Loss of bone mineral of the hip and proximal tibia following rupture of the Achilles tendon

Reduction in femoral neck and total hip bone mineral density following hospitalisation for diabetes-related foot ulceration

Management of diabetes-related foot ulceration (DFU) includes pressure offloading resulting in a period of reduced activity. The metabolic effects of this are unknown. This study aims to investigate changes in bone mineral density (BMD) and body composition 12 weeks after hospitalisation for DFU. A longitudinal, prospective, observational study of 22 people hospitalised for DFU was conducted. Total body, lumbar spine, hip and forearm BMD, and total lean and fat mass were measured by dual-energy X-ray absorptiometry (DXA) during and 12 weeks after hospitalisation for DFU. Significant losses in total hip BMD of the ipsilateral limb (- 1.7%, p < 0.001), total hip BMD of the contralateral limb (- 1.4%, p = 0.005), femoral neck BMD of the ipsilateral limb (- 2.8%, p < 0.001) and femoral neck BMD of the contralateral limb (- 2.2%, p = 0.008) were observed after 12 weeks. Lumbar spine and forearm BMD were unchanged. HbA1c improved from 75 mmol/mol (9.2%) to 64 mmol/mol (8.0%) (p = 0.002). No significant changes to lean and fat mass were demonstrated. Total hip and femoral neck BMD decreased bilaterally 12 weeks after hospitalisation for DFU. Future research is required to confirm the persistence and clinical implications of these losses.

A case-control pilot study of stress fracture in adolescent girls: the discriminative ability of two imaging technologies to classify at-risk athletes

Since stress fractures are common among adolescent athletes, it is important to identify bone assessment tools that accurately identify risk. We investigated the discriminative ability of two imaging technologies to classify at-risk athletes. Findings suggested that peripheral quantitative computed tomography (pQCT) has the ability to distinguish differences in bone structure in injured vs. uninjured limbs.

INTRODUCTION

Given the high stress fracture (SFX) prevalence among adolescent girls, an understanding of the most informative assessment tools to identify SFX risks are required. We investigated the discriminative ability of pQCT vs. dual-energy X-ray absorptiometry (DXA) to classify athletes with or without SFX.

METHODS

Twelve adolescent athletes diagnosed with a lower-extremity SFX were compared with 12 matched controls. DXA measured areal bone mineral density (aBMD) and content of the total body, and lumbar spine. Bilateral tibiae were assessed with pQCT. At the metaphysis (3%), total density (ToD), trabecular density (TrD), trabecular area (TrA), and estimated bone strength in compression (BSIc), and at the diaphysis (38% and 66%), total bone area (ToA), cortical density (CoD), cortical area (CoA), estimated bone strength in torsion (SSIp), and peri- and endocortical and muscle area (MuA) were obtained. Cortical bone mass/density around the center of mass and marrow density (estimate of adiposity) were calculated using ImageJ software. General estimated equations adjusting for multiple comparisons (Holm-Bonferroni method) were used to compare means between (1) injured limb of the case athletes vs. uninjured limb of the control athletes and (2) uninjured limb of the case athletes vs. uninjured limbs of the controls and injured vs. uninjured limb of case athletes with a SFX.

RESULTS

aBMD and content showed no significant differences between cases and controls. When comparing the injured vs. uninjured leg in the case athletes by pQCT at the 3% tibia, unadjusted TrD, total density, and BSIc were significantly lower (p < 0.05) in the injured vs. uninjured leg. Marrow density at the 66% site was 1% (p < 0.05) lower in the injured vs. uninjured leg.

CONCLUSIONS

These preliminary data in athletes with SFX suggest that pQCT has the ability to distinguish differences in bone structure in injured vs. uninjured limbs. No discriminative bone parameter classifications were identified between adolescent athletes with or without SFX.

Increasing age in Achilles rupture patients over time

BACKGROUND

The changing demographics of Achilles tendon rupture (ATR) patients have not fully been investigated. However, there has been a general suspicion that this injury is occurring in an increasingly older population, in terms of mean age. The aim of this study was to objectively show an increase in age in Achilles tendon rupture patients over time.

METHODS

Published literature on Achilles tendon ruptures was searched for descriptive statistics on the demographics of patients in the studies, specifically mean and median age of Achilles tendon rupture patients, gender ratio, percentage of athletics-related injuries, percentage of smokers, and BMI. Linear regression analyses were performed to determine the trend of patient demographics over time. A Welch one-way ANOVA was carried out to identify any possible differences in data obtained from different types of studies.

