Providing an Evidence Base for Tissue Sampling and Culture Interpretation in Suspected Fracture-Related Infection

BACKGROUND

The recent consensus definition for the diagnosis of fracture-related infection (FRI) includes the identification of indistinguishable microorganisms in at least 2 surgical deep-tissue specimens as a confirmatory criterion. However, this cut-off, and the total number of specimens from a patient with suspected FRI that should be sent for microbiological testing, have not been validated. We endeavored to estimate the accuracy of different numbers of specimens and diagnostic cut-offs for microbiological testing of deep-tissue specimens in patients undergoing surgical treatment for possible FRI.

METHODS

A total of 513 surgical procedures in 385 patients with suspected FRI were included. A minimum of 2 surgical deep-tissue specimens were submitted for microbiological testing; 5 or more specimens were analyzed in 345 procedures (67%). FRI was defined by the presence of any confirmatory criteria other than microbiology. Resampling was utilized to model the sensitivity and specificity of diagnostic cut-offs for the number of surgical specimens yielding indistinguishable microorganisms and for the total number of specimens. The likelihood of detecting all clinically relevant microorganisms was also assessed.

RESULTS

A diagnostic cut-off of at least 2 of 5 specimens with indistinguishable microorganisms identified by culture was 68% sensitive (95% confidence interval [CI], 62% to 74%) and 87% specific (95% CI, 81% to 94%) for the diagnosis of FRI. Two out of 3 specimens were 60% sensitive (95% CI, 55% to 66%) and 92% specific (95% CI, 88% to 96%). Submitting only 3 deep-tissue specimens risked missing clinically relevant microorganisms in at least 1 in 10 cases.

CONCLUSIONS

The present study was the first to validate microbiological criteria for the diagnosis of FRI, supporting the current confirmatory diagnostic criteria for FRI. Analysis of at least 5 deep-tissue specimens in patients with possible FRI is recommended.

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Management of critical-sized bone defects in the treatment of fracture-related infection: a systematic review and pooled analysis

PURPOSE

This systematic review determined the reported treatment strategies, their individual success rates, and other outcome parameters in the management of critical-sized bone defects in fracture-related infection (FRI) patients between 1990 and 2018.

METHODS

A systematic literature search on treatment and outcome of critical-sized bone defects in FRI was performed. Treatment strategies identified were, autologous cancellous grafts, autologous cancellous grafts combined with local antibiotics, the induced membrane technique, vascularized grafts, Ilizarov bone transport, and bone transport combined with local antibiotics. Outcomes were bone healing and infection eradication after primary surgical protocol and recurrence of FRI and amputations at the end of study period.

RESULTS

Fifty studies were included, describing 1530 patients, the tibia was affected in 82%. Mean age was 40 years (range 6-80), with predominantly male subjects (79%). Mean duration of infection was 17 months (range 1-624) and mean follow-up 51 months (range 6-126). After initial protocolized treatment, FRI was cured in 83% (95% CI 79-87) of all cases, increasing to 94% (95% CI 92-96) at the end of each individual study. Recurrence of infection was seen in 8% (95% CI 6-11) and amputation in 3% (95% CI 2-3). Final outcomes overlapped across treatment strategies.

CONCLUSION

Results should be interpreted with caution due to the retrospective and observational design of most studies, the lack of clear classification systems, incomplete data reports, potential underreporting of adverse outcomes, and heterogeneity in patient series. A consensus on classification, treatment protocols, and outcome is needed to improve reliability of future studies.

Getting it right first time: The importance of a structured tissue sampling protocol for diagnosing fracture-related infections

INTRODUCTION

Fracture-related infection (FRI) is an important complication following surgical fracture management. Key to successful treatment is an accurate diagnosis. To this end, microbiological identification remains the gold standard. Although a structured approach towards sampling specimens for microbiology seems logical, there is no consensus on a culture protocol for FRI. The aim of this study is to evaluate the effect of a structured microbiology sampling protocol for fracture-related infections compared to ad-hoc culture sampling.

METHODS

We conducted a pre-/post-implementation cohort study that compared the effects of implementation of a structured FRI sampling protocol. The protocol included strict criteria for sampling and interpretation of tissue cultures for microbiology. All intraoperative samples from suspected or confirmed FRI were compared for culture results. Adherence to the protocol was described for the post-implementation cohort.

RESULTS

In total 101 patients were included, 49 pre-implementation and 52 post-implementation. From these patients 175 intraoperative culture sets were obtained, 96 and 79 pre- and post-implementation respectively. Cultures from the pre-implementation cohort showed significantly more antibiotic use during culture sampling (P =  0.002). The post-implementation cohort showed a tendency more positive culture sets (69% vs. 63%), with a significant difference in open wounds (86% vs. 67%, P =  0.034). In all post-implementation culture sets causative pathogens were cultured more than once per set, in contrast to pre-implementation. Despite stricter tissue sampling and culture interpretation criteria, the number of polymicrobial infections was similar in both cohorts, approximately 29% of all culture sets and 44% of all positive culture sets. Significantly more polymicrobial cultures were found in early infections in the post-implementation cohort (P =  0.048). This indicates a better yield in the new protocol.

CONCLUSION

A standardised protocol for intraoperative sampling for bacterial identification in FRI is superior than an ad-hoc approach. It has a positive effect on both surgeon and microbiologist by increasing awareness about the problem at hand. This resulted in more microbiologically confirmed infections and more certainty when identifying causative pathogens.

Performance of automated multiplex polymerase chain reaction (mPCR) using synovial fluid in the diagnosis of native joint septic arthritis in adults

AIMS

This study aimed to assess the performance of an automated multiplex polymerase chain reaction (mPCR) technique for rapid diagnosis of native joint septic arthritis.

