Limb Immobilization Research Articles

Physiologic effects of long-term immobilization of the equine distal limb.

To describe the effects of distal limb immobilization and remobilization in the equine metacarpophalangeal joint. Randomized, prospective experimental study. Eight healthy, skeletally mature horses. One forelimb of each horse was immobilized in a fiberglass cast for 8 weeks; this was followed by 12 weeks of a treadmill-based training program after the cast had been removed. Clinical examinations, radiography, computed tomography (CT), nuclear scintigraphy, MRI, and histomorphometry were used to examine the third metacarpal (MC3), proximal phalanx, proximal sesamoid bones, and associated soft tissues in each horse. Serum and synovial fluid were collected for biomarker analyses. Distal limb immobilization resulted in persistent lameness (P < .001), effusion (P = .002), and a decreased range of motion (P = .012) as well as radiographically visible fragments (P = .036) in the cast forelimb. Bone density was decreased (P < .001) in MC3 according to CT, and trabecular bone fluid was increased (P < .001) according to MRI in the cast forelimb. The cast forelimbs had a change (P = .009) in the appearance of the deep digital flexor tendon according to MRI immediately after removal of the cast. Numerous clinical, radiographic, CT, and MR abnormalities were visible at the end of the study period. Eights weeks of cast immobilization induced changes in bone, cartilage, and periarticular soft tissues that were not reversed after 12 weeks of remobilization. Cast application should be used judiciously in horses with musculoskeletal injuries, balancing appropriate stabilization with potential morbidity secondary to cast placement.

Long-term limb immobilization modulates inhibition-related electrophysiological brain activity

The effect of long-term immobilization on the motor system has been described during motor preparation, imagination or execution, when the movement has to be performed. But, what happens when the movement has to be suppressed? Does long-term limb immobilization modulate physiological responses underlying motor inhibition? Event-related potentials (ERPs) were recorded in healthy participants performing a Go/Nogo task, either with both hands free to respond (T1/T4: before/after the immobilization) or when left-hand movements were prevented by a cast (T2: as soon as the cast was positioned; T3: after one week of immobilization). In the right (control) side, N140, N2, and P3 components showed the expected greater amplitude in Nogo than in Go trials, irrespective of the timepoint. On the contrary, in the left (manipulated) side, each component of the ERP responses to Nogo trials showed specific differences across timepoints, suggesting that the inhibition-related EEG activity is significantly reduced by the presence of the cast and the duration of the immobilization. Furthermore, inhibition-related theta band activity to Nogo stimuli decreased at post-immobilization blocked session (T3-blocked). Altogether these findings can be interpreted as a consequence of the plastic changes induced by the immobilization, as also demonstrated by the cast-related corticospinal excitability modulation (investigated by using TMS) and by the decreased beta band in response to Go and Nogo trials. Thus, only if we are free to move, then inhibitory responses are fully implemented. After one week of immobilization, the amount of inhibition necessary to block the movement is lower and, consequently, inhibitory-related responses are reduced.

Muscle Disuse Atrophy Caused by Discord of Intracellular Signaling.

Significance: Regular contractile activity plays a critical role in maintaining skeletal muscle morphological integrity and physiological function. If the muscle is forced to stop contraction, such as during limb immobilization (IM), the IGF/Akt/mTOR signaling pathway that normally stimulates protein synthesis and inhibits proteolysis will be suppressed, whereas the FoxO-controlled catabolic pathways such as ubiquitin-proteolysis and autophagy/mitophagy will be activated and dominate, resulting in muscle fiber atrophy. Recent Advances: Mitochondria occupy a central position in the regulation of both protein synthesis and degradation through several redox-sensitive pathways, including peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), mitochondrial fusion and fission proteins, mitophagy, and sirtuins. Prolonged IM downregulates PGC-1α due to AMPK (5'-AMP-activated protein kinase) and FoxO activation, thus decreasing mitochondrial biogenesis and causing oxidative damage. Decrease of mitochondrial inner membrane potential and increase of mitochondrial fission can trigger cascades of mitophagy leading to loss of mitochondrial homeostasis (mitostasis), inflammation, and apoptosis. The phenotypic outcomes of these disorders are compromised muscle function and fiber atrophy. Critical Issues: Given the molecular mechanism of the pathogenesis, it is imperative that the integrity of intracellular signaling be restored to prevent the deterioration. So far, overexpression of PGC-1α via transgene and in vivo DNA transfection has been found to be effective in ameliorating mitostasis and reduces IM-induced muscle atrophy. Nutritional supplementation of select amino acids and phytochemicals also provides mechanistic and practical insights into the prevention of muscle disuse atrophy. Future Directions: In light of the importance of mitochondria in regulating the various critical signaling pathways, future work should focus on exploring new epigenetic strategies to restore mitostasis and redox balance.

