices applied in patients with long-bone nonunions. Electrical stimulation (ES) involves the generation of an electrical or electromagnetic current through the ununited fracture. Such currents, which are present in physiologically healing bone, provide stimuli that favor a healing response to bone cells. These stimuli include the enhancement of transmembrane and intracellular calcium-mediated signal transduction and an increased synthesis of paracrine and autocrine growth factors by osteoblasts. Favorable healing union rates, ranging from 43% to 90%, as found by several clinical case series, have prompted the orthopedic community to, at least partially, adopt ES for the treatment of long bone nonunions. Nonetheless, randomized controlled trials have not provided definitive evidence of ES causing nonunions to heal more often than sham devices. This impediment is probably formed by small sample sizes, lack of consistency regarding the definition of union and nonunion, and variability in ES current used.

Low-intensity pulsed ultrasound: Nonunions

Nonunions occur in 5-10% of fractures and are characterized by the failure to heal without further intervention. Low intensity pulsed ultrasound therapy has been developed as an alternative to surgery in the treatment of nonunions. We describe a systematic review on trials of low-intensity pulsed ultrasound therapy for healing of nonunions. We searched the electronic databases Medline and the Cochrane library for articles on ultrasound and healing of nonunions published up to 2008. Trials selected for the review met the following criteria: treatment of at least one intervention group with low intensity pulsed ultrasound; inclusion of patients (humans) with one or more nonunions (defined as "established" or as a failure to heal for a minimum of eight months after initial injury); and assessment of healing and time to healing, as determined radiographically. The following data were abstracted from the included studies: sample size, ultrasound treatment characteristics, nonunion location, healing rate, time to fracture healing, fracture age, and demographic information. We found 79 potentially eligible publications, of which 14 met our inclusion criteria. Of these, eight studies were used for data abstraction. Healing rates averaged 87%, (range 65.6%-100%) among eight trials. Mean time to healing was 146.5 days, (range 56-219 days). There is evidence from trials that low-intensity pulsed ultrasound may be an effective treatment for healing of nonunions. More homogeneous and larger controlled series are needed to further investigate its efficacy.

Application of rhBMP-7 and platelet-rich plasma in the treatment of long bone non-unions: a prospective randomised clinical study on 120 patients

The purpose of this prospective randomised clinical study was to compare the efficacy of recombinant bone morphogenetic protein 7 (rhBMP-7) and platelet-rich plasma (PRP) as bone-stimulating agents in the treatment of persistent fracture non-unions. One hundred and twenty patients were randomised into two treatment groups (group rhBMP-7 vs. group PRP). Sixty patients with sixty fracture non-unions were assigned to each group (median age: 44 years, range 19-65, for the rhBMP-7 group and 41 years, range 21-62, for the PRP group, respectively). In the rhBMP-7 group, there were 15 tibial non-unions, 10 femoral, 15 humeral, 12 ulnar, and 8 radial non-unions. In the PRP group, there were 19 tibial non-unions, 8 femoral, 16 humeral, 8 ulnar, and 9 radial non-unions. The median number of operations performed prior to our intervention was 2 (range 1-5) and 2 (range 1-5) with autologous bone graft being used in 23 and 21 cases for the rhBMP-7 and PRP groups, respectively. Both clinical and radiological union occurred in 52 (86.7%) cases of the rhBMP-7 group compared to 41 (68.3%) cases of the PRP group, with a lower median clinical and radiographic healing time observed in the rhBMP-7 group (3.5 months vs. 4 months and 8 months vs. 9 months, respectively). This study supports the view that in the treatment of persistent long bone non-unions, the application of rhBMP-7 as a bone-stimulating agent is superior compared to that of PRP with regard to their clinical and radiological efficacy.

Variability in the assessment of fracture-healing in orthopaedic trauma studies

BACKGROUND

There is a lack of consensus among orthopaedic surgeons in the assessment of fracture-healing. We conducted a systematic review of recent clinical studies of long-bone fracture care that were published in three major orthopaedic journals to identify current definitions of fracture-healing.

METHODS

MEDLINE and the computerized databases for The Journal of Bone and Joint Surgery (American Volume), The Journal of Bone and Joint Surgery (British Volume), and the Journal of Orthopaedic Trauma were searched from January 1996 through December 2006 with use of title, abstract, keyword, and medical subject headings. Therapeutic clinical studies of long-bone fractures of the appendicular skeleton in adults in which fracture-healing was assessed were selected. Two reviewers independently identified articles and extracted data. Any disagreement was resolved by consensus. We qualitatively and quantitatively summarized the definition of fracture union and the reliability of the assessment of radiographic fracture-healing.

