Does the shoe-lace technique aid direct closure of fasciotomy wounds after acute compartment syndrome of the lower leg? A retrospective case-control study.

BACKGROUND AND OBJECTIVE: Tibia fractures are relatively common injuries that are accompanied with acute compartment syndrome in approximately 2% to 20% of cases. Although the shoe-lace technique, where vessel loops are threaded in a crisscross fashion and tightened daily, has been widely used, no studies have compared the shoe-lace technique with the conventional one. The aim of this study was to compare the shoe-lace technique with the conventional technique. METHODS: We identified 359 consecutive patients with intramedullary nailed tibia fracture and complete medical records including outpatient data between April 2007 and April 2015 from electronic patient database of our institute. The use of the shoe-lace technique was compared to conventional one (in which wounds were first left open with moist dressings). Main outcome measurement is direct closure of fasciotomy wounds. RESULTS: From 359 consecutive patients with intramedullary nailed tibia fracture, fasciotomy was performed on 68 (19%) patients. Of these, the shoe-lace technique was used in 47 (69%) patients while in 21 (31%) patients, the shoe-lace technique was not applied. Side-to-side approximation was successful in 36 patients (77%) in the shoe-lace+ group and 7 patients (33%) in the shoe-lace- group (p = 0.002). CONCLUSIONS: The main finding of our comparative study was that the shoe-lace technique seems to ease direct closure of lower leg fasciotomy wounds, and thus reduces the frequency of free skin grafts. Our finding needs to be confirmed in a high-quality randomized controlled trial.

Total hip arthroplasty, combined with a reinforcement ring and posterior column plating for acetabular fractures in elderly patients: good outcome in 34 patients.

Background and purpose - Low-energy acetabulum fractures are uncommon, and mostly occur in elderly patients. Determining the optimal operative treatment for such fractures is challenging. Here we investigated whether acutely performed total hip arthroplasty plus posterior column plating (THA) reduced complications and reoperations compared with open reduction and internal fixation (ORIF) in elderly patients with acetabular fractures. Patients and methods - We retrospectively reviewed the records of 59 patients, > 55 years of age, with complex acetabular fractures, caused by low-energy trauma, treated between January 2008 and September 2017. Of these patients, 34 underwent acute THA, and 25 ORIF alone. Patient and implant survival were compared between groups using Kaplan-Meier survival analysis and Cox multiple regression. Functional outcomes assessed by Oxford Hip Score (OHS) were compared between the THA patients and those 9 ORIF patients who underwent secondary THA due to posttraumatic hip osteoarthritis (OA) during follow-up. Results - Overall patient survival was 90% (95% CI 82-98) at 12 months, and 64% (CI 47-81) at 5 years. Of 25 ORIF patients, 9 required secondary THA due to posttraumatic OA. Large fragments on the weight-bearing acetabular dome upon imaging predicted ORIF failure and secondary THA. The acute THA group and secondary THA group had similar 12-month OHS. Interpretation - Acute THA including a reinforcement ring resulted in fewer reoperations than ORIF alone in elderly patients with acetabular fractures. These findings support acute THA as first-line treatment for complex acetabular fractures in elderly patients.

The effects of loading and estrogen on rat bone growth.

This study evaluated the contributions of locomotive loading and estrogen to the development of diaphysis of rat femur. A randomized 2x2 study design was used. Altogether, 70 female Sprague-Dawley rats were used, of which 10 were euthanized at entry. Of the remaining rats, 16 served as controls, and the rest, 44, underwent a unilateral sciatic neurectomy. The effect of estrogen was removed by ovariectomizing one-half of the neurectomized rats. After 27 wk, the animals were euthanized, and the femora were excised. Irrespective of loading or estrogen, the femur length and mineral mass increased by 142 and 687%, respectively. Axial growth was not modulated either by locomotive loading or estrogen, but the loading resulted in direction-specific changes in the cross-sectional geometry. The estrogen-related gains were evident on the endocortical surface, while the loading-related gains occurred on the periosteal surface. The loading and estrogen were significantly associated with increased bone strength (21 and 15%, respectively) in the mediolateral direction, but not in the anteroposterior direction. Axial growth and accrual of bone mineral mass of the rat femur are largely independent of locomotive loading or estrogen, whereas these factors specifically account for the femur function, as either a mechanical lever or a mineral reservoir for reproduction, respectively.