PATIENTS AND METHODS

Consecutive patients with suspected septic arthritis undergoing aseptic diagnostic joint aspiration were included. The aspirate was used for analysis by mPCR and conventional microbiological analysis. A joint was classed as septic according to modified Newman criteria. Based on receiver operating characteristic (ROC) analysis, the area under the ROC curve (AUC) values of the mPCR and the synovial fluid culture were compared using the z-test. A total of 72 out of 76 consecutive patients (33 women, 39 men; mean age 64 years (22 to 92)) with suspected septic arthritis were included in this study.

RESULTS

Of 72 patients, 42 (58%) were deemed to have septic joints. The sensitivity of mPCR and synovial fluid culture was 38% and 29%, respectively. No significant differences were found between the AUCs of both techniques (p = 0.138). A strong concordance of 89% (Cohen's kappa: 0.65) was shown. The mPCR failed to detect Staphylococcus aureus (n = 1) and Streptococcus pneumoniae (n = 1; no primer included in the mPCR), whereas the synovial fluid culture missed six microorganisms (positive mPCR: S. aureus (n = 2), Cutibacterium acnes (n = 3), coagulase-negative staphylococci (n = 2)).

CONCLUSION

The automated mPCR showed at least a similar performance to the synovial fluid culture (the current benchmark) in diagnosing septic arthritis, having the great advantage of a shorter turnaround time (within five hours). Cite this article: Bone Joint J 2019;101-B:288-296.

Insights into treatment and outcome of fracture-related infection: a systematic literature review

INTRODUCTION

Standardized guidelines for treatment of fracture-related infection (FRI) are lacking. Worldwide many treatment protocols are used with variable success rates. Awareness on the need of standardized, evidence-based guidelines has increased in recent years. This systematic literature review gives an overview of available diagnostic criteria, classifications, treatment protocols, and related outcome measurements for surgically treated FRI patients.

METHODS

A comprehensive search was performed in all scientific literature since 1990. Studies in English that described surgical patient series for treatment of FRI were included. Data were collected on diagnostic criteria for FRI, classifications used, surgical treatments, follow-up protocols, and overall outcome. A systematic review was performed according to the PRISMA statement. Proportions and weighted means were calculated.

RESULTS

The search yielded 2051 studies. Ninety-three studies were suitable for inclusion, describing 3701 patients (3711 fractures) with complex FRI. The population consisted predominantly of male patients (77%), with the tibia being the most commonly affected bone (64%), and a mean of three previous operations per patient. Forty-three (46%) studies described FRI at one specific location. Only one study (1%) used a standardized definition for infection. A total of nine different classifications were used to guide treatment protocols, of which Cierny and Mader was used most often (36%). Eighteen (19%) studies used a one-stage, 50 (54%) a two-stage, and seven (8%) a three-stage surgical treatment protocol. Ten studies (11%) used mixed protocols. Antibiotic protocols varied widely between studies. A multidisciplinary approach was mentioned in only 12 (13%) studies.

CONCLUSIONS

This extensive literature review shows a lack of standardized guidelines with respect to diagnosis and treatment of FRI, which mimics the situation for prosthetic joint infection identified many years ago. Internationally accepted guidelines are urgently required to improve the quality of care for patients suffering from this significant complication.

Diagnostic accuracy of serum inflammatory markers in late fracture-related infection: a systematic review and meta-analysis

AIMS

To assess the diagnostic value of C-reactive protein (CRP), leucocyte count (LC), and erythrocyte sedimentation rate (ESR) in late fracture-related infection (FRI).

MATERIALS AND METHODS

PubMed, Embase, and Cochrane databases were searched focusing on the diagnostic value of CRP, LC, and ESR in late FRI. Sensitivity and specificity combinations were extracted for each marker. Average estimates were obtained using bivariate mixed effects models.

RESULTS

A total of 8284 articles were identified but only six were suitable for inclusion. Sensitivity of CRP ranged from 60.0% to 100.0% and specificity from 34.3% to 85.7% in all publications considered. Five articles were pooled for meta-analysis, showing a sensitivity and specificity of 77.0% and 67.9%, respectively. For LC, this was 22.9% to 72.6%, and 73.5% to 85.7%, respectively, in five articles. Four articles were pooled for meta-analysis, resulting in a 51.7% sensitivity and 67.1% specificity. For ESR, sensitivity and specificity ranged from 37.1% to 100.0% and 59.0% to 85.0%, respectively, in five articles. Three articles were pooled in meta-analysis, showing a 45.1% sensitivity and 79.3% specificity. Four articles analyzed the value of combined inflammatory markers, reporting an increased diagnostic accuracy. These results could not be pooled due to heterogeneity.

CONCLUSION

The serum inflammatory markers CRP, LC, and ESR are insufficiently accurate to diagnose late FRI, but they may be used as a suggestive sign in its diagnosis.

The effect of local antibiotic prophylaxis when treating open limb fractures: A systematic review and meta-analysis

Objectives

As well as debridement and irrigation, soft-tissue coverage, and osseous stabilization, systemic antibiotic prophylaxis is considered the benchmark in the management of open fractures and considerably reduces the risk of subsequent fracture-related infections (FRI). The direct application of antibiotics in the surgical field (local antibiotics) has been used for decades as additional prophylaxis in open fractures, although definitive evidence confirming a beneficial effect is scarce. The purpose of the present study was to review the clinical evidence regarding the effect of prophylactic application of local antibiotics in open limb fractures.

Methods

A comprehensive literature search was performed in PubMed, Web of Science, and Embase. Cohort studies investigating the effect of additional local antibiotic prophylaxis compared with systemic prophylaxis alone in the management of open fractures were included and the data were pooled in a meta-analysis.

