Lower preoperative Hounsfield unit values are associated with intra-operative fractures in cementless bipolar hemiarthroplasty

Predicting fracture classification and prognosis with hounsfield units and femoral cortical index: A simple and cost-effective approach

BACKGROUND

The relationship between bone density and fracture has been widely studied and recognized, and the role of cortical bone in proximal femoral fractures has also been increasingly studied. However, both the determination of bone mineral density (BMD) and the determination of cortical mass are expensive and cumbersome. The purpose of this study is to investigate whether two readily available indicators, Hounsfield Units (HUs) and femoral cortical index (FCI), can be used to predict hip fracture classification and prognosis.

METHODS

A retrospective study was conducted on 110 patients with hip fragility fractures. Cortical index was calculated on fractured and contralateral femur FCI, with HUs calculated on the proximal femur. The correlation of the FCI and HU with diabetes, hypertension, and related indicators, such as albumin, creatinine, and urea nitrogen levels, were also analyzed in the study.

RESULTS

Both the Evans classification of intertrochanteric fractures and the Garden and Pauwels classifications of femoral neck fractures showed that as the severity of the fracture increased, the HUs and FCI decreased. Age and albumin level also had a negative correlation with HUs and FCI. There was also a significant correlation between HUs and FCI.

CONCLUSIONS

The HUs and FCI, which can be easily and quickly obtained, can be used to predict the classification and prognosis of hip fractures.

Prevalence of osteoporosis in patients awaiting unicompartmental knee arthroplasty: a cross-sectional study

Objectives

Osteoporosis may contribute to failure of unicompartmental knee arthroplasty (UKA), yet the prevalence of osteoporosis in the population awaiting UKA has not been adequately studied. The objectives of this study were to report the prevalence of osteoporosis in people awaiting UKA and the rate of anti-osteoporosis treatment, and to explore factors associated with osteoporosis prevalence in people awaiting UKA.

Methods

Participants awaiting UKA from January 2019 to May 2023 were consecutively enrolled. Participants ' age, gender, BMI, knee K-L score, VAS score, history of previous DXA testing, history of anti-osteoporosis treatment, and possible underlying risk factors were recorded. All participants were given a dual-energy x-ray absorptiometry (DXA) test after the visit. The diagnosis of osteoporosis was made according to the World Health Organization criteria. Compare the prevalence of osteoporosis between people waiting for UKA and the general population. Risk factors associated with osteoporosis were analyzed using multiple linear regression and binary logistic regression models.

Results

A total of 340 participants were included in the study, 259 in female and 81 in male, with a mean age of 63.53 years (range: 41-84 years), and all participants completed UKA and had DXA prior to UKA. The prevalence of osteoporosis was 40.88% (44.79% in female and 28.40% in male). The prevalence of osteoporosis was higher in female than in male (p<0.001). The prevalence of osteoporosis in the population waiting for UKA was significantly higher than that in the general population (p < 0.001). DXA testing was performed in 12.06% within 1 year prior to the visit. The percentage of those who had received anti-osteoporosis treatment was 20.59% (20.86% in osteoporosis, 22.39% in Osteopenia and 16.42% in normal bone mass). The correlation between age, gender, body mass index, visual analogue scale score and osteoporosis was statistically significant.

Conclusion

Osteoporosis is common in people waiting for UKA, but screening and treatment rates are low. Female patients of advanced age and low weight combined with significant pain should be considered for osteoporosis screening and appropriate treatment before UKA.

Effect of psoas and gluteus medius muscles attenuation on hip fracture type

INTRODUCTION

Sarcopenia is defined as a progressive loss of muscle mass and function with increased age. The measurement of muscle mass and attenuation on the axial computed tomography (CT) scan has been reported to be a good indicator for sarcopenia in previous literature. This study aimed to compare muscle mass between the intertrochanteric fracture and femoral neck fracture groups by accurately measuring muscle mass around the hip joint using a CT scan.

METHODS

The cases were matched according to age and gender on a 1-to-1 basis. As a result, a total of 400 patients, 200 patients in each group with the same age and gender characteristics, were included in the study. At the disc of L4-L5 level, the cross-sectional area (CSA) of the psoas muscle was evaluated, and at the disc of L5-S1 level, the CSA of the psoas, iliacus and gluteus medius muscles were evaluated. In addition, attenuation was evaluated using the average Hounsfield Unit (HU) for the specific area.