RESULTS

One hundred and twenty-three studies proved to be eligible. Union was defined on the basis of a combination of clinical and radiographic criteria in 62% of the studies, on the basis of radiographic criteria only in 37%, and on the basis of clinical criteria only in 1%. Twelve different criteria were used to define fracture union clinically, and the most common criterion was the absence of pain or tenderness at the fracture site during weight-bearing. In studies involving the use of plain radiographs, eleven different criteria were used to define fracture union, and the most common criterion was bridging of the fracture site. A quantitative measure of the reliability of the radiographic assessment of fracture union was reported in two studies.

CONCLUSIONS

We found a lack of consensus with regard to the definition of fracture-healing in the current orthopaedic literature. Without valid and reliable clinical or radiographic measures of union, the interpretation of fracture care studies remains difficult.

Clinical evaluation of medicinal products for acceleration of fracture healing in patients with osteoporosis

Pre-clinical studies indicate that pharmacologic agents can augment fracture union. If these pharmacologic approaches could be translated into clinical benefit and offered to patients with osteoporosis or patients with other risks for impaired fracture union (e.g. in subjects with large defects or open fractures with high complication rate), they could provide an important adjunct to the treatment of fractures. However, widely accepted guidelines are important to encourage the conduct of studies to evaluate bioactive substances, drugs, and new agents that may promote fracture union and subsequent return to normal function. A consensus process was initiated to provide recommendations for the clinical evaluation of potential therapies to augment fracture repair in patients with meta- and diaphyseal fractures. Based on the characteristics of fracture healing and fixation, the following study objectives of a clinical study may be appropriate: a) acceleration of fracture union, b) acceleration of return to normal function and c) reduction of fracture healing complications. The intended goal(s) should determine subsequent study methodology. While an acceleration of return to normal function or a reduction of fracture healing complications in and of themselves may be sufficient primary study endpoints for a phase 3 pivotal study, acceleration of fracture union alone is not. Radiographic evaluation may either occur at multiple time points during the healing process with the aim of measuring the time taken to reach a defined status (e.g. cortical bridging of three cortices or disappearance of fracture lines), or could be obtained at a single pre-determined timepoint, were patients are expected to reach a common clinical milestone (i.e. pain free full weight-bearing in weight-bearing fracture cases). Validated Patient Reported Outcomes (PRO's) measures will need to support the return to normal function co-primary endpoints. If reduction of complication rate (e.g. non-union) is the primary objective, the anticipated complications must be defined in the study protocol, along with their possible associations with the specified fracture type and fixation device. The study design should be randomized, parallel, double-blind, and placebo-controlled, and all fracture subjects should receive a standardized method of fracture fixation, defined as Standard of Care.

Expandable intramedullary nailing and platelet rich plasma to treat long bone non-unions

BACKGROUND

Roentgenographic and functional outcomes of expandable self locking intramedullary nailing and platelet rich plasma (PRP) gel in the treatment of long bone non-unions are reported.

MATERIALS AND METHODS

Twenty-two patients suffering from atrophic diaphyseal long bone non-unions were enrolled in the study. Patients were treated with removal of pre-existing hardware, decortication of non-union fragments, and fixation of pseudoarthrosis with expandable intramedullary nailing (Fixion, Disc'O Tech, Tel Aviv, Israel). At surgery, PRP was placed in the pseudoarthrosis rim.

RESULTS

The thirteen-month follow-up showed 91% (20/22 patients) of patients attaining bony union. The average time to union was 21.5 weeks. No infection, neurovascular complication, rotational malalignment, or limb shortening >4 mm were observed. The healing rate of non-unions was comparable to that observed in previous studies but with a lower complication frequency.

CONCLUSIONS

The combined use of self locking intramedullary nailing and PRP in the management of atrophic diaphyseal long bone non-unions seems to produce comparable results with less complications than previously reported. Further data are warranted to investigate the single contribution of PRP gel and Fixion nail.

Outcomes of isolated tibial shaft fractures treated at level 1 trauma centres

BACKGROUND

Although most tibial shaft fractures are expected to heal within 24 weeks, the long-term effects of these injuries on patients in terms of self-reported health status, disability, and pain are largely unknown.

OBJECTIVES

To investigate the clinical and patient-reported outcomes of patients with isolated tibial shaft fractures treated at the two level 1 adult trauma centres in Victoria, Australia.