Results

In total, eight studies which included 2738 patients were eligible for quantitative synthesis. The effect of antibiotic-loaded poly(methyl methacrylate) beads was investigated by six of these studies, and two studies evaluated the effect of local antibiotics applied without a carrier. Meta-analysis showed a significantly lower infection rate when local antibiotics were applied (4.6%; 91/1986) than in the control group receiving standard systemic prophylaxis alone (16.5%; 124/752) (p < 0.001) (odds ratio 0.30; 95% confidence interval 0.22 to 0.40).

Conclusion

This meta-analysis suggests a risk reduction in FRI of 11.9% if additional local antibiotics are given prophylactically for open limb fractures. However, due to limited quality, heterogeneity, and considerable risk of bias, the pooling of data from primary studies has to be interpreted with caution.

Cite this article: M. Morgenstern, A. Vallejo, M. A. McNally, T. F. Moriarty, J. Y. Ferguson, S. Nijs, WJ. Metsemakers. Bone Joint Res 2018;7:447–456. The effect of local antibiotic prophylaxis when treating open limb fractures: A systematic review and meta-analysis. DOI: 10.1302/2046-3758.77.BJR-2018-0043.R1

The value of quantitative histology in the diagnosis of fracture-related infection

Aims

This study aimed to investigate the role of quantitative histological analysis in the diagnosis of fracture-related infection (FRI).

Patients and Methods

The clinical features, microbiology culture results, and histological analysis in 156 surgically treated nonunions were used to stratify the likelihood of associated infection. There were 64 confirmed infected nonunions (one or more confirmatory criteria: pus, sinus, and bacterial growth in two or more samples), 66 aseptic nonunions (no confirmatory criteria), and 26 possibly infected nonunions (pathogen identified from a single specimen and no confirmatory criteria). The histological inflammatory response was assessed by average neutrophil polymorph (NPs) counts per high-power field (HPF) and compared with the established diagnosis.

Results

Assuming a cut-off of over five neutrophils per high-power field to diagnose septic nonunion, there was 80% sensitivity and 100% specificity (accuracy 90%). Using a cut-off of no neutrophils seen in any high-power field to diagnose aseptic nonunion, there was a sensitivity of 85% and a specificity of 98% (accuracy 92%).

Conclusion

Histology can be used in a bimodal fashion as a diagnostic test for FRI. The presence of more than five NPs/HPF had a positive predictive value for infected nonunion of 100%, while the complete absence of any NPs is almost always indicative of an aseptic nonunion (positive predictive value of 98%). Cite this article: Bone Joint J 2018;100-B:966–72.

Fracture-related infection: A consensus on definition from an international expert group

Fracture-related infection (FRI) is a common and serious complication in trauma surgery. Accurately estimating the impact of this complication has been hampered by the lack of a clear definition. The absence of a working definition of FRI renders existing studies difficult to evaluate or compare. In order to address this issue, an expert group comprised of a number of scientific and medical organizations has been convened, with the support of the AO Foundation, in order to develop a consensus definition. The process that led to this proposed definition started with a systematic literature review, which revealed that the majority of randomized controlled trials in fracture care do not use a standardized definition of FRI. In response to this conclusion, an international survey on the need for and key components of a definition of FRI was distributed amongst all registered AOTrauma users. Approximately 90% of the more than 2000 surgeons who responded suggested that a definition of FRI is required. As a final step, a consensus meeting was held with an expert panel. The outcome of this process led to a consensus definition of FRI. Two levels of certainty around diagnostic features were defined. Criteria could be confirmatory (infection definitely present) or suggestive. Four confirmatory criteria were defined: Fistula, sinus or wound breakdown; Purulent drainage from the wound or presence of pus during surgery; Phenotypically indistinguishable pathogens identified by culture from at least two separate deep tissue/implant specimens; Presence of microorganisms in deep tissue taken during an operative intervention, as confirmed by histopathological examination. Furthermore, a list of suggestive criteria was defined. These require further investigations in order to look for confirmatory criteria. In the current paper, an overview is provided of the proposed definition and a rationale for each component and decision. The intention of establishing this definition of FRI was to offer clinicians the opportunity to standardize clinical reports and improve the quality of published literature. It is important to note that the proposed definition was not designed to guide treatment of FRI and should be validated by prospective data collection in the future.

International survey among orthopaedic trauma surgeons: Lack of a definition of fracture-related infection

INTRODUCTION

Fracture-related infection (FRI) is one of the most challenging musculoskeletal complications in orthopaedic-trauma surgery. Although the orthopaedic community has developed and adopted a consensus definition of prosthetic joint infections (PJI), it still remains unclear how the trauma surgery community defines FRI in daily clinical practice or in performing clinical research studies. The central aim of this study was to survey the opinions of a global network of trauma surgeons on the definitions and criteria they routinely use, and their opinion on the need for a unified definition of FRI. The secondary aims were to survey their opinion on the utility of currently used definitions that may be at least partially applicable for FRI, and finally their opinion on the important clinical parameters that should be considered as diagnostic criteria for FRI.

METHODS

An 11-item questionnaire was developed to cover the above-mentioned aims. The questionnaire was administered by SurveyMonkey and was sent via blast email to all registered users of AO Trauma (Davos, Switzerland).

RESULTS

Out of the 26'563 recipients who opened the email, 2'327 (8.8%) completed the questionnaire. Nearly 90% of respondents agreed that a consensus-derived definition for FRI is required and 66% of the surgeons also agreed that PJI and FRI are not equal with respect to diagnosis, treatment and outcome. Furthermore, "positive cultures from microbiology testing", "elevation of CRP", "purulent drainage" and "local clinical signs of infection" were voted the most important diagnostic parameters for FRI.

CONCLUSION

This international survey infers the need for a consensus definition of FRI and provides insight into the clinical parameters seen by an international community of trauma surgeons as being critical for defining FRI.