RESULTS

The mean age of 400 patients (262 females, 138 male) included in the study was 78.49 ± 7.67 years. It was observed that the mean HU values of the patients in the femoral neck fracture group were significantly higher than the intertrochanteric fracture group (p < 0.001, p = 0.008; respectively). At the same time, the mean HU values of the gluteus medius muscle were higher in the femoral neck fracture group (p < 0.001), but in contrast with the psoas muscle, the CSA values of gluteus medius muscle were significantly higher in the intertrochanteric fracture group (p = 0.017).

CONCLUSIONS

Fatty degeneration of the psoas muscle among the muscles around the hip may affect the type of hip fracture. Elderly patients with strong psoas muscles may experience femoral neck fracture due to contraction and torsion during falling.

Relationship Between Acetabular Hounsfield Unit Values and Periprosthetic Fractures in Cementless Total Hip Arthroplasty: A Matched Case-Control Study

Background

The association between regional bone status around the acetabulum and the incidence of intraoperative acetabulum fractures has not been extensively studied. We investigated the association of Hounsfield unit (HU) values on computed tomography in the regions of the acetabulum with periprosthetic fractures.

Methods

We retrospectively reviewed records of 301 consecutive patients who underwent cementless total hip arthroplasty between October 2016 and December 2020. Using preoperative computed tomography taken in the 4 weeks preceding total hip arthroplasty, we measured HU values in 4 different acetabulum regions (anterior, medial, posterior, and superior). After identifying fracture cases, we identified a control group—matched in terms of sex, age, and preoperative diagnosis—selected in a 1:3 ratio among nonfracture patients treated in the same inclusive period. As the average HU values differed by region, we used the standardized value to compare fracture-site HUs. We ranked the standardized HU values for each acetabular site and compared the fracture site rank between the groups.

Results

Intraoperative acetabular fractures were observed in 10 hips (3.2%), occurring most frequently in the superior region (40%). The standardized HU values of the fracture site were statistically lower in the fracture group (P = .039). We compared the ranks of the standardized HUs of the fractured parts with those of the corresponding parts in the control group; the fracture site had a significantly lower standardized HU rank, indicating that fractures tended to occur in the relatively “weaker-than-expected” parts.

Conclusions

Periprosthetic fractures tended to occur at relatively weak parts of the acetabulum.

Minimally invasive lumbopelvic stabilization of sacral fragility fractures in immobilized geriatric patients: feasibility and early return to mobility

INTRODUCTION

In an aging society, the incidence of sacral fragility fractures is increasing and diagnosis is often delayed. Immobilization has devastating consequences especially in elderly patients. Short-term mobilization of these patients is crucial. The aim of this study is to evaluate the early return to mobility of immobilized geriatric patients with sacral fragility fractures treated with minimally invasive lumbopelvic stabilization.

METHODS

Retrospective analysis of thirteen consecutive patients (13 females) which could not be mobilized with conservative treatment, and thus were treated with minimally invasive lumbopelvic stabilization. Pain intensity measurement on an 11-point Numeric Rating Scale (NRS), Tinetti Mobility Test (TMT), and Timed Up and Go Test (TUGT) were performed preoperatively and 4 weeks postoperatively. Surgical and medical complications were analyzed.

RESULTS

Mean age at surgery was 83.92 ± 6.27 years and mean ASA score was 2.77 ± 0.42. NRS improved from a mean of 7.18 ± 0.98 preoperatively to a mean of 2.45 ± 0.93 4 weeks postoperatively (Ρ < 0.001). TMT score improved from a mean of 4.15 ± 3.67 preoperatively to a mean of 16.39 ± 4.61 4 weeks postoperatively (Ρ < 0.001). Due to immobilization, patients were not able finish TUGT preoperatively. Four weeks postoperatively TUGT reached a mean of 31.1 ± 11.08 s. There were two surgical complications (one wound healing disorder, one rod dislocation) in two patients that required revision surgery. Two patients developed pneumonia postoperatively.

CONCLUSIONS

Minimally invasive lumbopelvic stabilization of sacral fragility fractures is feasible in geriatric patients. Early mobilization of these patients is possible after surgery. The rate of complications is acceptable.