Angiotensin 1‐7 reduces muscle atrophy and function loss following 16 week denervation

Muscle atrophy is defined as a decrease in muscle mass that eventually leads to partial or complete muscle wasting. Muscle atrophy occurs in a variety of conditions including chronic diseases, limb immobilization and following a complete loss of muscle activity after spinal cord injury and peripheral nerve injury. A consequence of muscle atrophy is large force decrease associated with muscle mass loss as well as contractile components. The objective of this study was to determine whether angiotensin 1‐7 reduces the atrophy process and force loss following muscle denervation. Mouse extensor digitorum longus (EDL) and soleus were denervated by removing 3–4 mm of the sciatic nerve at the thigh level. Denervated mice were divided into 4 groups: i) denervated; ii) denervated and treated with angiotensin 1‐7; iii) denervated and treated with diminazene aceturate (DIZE), a ACE2 activator, to locally increase Ang 1‐7 levels, and iv) denervated and treated with sucrose. A 5th group of mice was used as control, i.e., normal innervated muscle. The results show that angiotensin 1‐7 significantly prevented muscle mass loss and fully prevented the loss of normalized force to cross sectional area that normally occurs over a 16 week denervation period. The maintenance of the normalized maximum force by angiotensin 1‐7/DIZE was in part due to a prevention of the loss of membrane excitability that occurs because denervated fibers are depolarized. This study is thus providing evidence that angiotensin1, 7 has therapeutic potential to prevent function loss following prolonged denervation.Support or Funding InformationThis project was supported by a grant from the National Science and Engineering Research Council of Canada (NSERC).

Effects of Dexamethasone on HDAC4 Expression and Cellular Localization in C2C12 Cell‐Derived Myotubes: Implications for Skeletal Muscle Atrophy

Skeletal muscle can rapidly decrease its mass and force to various conditions such as denervation, mechanical unload, kidney disease, sepsis and hormonal stimuli such as corticoids. Although it is well known that such conditions can trigger a set of genes related to atrophy (mainly Atrogin‐1 and MuRF1), the specific cellular processes that control atrophy under different conditions are not well understood. Accordingly, histone deacetylases (HDACs) can be important modulators of skeletal muscle atrophy and it has been shown that HDAC4 can trigger Atrogin‐1, and MuRF‐1 expression in denervation model. Nonetheless, it is not known whether HDCA4 is modulated in models involving hormonal stimulation such as corticoids. Thus, our objective was to investigate HDAC4 expression and localization in C2C12 cell‐derived myotubes submitted to dexamethasone treatment. We examined HDAC4 localization, gene expression and protein content on a in vivo, and in vitro models. C2C12 cells, treated with dexamethasone (10 nM) for 12h, 24h and 48h and the results are expressed by means ± SD, and the statistical analysis was performed using Student’s t test (p ≤ 0.05). Initially we confirmed the responsiveness of HDCA4 to atrophy mediated mechanical unload. As expected, we found a marked increase in HDCA4 mRNA expression (~3 fold, p&lt;0.05) after 7 days of hind limb immobilization. Other marker of atrophy was also induced (Atrogin‐1 1.7 fold; p &lt;0.05). In C2C12 cell‐derived myotubes, we confirmed decreased in myotube diameter induced by dexamethasone (~25% p&lt;0.05). In addition, we observed increased HDAC4 mRNA levels after 24 h of dexamethasone treatment (~1.8 fold, p&lt;0.05). Atrogin‐1 mRNA level, as expected, was also elevated (~1.6 fold, p&lt;0.05). Concerning cell location, our preliminary findings suggest a nuclear accumulation of HDAC4 in myotubes treated with dexamethasone. As time course and dose response experiments are ongoing, overall, these results provide further insight into molecular mechanisms involving HDAC4 responses in skeletal muscle. This project was approved by the Ethics Committee on the Use of Animals by the University of São Paulo (Protocol No. 2034200718).Support or Funding InformationFAPESP; CAPES; CNPq