Single-stage treatment of chronic osteomyelitis with a new absorbable, gentamicin-loaded, calcium sulphate/hydroxyapatite biocomposite: a prospective series of 100 cases

AIMS

Chronic osteomyelitis may recur if dead space management, after excision of infected bone, is inadequate. This study describes the results of a strategy for the management of deep bone infection and evaluates a new antibiotic-loaded biocomposite in the eradication of infection from bone defects.

PATIENTS AND METHODS

We report a prospective study of 100 patients with chronic osteomyelitis, in 105 bones. Osteomyelitis followed injury or surgery in 81 patients. Nine had concomitant septic arthritis. 80 patients had comorbidities (Cierny-Mader (C-M) Class B hosts). Ten had infected nonunions. All patients were treated by a multidisciplinary team with a single-stage protocol including debridement, multiple sampling, culture-specific systemic antibiotics, stabilisation, dead space filling with the biocomposite and primary skin closure.

RESULTS

Patients were followed up for a mean of 19.5 months (12 to 34). Infection was eradicated in 96 patients with a single procedure and all four recurrences were successfully managed with repeat surgery. Adverse events were uncommon, with three fractures, six wound leaks and three unrelated deaths. Outcome was not dependant on C-M host class, microbial culture, wound leakage or presence of nonunion.

CONCLUSION

This single-stage protocol, facilitated by the absorbable local antibiotic, is effective in the treatment of chronic osteomyelitis. It offers a more patient-friendly treatment compared with other published treatment options. Cite this article: Bone Joint J 2016;98-B:1289-96.

Pharmacokinetics of gentamicin eluted from a regenerating bone graft substitute: In vitro and clinical release studies

Objectives

Deep bone and joint infections (DBJI) are directly intertwined with health, demographic change towards an elderly population, and wellbeing.

The elderly human population is more prone to acquire infections, and the consequences such as pain, reduced quality of life, morbidity, absence from work and premature retirement due to disability place significant burdens on already strained healthcare systems and societal budgets.

DBJIs are less responsive to systemic antibiotics because of poor vascular perfusion in necrotic bone, large bone defects and persistent biofilm-based infection. Emerging bacterial resistance poses a major threat and new innovative treatment modalities are urgently needed to curb its current trajectory.

Materials and Methods

We present a new biphasic ceramic bone substitute consisting of hydroxyapatite and calcium sulphate for local antibiotic delivery in combination with bone regeneration. Gentamicin release was measured in four setups: 1) in vitro elution in Ringer’s solution; 2) local elution in patients treated for trochanteric hip fractures or uncemented hip revisions; 3) local elution in patients treated with a bone tumour resection; and 4) local elution in patients treated surgically for chronic corticomedullary osteomyelitis.

Results

The release pattern in vitro was comparable with the obtained release in the patient studies. No recurrence was detected in the osteomyelitis group at latest follow-up (minimum 1.5 years).

Conclusions

This new biphasic bone substitute containing antibiotics provides safe prevention of bone infections in a range of clinical situations. The in vitro test method predicts the in vivo performance and makes it a reliable tool in the development of future antibiotic-eluting bone-regenerating materials.

Cite this article: M. Stravinskas, P. Horstmann, J. Ferguson, W. Hettwer, M. Nilsson, S. Tarasevicius, M. M. Petersen, M. A. McNally, L. Lidgren. Pharmacokinetics of gentamicin eluted from a regenerating bone graft substitute: In vitro and clinical release studies. Bone Joint Res 2016;5:427–435. DOI: 10.1302/2046-3758.59.BJR-2016-0108.R1.

The Effect of Graduated Compression Stockings on Lower Limb Venous Haemodynamics

Objectives:

To compare the effect of four types of thigh-length graduated compression stockings (GCS) on lower limb venous blood flow using strain-gauge Plethysmography (SGP).

Design:

A randomized controlled study.

Setting:

Inpatient Orthopaedic Centre.

Patients:

200 preoperative patients admitted for elective lower limb orthopaedic surgery.

Interventions:

Patients were randomized to five groups to wear one of four types of GCS or no stocking (control). Resting venous flow parameters were measured prior to application of GCS and after 20 min bed rest with the stockings in situ.

Main outcome measures:

Effects on resting venous capacitance (Vc) and venous outflow (Vo).

Results:

In the control group 20 min bed rest had no effect on the parameters studied. Both Vc and Vo were significantly increased ( p<0.001) in all the groups wearing stockings. There was a significant variation in the changes in outflow produced by the different stocking types ( p<0.05).

Conclusions:

GCS have a beneficial effect on lower limb venous outflow, preventing venous stasis, an important factor in the development of deep venous thrombosis. This effect varies depending on which type of stocking is used.

The use of a biodegradable antibiotic-loaded calcium sulphate carrier containing tobramycin for the treatment of chronic osteomyelitis: a series of 195 cases

We report our experience using a biodegradable calcium sulphate antibiotic carrier containing tobramycin in the surgical management of patients with chronic osteomyelitis. The patients were reviewed to determine the rate of recurrent infection, the filling of bony defects, and any problems with wound healing. A total of 193 patients (195 cases) with a mean age of 46.1 years (16.1 to 82.0) underwent surgery. According to the Cierny-Mader classification of osteomyelitis there were 12 type I, 1 type II, 144 type III and 38 type IV cases. The mean follow-up was 3.7 years (1.3 to 7.1) with recurrent infection occurring in 18 cases (9.2%) at a mean of 10.3 months post-operatively (1 to 25.0). After further treatment the infection resolved in 191 cases (97.9%). Prolonged wound ooze (longer than two weeks post-operatively) occurred in 30 cases (15.4%) in which there were no recurrent infection. Radiographic assessment at final follow-up showed no filling of the defect with bone in 67 (36.6%), partial filling in 108 (59.0%) and complete filling in eight (4.4%). A fracture occurred in nine (4.6%) of the treated osteomyelitic segments at a mean of 1.9 years (0.4 to 4.9) after operation. We conclude that Osteoset T is helpful in the management of patients with chronic osteomyelitis, but the filling of the defect in bone is variable. Prolonged wound ooze is usually self-limiting and not associated with recurrent infection.