Prevalence and Treatment of Osteoporosis Prior to Elective Shoulder Arthroplasty

Introduction:

The rate of preoperative osteoporosis in lower extremity arthroplasty is 33%. The prevalence of osteoporosis in shoulder arthroplasty patients is inadequately studied. The purpose of this study was to (1) determine the prevalence of osteoporosis in patients undergoing elective shoulder arthroplasty, (2) report the percentage of patients having dual-energy x-ray absorptiometry (DEXA) testing before surgery, and (3) determine the percentage of patients who have been prescribed osteoporosis medications within 6 months before or after surgery.

Methods:

This retrospective case series included all adults aged 50 years and older who underwent elective shoulder arthroplasty at a single tertiary care center over an 8-year period. National Osteoporosis Foundation (NOF) criteria for screening and treatment were applied.

Results:

Two hundred fifty-one patients met the inclusion criteria; 171 (68%) met the criteria for DEXA testing, but only 31 (12%) had this testing within 2 years preoperatively. Eighty patients (32%) met the NOF criteria for receipt of pharmacologic osteoporosis treatment, and 17/80 (21%) received a prescription for pharmacotherapy.

Discussion:

Two-thirds of elective shoulder arthroplasty patients meet the criteria to have bone mineral density measurement done, but less than 20% have this done. One in three elective shoulder arthroplasty patients meet the criteria to receive osteoporosis medications, but only 20% of these patients receive therapy.

Association of Perioperative Computed Tomography Hounsfield Units and Failure of Femoral Neck Fracture Fixation

OBJECTIVES

To determine whether Hounsfield units (HUs) measured on perioperative computed tomographic scans are associated with radiographic outcomes and reoperations after femoral neck fracture fixation.

DESIGN

Retrospective cohort study.

SETTING

Level I trauma center.

PATIENTS

One hundred fourteen patients age ≥18 years, who presented to a Level I trauma center, and who underwent surgical fixation of intracapsular femoral neck fracture and had perioperative computed tomographic scans and adequate follow-up.

INTERVENTION

None.

MAIN OUTCOME MEASUREMENTS

Screw penetration, femoral neck shortening >5 mm, and revision surgery.

RESULTS

A median follow-up was 23 months. An HU measurement of the femoral head was significantly associated with screw penetration and femoral neck shortening but not revision surgery. Patients with middle femoral head HU measurements <146 had 17 times (95% confidence interval: 4.32-78.9, P < 0.001) increased odds of screw penetration. Greater than 5 mm shortening was seen in patients with HUs <212.5 in the low head section by an odds ratio of 7.8 (95% confidence interval: 2.15-33.0, P = 0.014).

CONCLUSION

Outcome differences regarding screw penetration and femoral neck shortening related to the HU or densities of femoral head and neck at the time of fracture are significant. These findings can help the clinician with developing a treatment plan for either arthroplasty or fixation of a femoral neck fracture based on objective bone quality measurements rather than relying on an arbitrary age recommendation.

LEVEL OF EVIDENCE

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

Use of Bone Health Evaluation in Orthopedic Surgery: 2019 ISCD Official Position

This position development conference (PDC) Task Force examined the assessment of bone status in orthopedic surgery patients. Key questions included which orthopedic surgery patients should be evaluated for poor bone health prior to surgery and which subsets of patients are at high risk for poor bone health and adverse outcomes. Second, the reliability and validity of using bone densitometry techniques and measurement of specific geometries around the hip and knee before and after arthroplasty was determined. Finally, the use of computed tomography (CT) attenuation coefficients (Hounsfield units) to estimate bone quality at anatomic locations where orthopedic surgery is performed including femur, tibia, shoulder, wrist, and ankle were reviewed. The literature review identified 665 articles of which 198 met inclusion exclusion criteria and were selected based on reporting of methodology, reliability, or validity results. We recommend that the orthopedic surgeon be aware of established ISCD guidelines for determining who should have additional screening for osteoporosis. Patients with inflammatory arthritis, chronic corticosteroid use, chronic renal disease, and those with history of fracture after age 50 are at high risk of osteoporosis and adverse events from surgery and should have dual energy X-ray absorptiometry (DXA) screening before surgery. In addition to standard DXA, bone mineral density (BMD) measurement along the femur and proximal tibia is reliable and valid around implants and can provide valuable information regarding bone remodeling and identification of loosening. Attention to positioning, selection of regions of interest, and use of special techniques and software is required. Plain radiographs and CT provide simple, reliable methods to classify the shape of the proximal femur and to predict osteoporosis; these include the Dorr Classification, Cortical Index, and critical thickness. Correlation of these indices to central BMD is moderate to good. Many patients undergoing orthopedic surgery have had preoperative CT which can be utilized to assess regional quality of bone. The simplest method available on most picture archiving and communications systems is to simply measure a regions of interest and determine the mean Hounsfield units. This method has excellent reliability throughout the skeleton and has moderate correlation to DXA based on BMD. The prediction of outcome and correlation to mechanical strength of fixation of a screw or implant is unknown.