Motor Imagery Training During Arm Immobilization Prevents Corticomotor Idling: An EEG Resting-State Analysis.

Limb disuse causes overt, measurable alterations in motor functions. Motor imagery (MI) practice has been used as a behavioral strategy to prevent motor impairments due to limb disuse or immobilization. Yet, how MI operates at the neural level in the context of short-term limb immobilization remains understudied. We hypothesized that MI treatment applied during 12h of arm immobilization prevents immobilization-related changes in resting-state electroencephalographic (rsEEG) power and functional connectivity. Fourteen participants first underwent rsEEG after 12h of normal motor activity (without immobilization). Then, rsEEG recording was performed after 12h of arm immobilization either with MI treatment or without, each conditionseparated by 1week, according to a randomized within-subjects design. MI treatment consisted in performing varied visual and kinaesthetic MI exercises (5 sessions of 15min every two hours). The results showed that in the delta, theta, alpha and beta frequency bands, interhemispheric difference in sensors power over the motor cortex (i.e. C3 vs. C4) was reduced after arm immobilization, while it did not change when MI treatment was delivered during the immobilization period. Moreover, functional connectivity across the sensors-network in the delta (1-4Hz) and alpha (8-12Hz) frequency bands decreased after immobilization while it was restored by MI treatment. To conclude, MI counteracts functional neural changes within and between motor regions in the context of limb immobilization. Practical applications for motor rehabilitation strategies, particularly in stroke patients, are also discussed.

Chronic Alcohol Dysregulates Skeletal Muscle Myogenic Gene Expression after Hind Limb Immobilization in Female Rats.

Alcohol use and aging are risk factors for falls requiring immobilization and leading to skeletal muscle atrophy. Skeletal muscle regeneration is integral to post-immobilization recovery. This study aimed to elucidate the effects of alcohol and ovarian hormone loss on the expression of genes implicated in muscle regeneration. Three-month-old female rats received an ovariectomy or a sham surgery, consumed an alcohol-containing or control diet for 10 weeks, were subjected to unilateral hind limb immobilization for seven days, and finally were allowed a three (3d)- or 14 (14d)-day recovery. Immobilization decreased the quadriceps weight at 3d and 14d, and alcohol decreased the quadriceps weight at 14d in the nonimmobilized hind limb (NI). At 3d, alcohol decreased gene expression of myoblast determination protein (MyoD) in the immobilized hind limb (IMM) and myocyte enhancer factor (Mef)2C and tumor necrosis factor (TNF)α in NI, and ovariectomy increased MyoD and decreased TNFα expression in NI. At 14d, alcohol increased the gene expression of Mef2C, MyoD, TNFα, and transforming growth factor (TFG)β in IMM and decreased monocyte chemoattractant protein (MCP)1 expression in NI; ovariectomy increased TNFα expression in NI, and alcohol and ovariectomy together increased Mef2C expression in NI. Despite increased TGFβ expression, there was no concomitant alcohol-mediated increase in collagen in IMM at 14d. Overall, these data indicate that alcohol dysregulated the post-immobilization alteration in the expression of genes implicated in regeneration. Whether alcohol-mediated molecular changes correspond with post-immobilization functional alterations remains to be determined.

