SF-36 physical function and general health domains are independent predictors of acute hospital length of stay after hip fracture surgery

OBJECTIVE

The demographics and co-morbidities of individuals may impact healthcare consumption, but it is less understood how premorbid physical and mental function may influence these effects. The aim of this study is to determine patient's pre-fracture quality of life and mobility affect acute hospital burden in the management of hip fracture, using length of stay (LOS) as a proxy for healthcare resource.

MATERIALS AND METHODS

This is a retrospective study which investigated hip fracture patients who underwent surgery over the period of 2017-2020. Variables collected include LOS, age, gender, race, marital status, payer type, ASA score, time to surgery (TTS), type of surgery, fracture type, POD1 mobilization, discharge disposition, pre-fracture SF-36, EQ-5D and Parker mobility score (PMS) based on patient's recollection on admission. These variables were correlated with LOS using binary logistic regression on SAS.

RESULTS

There were 1045 patients, and mean age was 79.5 + 8.57 (range 60-105) years with an average LOS 13.64 + 10.0 days (range 2-114). On univariate analysis, PMS, EQ-5D and all domains of SF-36 except bodily pain (BP), emotional role and mental health were associated significantly with LOS. Amongst the QOL and PMS scores, only the domains of SF-36 Physical Function (PF) (OR = 0.993, p = 0.0068) and General Health perception (GH) (OR 0.992, p = 0.0230) remained significant on the multivariate model.

CONCLUSION

Our study showed that poor premorbid scores of SF36 PF and GH are independent factors associated with longer LOS in hip fracture patients after surgery, regardless of fracture type, age and ASA status. Hence, premorbid SF36 PF and GH can be used to identify patients that are at risk of prolonged hospital stay and employ targeted strategies to facilitate rehabilitation and discharge planning.

Excess mortality after hip fracture: fracture or pre-fall comorbidity?

Comorbidity and hip fracture independently increased mortality risk for 9 years in both sexes, with a significant additive interaction in the first year among women and through 6 years among men.

INTRODUCTION

Hip fracture is associated with a persistently elevated mortality risk, but it is unknown whether the elevated risk is due to the fracture or to pre-fracture comorbidity.

METHODS

In a population-based study in Singapore with 9 years of follow-up, patients age > 50 with first hip fracture from 2008 to 2017 were pair-matched to a cohort without hip fracture by age, sex, ethnicity, and pre-fracture Charlson Comorbidity Index (CCI). We investigated additive interaction using the relative excess risk due to interaction (RERI) and multiplicative interaction using the ratio of relative risks.

RESULTS

Twenty-two thousand five hundred ninety of 22,826 patients with a first hip fracture in 2008-2017 were successfully matched. Hip fracture and comorbidity independently increased mortality risk for 9 years in both sexes. After adjustment for comorbidity, excess mortality risk continued to persist for 9 years post-fracture in both men and women. Women with a hip fracture and pre-fracture CCI > 4 had a higher relative risk (RR) of mortality at 9 years of 3.29 [95% confidence interval (CI) 3.01, 3.59] than those without comorbidity (RR 1.51, 95%CI 1.36, 1.68) compared to the referent without hip fracture or comorbidity. An additive interaction between hip fracture and pre-fracture CCI > 4 was observed in the first post-fracture year` [relative excess risk due to interaction (RERI) 1.99, 95%CI 0.97, 3.01]. For men with CCI ≥ 4, the positive additive interaction was observed through 6 years.

CONCLUSIONS

Excess mortality risks post-fracture are attributable to both the fracture and pre-fracture comorbidity. Early interventions in hip fracture patients with high comorbidity could reduce their excess mortality.

Preoperative severe vitamin D deficiency is a significant independent risk factor for poorer functional outcome and quality of life 6 months after surgery for fragility hip fractures

Hip fractures are common in the elderly, and many patients with hip fractures have low vitamin D levels. This study found that severe vitamin D deficiency is linked to poorer recovery of function and quality of life after hip fracture surgery.

INTRODUCTION

Vitamin D deficiency is prevalent in hip fracture patients and associated with increased mortality and complications. However, there is limited long-term data on how vitamin D levels affect functional outcomes after hip fracture surgery. The aim of this study is to ascertain the association between vitamin D levels and recovery from hip surgery.

METHODS

Patients who underwent hip fracture surgery from January 2012 to December 2016 and had vitamin D levels assessed during admission were included. Retrospective analysis was performed on patients' demographic data such as age, gender and clinical parameters such as preoperative vitamin D, haemoglobin levels, Charlson Comorbidity Index (CCI), and type and site of surgery. Patients were divided according to four different vitamin D levels-severe vitamin D deficiency (≤10 ng/mL), mild deficiency (10-20 ng/ml), insufficiency (20-30 ng/ml), and normal (>30ng/ml). Functional outcomes were measured by Harris Hip Score (HHS), Parker Mobility Score (PMS), and individual domains of 36-Item Short Form Health Survey (SF36). Univariate and multivariate analyses were conducted to examine the association between vitamin D deficiency and functional outcome scores.

RESULTS

Out of 664 patients identified, 9% had severe vitamin D deficiency and 39% mild deficiency. Patients with severe vitamin D deficiency had significantly poorer baseline and 6-month PMS and SF36 Physical Functioning (PF). In multivariate analysis, severe vitamin D deficiency was associated with lower 6-month PMS and SF36 PF.