RESULTS

The patient demographics from 142 studies were recorded, with all ATR injuries occurring between the years 1953 and 2014. There was no significant difference in the mean age data reported by varying study types, i.e. randomized controlled trial, cohort study, case series, etc. (P=0.182). There was a statistically significant rise in mean age of ATR patients over time (P<0.0005). There was also a statistically significant drop in percentage of male ATR patients (P=0.02). There is no significant trend for percentage of athletics-related injuries, smoking or BMI.

CONCLUSION

Since 1953 to present day, the mean age at which ATR occurs has been increasing by at least 0.721 years every five years. In the same time period, the percentage of female study patients with ATR injuries has also been increasing by at least 0.6% every five years.

LEVEL OF EVIDENCE

Level III; Retrospective cohort study.

Bone mineral decreases in the calcanei in men after arthroscopic shoulder surgery: a prospective study over 5 years

PURPOSE

It is well known that injuries and surgical procedures in the lower extremities affect bone mineral both in the injured limb and in the contralateral limb. The possible effect on bone mineral after upper extremity surgery is not well studied, and the aim of this study was to study the effect on bone mineral in the calcanei after arthroscopic shoulder surgery.

METHODS

Twenty-two men scheduled for arthroscopic shoulder surgery underwent bone mineral area (BMA) mass measurements in both calcanei using the Calscan DXL device prior to surgery and after 6, 18, 36 and 60 months. On every occasion, the Tegner activity score and EuroQoL 5-dimensions (EQ-5D) were assessed.

RESULTS

During 5 years, there was a significant decrease in the BMA in both calcanei (p = 0.003). The Tegner activity score decreased from preinjury to the operation and did not increase significantly after the operation. The EQ-5D increased significantly after the operation.

CONCLUSION

The bone mineral in the calcanei in men during the 5-year study period decreased more than the expected age-dependent decline after arthroscopic shoulder surgery. There was an increase in health-related quality of life as measured with the EQ-5D after arthroscopic Bankart reconstruction.

LEVEL OF EVIDENCE

Case-control study, Level III.

Low bone mineral density is not related to failure in femoral neck fracture patients treated with internal fixation

BACKGROUND AND PURPOSE

Internal fixation (IF) in femoral neck fractures has high reoperation rates and some predictors of failure are known, such as age, quality of reduction, and implant positioning. Finding new predictors of failure is an ongoing process, and in this study we evaluated the importance of low bone mineral density (BMD).

PATIENTS AND METHODS

140 consecutive patients (105 females, median age 80) treated with IF had a dual-energy X-ray absorptiometry (DXA) scan of the hip performed median 80 days after treatment. The patients' radiographs were evaluated for fracture displacement, implant positioning, and quality of reduction. From a questionnaire completed during admission, 2 variables for comorbidity and walking disability were chosen. Primary outcome was low hip BMD (amount of mineral matter per square centimeter of hip bone) compared to hip failure (resection, arthroplasty, or new hip fracture). A stratified Cox regression model on fracture displacement was applied and adjusted for age, sex, quality of reduction, implant positioning, comorbidity, and walking disability.

RESULTS

49 patients had a T-score below -2.5 (standard deviation from the young normal reference mean) and 70 patients had a failure. The failure rate after 2 years was 22% (95% CI: 12-39) for the undisplaced fractures and 66% (CI: 56-76) for the displaced fractures. Cox regression showed no association between low hip BMD and failure. For the covariates, only implant positioning showed an association with failure.

INTERPRETATION

We found no statistically significant association between low hip BMD and fixation failure in femoral neck fracture patients treated with IF.

Restoration of strength despite low stress and abnormal imaging after Achilles injury

PURPOSE

To determine the usefulness of clinical imaging in predicting the mechanical properties of rabbit Achilles tendons after acute injury.

METHODS

We created a 2 x 7-mm full-thickness central tendon defect in one Achilles tendon of healthy rabbits. Rabbits in groups of 10 were killed immediately and 4 and 8 wk after surgery (n = 30). We then performed magnetic resonance (MR) imaging, ultrasonography (US), bone mineral densitometry (BMD), and mechanical testing to failure using a dual-cryofixation assembly on experimental and contralateral tendons. The main outcome measures included tendon dimensions, optical density (OD) of T1-weighted, proton density (PD), and T2-weighted MR sequences, US focal abnormalities, BMD of the calcaneus, and stress and peak load to failure.