Giant-cell-rich pseudotumour in Paget's disease

Paget's disease (PD) of the bone is a disorder of bone remodelling that may be polyostotic or monostotic. Although development of a sarcoma in PD is well-recognised, it is less well recognised that pseudosarcomas in bone and soft tissue can also arise in this condition. In this report we document the case of a large giant-cell-rich pseudotumour that developed in the tibia and overlying soft tissues in a case of polyostotic PD. Bone and soft tissues were highly vascular and contained abundant haemorrhage with focal areas of new bone formation and a diffuse infiltrate of osteoclastic giant cells. The lesion has not recurred or produced metastases 3 years after removal. Clinicians should be aware that a benign giant-cell-rich pseudotumour can develop in PD and that it needs to be distinguished from other giant-cell-rich tumours.

Outcome of arthrodesis of the hindfoot as a salvage procedure for complex ankle pathology using the Ilizarov technique

Achieving arthrodesis of the ankle can be difficult in the presence of infection, deformity, poor soft tissues and bone loss. We present a series of 48 patients with complex ankle pathology, treated with the Ilizarov technique. Infection was present in 30 patients and 30 had significant deformity before surgery. Outcome was assessed clinically and with patient-reported outcome measures (Modified American Orthopaedic Foot and Ankle Society (MAOFAS) scale and the Short-Form (SF-36)).

Arthrodesis was achieved in 40 patients with the Ilizarov technique alone and in six further patients with additional surgery. Infection was eradicated in all patients at a mean follow-up of 46.6 months (13 to 162). Successful arthrodesis was less likely in those with comorbidities and in tibiocalcaneal fusion compared with tibiotalar fusion.

These patients had poor general health scores compared with the normal population before surgery. The mean MAOFAS score improved significantly from 24.3 (0 to 90) pre-operatively to 56.2 (30 to 90) post-operatively, but there was only a modest improvement in general health; the mean SF-36 improved from 44.8 (19 to 66) to 50.1 (21 to 76). There was a major benefit in terms of pain relief.

Arthrodesis using the Ilizarov technique is an effective treatment for complex ankle pathology, with good clinical outcomes and eradication of infection. However, even after successful arthrodesis general health scores remain limited.

Cite this article: Bone Joint J 2013;95-B:371–7.

Biliary events and an increased risk of new onset irritable bowel syndrome: a population-based cohort study

BACKGROUND

Prospective data are lacking to determine if irritable bowel syndrome (IBS) is a risk factor for cholecystectomy, or if biliary disease and cholecystectomy predisposes to the development of IBS.

AIM

To test the hypothesis that IBS and biliary tract disease are associated.

METHODS

Validated symptom surveys sent to cohorts of Olmsted County, MN, (1988-1994) with follow-up in 2003. Medical histories were reviewed to determine any 'biliary events' (defined by gallstones or cholecystectomy). Analyses examined were: (i) time to a biliary event post-initial survey and separately and (ii) risk of IBS (Rome II) in those with vs. without a prior biliary event.

RESULTS

A total of 1908 eligible subjects were mailed a follow-up survey. For analysis (i) of the 726 without IBS at initial survey, 44 (6.1%) had biliary events during follow up, in contrast to 5 of 93 (5.4%) with IBS at initial survey (HR 0.8, 95% CI 0.3-2.1). For analysis (ii) of the 59 subjects with a biliary event at initial survey, 10 (17%) reported new IBS on the follow-up survey, while in 682 without a biliary event up to 1.5 years prior to the second survey, 58 (8.5%) reported IBS on follow-up (OR = 2.2, 95% CI 1.1-4.6, P = 0.03).

CONCLUSION

There is an increased risk of new IBS in community subjects who have been diagnosed as having a biliary event.

Chronic sternal osteomyelitis complicating primary manubriosternal septic arthritis

We present a 40-year-old woman complaining of worsening chest pain. She was previously treated with a prolonged course of antibiotics for suspected sternal osteomyelitis. Radiological investigations were suggestive of ongoing inflammation within the manubriosternal joint. Formal surgical debridement yielded evidence corroborating the diagnosis although microbiological samples were negative. Prolonged empirical treatment with intravenous antibiotics leads to a complete resolution of symptoms. Primary culture-negative manubriosternal septic arthritis is rare, and suboptimal treatment, particularly if confused with other conditions such as synovitis, acne, pustulosis, hyperostosis and osteitis (SAPHO) syndrome, compounds its considerable morbidity.

Altered venous function and deep venous thrombosis following proximal femoral fracture

The effect of surgery for femoral neck fracture on lower limb venous blood flow and its relationship to deep vein thrombosis was investigated in 179 patients. Blood flow was measured using strain gauge plethysmography before surgery, in the 1st week after surgery, and at 6 week review. There was a significant reduction in both venous outflow and venous capacitance, affecting both fractured and non-fractured legs but significantly greater in the fractured leg. Venous function remained significantly impaired in both lower limbs 6 weeks after surgery. There was a significant correlation between the reduction in venous function and the development of deep vein thrombosis.

Changes in coagulability as measured by thrombelastography following surgery for proximal femoral fracture

The effect of surgery for femoral neck fracture on whole blood coagulation and the relationship of altered coagulation to deep venous thrombosis were investigated in 250 patients. Whole blood coagulation was measured using thrombelastography preoperatively, in the early postoperative period and at 6-week review. Significant hypercoagulability was demonstrated after surgery and persisted to 6-week review. A significant correlation between hypercoagulability and the development of deep venous thrombosis is demonstrated. Hypercoagulability is shown to be a major factor in thrombosis formation following proximal femoral neck fracture surgery.