CONCLUSION

Preoperative severe vitamin D deficiency is an independent risk factor for poorer recovery of function and quality of life after hip fracture surgery.

Appropriate attitude promotes mask wearing in spite of a significant experience of varying discomfort

BACKGROUND

Despite increasing evidence to support mask effectiveness in mitigating the spread of COVID-19, there is still raging controversy regarding the use of masks. Evaluation of public perceptions, attitudes and the individuals' experience towards mask-wearing is integral to ensuring reasonable compliance and allows authorities to address concerns held by the population.

METHODS

A cross-sectional survey of lay-people was conducted within a high volume tertiary level institution in Singapore, from 16 October to 16 November 2020. Surveys administered evaluated five questions: 1) duration of mask wear per day, 2) mask-type used, 3) perceived necessity, 4) discomfort level experienced and 5) causes for discomfort.

RESULTS

Out of 402 respondents, 67.2% primarily wore disposable surgical masks. 72% felt mask-wearing was necessary to control COVID-19 transmission. 78.4% reported discomfort while wearing masks, with mean discomfort levels of 4.21 out of 10. Impairment to breathing and communication difficulties were the most common discomforts faced. Younger respondents complained of higher incidence of dermatological issues and sweating (p < 0.05). Respondents who wore masks for longer duration reported higher incidence of dermatological issues (p = 0.001) and sweating (p = 0.032).

CONCLUSION AND RELEVANCE

Even with an available vaccine, adjunctive public health measures such as mask-wearing will likely continue in order to curb COVID-19 transmission. Experience from past pandemics is likely to propagate self-protective behavior within a community. Our study identified several common mask-wearing discomforts, allowing respective organizations valuable market feedback for research and development. With appropriate public attitudes, effective mask-wearing compliance can be attained in a concerted effort against the coronavirus.

Effect of leg dominance on early functional outcomes and return to sports after anterior cruciate ligament reconstruction

INTRODUCTION

The effect of leg dominance on anterior cruciate ligament (ACL) injuries has been studied with some studies noting a propensity for injuries in the non-dominant leg. Its effect on post-ACL reconstruction recovery, however, is not well known. The authors hypothesize that dominant limb injuries undergo rehabilitation faster and positively affect early functional outcome scores and return to sports and set about studying these effects.

METHODS

This is a retrospective study of 254 patients from a single institution who underwent ACL reconstruction for acute ACL ruptures and the results were compared between patients with dominant and non-dominant limb injuries. Objective measurements including the KT-1000, single-leg hop distance and Biodex knee extension peak torque were used to evaluate recovery. Pre- and post-operative functional outcome scores such as the International Knee Documentation Committee (IKDC), Tegner activity score and Lysholm knee scale were documented.

RESULTS

Early functional outcomes were similar. Minimal clinically important difference (MCID) improvement in IKDC scores was achieved in 69.7% of the dominant versus 66.0% of the non-dominant injury group (p = 0.99), 75.2% versus 79.6% (p = 0.45) for the Lysholm knee scale, and 81.6% versus 84.9% (p = 0.50) for the Tegner activity score. The majority of patients in both subgroups had a return of at least 80% of peak knee flexion and extension peak torque at 5.4 months post-operatively; 92.9% of subjects with a non-dominant leg injury and 87.2% with a dominant leg injury had returned to their pre-injury sports 1 year from surgery.

CONCLUSIONS

Results from this study suggest that despite theoretical differences, leg dominance does not have a significant impact on short-term functional outcomes and return to sports. Objective measurements suggest that limb strength recovers at a comparable rate. Injuries to either leg demonstrate equally positive improvement post-ACL reconstruction given the same post-operative rehabilitation.

LEVEL OF EVIDENCE

III, retrospective comparative study.

LEVEL OF EVIDENCE

III, retrospective cohort study.

Cephalomedullary blade cut-ins: a poorly understood phenomenon

OBJECTIVES

Proximal femoral nail antirotation (PFNA) cut-in is a unique phenomenon seen in pertrochanteric hip fractures treated with the PFNA. Cut-in refers to the superomedial migration of the proximal femoral blade into the femoral head and hip joint. We recognize that cut-in is a completely separate entity from the well-described cut-out failure. This study assesses relevant radiological and patient risks factors for cut-in.

DESIGN

Retrospective multicenter study looking at patients with pertrochanteric hip fractures managed with the Synthes PFNA SETTING: Four tertiary hospitals over 7 years.

PATIENTS

Patients with cut-ins were identified.

OUTCOME MEASUREMENT

The radiological appearance of this mode of failure was assessed and compared to cut-outs. Patient demographics, fracture configuration, time to implant failure (cut-in), bone mineral density, tip-apex distance, neck-shaft angle and position of the tip of the helical blade in the femoral head were collected.

RESULTS

There was a total of 1027 patients across 4 institutions with 23 patients with cut-in. Average neck-shaft angle was 133 degrees. 16 out of 19 patients had severe osteoporosis with BMD < - 2.5. 14 of 23 patients had poor placement of the blade. 13 of 23 had a tip-apex distance of more than 20 mm.

CONCLUSION

We propose a standardized nomenclature of "cut-in" for the phenomenon of superomedial migration of the proximal femoral blade. An anatomical neck-shaft reduction, accurate blade placement and increased surveillance for patients with severe osteoporosis are required to reduce the incidence and morbidity of cut-in.