RESULTS

On MR imaging and US, all dimensions of the injured tendons after 2 wk and more were greater than those of the contralateral tendons (P < 0.05). The mean T1-weighted OD was greater at 4 wk (256 +/- 53) and 8 wk (184 +/- 24) than immediately after surgery (149 +/- 15). Mechanical stress was markedly lower in the experimental than in the contralateral tendons at both 4 wk (39 +/- 9 vs 77 +/- 16 N x mm(-2)) and 8 wk (58 +/- 6 vs 94 +/- 26 N x mm(-2); P < 0.05). Mean peak load to failure was significantly lower immediately after surgery (332 +/- 128 N) than at 4 and 8 wk (712 +/- 106 and 836 +/- 90 N, respectively). Both high T1-weighted OD (r = -0.73) and PD OD (r = -0.69) correlated with lower mechanical stress (P < 0.05). In the experimental tendons, higher T1-weighted OD correlated with lower peak load (r = -0.46; P < 0.05).

CONCLUSIONS

Normal peak loads 4 wk after injury were withstood by an enlarged tendon of lower stress. These findings support progressive physical loading 4 wk after an Achilles tendon injury. T1-weighted OD constituted a marker of tendon mechanical recovery.

Mechanical alterations of rabbit Achilles' tendon after immobilization correlate with bone mineral density but not with magnetic resonance or ultrasound imaging

OBJECTIVE

To assess the usefulness of magnetic resonance imaging (MRI), ultrasound (US) imaging, or bone mineral density (BMD) in predicting the mechanical properties of immobilized rabbit Achilles' tendons.

DESIGN

Experimental study.

SETTING

Basic university laboratory.

ANIMALS

Twenty-eight rabbits.

INTERVENTIONS

Twelve rabbits had 1 hindlimb casted for 4 weeks and 10 rabbits were casted for 8 weeks. Contralateral legs and 12 normal hindlimbs served as controls.

MAIN OUTCOME MEASURES

Achilles' tendon dimensions on MRI and US, T1- and T2-signal intensities on MRI, classification of abnormalities on MRI and US; BMD of the calcaneus with dual-energy x-ray absorptiometry. Biomechanic measures consisted of peak load, stiffness, and stress. Imaging variables were correlated with biomechanic alterations.

RESULTS

Immobilized Achilles' tendons were weaker and showed decreased mechanical stress compared with their contralateral legs and controls (all P<.05). MRI and US revealed larger Achilles' tendons after immobilization. However, neither increased MRI nor US signal abnormality was found. BMD was lower in immobilized calcanei and larger in contralateral legs than controls. Only BMD correlated with both the decreased peak load (R2=.42, P<.05) and stress (R2=.54, P<.05) of immobilized Achilles' tendon.

CONCLUSIONS

This study established weakened mechanical properties of immobilized Achilles' tendons. BMD of the calcaneus, but not MRI and US, was predictive of the mechanical alterations in immobilized Achilles' tendons. BMD may be a useful biomarker to monitor disease and recovery in Achilles' tendons.

Comparison of the relative benefits of 2 versus 10 days of soft collar cervical immobilization after acute whiplash injury

OBJECTIVE

To investigate the effects of 2-day and 10-day immobilization of the cervical spine on pain, range of motion (ROM), and disability of patients with Quebec Task Force (QTF) grade II whiplash injuries.

DESIGN

Randomized controlled trial.

SETTING

University hospital emergency department.

PARTICIPANTS

Seventy patients with acute QTF grade II whiplash injuries.

INTERVENTIONS

At the intake examination within 24 hours after the whiplash trauma, the patients were randomized to 2 therapy groups (2-d or 10-d immobilization with a soft cervical collar). All patients received pain drugs (nonsteroidal anti-inflammatory drugs) and after 7 days, all patients started a standardized physiotherapy program 2 to 3 times a week.

MAIN OUTCOME MEASURES

Patients' pain and disability scores were assessed using visual analog scales and ROM was assessed using a goniometer. All parameters were measured within 24 hours after injury and after 2 and 6 months.

RESULTS

After 2 months, the different periods of immobilization (2d or 10d) were associated with comparable improvements in pain symptoms (median, 4.60 vs 4.65), ROM (median, 100.0 degrees vs 117.5 degrees ), and disability score (median, 4.90 vs 5.15). No statistically significant differences could be identified between the 2 treatment groups. After 6 months, persistent pain was reported by 4 patients in each group (12.5%).