Task-dependent modulation of corticospinal excitability and inhibition following strength training

This study determined whether there are task-dependent differences in cortical excitability following different types of strength training. Transcranial magnetic stimulation (TMS) measured corticospinal excitability (CSE) and intracortical inhibition (ICI) of the biceps brachii muscle in 42 healthy subjects that were randomised to either paced-strength-training (PST, n = 11), self-paced strength-training (SPST, n = 11), isometric strength-training (IST, n = 10) or to a control group (n = 10). Single-pulse and paired-pulse TMS were applied prior to and following 4-weeks of strength-training. PST increased CSE compared to SPST, IST and the control group (all P < 0.05). ICI was only reduced (60%) following PST. Dynamic strength increased by 18 and 25% following PST and SPST, whilst isometric strength increased by 20% following IST. There were no associations between the behavioural outcome measures and the change in CSE and ICI. The corticospinal responses to strength-training are task-dependent, which is a new finding. Strength-training that is performed slowly could promote use-dependent plasticity in populations with reduced volitional drive, such as during periods of limb immobilization, musculoskeletal injury or stroke.

Does well-functioning hand constraint induce stress in forced-use therapy for children with unilateral cerebral palsy?

This study investigated the stress induced by well-functioning hand constraint in forced-use therapy (FUT) for children with unilateral spastic cerebral palsy (CP).Seventeen children with unilateral spastic CP (mean age 5.8 years) received FUT: 4-week unaffected upper limb immobilization with a short-arm Scotchcast and were encouraged to incorporate it to their daily routines and plays. They were evaluated at pretreatment, immediate post-treatment, and 6 months post-treatment. The Korea-Child Behavior Checklist (K-CBCL) was used to assess the stress degree; box and block test (BBT), Erhardt Developmental Prehension Assessment (EDPA), Quality of Upper Extremity Skill Test (QUEST), and Pediatric Motor Activity Log (PMAL), upper limb function; and Pediatric Evaluation of Disability Inventory (PEDI), daily living activities.In the preschoolers, most scores of K-CBCL tended to increase after FUT; however, there was no significant change in all scale findings after FUT. In the school-aged children, most scores of K-CBCL tended to decrease after FUT; however, there was no significant change in all scale findings after FUT. The findings of the BBT, QUEST, PMAL how often and well subscales significantly improved post-treatment (P < .05).The 4-week FUT with well-functioning hand constraint significantly improved the UL function and did not induce emotional and behavioral problems in children with unilateral spastic CP.

Redox Control of Proteolysis During Inactivity-Induced Skeletal Muscle Atrophy.

Significance: Skeletal muscles play essential roles in key body functions including breathing, locomotion, and glucose homeostasis; therefore, maintaining healthy skeletal muscles is important. Prolonged periods of muscle inactivity (e.g., bed rest, mechanical ventilation, or limb immobilization) result in skeletal muscle atrophy and weakness. Recent Advances: Disuse skeletal muscle atrophy occurs due to both accelerated proteolysis and decreased protein synthesis with proteolysis playing a leading role in some types of inactivity-induced atrophy. Although all major proteolytic systems are involved in inactivity-induced proteolysis in skeletal muscles, growing evidence indicates that both calpain and autophagy play an important role. Regulation of proteolysis in skeletal muscle is under complex control, but it is established that activation of both calpain and autophagy is directly linked to oxidative stress. Critical Issues: In this review, we highlight the experimental evidence that supports a cause and effect link between reactive oxygen species (ROS) and activation of both calpain and autophagy in skeletal muscle fibers during prolonged inactivity. We also review the sources of oxidant production in muscle fibers during inactivity-induced atrophy, and provide a detailed discussion on how ROS activates both calpain and autophagy during disuse muscle wasting. Future Directions: Future studies are required to delineate the specific mechanisms by which ROS activates both calpain and autophagy in skeletal muscles during prolonged periods of contractile inactivity. This knowledge is essential to develop the most effective strategies to protect against disuse muscle atrophy. Antioxid. Redox Signal. 33, 559-569.

