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.

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.

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.

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.

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.

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.

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.

Knee locking secondary to osteochondral fracture of the patella: an unusual presentation.

Acute locking is a sign of internal derangement of the knee and is an orthopaedic surgical emergency. Differential diagnoses of this condition are torn meniscus, intra-articular loose bodies and torn anterior cruciate ligament. We present a 15-year-old schoolboy who developed acute locking of the knee during dancing. Arthroscopy revealed that he had sustained an osteochondral fracture of the patella and the loose fragment from it caused locking of the knee. That this was not pseudo-locking was confirmed by examination of the knee under anaesthesia. Locking of the knee by a loose osteochondral fragment following acute dislocation of the patella, though rare, should be considered as a possible cause of true locking.

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.

Influence of patellar thickness on results of total knee arthroplasty: does a residual bony patellar thickness of

With patellar thickness averaging 24.0 mm and 21.9 mm in Singapore men and women undergoing total knee arthroplasty, achievement of precut thickness is difficult if the recommended residual bony thickness of 15 mm is maintained. We retrospectively compared the clinical outcome of 56 patellae resurfaced 12 mm (mean residual thickness, 13.7 mm). Both groups were comparable in terms of demographic characteristics, presentation, precut patellar thickness, and operative details (P> .05). Knee scores (P= .627), extensor mechanism function (P= .625), and postoperative range of motion (P= .344) were comparable. Differences in the overall (P= .167) and patellar (P= .061) complication rates as determined by chi-square test on the SPSS 10.0 program were not significant, although there were 4 patella-related complications in group 2. Increased patella-related complications may be associated with an excessive patellar composite of the patellofemoral articulation. A residual patellar thickness of <12 mm did not appear to affect the clinical outcome in this series.