Scanning Electron Microscopy Study of Retrieved Implants Suggests a Ratcheting Mechanism Behind Medial Migration in Cephalomedullary Nailing of Hip Fractures

Introduction:

Medial migration is the paradoxical migration of the femoral neck element (FNE) superomedially against gravity with respect to the intramedullary component of the cephalomedullary device, increasingly seen in the management of pertrochanteric hip fractures with the intramedullary nail. We postulate that the peculiar anti-gravity movement of the FNE in the medial migration phenomenon stems from a ratcheting mechanism at the intramedullary nail-FNE interface, which should inadvertently produce unique wear patterns on the FNE that can be seen with high-powered microscopy. By examining the wear patterns on retrieved implants from patients with medial migration, our study aims to draw clinical correlations to the ratcheting mechanism hypothesis.

Material and Methods:

Four FNEs were retrieved from revision surgeries of four patients with prior intramedullary nail fixation of their pertrochanteric hip fractures complicated by femoral head perforation. The FNEs were divided into two groups based on whether or not there was radiographic evidence of medial migration prior to the revisions. Wear patterns on the FNEs were then assessed using both scanning electron microscopy and light microscopy.

Results:

Repetitive, linearly-arranged, regularly-spaced, unique transverse scratch marks were found only in the group with medial migration, corresponding to the specific segment of the FNE that passed through the intramedullary component of the PFNA during medial migration. These scratch marks were absent in the group without medial migration.

Conclusion:

Our findings are in support of a ratcheting mechanism behind the medial migration phenomenon with repetitive toggling at the intramedullary nail-FNE interface and progressive propagation of the FNE against gravity.

Natural history of incomplete atypical femoral fractures in patients after a prolonged and variable course of bisphosphonate therapy-a long-term radiological follow-up

Understanding the natural history of lateral femoral stress fractures helps to guide their management. Improvement in their radiographic characteristics is rare. Progression was generally sequential, most developing an incomplete fracture line before fracture displacement. Stopping bisphosphonates decreased the fracture rate, a feasible management option for lesions without incomplete fracture lines.

INTRODUCTION

Retrospective study evaluating the natural history of lateral femoral stress fractures (FSF) by serial radiography over a variable period of time in a cohort of patients treated for some time with bisphosphonates for osteoporosis, whilst also identifying the fracture response in cases where bisphosphonates were discontinued.

METHODS

The radiographs of 76 consecutive patients (92 femurs) with 161 FSF were reviewed to document their change over time. Femurs were classified into the following: A-normal, B-focal cortical thickening, C-dreaded black line and D-displaced fracture. Bisphosphonate history was recorded.

RESULTS

66.5% FSF showed group stability between the first and last radiographs: group B (79.1%), group C (45.7%). 28.6% progressed, mostly following an ordered sequence starting from group A, progressing to B, then C, before culminating in D. Progression rate was as follows: A-100% (11/11), B-18.3% (21/115), C-40% (14/35). Regression in FSF was uncommon-5.6% (8/161). 34.8% (32/92) sustained displaced fractures. Kaplan-Meier analysis showed statistically significant difference between the groups; median survival (95% CI): A-4189 (-), B-3383.0 (-), C-1807 (0.0-3788.6) and progression to displaced fracture when bisphosphonate had been stopped for at least 6 months. The group without recent bisphosphonates had a lower group progression rate (17.1%, 12/70). Nevertheless, 10.9% (5/46) progressed to displaced fracture. This group also had the highest proportion of stable (77.1%, 54/70) and regressive lesions (5.7%, 4/70).

CONCLUSIONS

In FSF, there is natural progression from normal bone, to focal cortical thickening, to dreaded black line and eventually to displaced fracture. Most lesions persist, remaining static or progressing, especially if a dreaded black line is present and bisphosphonates are continued. Regression is uncommon and more frequent when bisphosphonates are discontinued. Despite stopping bisphosphonates, there remains a 10.9% risk of progression to displaced fracture.

Periprosthetic Fractures after Total Knee Arthroplasty: the Influence of Pre-Operative Mechanical Factors versus Intraoperative Factors

Introduction: Periprosthetic fractures are a devastating complication following total knee arthroplasty. Little is known about the effect of mechanical factors on the incidence of periprosthetic fractures. The aim of this study was to examine the correlation between pre-operative mechanical factors, like side of surgery, coronal alignment and pre-operative range of motion and intra-operative factors, and the incidence of a periprosthetic fracture, following primary total knee arthroplasty (TKA).

Materials and Methods: Forty-two patients with periprosthetic fractures (PPF) after primary TKA were identified from our hospital arthroplasty registry. These patients were matched two-to-one for gender and age at primary knee arthroplasty to 84 patients without PPF. The incidence of periprosthetic fracture with regards to laterality, coronal alignment and pre-operative range of motion was analysed. Intra-operative factors like implant type, patellar resurfacing and notching were also analysed using logistic regression.

Results: Coronal alignment, pre-operative range of motion and patella resurfacing were not significant predictors of periprosthetic fractures. Anterior femoral notching was found to be significantly higher in the fracture group with an odds ratio of 17. Left sided surgery was also significantly higher in the periprosthetic fracture group.

Conclusion: Periprosthetic fractures are 17 times more likely to occur in a knee with anterior femoral notching. Preoperative factors like coronal alignment and poor preoperative range of motion do not seem to increase the risk of periprosthetic fractures after TKA.