Management and serious risk factors associated with unintentional injuries in paediatric emergencies in Spain

IntroductionThirty-eight million patients with injuries are treated in Emergency Departments every year, 90% of them being in the form of unintentional injuries (UIs). There are currently no global records of its management in Spain, or the risk factors that may be associated with them. The objective of this study is to describe the management of UIs in Spanish paediatric emergency departments, and to analyse factors related to the presence of serious injuries. Material and methodsA sub-study of a prospective multicentre observational study conducted over 12 months in 11 hospitals of the Spanish Paediatric Emergency Research Group (RiSEUP-SPERG), including children from 0 to 16 years of age consulting for UIs. Epidemiological data, circumstances of the injury, and data on emergency care and discharge destination were recorded on the 13th day of each month. ResultsA total of 10,175 episodes were recorded, of which 1,941 were UIs 19.1%), including 1,673, of which 257 (15.4%) were severe. The most frequent complementary test was simple radiography (60.0%), and the most frequent procedure was limb immobilisation (38.6%). A significant relationship was found between presenting with a severe UI and age >5 years [OR 2.24 (95% CI: 1.61–3.16)], history of fracture [OR 2.05 (95% CI: 1.22–3.43)], or sports activity as a mechanism of injury [OR 1.76 (95% CI: 1.29–2.38)], among others. ConclusionIn Spain, most UIs are not serious. X-rays and immobilisation of extremities are the most frequently performed tests and procedures. Severe UIs were associated with individual factors, such as age >5 years or history of fracture, and with sports activity as a mechanism associated with severity. It is vital to implement measures to improve the prevention of these injuries and to support the training of caregivers through educational programmes.

Pharmacological thromboprophylaxis to prevent venous thromboembolism in patients with temporary lower limb immobilization after injury: systematic review and network meta‐analysis

BackgroundThromboprophylaxis has the potential to reduce venous thromboembolism (VTE) following lower limb immobilization resulting from injury. ObjectivesWe aimed to estimate the effectiveness of thromboprophylaxis, compare different agents, and identify any factors associated with effectiveness. MethodsWe undertook a systematic review and network meta‐analysis (NMA) of randomized trials reporting VTE or bleeding outcomes that compared thromboprophylactic agents with each other or to no pharmacological prophylaxis, for this indication. An NMA was undertaken for each outcome or agent used, and a series of study‐level network meta‐regressions examined whether population characteristics, type of injury, treatment of injury, or duration of thromboprophylaxis were associated with treatment effect. ResultsData from 6857 participants across 13 randomized trials showed that, compared with no treatment, low molecular weight heparin (LMWH) reduced the risk of any VTE (odds ratio [OR]: 0.52; 95% credible interval [CrI]: 0.37‐0.71), clinically detected deep vein thrombosis (DVT) (OR: 0.39; 95% CrI: 0.12‐0.94) and pulmonary embolism (PE) (OR: 0.16; 95% CrI: 0.01‐0.74), whereas fondaparinux reduced the risk of any VTE (OR: 0.13; 95% CrI: 0.05‐0.30) and clinically detected DVT (OR: 0.10; 95% CrI: 0.01‐0.86), with inconclusive results for PE (OR: 0.40; 95% CrI: 0.01‐7.53). ConclusionsThromboprophylaxis with either fondaparinux or LMWH appears to reduce the odds of both asymptomatic and clinically detected VTE in people with temporary lower limb immobilization following an injury. Treatment effects vary by outcome and are not always conclusive. We were unable to identify any treatment effect modifiers other than thromboprophylactic agent used.

Muscle protein breakdown is impaired during immobilization compared to during a subsequent retraining period in older men: no effect of anti-inflammatory medication

Muscle inactivity reduces muscle protein synthesis (MPS), whereas a subsequent period of rehabilitation resistance training (retraining) increases MPS. However, less is known regarding muscle protein breakdown (MPB) during such conditions. Furthermore, nonsteroidal anti-inflammatory drugs (NSAIDs) may have a dampening effect on MPB during periods of inactivity in older individuals. Thus, we measured the average MPB, by use of the deuterated water methodology, during an immobilization period and a subsequent retraining period in older individuals with and without NSAID treatment. Eighteen men (60–80 years: range) were randomly assigned to ibuprofen (1200 mg/d, Ibu) or placebo (Plc). One lower limb was immobilized in a cast for 2 weeks and retrained for 2 weeks, and 2 × 20 g of whey protein was ingested daily during both periods. Besides MPB, the protein expression of different muscle degradation signaling molecules was investigated. MPB was lower during immobilization compared to retraining (p < 0.01). NSAID treatment did not affect the MPB rate during immobilization or retraining (p > 0.05). The protein expression of muscle degradation signaling molecules changed during the study intervention but were unaffected by NSAID treatment. The finding that MPB was lower during immobilization than during retraining indicates that an increased MPB may play an important role in the muscle protein remodeling processes taking place within the initial retraining period. Moreover, NSAID treatment did not significantly influence the MPB rate during 2 weeks of lower limb immobilization or during 2 weeks of subsequent retraining in older individuals.