Pathogenesis of age-related osteoporosis: impaired mechano-responsiveness of bone is not the culprit.

BACKGROUND: According to prevailing understanding, skeletal mechano-responsiveness declines with age and this apparent failure of the mechano-sensory feedback system has been attributed to the gradual bone loss with aging (age-related osteoporosis). The objective of this study was to evaluate whether the capacity of senescent skeleton to respond to increased loading is indeed reduced as compared to young mature skeleton. METHODS AND FINDINGS: 108 male and 101 female rats were randomly assigned into Exercise and Control groups. Exercise groups were subjected to treadmill training either at peak bone mass between 47-61 weeks of age (Mature) or at senescence between 75-102 weeks of age (Senescent). After the training intervention, femoral necks and diaphysis were evaluated with peripheral quantitative computed tomography (pQCT) and mechanical testing; the proximal tibia was assessed with microcomputed tomography (microCT). The microCT analysis revealed that the senescent bone tissue was structurally deteriorated compared to the mature bone tissue, confirming the existence of age-related osteoporosis. As regards the mechano-responsiveness, the used loading resulted in only marginal increases in the bones of the mature animals, while significant exercise-induced increases were observed virtually in all bone traits among the senescent rats. CONCLUSION: The bones of senescent rats displayed a clear ability to respond to an exercise regimen that failed to initiate an adaptive response in mature animals. Thus, our observations suggest that the pathogenesis of age-related osteoporosis is not attributable to impaired mechano-responsiveness of aging skeleton. It also seems that strengthening of even senescent bones is possible--naturally provided that safe and efficient training methods can be developed for the oldest old.

Skeletal effects of estrogen and mechanical loading are structurally distinct.

Estrogen has been suggested to influence skeletal homeostasis by both increasing the sensitivity of the feedback control system for skeletal rigidity and acting directly on bone surfaces. The objective of the present study was to explore the proposed interaction between the skeletal effects of estrogen and locomotion. Thirty 3-week-old littermates of female Sprague-Dawley rats were first randomly assigned into bilateral sham (E(+)) or ovariectomy (E(-)) surgery after which, the left hindlimb each study animal was cast immobilized (L(-)) while the right limb served as locomotively loaded control (L(+)), a classic 2x2 factorial study design. After 8-week study period, femoral neck, femur midshaft and distal metaphysis were analyzed by peripheral quantitative computed tomography (pQCT), microcomputed tomography (microCT), and mechanical testing. The loading-induced effects were virtually identical in the estrogen-replete (E(+)) and estrogen-deplete (E(-)) groups (Femoral neck: +78% vs. +69% in the tCSA, +74% vs. +55% in the tBMC, -6.0% vs. -7.2% in the tBMD, and +33% vs. +58% in the F(max); Femoral midshaft: +6.9% vs. +3.9% in the cCSA, +13% vs. +13% in the tCSA, +23% vs. +16% in the cBMC, +5.2% vs. +5.1% in the cBMD, and +8.0% vs. +8.0% in the F(max), respectively. All comparisons, NS), challenging the alleged modulatory effect of estrogen on skeletal mechanosensitivity. Estrogen did not have an independent effect on the periosteal apposition at any of the evaluated bone regions. Instead, according to its primary reproductive function, the effects of estrogen were restricted to accrual of bone mass only, the stimulus being apparent at the endosteal surface of cortex and trabecular structure of the distal metaphysis. In conclusion, the present results indicate that that the actions of estrogen and loading on bone structure are independent and additive in nature.

Three-point bending of rat femur in the mediolateral direction: introduction and validation of a novel biomechanical testing protocol.