Medial migration in cephalomedullary nail fixation of pertrochanteric hip fractures: A biomechanical analysis using a novel bidirectional cyclic loading model

Objectives

The paradoxical migration of the femoral neck element (FNE) superomedially against gravity, with respect to the intramedullary component of the cephalomedullary device, is a poorly understood phenomenon increasingly seen in the management of pertrochanteric hip fractures with the intramedullary nail. The aim of this study was to investigate the role of bidirectional loading on the medial migration phenomenon, based on unique wear patterns seen on scanning electron microscopy of retrieved implants suggestive of FNE toggling.

Methods

A total of 18 synthetic femurs (Sawbones, Vashon Island, Washington) with comminuted pertrochanteric fractures were divided into three groups (n = 6 per group). Fracture fixation was performed using the Proximal Femoral Nail Antirotation (PFNA) implant (Synthes, Oberdorf, Switzerland; n = 6). Group 1 was subjected to unidirectional compression loading (600 N), with an elastomer (70A durometer) replacing loose fracture fragments to simulate surrounding soft-tissue tensioning. Group 2 was subjected to bidirectional loading (600 N compression loading, 120 N tensile loading), also with the elastomer replacing loose fracture fragments. Group 3 was subjected to bidirectional loading (600 N compression loading, 120 N tensile loading) without the elastomer. All constructs were tested at 2 Hz for 5000 cycles or until cut-out occurred. The medial migration distance (MMD) was recorded at the end of the testing cycles.

Results

The MMDs for Groups 1, 2, and 3 were 1.02 mm, 6.27 mm, and 5.44 mm respectively, with reliable reproduction of medial migration seen in all groups. Bidirectional loading groups showed significantly higher MMDs compared with the unidirectional loading group (p < 0.01).

Conclusion

Our results demonstrate significant contributions of bidirectional cyclic loading to the medial migration phenomenon in cephalomedullary nail fixation of pertrochanteric hip fractures.

Cite this article: G. W. Law, Y. R. Wong, A. K-S. Yew, A. C. T. Choh, J. S. B. Koh, T. S. Howe. Medial migration in cephalomedullary nail fixation of pertrochanteric hip fractures: A biomechanical analysis using a novel bidirectional cyclic loading model. Bone Joint Res 2019;8:313–322. DOI: 10.1302/2046-3758.87.BJR-2018-0271.R1.

Pre-discharge prognostic factors of physical function among older adults with hip fracture surgery: a systematic review

INTRODUCTION

To identify, organize, and assess the evidence level of pre-discharge prognostic factors of physical function beyond discharge after hip fracture surgery.

METHODS

We performed a systematic search of four databases (PubMed, Embase, CINAHL, PsycINFO) for longitudinal studies of prognostic factors of physical function at ≥ 1 month among older adults ≥ 50 years old with surgically treated hip fracture, complemented with hand-searching. Two reviewers independently screened papers for inclusion and assessed the quality of all the included papers using the Quality in Prognosis Studies (QUIPS) tool. We assigned the evidence level for each prognostic factor based on consistency in findings and study quality.

RESULTS

From 98 papers that met our inclusion criteria, we identified 107 pre-discharge prognostic factors and organized them into the following seven categories: demographic, physical, cognitive, psychosocial, socioeconomic, injury-related, and process of care. Potentially modifiable factors with strong or moderate evidence of an association included total length of stay, physical function at discharge, and grip strength. Factors with strong or moderate evidence of no association included gender, fracture type, and time to surgery. Factors with limited, conflicting, or inconclusive evidence included body-mass index, psychological resilience, depression, and anxiety.

CONCLUSIONS

Our findings highlight potentially modifiable prognostic factors that could be targeted and non-modifiable prognostic factors that could be used to identify patients who may benefit from more intensive intervention or to advise patients on their expectations on recovery. Examining the efficacies of existing interventions targeting these prognostic factors would inform future studies and whether any of such interventions could be incorporated into clinical practice.

Externalised locking compression plate as an alternative to the unilateral external fixator: a biomechanical comparative study of axial and torsional stiffness

Objectives

External fixators are the traditional fixation method of choice for contaminated open fractures. However, patient acceptance is low due to the high profile and therefore physical burden of the constructs. An externalised locking compression plate is a low profile alternative. However, the biomechanical differences have not been assessed. The objective of this study was to evaluate the axial and torsional stiffness of the externalised titanium locking compression plate (ET-LCP), the externalised stainless steel locking compression plate (ESS-LCP) and the unilateral external fixator (UEF).

Methods

A fracture gap model was created to simulate comminuted mid-shaft tibia fractures using synthetic composite bones. Fifteen constructs were stabilised with ET-LCP, ESS-LCP or UEF (five constructs each). The constructs were loaded under both axial and torsional directions to determine construct stiffness.

Results

The mean axial stiffness was very similar for UEF (528 N/mm) and ESS-LCP (525 N/mm), while it was slightly lower for ET-LCP (469 N/mm). One-way analysis of variance (ANOVA) testing in all three groups demonstrated no significant difference (F(2,12) = 2.057, p = 0.171).

There was a significant difference in mean torsional stiffness between the UEF (0.512 Nm/degree), the ESS-LCP (0.686 Nm/degree) and the ET-LCP (0.639 Nm/degree), as determined by one-way ANOVA (F(2,12) = 6.204, p = 0.014). A Tukey post hoc test revealed that the torsional stiffness of the ESS-LCP was statistically higher than that of the UEF by 0.174 Nm/degree (p = 0.013). No catastrophic failures were observed.