Eccentric, but not concentric blood flow restriction resistance training increases muscle strength in the untrained limb

ObjectivesLittle is known regarding the variables or mechanisms mediating cross-education as a result of resistance training. Therefore, the purpose of the present study was to examine the effects of low-load eccentric-only blood flow restriction (Ecc-BFR) and low-load concentric-only BFR (Con-BFR) on indices of cross-education. DesignThirty-six women were randomly assigned to 4-wks of unilateral resistance training with Ecc-BFR (n = 12), Con-BFR (n = 12) or control (no intervention, n = 12) group. Eccentric peak torque, concentric peak torque, maximal voluntary isometric contraction torque, muscle thickness, and muscle activation were assessed from the contralateral, untrained arm. ResultsMuscle strength (collapsed across mode) increased from 0-wk to 2-wks (4.9%) and 4-wks (13.0%) for Ecc-BFR only. There were increases in muscle activation (collapsed across mode and group) regardless of training modality, but there were no changes in muscle size for any of the conditions. ConclusionsThe findings of the present study indicated that low-load Ecc-BFR increased muscle strength. The increases in muscle strength as a result of Ecc-BFR were not mode-specific. Thus, low-load Ecc-BFR provides a unique alternative to maintain muscle function in an untrained limb that may have application during limb immobilization and rehabilitation practices.

Declines in skeletal muscle quality vs. size following two weeks of knee joint immobilization.

BackgroundDisuse of a muscle group, which occurs during bedrest, spaceflight, and limb immobilization, results in atrophy. It is unclear, however, if the magnitude of decline in skeletal muscle quality is similar to that for muscle size. The purpose of this study was to examine the effects of two weeks of knee joint immobilization on vastus lateralis and rectus femoris echo intensity and cross-sectional area.MethodsThirteen females (mean ± SD age = 21 ± 2 years) underwent two weeks of left knee joint immobilization via ambulating on crutches and use of a brace. B-mode ultrasonography was utilized to obtain transverse plane images of the immobilized and control vastus lateralis and rectus femoris at pretest and following immobilization. Effect size statistics and two-way repeated measures analyses of variance were used to interpret the data.ResultsNo meaningful changes were demonstrated for the control limb and the rectus femoris of the immobilized limb. Analyses showed a large increase in vastus lateralis echo intensity (i.e., decreased muscle quality) for the immobilized limb (p = .006, Cohen’s d = .918). For vastus lateralis cross-sectional area, no time × limb interaction was observed (p = .103), but the effect size was moderate (d = .570). There was a significant association between the increase in vastus lateralis echo intensity and the decrease in cross-sectional area (r = − .649, p = .016).ConclusionIn female participants, two weeks of knee joint immobilization resulted in greater deterioration of muscle quality than muscle size. Echo intensity appears to be an attractive clinical tool for monitoring muscle quality during disuse.

Hydrocolloid Membrane Dressing in Shearing Injuries in the Distal Part of the Pelvic Limbs in Dogs