CONCLUSIONS

In patients with QTF grade II whiplash injuries, there is no short- or long-term difference between 2-day and 10-day immobilization with a cervical collar in terms of pain, ROM, or disability.

Bone and Lean Tissue Changes Following Cranial Cruciate Ligament Transection and Stifle Stabilization

Following cranial cruciate ligament transection and extracapsular stabilization, dual-energy X-ray absorptiometry was used to analyze bone mineral content and lean tissue mass in the surgical and nonsurgical legs (n=14) at 0, 2, 4, and 8 weeks, and to evaluate bone mineral content and bone mineral density (BMD) of the proximal, mid-, and distal tibia of both the surgical and nonsurgical legs (n=15) at 0, 5, and 10 weeks. There was significant loss of bone mineral content and lean tissue in the surgical leg compared to the nonsurgical leg. Significant loss in bone mineral content and BMD was detected in the tibia of the surgical leg and was most pronounced in the metaphyseal region.

Thawing of frozen calcaneus bone specimens has no effect on the bone mineral density using dual energy x-ray absorptiometry: a study in rabbits and humans

The purpose of this paper is to study whether the deep freezing of bone and later thawing affects the bone mineral density (BMD) measurement. We used 56 calcanei from 28 adult female New Zealand white rabbits and 102 human calcanei from 51 donors post-mortem (27 men and 24 women, age 30-89). Dual energy x-ray absorptiometry evaluated BMD of the frozen specimen and of the thawed specimen. A main analysis compared BMD of each specimen in the frozen and thawed states. The mean BMD of 224 areas of frozen rabbits' calcanei was 0.31 +/- 0.08 g cm(-2) (95% confidence interval (CI) from 0.30 to 0.32 g cm(-2)) while the mean BMD of thawed rabbits' calcanei was 0.31 +/- 0.08 g cm(-2) (95% CI from 0.30 to 0.32 g cm(-2); paired t-test p > 0.01). The mean BMD of 306 areas of frozen human calcaneus was 0.73 +/- 0.22 g cm(-2) (95% CI from 0.70 to 0.76 g cm(-2)) while the mean BMD of thawed human calcaneus was 0.73 +/- 0.22 g cm(-2) (95% CI from 0.70 to 0.76 g cm(-2); p > 0.01). For both the rabbit and the human calcanei, a Bland-Altman analysis showed a mean difference between the BMD in the frozen and thawed states of 0.00 (limits of agreement, rabbit: -0.07 to 0.08 g cm(-2), human: -0.16 to 0.21 g cm(-2)). A high correlation was observed between calcaneus BMD in the frozen and thawed states (r = 0.94, 0.97, 0.92 and 0.99 respectively in all rabbit calcanei, all human calcanei, immobilized rabbit calcanei and osteopenic human calcanei, all p < 0.01). Bone mineral density is not affected by deep freezing and later thawing of the specimen. Therefore, the specimens need not be thawed to obtain valid and precise BMD measurement. These results are relevant to general musculoskeletal as well as osteoporosis research where the specimens undergo multiple tests in series.

Bone mineral density, gait analysis, and patient satisfaction, before and after ankle arthroplasty

Bone mineral density (BMD) and patient satisfaction were measured and gait analysis was performed in patients treated with unilateral dual-coated ankle arthroplasty. The study comprised 14 patients (eight women and six men) measured preoperatively and at a median of 15 (range, 12-26) months after surgery. BMD was measured bilaterally in the distal tibia and in the calcaneus. A plantar pressure analysis was performed, including foot contact duration and a new index for describing the ground reaction force curve called the Valley Index (VI). The patients also evaluated their level of pain, ability to cope with daily activities, adaptation of shoes, and walking ability before surgery and at follow-up on a visual analogue scale (VAS). Bone mass significantly increased adjacent to the tibial part of the prosthesis. The patients experienced less pain and improved walking and performance in daily activities. There was also a decrease in foot contact duration as well as an increase in VI and ankle range of motion. Change in bone mass was the variable that correlated best with the patients' evaluation of the general outcome of ankle arthroplasty. Correlations among other variables are described. The study concluded that a fairly simple analysis of the ground reaction force curve, bone mass measurements, and VAS can demonstrate that ankle arthroplasty is able to normalize gait, decrease foot contact duration, increase bone mass, and reduce pain.