Conclusion

Using the LCP as an external fixator may provide a viable and attractive alternative to the traditional UEF as its lower profile makes it more acceptable to patients, while not compromising on axial and torsional stiffness.

Cite this article: B. F. H. Ang, J. Y. Chen, A. K. S. Yew, S. K. Chua, S. M. Chou, S. L. Chia, J. S. B. Koh, T. S. Howe. Externalised locking compression plate as an alternative to the unilateral external fixator: a biomechanical comparative study of axial and torsional stiffness. Bone Joint Res 2017;6:216–223. DOI: 10.1302/2046-3758.64.2000470.

Predictors for rehabilitation outcome in Asian geriatric hip fracture patients

PURPOSE

To identify predictors for rehabilitation outcome in Asian geriatric hip fracture patients.

METHODS

Records of 153 consecutive Asian patients aged 61 to 99 years who underwent surgery for hip fracture and were followed up for at least one year were reviewed. They were stratified into 4 agegroups: 60-69 years (n=27), 70-79 years (n=70), 80-89 years (n=50), and ≥90 years (n=6). Any comorbidity, regardless of severity, was recorded. Pre-injury and postoperative functional status was evaluated using the 36-item Short Form Health Survey. Relative functional gain (RFG) is equal to absolute functional gain (physical component summary [PCS] score at one year minus PCS score at 6 weeks) divided by the maximum potential gain (maximum PCS score minus PCS score at 6 weeks). RFG of <0.5 and ≥0.5 is defined as poor and good rehabilitation outcome, respectively.

RESULTS

In univariate analysis, age 80-89 years (p=0.026), arthritis (p=0.082), and hypercholesterolaemia (p=0.014) were predictors for RFG. In multivariate analysis, age 80-89 years (p=0.016) remained a predictor for poor RFG, and hypercholesterolaemia remained a predictor for good RFG.

CONCLUSION

Poor rehabilitation outcome was associated with patient age of 80-89 years; an orthogeriatric approach may be beneficial in optimising rehabilitation outcome in elderly hip fracture patients.

Post-operative outcomes of atypical femoral subtrochanteric fracture in patients on bisphosphonate therapy

Management of bisphosphonate-associated subtrochanteric fractures remains opinion- or consensus-based. There are limited data regarding the outcomes of this fracture.

We retrospectively reviewed 33 consecutive female patients with a mean age of 67.5 years (47 to 91) who were treated surgically between May 2004 and October 2009. The mean follow-up was 21.7 months (0 to 53). Medical records and radiographs were reviewed to determine the post-operative ambulatory status, time to clinical and radiological union and post-fixation complications such as implant failure and need for second surgery.

The predominant fixation method was with an extramedullary device in 23 patients. 25 (75%) patients were placed on wheelchair mobilisation or no weight-bearing initially. The mean time to full weight-bearing was 7.1 months (2.2 to 29.7). The mean time for fracture site pain to cease was 6.2 months (1.2 to 17.1). The mean time to radiological union was 10.0 months (2.2 to 27.5). Implant failure was seen in seven patients (23%, 95 confidence interval (CI) 11.8 to 40.9). Revision surgery was required in ten patients (33%, 95 CI 19.2 to 51.2).

A large proportion of the patients required revision surgery and suffered implant failure. This fracture is associated with slow healing and prolonged post-operative immobility.

Cite this article: Bone Joint J 2014;96-B:658–64.

A case of an atypical femoral fracture associated with bacterial biofilm--pathogen or bystander?

We report a case of an 86-year-old woman with an atypical femoral fracture (AFF) who was treated with intramedullary nailing followed by lateral femoral plating. She developed a second femoral shaft fracture distal to the intramedullary nail which required a second operation. Biopsy of the periosteum overlying the site of the initial proximal AFF was sent for pathogen analysis. Using the Ibis T5000 platform and the BAC plate assay, a polymicrobial infection was diagnosed consisting of Bifidobacterium subtile and Pseudomonas mendocina. This raises the possibility that bacterial infections may play some role in atypical fractures of the femur.

Bilateral ulna fractures associated with bisphosphonate therapy

We report a case of bilateral ulna stress fractures following bilateral femoral fractures associated with long-term bisphosphonate use. The patient is an 84-year-old woman receiving 15 years of bisphosphonate therapy. She did not have any preexisting medical conditions which are known secondary causes of bone loss. She was mostly housebound and used a walking frame for ambulation. She presented with atraumatic right ulna pain and subsequent atraumatic left ulna pain a month later. She was treated conservatively in backslabs and her bisphosphonate was stopped. Investigations did not reveal any secondary causes of osteoporosis or metabolic bone disorders.

Fasciotomy and surgical tenotomy for recalcitrant lateral elbow tendinopathy: early clinical experience with a novel device for minimally invasive percutaneous microresection

BACKGROUND

The optimal choice for intervention for recalcitrant lateral elbow tendinopathy remains unclear as various treatment modalities have documented comparable results in the literature.

PURPOSE

To explore the safety, tolerability, and early efficacy of a new minimally invasive mode of treatment that delivers focused, calibrated ultrasonic energy, effectively microresecting the pathological tendon and removing only pathological tissue.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Seven male and 13 female patients aged 33 to 65 years averaging 12.5 months (range, 4-48) of failed nonoperative therapy underwent the ultrasonic microresection procedure in an outpatient clinic setting. The procedure involved a sterile, ultrasound-guided percutaneous microresection with a proprietary device (TX1) performed through a stab incision under local anesthesia. The duration of the procedure and complications of the device or procedure were assessed. Outcome parameters included patient satisfaction; visual analog scale (VAS) pain scores; Disabilities of the Arm, Shoulder and Hand (DASH) scores at 1, 3, 6, and 12 months; and ultrasound assessment at 3 and 6 months.