Background: Shearing wounds on the limbs of dogs usually affect the regions distally from the radiocarpal joint at the thoracic limb and from the tibiotarsal joint at the pelvic limb. The tissue coverage and re-epithelialization of the injured region are important factors that should be considered in the definitive surgical treatment. The hydrocolloid membrane promotes selective autolytic debridement and accelerates the formation of granulation tissue and epithelialization. The present study aims to describe the treatment with hydrocolloid membrane dressing of three cases of shearing wounds with concomitant orthopedic injuries in the pelvic limbs of dogs.Case: Three dogs with pelvic limb injuries after vehicular trauma were selected for treatment. Two patients had shearing lesions on the medial aspect of the pelvic limb with exposure of the tibia and fibula, the talus and the tibiotarsal joint, associated with bone loss on the medial surface of the limb and rupture of the medial collateral ligament of the tarsus. Another patient had a shearing wound on the dorsal surface of the distal region of the pelvic limb, with injury of the digital extensor tendons and bone exposure of the second and third metatarsals. Initially, the surgical debridement of the lesion was performed and during the first five days after trauma the wound was cleansed with chlorhexidine solution and topical application of crystallized sugar daily. In this initial period a dry adherent dressing was used on the lesions, without bandages for immobilization of the pelvic limb. In all dogs, the hydrocolloid membrane was applied from the sixth day after initial wound management. Immediately after the application of the hydrocolloid membrane, temporary immobilization of the affected pelvic limb with a padded Robert Jones bandage was performed. The first changes of the hydrocolloid membranes were performed after five days of their use. Subsequently, the membranes changes became more spaced and were performed within a period between 7 to 10 days. After wound repair, in one of the dogs with a shearing injury in the medial surface of the pelvic limb, the rupture of the medial collateral ligament was surgically treated with the use of anchor screws and nylon thread for the ligament reconstruction. The other dog presented with lesion in the medial surface of the pelvic limb and collateral ligament rupture was not submitted to late orthopedic surgical treatment. The latter was clinically managed and developed valgus deviation of the affected pelvic limb, but with functional use of the limb. The dog with a shearing lesion on the dorsal surface of the pelvic limb and injury to the extensor tendons was managed conservatively with use of orthosis and, after 45 days of initial trauma, the dog showed a functional lameness and absence of pain in the affected limb.Discussion: In all animals, the hydrocolloid membrane was applied on the wound from the sixth day after the initial lesion treatment. As the wound was healing the hydrocolloid dressing was changed in a more spaced period and this management allowed the proper tissue healing without complications. The wound treatment with dressing was aided by the application of temporary limb immobilization with padded bandage, until a late orthopedic procedure was performed or a final clinical resolution occurred. In general, the shearing wounds healed in a period ranging from 28 to 38 days. In conclusion, the use of the hydrocolloid membrane dressing associated with limb immobilization was an effective method for treatment of patients with shearing wounds, allowing proper healing of the affected tissues and good recovery of the limb function. The hydrocolloid membrane has the main benefits to allow the spaced changes of the dressings and the ability to stimulate the rapid healing of the wound.

Thromboprophylaxis in lower limb immobilisation after injury (TiLLI)

Venous thromboembolic disease is a major global cause of morbidity and mortality. An estimated 10 million episodes are diagnosed yearly; over half of these episodes are provoked by hospital admission/procedures...

Temporal Muscle-specific Disuse Atrophy during One Week of Leg Immobilization.

Musculoskeletal injuries necessitate periods of disuse (i.e., limb immobilization) during which rapid skeletal muscle atrophy occurs. The relative susceptibility of different muscles of the thigh to disuse atrophy remains uninvestigated. We assessed muscle disuse atrophy of individual thigh muscles throughout 1 wk of unilateral knee immobilization. Thirteen healthy, young (20.2 ± 0.6 yr) men underwent 7 d of unilateral leg immobilization via knee bracing. Magnetic resonance imaging scans were performed bilaterally prior to, and following 2 and 7 d of immobilization to determine the volume and anatomical cross-sectional area of the individual muscle groups of the upper legs. In contrast to the control leg, total thigh muscle volume had decreased by 1.7% ± 0.3% (P < 0.01) and 5.5% ± 0.6% (P < 0.001) in the immobilized leg after 2 and 7 d of disuse, respectively. Muscle loss was significantly greater in the Musculus quadriceps (day 2; 1.7% ± 0.3% (P < 0.05) and day 7; 6.7% ± 0.6%) when compared with the Musculus hamstrings (day 2; 1.4% ± 0.2% (P < 0.01) and day 7; 3.5% ± 0.3%) after 7 d of disuse (P < 0.001). Individual muscles of the thigh exhibited different atrophy rates with the Musculus vastus lateralis anatomical cross-sectional area showing the greater (2.6% ± 0.4% and 7.2% ± 0.8%), and the Musculus gracilis the lesser (1.1% ± 0.7% and 2.3% ± 1.0%) decline following 2 and 7 d of immobilization, respectively (P < 0.01). Thigh muscle disuse atrophy occurs rapidly and is already evident within 2 d of leg immobilization and progresses at a similar rate over the next 5 d (~0.8% muscle loss per day). M. quadriceps muscle shows more atrophy when compared with the M. hamstrings.