Graduated compression stockings: knee length or thigh length

The mechanisms by which graduated compression stockings prevent deep venous thrombosis are not completely understood. In the current study the physiologic effect of low-pressure graduated compression stockings on the venous blood flow in the lower limb and the practical aspects of their use were assessed. Patients having elective orthopaedic surgery at a university orthopaedic department were randomized into five groups to wear two different types of graduated compression stockings in thigh and knee lengths. Patients in the fifth control group did not wear graduated compression stockings. Venous occlusion strain gauge plethysmography was used to measure venous flow. After 20-minutes bed rest there was a highly significant increase in venous capacitance and venous outflow in patients in all of the four groups wearing stockings. There was no difference in the mean of the percentage change of venous capacitance in patients in the four groups wearing stockings. The knee length Brevet stockings were less efficient in increasing the venous outflow. There was no significant change in the venous capacitance and venous outflow in patients in the control group. Visual assessment of the fit and use of stockings was done, and patients' subjective opinion of comfort was sought. The knee length graduated compression stockings wrinkled significantly less, and significantly fewer patients reported discomfort with them. All stockings were reported to be difficult to use. Thigh and knee length stockings have a significant effect on decreasing venous stasis of the lower limb. Knee length graduated compression stockings are similarly efficient in decreasing venous stasis, but they are more comfortable to wear, and they wrinkle less.

Baumann's confusing legacy

Dr Ernst Baumann has been credited with describing an angle that can be measured from radiographs taken of children's elbows. This article presents three variations in the definition of this angle that we found in the orthopaedic literature. Variation I is the angle between the long axis of the humerus and a line through the physis of the lateral condyle of the distal humerus. Variation II is the angle between the perpendicular to the long axis of the humerus and a line through the physis of the lateral condyle. Variation III is the angle between the line through the physis of the lateral condyle and a line connecting a point on the edge of the trochlea to a point at the lateral limit of the physis of the lateral condyle. By reading translations of two of Baumann's own articles, we have realised that he used variation I when assessing the radiographs. He did, however, believe that the reciprocal angle, variation II equalled the carrying angle of the elbow and this can be demonstrated by Fig. 1, which has been taken from an article that was published in 1929. The relationship between this angle and the carrying angle has since been proven to be more complex than Baumann believed. We recommend that a descriptive term such as the 'shaft-physeal' angle would cause less confusion and variation in the definition of this angle.

Numerical model of deep venous thrombosis detection using venous occlusion strain gauge plethysmography

Strain gauge plethysmography (SGP) is a non-invasive method used in the detection of deep venous thrombosis (DVT). The technique is based on the measurement of calf volume changes in response to venous occlusion by a thigh cuff, the volume changes reflecting the rates of arterial inflow and venous outflow. A numerical model of the blood circulation within the limb and the response of this to a SGP test has been derived, based on treating the different parts of the circulatory system in the leg as resistance and capacitance elements. The simulation results were compared with clinical studies and support the ability of SGP to detect non-occlusive clots of more than 50-60% of the lumen, as well detecting calf vein occlusion. The non-linear behaviour of the venous compliance with intra-luminal pressure appears to be a particularly important factor within the model. In addition, increases in venous tone due to post-operative venospasm were shown to be a potential source of false positive results.

Attitudes to, and utilization of, low molecular weight heparins in joint replacement surgery

A postal survey was carried out to determine the attitudes to the use of low molecular weight heparin (LMWH) in joint replacement among two representative groups of orthopaedic surgeons practising in the UK. 72% of hip surgeons and 51% of knee surgeons replying had used LMWHs for deep vein thrombosis prophylaxis in joint replacement patients. Of these, 48% had discontinued LMWH use due to bleeding complications. Among those continuing to use LMWHs, 88% had witnessed excessive bruising around the wound and 53% had experienced increased wound bleeding or haematomas. Although LMWHs have been shown to reduce post-operative thromboembolism in these groups, clinical experience has revealed an increased incidence of bleeding complications associated with their use. This has prevented their routine use in joint replacement, as was the case with unfractionated heparin in the past.

Primary free-flap cover of open tibial fractures

Seventeen consecutive patients with Grade IIIB open tibial fractures had definitive treatment of both the fracture and soft tissues performed within 72 h of injury. Free tissue transfer was used for cover in each case. There were no cases of deep infection. Flap survival was 100 per cent. The mean time to fracture healing was 10 months, and mean time to walking unaided was 12 months. The average length of stay in hospital was 82 days. The findings suggest that immediate radical debridement followed by adequate soft tissue cover is a safe and effective method for treating these severe injuries.

The effect of active movement of the foot on venous blood flow after total hip replacement

Surgeons often encourage patients to move their feet in an attempt to prevent venous stasis, but there is little evidence that this measure is beneficial. We investigated the effect of active movement of one foot on the venous blood flow four days after total hip replacement. The actual venous outflow at rest was measured with use of venous occlusion strain-gauge plethysmography in thirty-eight patients. The patients were randomly allocated to the control group (eighteen patients) or the exercise group (twenty patients). A baseline measurement was followed by a one-minute period of rest (control group) or of maximum plantar flexion and dorsiflexion of the foot, ankle, and toes at a rate of thirty cycles per minute (exercise group). The venous outflow was measured again at two, seven, twelve, and thirty minutes in both groups. Movement of the foot for one minute produced a significant and sustained increase (p < 0.002) in the venous outflow (mean maximum increase, 22 per cent). The value remained greater than the baseline level for thirty minutes (mean increase, 6.5 per cent) (p < 0.2). The increase was gradual, reaching a maximum twelve minutes after the completion of exercise. Our results confirm the beneficial hemodynamic effects of active movement of the foot in the postoperative period and suggest that patients should move the feet and ankles postoperatively as part of a prophylactic regimen directed at decreasing the risk of venous thrombosis.