UNLABELLED: Mediolateral three-point bending of the rat midfemur was developed to enable the assessment of the mechanical competence of the elliptic bone cross-section in terms of its widest diameter, the apparent primary direction of bone adaptation to loading. INTRODUCTION: Today, the most commonly used method to characterize the biomechanical properties of appendicular long bones is the three-point bending testing of the midfemur in the anteroposterior (AP) direction. However, as the diameter of the elliptic cross-section of femoral diaphysis is widest in the orthogonal mediolateral (ML) direction, the femoral diaphysis should also show the highest resistance to bending along this direction. The objective of this study was thus to introduce and validate a mechanical testing protocol for femoral midshaft along the ML direction. MATERIALS AND METHODS: To determine the repeatability of the novel testing protocol, 38 pairs of rat femora underwent a comprehensive structural analysis by pQCT followed by ML three-point bending. For comparison of the repeatability, corresponding tests were performed on the femoral neck. To validate the novel testing direction, the left hindlimb of 24 rats was neurectomized for 6 months, whereas the right limb served as an intact control. After excision, one half of these pairs of femora were randomly subjected to three-point bending test in the conventional AP direction and the remaining in the orthogonal ML direction. RESULTS: The precision (CVrms) of breaking load, stiffness, and energy absorption of the femoral midshaft in the ML direction was 3.8%, 6.6%, and 14.5%, respectively. The corresponding values for femoral neck compression test were 7.6%, 17.9%, and 18.7%, respectively. The loading-induced effect on the femoral midshaft (difference between the neurectomized [nonloaded] and contralateral intact [loaded] femur) was +2.2%, +1.9%, and +2.1% in the AP direction and -18.9%, -17.6%, and -20.3% in the ML direction (p < 0.01 for all comparisons), respectively. CONCLUSIONS: Our results show that testing of rat femoral midshaft in the ML direction is a precise and biologically valid method to determine the structural strength of this widely used skeletal site in experimental bone research.

Paricalcitol [19-nor-1,25-(OH)2D2] in the treatment of experimental renal bone disease.

UNLABELLED: Paricalcitol is a less hypercalcemic vitamin D analog that has been shown to suppress secondary hyperparathyroidism and to prevent the associated histomorphometric changes in bone. In this study, we show that paricalcitol also ameliorates the renal insufficiency-induced loss of bone mineral and the mechanical competence of bone. INTRODUCTION: Renal bone disease is a common consequence of chronic renal insufficiency and the associated secondary hyperparathyroidism (SH). Paricalcitol [19-nor-1,25(OH)(2)D(2)] has been shown to ameliorate SH and prevent renal failure-induced histomorphometric changes in bone with minimal calcemic and phosphatemic activity. However, information about its efficacy on restoration of bone structural strength is lacking. In this study, we explored the effects of paricalcitol treatment on bone structure and strength in a model of advanced renal disease. MATERIALS AND METHODS: Forty-five 8-week-old rats were randomly assigned to either surgical 5/6 nephrectomy (NTX) or Sham-operation. After a 15-week postoperative disease progression period, the NTX rats were further allocated to uremic control (NTX) and treatment (NTX + paricalcitol) groups, the latter of which received paricalcitol for the subsequent 12 weeks. After 27 weeks, the animals were killed, plasma samples were collected, and both femora were excised for comprehensive analysis of the femoral neck and midshaft (pQCT and biomechanical testing). RESULTS: High mortality that exceeded 30% was observed in both NTX groups. NTX induced over a 13-fold increase in plasma PTH, whereas this increase was only 5-fold after paricalcitol treatment. At the femoral neck, NTX was associated with an 8.1% decrease (p < 0.05) in vBMD and a 16% decrease in breaking load (p < 0.05) compared with the Sham group, whereas paricalcitol treatment completely prevented these changes. At the femoral midshaft, the NTX resulted in a 6.6% decrease in cortical BMD (p < 0.01 versus Sham), and this change was also prevented by paricalcitol. CONCLUSIONS: Paricalcitol administration prevented renal insufficiency-associated decreases in BMD in the femoral neck and the femoral midshaft and restored bone strength in the femoral neck. Therefore, paricalcitol can efficiently ameliorate renal insufficiency-induced loss of bone mineral and mechanical competence of bone.

Femoral neck response to exercise and subsequent deconditioning in young and adult rats.