RESULTS

The median duration for the sterile confirmatory ultrasound examination (phase 1) was 88.5 seconds (range, 39-211; SD, ±47.6), the median duration of the procedure proper (phase 2) was 10.1 minutes (range, 4.1-19.4; SD, ±3.7), and the median energy time (duration the TX1 device was activated) was 32.5 seconds (range, 18-58; SD, ±11.0). No complications were encountered. A significant improvement in VAS score (from 5.5 to 3.3; P < .001) occurred by 1 week, and significant improvements in both DASH-Compulsory (from 21.7 to 11.3; P = .001) and DASH-Work (from 25.0 to 6.3; P = .012) scores occurred by 1 month. The VAS scores further improved at 3, 6, and 12 months (from 2.0 to 1.0 to 0.50; P = .003 and .023). The DASH-Compulsory score improved significantly from 3 to 6 months (from 8.6 to 4.6; P = .003), and both the DASH-Compulsory and DASH-Work scores were sustained by 12 months. Sonographically reduced tendon thickness (19 patients), resolved or reduced hypervascularity (17 patients), and reduced hypoechoic area (18 patients) occurred by 6 months. Nineteen of the 20 patients (95%) expressed satisfaction with the procedure, with 9 patients being very satisfied with their overall experience at 6 months after the procedure, 10 patients somewhat satisfied, and 1 patient neutral.

CONCLUSION

Ultrasonic microresection of diseased tissue with the TX1 device provides a focally directed, safe, specific, minimally invasive, and well-tolerated treatment for recalcitrant lateral elbow tendinopathy in an office-based or ambulatory surgical setting with good evidence of some level of efficacy in 19 of 20 patients (95%) that is sustained for at least 1 year.

Distribution of atypical fractures and cortical stress lesions in the femur: implications on pathophysiology

INTRODUCTION

Some authors have hypothesised that atypical femur fractures occur due to tensile mechanism of failure. We studied the distribution of such lesions along the femur shaft to determine if they concentrate in regions that are subject to tensile loading.

METHODS

From May 2004 to March 2010, radiological reviews of 48 patients aged 69 +/- 10.4 (range 47-92) years with atypical femoral fractures and lesions were performed. The absolute distance of each lesion from the greater trochanter and the ratio of the distance of each lesion from the greater trochanter expressed as a percentage of the entire femur length were measured.

RESULTS

All periosteal reactions and cortical stress lesions occurred in the lateral cortex. There were 35 right femoral lesions (28 complete fractures and seven cortical stress reactions), with a median distance of 108.3 +/- 54.0 (range 67.0-270.4) mm from the greater trochanter and a median ratio of 23.9 +/- 11.7 (range 15.7-58.6) percent of the entire femoral length. There were 38 left femoral lesions (27 complete fractures and 11 cortical stress reactions), with a median distance of 109.9 +/- 43.1 (range 73.6-246.2) mm from the greater trochanter and a median ratio of 24.4 +/- 9.1(range 16.3-51.1) percent of the entire femoral length.

CONCLUSION

Based on previously established femoral shaft loading characteristics, atypical lesions were clustered at the region of maximal tensile loading. No lesion occurred in regions that were subject to compressive loading. This unique distribution supports a tensile mechanism of failure in such lesions.

One-year outcome of hip fracture patients admitted to a Singapore hospital: quality of life post-treatment

INTRODUCTION

A prospective and consecutive documentation of hip fracture care was performed. Outcomes, including quality of life, mortality, complication rates, were documented; and mobility, ambulatory status, freedom from pain and activities of daily living one year before and after treatment, were compared.

METHODS

We prospectively reviewed the medical records of 70 consecutive patients admitted to the Singapore General Hospital, following either a cervical or intertrochanteric femoral fracture from February 2004 to May 2004. Patients' progress was reviewed at one year post-treatment, and the EuroQOL was used to quantify the patients' quality of life. Description of any problems encountered was also recorded.

RESULTS

The follow-up rate at one year for the 70 patients described in this report was 98.6 percent. Mortality rate was 27.1 percent. Early complication rate was 5.7 percent. Outcome was satisfactory in all but two patients. Mortality for surgically-operated patients was 25.4 percent. About a quarter of the patients had excellent ambulatory status and 40.0 percent were able to walk independently. Eight percent suffered from falls after discharge, but no recurrence of hip fracture was recorded. None was re-admitted under suspicion of hip fracture. The average self-scoring system (EuroQOL) yielded an average of 66.6 out of 100.

CONCLUSION

Hip fractures can be treated surgically with good results and low early complication rates, without drastically affecting patients' quality of life.

Arthroscopic internal marsupialization of meniscal cysts

Meniscal cysts begin with extrusion of synovial fluid through a tear of the meniscus, enlarging probably as a result of a one-way valve effect of the tear flap. We describe a technique of arthroscopic internal marsupialization of meniscal cysts with or without meniscectomy. A 5 mm channel was created in the capsule adjacent to the cyst arthroscopically for decompression of the cyst into the joint, thus equalising pressures between the cystic and intra-articular compartments. Only unstable meniscal tears were debrided down to a stable rim while intact meniscii or stable tears were left alone. Eight patients with MRI confirmed atraumatic medial or lateral meniscal cysts underwent surgery. At a mean follow-up of 39.1 months (12-94 months, S.D. 26.4), Tegner scores averaged 5.1 (3-8, S.D. 2.1) and Lysholm scores averaged 94.4 (85-100, S.D. 5.4). No cyst recurred. Arthroscopic internal marsupialization effectively decompresses meniscal cysts and prevents their recurrence, while preserving meniscal tissue and minimising arthrosis of the knee joint.