Venous haemodynamics in both legs after total knee replacement

We studied the effect of total knee replacement on venous flow in 110 patients. Resting venous blood flow was measured using strain-gauge plethysmography before operation, after surgery and after discharge from hospital. There was a significant reduction in mean venous capacitance (p < 0.001) and mean venous outflow (p < 0.004) affecting only the operated leg. Both improved significantly after mobilisation in the early postoperative period, returning to preoperative levels by six days after surgery and before discharge from hospital. Our findings showed that venous stasis may contribute to deep-vein thrombosis only in the first few days after total knee replacement. This would be the most important period for the use of flow-enhancing prophylactic devices. Comparison with changes in blood flow after total hip replacement identified different patterns of altered haemodynamics suggesting that there are different mechanisms of venous stasis and thrombogenesis in hip and knee arthritis and during surgery for these conditions.

Selection of murine lymphoid and hematopoietic cells using polystyrene tissue culture devices containing covalently immobilized antibody

We have established rapid procedures that negatively deplete and positively select for specific murine cell populations. By using polystyrene tissue culture flasks containing a covalently bound mouse anti-rat antibody and specific anti-mouse, cell-surface antigen antibodies, we easily and efficiently depleted greater than 90% of the mature lineage cells from murine bone marrow. This selection procedure resulted in an enrichment of progenitor colonies (CFU-Cs) in murine bone marrow. Using the same polystyrene tissue culture devices, we can directly isolate CD117+ (c-kit+) murine hematopoietic cells. As few as 2000 of these CD117+ cells rescued and reconstituted lethally irradiated recipients in a murine bone marrow transplant model.

A pilot study of panoramic film density at selected sites in the mandible to predict osteoporosis

Osteoporosis is the most common metabolic disease and presents a major public health problem among the elderly. This retrospective pilot study was designed to determine the strength of association of spinal bone density and the density of selected mandibular sites as determined from panoramic radiographs. Panoramic films of known low bone density and high bone density women between the ages of 50 and 75 were evaluated. These films were randomized and then converted to digital images for density analysis. Significant differences were noted between the groups at the 95th percentile. Further study is needed to ascertain the value of panoramic radiology as an adjunct diagnostic tool in the screening of patients thought to be at high risk of developing osteoporosis.

Conditions peculiar to the tongue

The tongue is the organ of taste, and it functions in speech, mastication, and the deglutition of food. This muscular organ is affected by many conditions and diseases, including a variety of developmental, traumatic, inflammatory, infectious, and neoplastic lesions.

Long-term reconstitution of mice after ex vivo expansion of bone marrow cells: differential activity of cultured bone marrow and enriched stem cell populations

In this report, we evaluated the short-term expansion of murine bone marrow mononuclear cells (BMMNC) and enriched stem cell populations to determine the capacity of these cells for long-term rescue and engraftment to lethally irradiated recipients. In our study, nonadherent bone marrow mononuclear cell (NBM-MNC) and Thy1+Lin- stem cells populations were cultured with interleukin-3 (IL-3) or IL-3 plus stem cell factor (SCF) for periods up to 6 days. By day 6 of culture, the mononuclear cells (MNC) decreased to 6% of input cell number, whereas Thy1+Lin- cells increased by 2310%. Doses of 95,000; 100,000; 50,000; and 250,000 NBM-MNCs at 0, 1, 2, and 6 days of culture, respectively, rescued 50% of lethally irradiated mice. When 250,000 MNCs were cultured for 0, 1, 2, and 6 days, 71, 61, 100, and 50% of the animals survived lethal irradiation for greater than 24 weeks. In contrast, doses of 8,000 and 21,000 Thy1+Lin- cells cultured 0 and 1 day, respectively, yielded 50% survival rates. These same cells cultured for 6 days failed to rescue recipients even at high doses. Twenty thousand Thy1+Lin- cells cultured for 0, 1, 2, and 6 days, even in the presence of SCF, produced decreasing survival rates of 86, 43, 26, and 0%, respectively. The proliferative responses of these different populations in combination with their long-term rescue abilities indicated that the absolute number of long-term rescue units (LD50, 24 weeks) in the cultured Thy1+Lin- population decreased faster than in similarly cultured NBM-MNCs. Studies evaluating donor cell engraftment demonstrated that animals rescued with cultured Thy1+Lin- and NBM-MNCs maintained high levels of donor reconstitution [7]. The percent donor T cell engraftment did not significantly change between 2 and 17 months post-bone marrow transplantation (post-BMT). Therefore, those animals who received sufficient cells to survive lethal irradiation generally established and maintained high levels of donor engraftment. The data suggest a role for accessory cells and/or factors in the preservation of stem cell activity.

Postphlebitic syndrome after hip arthroplasty. 43 patients followed at least 5 years

We reviewed 43 patients using clinical scoring for evidence of postphlebitic syndrome at least 5 years after hip replacement. All had had a venogram as part of a screening study at the time of surgery. The postphlebitic syndrome was identified in 13 patients and was disabling in 6. The syndrome was present in 9 of the 11 patients with a venographically proven deep vein thrombosis (DVT) and in 4 of the 32 without DVT. Postphlebitic sequelae had developed despite anticoagulant therapy for the acute DVT. The postphlebitic syndrome following asymptomatic deep vein thrombosis is an important long-term complication of total hip replacement.