Osteoporosis Is Common and Undertreated Prior to Total Joint Arthroplasty

BACKGROUND

Osteoporosis is common in total joint arthroplasty (TJA) patients and likely contributes to the increasing incidence of periprosthetic fracture. Despite this, the prevalence of osteoporosis in patients undergoing elective TJA is inadequately studied. We hypothesize that preoperative osteoporosis is underrecognized and undertreated in the TJA population. The purpose of this study is to report preoperative osteoporosis screening rates and prevalence prior to TJA and rates of pharmacologic osteoporosis treatment in the TJA population.

METHODS

This is a retrospective case series of 200 consecutive adults (106F, 94M) aged 48-92 years who underwent elective TJA (100 total hip, 100 total knee) at a single tertiary-care center. Charts were retrospectively reviewed to determine preoperative osteoporosis risk factors, prior dual-energy X-ray absorptiometry (DXA) testing, and prior osteoporosis pharmacotherapy. Fracture risk was estimated using the Fracture Risk Assessment Tool and the National Osteoporosis Foundation criteria for screening and treatment were applied to all patients.

RESULTS

One hundred nineteen of 200 patients (59.5%) met criteria for DXA testing. Of these 119, 21 (17.6%) had DXA testing in the 2 years prior to surgery, and 33% had osteoporosis by T-score. Forty-nine patients (24.5%) met National Osteoporosis Foundation criteria for pharmacologic osteoporosis treatment, and 11 of these 49 received a prescription for pharmacotherapy within 6 months before or after surgery.

CONCLUSION

One quarter of TJA patients meet criteria to receive osteoporosis medications, but only 5% receive therapy preoperatively or postoperatively. This lack of preoperative osteoporosis screening and treatment may contribute to periprosthetic fracture risk.

Adaptive change in temporomandibular joint tissue and mandibular morphology following surgically induced anterior disc displacement by bFGF injection in a rabbit model

PURPOSE

The purpose of this study was to examine the effect of injecting basic fibroblast growth factor following surgical induced anterior disc displacement in temporomandibular joints (TMJ).

MATERIALS AND METHODS

Adult male Japanese white rabbits (n = 16; 2.0-2.5 kg; 10 weeks old) were assigned to experimental and control groups. In the experimental group, anterior disc displacement was induced in the bilateral TMJ. Recombinant human basic fibroblast growth factor (rh bFGF) 0.1 μg/1 μL aqueous solution was injected into the left retro-discal connective tissue close to the disc (ADL group), and saline alone was injected into the same site on the right (ADR group). In the control group, a sham operation without disc position change was performed in the bilateral TMJ (CR group and CL group). Four animals from the experimental (ADR and ADL) and control (CR and CL) groups were sacrificed at 1 and 12 weeks postoperatively to evaluate the mandibular morphology and computed tomographic (CT) value of the condylar head, using 3 dimensional computed tomography. Furthermore, cartilage layers and disc tissue were examined histologically.

RESULTS

Regarding CT value at the 0° site of the condylar surface, ADR showed the lowest value after 1 week (P = 0.0325). However, there were no significant differences among the 4 groups regarding CT values at the other degree sites after 1 and 12 weeks. Regarding mandibular length, ADR showed the lowest value after 12 weeks (P = 0.0079). In condylar width, ADR showed the lowest value after 1 week (P = 0.0097).

CONCLUSION

This study suggested that surgically induced anterior disc displacement could affect condylar morphology in the early stage, and could decrease mandibular length in the late stage. However, bFGF injection into the TMJ might prevent the degenerative change derived from anterior disc displacement and inhibition of sequential mandibular growth.