UNLABELLED: Aged bones have been considered to have reduced capacity to respond to changes in incident loading. By subjecting young and adult rats to increased loading and subsequent deconditioning, we observed quantitatively similar adaptive responses of bone in these two groups, but young skeletons adapted primarily through geometric changes and adult bones through increased volumetric density. Loss of the exercise-induced bone benefits did not depend on age. INTRODUCTION: Aging has been shown to decrease the sensitivity of the mechanosensory cells of bones to loading-induced stimuli, presumably resulting in not only reduced capacity but also different adaptive mechanism of the aged skeleton to altered loading, as well as poorer capacity to preserve exercise-induced bone benefits. MATERIALS AND METHODS: Fifty young (5-week-old) and 50 adult (33-week-old) male rats were randomized into control and exercise (+deconditioning) groups. After a 14-week progressively intensified running program, one-half of the exercised rats (both young and adult) were killed, and the remaining rats underwent subsequent 14-week period of deconditioning (free cage activity). A comprehensive analysis of the femoral neck was performed using peripheral quantitative computed tomography and mechanical testing. RESULTS: In comparison with the controls, both young and adult exercised rats had significant increases in almost all measured parameters: +25% (p < 0.001) and +10% (not significant [NS]) in the cross-sectional area; +28% (p < 0.001) and +18% (p < 0.001) in bone mineral content; +11% (p < 0.05) and +23% (p < 0.001) in bone mineral density; and +30% (p < 0.01) and +28% (p < 0.01) in the breaking load, respectively. The skeletal responses were not statistically different between the young and adult rats. After the 14-week period of deconditioning, the corresponding exercised-to-controls differences were +17% (p < 0.05) and +10% (NS), +18% (p < 0.05) and +13% (p < 0.05), +2% (NS) and +2% (NS), and +11% (NS) and +6% (NS), respectively. Again, the response differences were not significant between the age groups. CONCLUSION: Quantitatively, the capacity of the young and adult skeleton to adapt to increased loading was similar, but the adaptive mechanisms appeared different: growing bones seemed to primarily display geometric changes (increase in bone size), whereas the adult skeleton responded mainly through an increase in density. Despite this apparent difference in the adaptive mechanism, aging did not modulate the ability of the skeleton to preserve the exercise-induced bone gain, because the bone loss was similar in the young and adult rats after cessation of training.

The bone gain induced by exercise in puberty is not preserved through a virtually life-long deconditioning: a randomized controlled experimental study in male rats.

To investigate the controversial issue whether exercise-induced positive effects on bone can be maintained after cessation of exercise, 100 5-week-old male Sprague-Dawley rats were used to assess the effects of long-term exercise (EX, treadmill running) and subsequent deconditioning (DC, free cage activity) on the femoral neck and femoral midshaft. At entry, the rats were randomly assigned into eight groups: four control groups (C14, C28, C42, and C56), and four exercise groups (EX, EX + DC14, EX + DC28, and EX + DC42). Rats in the exercise groups were first subjected to a 14-week period of progressively intensifying running, after which the rats of group EX were killed and the remaining exercise groups (EX + DC14, EX + DC28, and EX + DC42) were allowed to move freely in their cages for a subsequent deconditioning period of 14, 28, or 42 weeks, whereas control rats were kept free in their cages for the entire study period (0-56 weeks) and killed with their respective exercise group. At each time point, a comprehensive analysis of the femoral neck and midshaft characteristics (peripheral quantitative computed tomography analysis and fracture load [Fmax]) was performed. In comparison with their age-matched controls, 14 weeks of treadmill training resulted in significant (p < 0.05) increases in all measured femoral neck parameters of the growing male rats (i.e., +25% in total cross-sectional area [tCSA], +28% in total bone mineral content [tBMC], +11% in total bone mineral density [tBMD], and +30% in Fmax). On the contrary, no exercise-induced positive effects were seen in femoral midshaft. The exercise-induced benefits in the femoral neck were partially maintained during the deconditioning period of 14 weeks, the tCSA being + 17%, tBMC + 18% (both p < 0.05), and the Fmax + 11% (p = 0.066) higher in the exercised group than control group. However, after 42 weeks of deconditioning, these benefits were eventually lost. In conclusion, exercise through the period of the fastest skeletal growth results in significant improvements in size, mineral mass, and strength of the femoral neck of male rats. However, these exercise-induced bone benefits are eventually lost if exercise is completely ceased, and thus, continued training is probably needed to maintain the positive effects of youth exercise into adulthood. Further studies should focus on assessing the minimal level of activity needed to maintain the exercise-induced bone gains.