METHODS

Sixty patients with isolated tibial shaft fractures treated at the Royal Melbourne Hospital and the Alfred Hospital between August 2003 and August 2004 were identified via the Victorian Orthopaedic Trauma Outcomes Registry (VOTOR). Patient-reported outcomes were prospectively measured 1 year post-injury using the 12-Item Short-Form Health Survey (SF-12) (also administered at baseline); the Work subscale of the Sickness Impact Profile; and a Numerical Rating Scale for pain. A priori defined clinical outcomes were also determined by retrospectively reviewing hospital medical records and X-rays.

RESULTS

Full weight-bearing status was achieved after a median inter quartile range (IQR) time of 14.0 (12.5-20.0) weeks, and the median (IQR) time to radiological union was 35.8 (23.3-51.6) weeks. Sixty percent of patients completed the SF-12 at both baseline and 12 months post-injury. Although there were no clear changes in mental health scores (median change=+1.0; IQR=-3.5 to 4.0; p=0.52), physical health scores were significantly reduced (median change=-3.0; IQR=-19.5 to 0.3; p=0.003). Additionally, 47% of patients reported work-related disability and 40% experienced persistent pain 1 year post-injury.

CONCLUSIONS

These results indicate that long-term physical disability remains a problem for many patients following tibial shaft fracture, and they should be considered when providing prognostic information to patients. Further research is required to identify the specific health problems experienced as well as the factors contributing to disability in order to inform post-fracture rehabilitation planning.

Outcome assessment in clinical trials of fracture-healing

Although there are numerous methods for defining fracture-healing in clinical studies, no consensus exists regarding the most valid and reliable manner for assessing union or for determining which outcomes are most important. This article summarizes and describes methods for the clinical assessment of fracture-healing and reports results from a systematic review of prevalent definitions currently used in published clinical studies. Conventional radiography and ad hoc clinical definitions continue to be the most commonly used means of assessing fracture-healing in clinical studies. Investigators must improve upon and apply more rigorous outcome assessment in clinical trials, emphasize patient-important outcomes, and report factors that may bias estimated effects.

Clinical trial design in fracture-healing research: meeting the challenge

The rapidly growing global burden of road-traffic accidents and fragility fractures makes research on fracture repair a vital component of the efforts needed to face this rising public health challenge. The focus on developing new and innovative strategies to treat fractures is easily justifiable given the potential human benefit from such discoveries. Randomized trials remain the standard to which the evaluation of novel fracture-healing therapies must continue to evolve. This article reviews randomized controlled trials in the context of the hierarchy of evidence, special challenges to their conduct in the setting of surgical research, and lessons learned from fracture-healing trials published to date. Suggestions are made regarding the optimal characteristics of fracture models and logistical consideration for ensuring the success of future trials. The realization that surgical trials have unique methodological and interpretative challenges has fueled a renewed vision of the design and execution of large, definitive clinical trials with a meaningful impact on the lives of patients.

Bone morphogenetic proteins in clinical applications

The role of bone morphogenetic proteins (BMPs) in bone healing has been shown in numerous animal models. To date, at least 20 BMPs have been identified, some of which have been shown in vitro to stimulate the process of stem cell differentiation into osteoblasts in human and animal models. Having realized the osteoinductive properties of BMPs and having identified their genetic sequences, recombinant gene technology has been used to produce BMPs for clinical application - most commonly, as alternatives or adjuncts in the treatment of cases in which fracture healing is compromised. BMP-2 and BMP-7 are approved for clinical use in open fractures of long bones, non-unions and spinal fusion. However, despite significant evidence of their potential benefit to bone repair and regeneration in animal and preclinical studies, there is, to date, a dearth of convincing clinical trials. The purpose of this paper is to give a brief overview of BMPs and to critically review the clinical data currently available on the use of BMP-2 and BMP-7 in fracture healing.

Prevalence of long-bone non-unions

Despite the enormous progress made during recent decades in the treatment of long-bone fractures, fracture healing is still haunted by complications and above all non-unions. Non-unions represent a particular challenge, and the difficulties surrounding their management are frequently underestimated. Knowledge of the epidemiology of long-bone non-union can assist the treating surgeon in the application of the optimum fracture treatment.