Efficient and sustained gene expression in primary T lymphocytes and primary and cultured tumor cells mediated by adeno-associated virus plasmid DNA complexed to cationic liposomes

We have used cationic liposomes to facilitate adeno-associated virus (AAV) plasmid transfections of primary and cultured cell types. AAV plasmid DNA complexed with liposomes showed levels of expression several fold higher than those of complexes with standard plasmids. In addition, long-term expression (> 30 days) of the gene, unlike the transient expression demonstrated by typical liposome-mediated transfection with standard plasmids, was observed. Southern analysis of chromosomal DNA further substantiated the hypothesis that the long-term expression was due to the presence of the transgene in the AAV plasmid-transfected group and not in the standard plasmid-transfected group. AAV plasmid-liposome complexes induced levels of transgene expression comparable to those obtained by recombinant AAV transduction. Primary breast, ovarian, and lung tumor cells were transfectable with the AAV plasmid DNA-liposome complexes. Transfected primary and cultured tumor cells were able to express transgene product even after lethal irradiation. High-level gene expression was also observed in freshly isolated CD3+, CD4+, and CD8+ T cells from normal human peripheral blood. Transfection efficiency ranged from 10 to 50% as assessed by intracellular interleukin-2 levels in interleukin-2-transfected cells. The ability to express transgenes in primary tumor and lymphoid cells may be applied toward tumor vaccine studies and protocols which may eventually permit highly specific modulation of the cellular immune response in cancer and AIDS.

Deep venous thrombosis in orthopaedic patients. Improving the specificity of diagnosis

The diagnosis of deep vein thrombosis after total joint arthroplasty is difficult. The most widely used method of detection is physical examination and selective venography, which are unreliable and expensive even when symptoms and signs are prominent. This study employed computerized strain gauge plethysmography (CSGP) to select symptomatic patients for venography. The incidence of detection by CSGP was increased from 16% to 81.7%. Repeated CSGP also was investigated, but although specificity was further enhanced, it was at the expense of sensitivity. The negative predictive value of the CSGP screening was high and comparable to that of venography and indicates that CSGP is useful in the management of patients with symptoms suggestive of deep vein thrombosis. Computerized strain gauge plethysmography results emphasize the low specificity and poor feasibility of clinical examination and venography. Computerized strain gauge plethysmography is strongly advocated as a selection procedure for invasive venography in total joint arthroplasty patients.

Total hip replacement, lower limb blood flow and venous thrombogenesis

The effect of Charnley cemented total hip replacement on venous blood flow in the legs and its relationship to deep-vein thrombosis were investigated in 413 patients. Blood flow was measured using strain-gauge plethysmography before operation, after surgery, and after discharge from hospital. There was a significant reduction in both venous capacitance and venous outflow, affecting both legs but greater in the operated leg. Venous flow remained significantly below preoperative levels in the operated leg six weeks after surgery. There was a highly significant correlation between the degree of reduction in blood flow and the development of postoperative deep-vein thrombosis. Venous stasis was shown to be a major factor in venous thrombogenesis.

Two-stage management of chronic osteomyelitis of the long bones. The Belfast technique

We treated 37 patients with chronic osteomyelitis of the tibia (25), femur (9), radius (2) and humerus (1) by a two-stage technique, comprising radical debridement of all infected bone and soft tissue with the provision of soft-tissue cover, and delayed autogenous bone grafting when necessary. All patients were reviewed at an average of 49 months (12 to 121). Infection-free bone union was achieved in 34. No patient required amputation. Wide excision of all compromised tissue and the closure of bone within a healthy vascularised soft-tissue envelope are essential if infection is to be eradicated. The combined assessment and management of such patients by an orthopaedic surgeon and a plastic surgeon are advocated.

Arteriographic study of the rabbit lower limb

The rabbit hind limb has been used extensively as an orthopaedic model in the investigation of fracture pathology and healing and the effects of vascular abnormalities. However, a detailed description of the normal arterial supply appears to be absent from the literature. A study of the entire arterial vasculature has been undertaken using a lead oxide injection technique developed for this and other orthopaedic studies. This technique has proved reliable and inexpensive, giving high-quality arteriography, which is easily interpreted. Accurate description of the arterial anatomy is possible without the need for repeated dissection. The rabbit lower limb shows some interesting variations in blood supply, particularly below the knee. The foot has three distinct patterns of blood supply, depending on the presence or absence of the peroneal artery and the degree of dominance of the dorsalis pedis artery. This arrangement has not previously been described and differs from the situation in other mammals. The arteriographic technique and the anatomical description have allowed the interpretation of changes occurring in the vasculature after injury in a fracture model.

Optimizing electroporation parameters for a variety of human hematopoietic cell lines

The parameters affecting electroporation of four human hematopoietic cell lines were investigated. The optimal conditions for electroporation are described for both transient and stable expression of foreign genes. A correlation exists between the levels of transient gene expression and stable transfection frequency. In addition, linear DNA yields higher stable transfection frequencies than supercoiled DNA. The cumulative results indicate that electroporation is a simple and useful method for obtaining transient and stable expression of foreign genes in human hematopoietic cells.

Inducible gene expression from multiple promoters by the tumor-promoting agent, PMA

Phorbol ester tumor promoters affect a broad scope of changes in mammalian cells. This report describes the activation of expression of an introduced chloramphenicol acetyltransferase (CAT) reporter gene by the phorbol ester, phorbol 12-myristate 13-acetate (PMA), in a variety of fibroblast and hematopoietic cell lines. PMA-mediated activation appears to be promoter region specific, yet widespread. Enhanced gene expression is observed for four out of five promoter systems tested, and, in some cases, is dependent on the cellular environment. Further experiments indicate that PMA mediates elevated gene expression by rapidly increasing steady state levels of CAT mRNA. The broad range of promoters affected by PMA may help explain the high potency of this agent in tumor production.