Subtrochanteric insufficiency fractures in patients on alendronate therapy: a caution

We carried out a retrospective review over ten months of patients who had presented with a low-energy subtrochanteric fracture. We identified 13 women of whom nine were on long-term alendronate therapy and four were not. The patients treated with alendronate were younger, with a mean age of 66.9 years (55 to 82) vs 80.3 years (64 to 92) and were more socially active. The fractures sustained by the patients in the alendronate group were mainly at the femoral metaphyseal-diaphyseal junction and many had occurred after minimal trauma. Five of these patients had prodromal pain in the affected hip in the months preceding the fall, and three demonstrated a stress reaction in the cortex in the contralateral femur. Our study suggests that prolonged suppression of bone remodelling with alendronate may be associated with a new form of insufficiency fracture of the femur. We believe that this finding is important and indicates the need for caution in the long-term use of alendronate in the treatment of osteoporosis.

The use of computer navigation in performing minimally invasive surgery for intertrochanteric hip fractures--The experience in Singapore

OBJECTIVE

Intertrochanteric hip fractures are very common and early mobilisation correlates with a better outcome. The ideal surgical procedure should protect the soft tissue envelope, thereby preserving blood supply and reducing blood loss. Furthermore, occupational exposure to fluoroscopy that is used in hip fracture fixation remains a concern amongst orthopaedic surgeons. Computer-aided surgery can help to reduce reliance on fluoroscopy. We therefore combined the principles of minimally invasive plate osteosynthesis (MIPO) and computer navigation to describe a new procedure. We also present our results using this technique of minimally invasive computer-navigated dynamic hip screw fixation (navMIS-DHS), and compare it to computer-navigated open DHS fixation (nav-DHS) and to conventional open DHS fixation (conv-DHS).

MATERIALS AND METHODS

This paper has three parts. In the first part, we describe the procedure of navMIS-DHS in detail. In the second part, we present our initial retrospective pilot series of 35 cases. Amongst them we performed 5 navMIS-DHS, 3 nav-DHS and 27 conv-DHS. There were also two cases of conv-DHS deliberately performed with a mini-incision in an attempt to see if we could duplicate the 5 cm incision that we achieved with navMIS-DHS. All patients were followed up for a minimum of 6 months. In the third part, we performed a single surgeon prospective evaluation of navMIS-DHS versus conv-DHS involving 43 fractures in two arms.

RESULTS

We were able to achieve reduction in fluoroscopy time. There was also reduction in opiate requirement post-operatively in the minimally invasive procedure. The incision sizes were also smaller. The prospective study also showed less wound-related complications in navMIS-DHS and a shorter time to ambulation. Implant positions were acceptable but we have also described how it may be improved.

CONCLUSIONS

Navigated MIS-DHS, by virtue of less pain, better healing, earlier rehabilitation and potentially shorter hospital stay, would benefit both the patients and reduce the economic strain on the health care system. It is a safe and reproducible procedure. Technical difficulties are present and these need to be addressed with further modifications of technique, and instrumentation.

Cancellous screw fixation for femoral neck fractures: one hundred and sixteen patients

INTRODUCTION

This paper evaluates the efficacy and safety of the use of cancellous screw fixation in the treatment of intracapsular femoral neck fractures in our local population.

MATERIALS AND METHODS

A retrospective analysis of the results of 116 cases that were performed in Singapore General Hospital and Changi General Hospital over a 2-year period was undertaken. The minimum period of follow-up was 2 years.

RESULTS

The median age of the study group was 71 years and approximately two-thirds were females. There were 104 (90%) cases of undisplaced (Garden 1 and 2) fractures and 12 (10%) displaced (Garden 3 and 4) fractures. The specific complication rate was much higher in the displaced group of patients. At 2 years' postoperation, 85% returned to their premorbid level of ambulation and 90% reported good pain relief. The 1-year mortality rate was 7%.

CONCLUSION

Cancellous screw fixation is a relatively safe and useful operation. It achieved our aim of returning most patients to their pre-fracture level of ambulation and providing good pain relief.

Radionuclide synovectomy and chronic haemophilic synovitis in Asians: a retrospective study

Radionuclide synovectomy has been identified as the procedure of choice in treating chronic haemophilic synovitis among Caucasian populations. Its effectiveness among East Asians has not been studied. A retrospective study was carried out on 12 Asian haemophiliacs who underwent 12 radionuclide synovectomies. The average follow-up was 30.7 months (range 6-55) for primary procedures. 32P chromic phosphate and 188Re-tin colloid were injected into target joints according to protocol. There was a significant 80% decrease in the median frequency of haemarthrosis from 1.4 per month (range 0.2-7.0) to 0.25 per month (range 0.0-1.8) (P<0.05). Half of the patients had excellent results by 1 year of synovectomy. The median factor usage for target joint haemarthrosis postsynovectomy was 792 units per month (range 0-3209) reduced significantly from a presynovectomy level of 1452 units per month (range 306-7125) (P<0.05). Patients also reported a reduction in joint pain scores, and an improvement in joint mobility and quality of life. The majority of patients were satisfied with the overall outcome of radionuclide synovectomy. Radionuclide synovectomy appears to be effective in reducing the incidence of target joint haemarthrosis and quantity of factor usage for such bleeds among Asians with haemophilic synovitis.