Fracture healing assessment comparing stiffness measurements using radiographs

Based on published reports, we presumed radiographs would be unreliable as a sole measure of fracture healing. To confirm this presumption we correlated radiographic fracture healing assessments with fracture stiffness measurements. We showed 100 plain radiographs of fractures with corresponding fracture stiffness measurements to 92 observers. The radiographs were shown twice to assess intraobserver variation. Observers were divided into three groups and asked to determine whether each fracture had healed (union corresponded to a fracture stiffness greater than 15 nm/degrees). Group 1 based fracture healing on the general appearance of healing. Groups 2 and 3 assessed fracture healing based on the number of cortices bridged by callus. In Group 2, the fracture was considered healed if two or more cortices were bridged on both radiographic views and in Group 3 if three or more cortices were bridged by callus. All groups performed poorly. There was no difference in terms of correct prediction of healing between methods, although there was a trend toward more reliability with cortical callus bridging assessment. We found substantial intraobserver variability, which improved using cortical bridging methods. Observers were less reliable at predicting healing when there was a metaphyseal extension to a diaphyseal fracture.

Recombinant human bone morphogenetic protein-2 in open tibial fractures. A subgroup analysis of data combined from two prospective randomized studies

BACKGROUND

The use of recombinant human bone morphogenetic protein-2 (rhBMP-2) to improve the healing of open tibial shaft fractures has been the focus of two prospective clinical studies. The objective of the current study was to perform a subgroup analysis of the combined data from these studies.

METHODS

Two prospective, randomized clinical studies were conducted. A total of 510 patients with open tibial fractures were randomized to receive the control treatment (intramedullary nail fixation and routine soft-tissue management) or the control treatment and an absorbable collagen sponge impregnated with one of two concentrations of rhBMP-2. The rhBMP-2 implant was placed over the fracture at the time of definitive wound closure. For the purpose of this analysis, only the control treatment and the Food and Drug Administration-approved concentration of rhBMP-2 (1.50 mg/mL) were compared. Patients who anticipated receiving planned bone-grafting as part of a staged treatment were excluded from enrollment.

RESULTS

Fifty-nine trauma centers in twelve countries participated, and patients were followed for twelve months postoperatively. Two subgroups were analyzed: (1) the 131 patients with a Gustilo-Anderson type-IIIA or IIIB open tibial fracture and (2) the 113 patients treated with reamed intramedullary nailing. The first subgroup demonstrated significant improvements in the rhBMP-2 group, with fewer bone-grafting procedures (p = 0.0005), fewer patients requiring invasive secondary interventions (p = 0.0065), and a lower rate of infection (p = 0.0234), compared with the control group. The second subgroup analysis of fractures treated with reamed intramedullary nailing demonstrated no significant difference between the control and the rhBMP-2 groups.

CONCLUSIONS

The addition of rhBMP-2 to the treatment of type-III open tibial fractures can significantly reduce the frequency of bone-grafting procedures and other secondary interventions. This analysis establishes the clinical efficacy of rhBMP-2 combined with an absorbable collagen sponge implant for the treatment of these severe fractures.

Delayed union and nonunion following closed treatment of diaphyseal pediatric forearm fractures

Delayed unions and nonunions of diaphyseal pediatric forearm fractures are exceedingly uncommon. In the past they generally have been reported in conjunction with open fracture or initial operative management of these fractures. The authors report six cases that occurred in low-energy, closed fractures initially managed with casting. The cases all occurred in teenage patients from age 13 to 16, and all cases involved the ulna. The mid-diaphysis was the most common location, and this may represent a watershed zone of perfusion with a relatively poor intraosseous blood supply. All of these patients were managed with compression plating with or without bone grafting. Three of these patients had rapid healing in an average of 2 months, while one had an inadequate radiographic record and another was lost to follow-up. The other patient had a more prolonged course to healing after surgery.

Tricalcium phosphate granules or rigid wedge preforms in open wedge high tibial osteotomy: a radiological study with a new evaluation system

The capacity of two forms of porous beta-tricalcium phosphate bone substitutes (TCP) to promote bone healing in open wedge high tibial osteotomy (OWHTO) was studied. We reviewed the X-rays of 27 osteotomies, with either TCP wedges or TCP granules as filling material, to compare the bone healing rates and bone remodelling, at specific postoperative intervals. A new radiologic rating system for OWHTO was created and tested for clinical applicability. All osteotomies healed uneventfully and complete resorption of TCP was demonstrated at 1 year postoperative in 85% (n = 23) of the procedures. In 44% (n = 10) of these 23 procedures, the osteotomy site was no longer visible. No difference in bone healing rate and bone remodelling was found when comparing the use of granules to a wedge, and no adverse effects of TCP were observed. The good inter- (k = 0.7) and intraobserver (k = 0.6) reliability of the new radiologic rating system enables clinical use. Good bone healing was found in OWHTO with both wedges and granules of TCP.