A 10-year Retrospective Case-Series of Venous Thrombo-Embolism frequency in Patients Treated with Total Contact Casts

Category:DiabetesIntroduction/Purpose:Venous Thrombo-Embolism (VTE) is a recognized complication of lower limb immobilization. In the neuropathic patient total contact casting (TCC) is used in the management of acute charcot neuroathropathy and/or to off-load neuropathic ulcers. To our knowledge, there is currently no literature stating the prevalence of VTE in patients, despite the possibility of prolonged lower limb immobilization. There are also no recommendations regarding VTE prophylaxis in the setting of TCCs. We report a retrospective case series assessing the frequency of symptomatic VTE in the patients treated with TCCs. Given that diabetic foot disease manifests as one of many co-morbidities in this medically complex group of patients we hypothesize that the rate of occurrence of VTE should be higher than that of the general population.Methods:Patients undergoing TCC between 2006 and 2018 were identified using plaster room records. These patients subsequently had electronic clinical letters and radiological reports assessed for details around the TCC episode, past medical history and any VTE events.Results:There were 143 TCC episodes in 105 patients. Average age at cast application was 55 years. The mean time in a cast was 45 days (range from 5 days to 8 months). 3 out of 4 patients had neuropathy as a consequence of diabetes. One TCC related VTE (0.7% of casting episodes) was documented. This was a proximal DVT confirmed on USS 9 days following cast removal. Only 3 patients received VTE prophylaxis while in TCC.Conclusion:Despite these complex patients having a multitude of co-morbidities the frequency of VTE in the TCC setting remains similar to that of the general population. This may be due to the fact that TCCs permit weight bearing or that Charcot arthropathy leads to a high outflow state, potentially turning Virchow’s triad in the patient’s favour. This case series suggests that, while all patients should be individually VTE risk assessed as for any lower limb immobilization, chemical thromboprophylaxis is not routinely indicated in the context of TCCs.

Effects of treadmill running and limb immobilization on knee cartilage degeneration and locomotor joint kinematics in rats following knee meniscal transection

This study examined the effects of reduced and elevated weight bearing on post-traumatic osteoarthritis (PTOA) development, locomotor joint kinematics, and degree of voluntary activity in rats following medial meniscal transection (MMT). Twenty-one adult rats were subjected to MMT surgery of the left hindlimb and then assigned to one of three groups: (1) regular (i.e., no intervention), (2) hindlimb immobilization, or (3) treadmill running. Sham surgery was performed in four additional rats. Voluntary wheel run time/distance was measured, and 3D hindlimb kinematics were quantified during treadmill locomotion using biplanar radiography. Rats were euthanized 8weeks after MMT or sham surgery, and the microstructure of the tibial cartilage and subchondral bone was quantified using contrast enhanced micro-CT. All three MMT groups showed signs of PTOA (full-thickness lesions and/or increased cartilage volume) compared to the sham group, however the regular and treadmill-running groups had greater osteophyte formation than the immobilization group. For the immobilization group, increased volume was only observed in the anterior region of the cartilage. The treadmill-running group demonstrated a greater knee varus angle at mid-stance than the sham group, while the immobilization group demonstrated greater reduction in voluntary running than all the other groups at 2 weeks post-surgery. Elevated weight-bearing via treadmill running at a slow/moderate speed did not accelerate PTOA in MMT rats when compared to regular weight-bearing. Reduced weight-bearing via immobilization may attenuate overall PTOA but still resulted in regional cartilage degeneration. Overall, there were minimal differences in hindlimb kinematics and voluntary running between MMT and sham rats.