Early-onset inflammatory responses in vivo to adenoviral vectors in the presence or absence of lipopolysaccharide-induced inflammation

Adenoviral vectors (Ad) have potential for use in pulmonary gene transfer for treating cystic fibrosis (CF). However, Ad may induce inflammation even in the absence of gene expression. Endotoxin from gram-negative bacteria in the airways of CF patients may also induce inflammation, and may further inhibit vector delivery and gene transfer. We used a mouse model to study the time course of Ad-induced lung inflammation and to assess additivity with lipopolysaccharide (LPS)-induced inflammatory responses. C3H/HeJ endotoxin-resistant (RES) mice hyporesponsive to inflammatory stimuli and normoresponsive C3HeB/FeJ endotoxin-sensitive (SEN) mice were studied to characterize inflammatory responses that follow intratracheal instillation of inactivated Ad, with or without simultaneous inhalation exposure to LPS. Instillation of 10(10) Ad particles dramatically increased bronchoalveolar lavage fluid (BALF) concentrations of tumor necrosis factor (TNF)-alpha and interleukin (IL)-6 at 3 to 6 h and induced profound neutrophilia, maximal at 12 to 24 h. SEN mice had tenfold greater responses than did RES mice at 6, 12, and 24 h. Mice exposed to Ad alone, LPS alone, or Ad + LPS had significant inflammation at the 3-h time point as demonstrated by BALF neutrophils, TNF-alpha, and IL-6. With all three treatments, SEN mice had a five- to 300-fold greater response than did RES mice. Importantly, Ad + LPS yielded no greater inflammatory response than LPS without Ad. These data demonstrate that replication-deficient Ad induce early inflammation and LPS-induced inflammation is not augmented by concurrent treatment with Ad.

Double level fractures of the femur treated with closed intramedullary nailing

The treatment of segmental multilevel fractures of the femur is problematic. Open methods of fracture fixation which strip the soft tissue attachments from the bone cause devascularisation of the middle segment. Mechanical fixation using 2 separate plates results in a stress riser. The use of closed intramedullary nail addresses some of the problems in this difficult group of fractures, preserving the soft tissue envelope and eliminating stress risers. However, vascularity of the middle segment may still be compromised. Six cases of fractures of the femur that were segmental in nature or associated with a fracture around the hip were treated with a closed intramedullary locked nail. The average operating time was 123 minutes and there were no infections. Average time to union was 7.2 months. Two cases required re-operation, one to correct a residual internal rotation deformity and one required dynamisation to eliminate the gap at the fracture site.

Factors affecting healing of below knee amputation

Between January and December 1992, 54 diabetic patients with 60 below knee amputations performed in the Department of Orthopaedic Surgery O, Singapore General Hospital were available for evaluation. The average follow-up period was 16.3 months with a range of 13 to 24 months. Five patients had stump necrosis and above knee amputation was performed. Eight patients had partial stump necrosis and required debridement with or without secondary procedures. The other patients had uneventful stump healing which was defined as healing of the stump wound without complications and remained intact for at least 6 months after surgery. Absence of popliteal pulse, presence of central cardiovascular disease and absence of intraoperative skin flap bleeding were found to be associated with higher incidence of stump necrosis.

Effect of Pasteurella multocida toxin on physeal growth in young pigs

OBJECTIVE

To determine whether Pasteurella multocida toxin (PMT) affects growth of the proximal portion of the humerus of young pigs.

ANIMALS

20 colostrum-deprived, cesarean-derived pigs.

DESIGN AND PROCEDURE

5 groups (n = 4/group) of pigs were formed. Group-1 pigs received 0.1 ml of phosphate-buffered saline solution for 4 weeks; group-2 pigs received 0.05 microgram of PMT/kg of body weight at 14 and 21 days; group-3 pigs received 0.05 microgram of PMT/kg at 28 and 35 days; group-4 pigs received 0.1 microgram of PMT/kg at 14 and 21 days; and group-5 pigs received hyperimmune serum (from a sow given purified toxin) on days 13, 20, 27, and 34, and 0.1 microgram of PMT/kg on days 14, 21, 28, and 35.

RESULTS

All pigs given 0.1 microgram of PMT/kg without serum died or were euthanatized, as were 4 pigs given 0.05 microgram of PMT/kg. These pigs had increased serum interleukin 1 and 6 bioactivities. Pigs surviving 0.05 microgram of PMT had decreased weight gain, rough coat, marked atrophy of the ventral concha (as determined by turbinate perimeter ratios), and small stature. The surviving pigs also had reduced area and decreased proliferation indices in physeal chondrocytes on the basis of bromodeoxyuridine immunoreactivity. Control and serum-treated pigs gained weight, had no clinical effects, had similar physeal areas, and had higher cell proliferation indices.

CONCLUSIONS

PMT inhibits endochondral bone formation by reducing physeal area and chondrocyte proliferation in vivo. Hyperimmune serum neutralizes the effects of toxin on weight gain, clinical appearance, physeal area, and chondrocyte proliferation.

CLINICAL RELEVANCE

PMT may affect growth of the skeletal system. Antiserum to PMT is protective.