Therapeutic ultrasound and fracture healing: a survey of beliefs and practices

OBJECTIVE

To explore current beliefs among senior physiotherapy (PT) students and orthopedic surgeons on the clinical utility of therapeutic ultrasound for assisting fracture healing.

DESIGN

Cross-sectional survey.

SETTING

University.

PARTICIPANTS

Orthopedic surgeons, senior orthopedic surgery residents, and PT students in their final 6 months of study.

INTERVENTIONS

Not applicable. Main outcome measures Percentage of respondents reporting specific perceptions on (1) the role of therapeutic ultrasound in fracture healing, (2) clinical use of therapeutic ultrasound for fracture healing, (3) rationale for not using therapeutic ultrasound for healing fractures, and (4) what constitutes a clinically significant difference in fracture healing time. Between-group comparisons were conducted for survey responses.

RESULTS

The response rate was 20 of 22 (90.9%) orthopedic surgeons, 5 of 5 (100%) senior orthopedic residents, and 34 of 50 (68.0%) senior PT students. The majority of senior PT students (58.8%) and orthopedic residents and surgeons (60.0%) surveyed reported the belief that therapeutic ultrasound may help in assisting fracture healing in some cases. However, the majority of respondents do not use this modality (60.0% of surgeons, 88.2% of Senior PT students), with most surgeons (32.0%) citing lack of evidence and most senior PT students (58.8%) indicating lack of availability as the predominant barrier. Thirty-two percent of surgeons felt that ultrasound was contraindicated and harmful to healing fractures, or that it was of no use, and 20.5% of PT students reported the belief that ultrasound was contraindicated and was, or may be, harmful to healing bone. Most orthopedic residents and surgeons (52.0%) reported that a reduction in fracture healing time of 4 weeks would be clinically significant versus senior PT students, the majority of whom (64.7%) indicated that a reduction of 2 weeks would be clinically significant.

CONCLUSIONS

Some surgeons and PT students believed that therapeutic ultrasound is contraindicated and harmful to healing bone; however, most believed that therapeutic ultrasound may help in assisting fracture healing, in at least some cases. Current usage of this modality is rare, primarily due to the perceived lack of evidence and lack of availability. Large randomized trials are needed to define further the role of ultrasound in fracture healing.

Delayed osteotomy but not fracture healing in pediatric osteogenesis imperfecta patients receiving pamidronate

This study evaluated factors influencing fracture (n = 197) and osteotomy (n = 200) healing in children with moderate to severe OI. Pamidronate treatment was associated with delayed healing after osteotomy, but not after fracture. The data suggest that both pamidronate and mechanical factors influence bone healing in this cohort.

INTRODUCTION

Intravenous pamidronate is widely used to treat children with moderate to severe osteogenesis imperfecta (OI). However, the effect of this treatment on bone healing is not well characterized. We therefore retrospectively analyzed the healing of lower limb fractures and osteotomies in children with moderate to severe OI, both before and after the start of pamidronate treatment.

MATERIALS AND METHODS

Bone healing was evaluated on standard radiographs after 197 lower limb fractures (132 femur and 65 tibia) in 82 patients (age at fracture, 0.0-19.9 years) and 200 intramedullary rodding procedures in 79 patients (age at surgery, 1.2-19.8 years). Delayed healing was diagnosed when a fracture or osteotomy line was at least partially visible 12 months after the event.

RESULTS

Delayed fracture healing was observed more frequently during than before pamidronate treatment. However, the effect of pamidronate was no longer significant when age differences were taken into account (odds ratio [OR], 1.76; 95% CI, 0.61-5.10). Better mobility status was a strong independent predictor of delayed healing after fractures that occurred during pamidronate treatment. After osteotomies, delayed healing was more frequent when pamidronate had been started before surgery (OR, 7.29; 95% CI, 2.62-20.3), and this effect persisted after adjustment for multiple confounders. During pamidronate treatment, older age (OR per year of age, 1.25; 95% CI, 1.06-1.47) and osteotomy of the tibia (OR, 3.51; 95% CI, 1.57-7.82) were independent predictors of delayed healing.

CONCLUSIONS

This study suggests that pamidronate therapy is associated with delayed healing of osteotomy sites after intramedullary rodding procedures. Better mobility status, but not pamidronate treatment, seems to be predictive of delayed healing after fractures.