Recurrence of Scaphoid Stress Fracture: A Case Report

Background Scaphoid stress fractures are rare and typically present in young, elite male athletes. Due to the infrequency in which these injuries are encountered, the optimum management is not established. Case Description We present the case of a 20-year-old male gymnast with bilateral stress fractures of the scaphoid waist. Following conservative treatment, clinical and radiological signs of union were seen bilaterally. Eight months after return to normal activities, a unilateral recurrence of the stress fracture occurred. This was successfully treated with internal fixation and bone grafting. Literature Review Scaphoid stress fractures are most frequently seen in gymnasts but also occur in participants of other sports involving repetitive loading of an extended wrist. This action conveys force predominantly through the waist of the scaphoid. Most case studies have reported high union rates, whether treated operatively or conservatively, and the patients returned to high-level sport with no further problems. Stress fracture recurrence has been reported in other bones such as the metatarsal and tibia but never before in the scaphoid. Our case is unusual in that the patient suffered ongoing problems due to a recurrence of the scaphoid stress fracture after returning to normal activities. Clinical Relevance Clinicians should be aware that scaphoid stress fracture recurrence can occur, counsel patients accordingly, and remain vigilant after apparent union. We would recommend early fixation to allow a quicker return to function and prevention of recurrence.

Knowledge Assessment of Stress Bone Fractures among Soldiers in Saudi Arabia

Background: Stress fractures are well perceived in military preparing and athletes. Aside from knowledge of the frequency of these fractures and their impact on the economy and lost training hours, there are just a few studies in Saudi Arabia that show the real incidence of these fractures. The precise incidence must be known in order to provide recommendations for future preventative initiatives. This study aims to assess the knowledge of stress fractures among Saudi soldiers. Methodology: An observational cross-sectional study was conducted in medical centers; these centers are located in Saudi Arabia on male and female patients of all ages who are in Saudi military society to assess the knowledge of stress fractures among Saudi military society. Data collection was done by questionnaire that distributed between Saudi soldiers. Data was entered and analyzed using (SPSS) program, version 20 (IBM SPSS Statistics for Windows, Version 20.0. Armonk, NY: IBM Corp.). Results: Of all 1178 studied participants, 51.5% aged between 20- 30 years old. 91.7% were males. 47.5% of all participants had never heard of stress fractures before, 26.2% heard about it when joined military and 17.4% heard about it before joining the military field. 20.8% of all participants had stress fractures before, 10.4% were diagnosed through x-rays and medical history with the doctor, 4.6% were diagnosed through medical history only, and 2.4% diagnosed themselves. 85.3% of all participants agreed that stress fractures occur due to repetitive loading on the bones, 76.6% agreed that predominance of stress fractures of the lower extremities, over fractures of the upper extremities, 67.6% reported that stress fractures can be treated with painkillers, physiotherapy and reduce the risk and 78.6% agreed that stress fractures can be prevented by wearing appropriate footwear. Conclusion: Participants and relatively good knowledge of stress fractures. Knowledge of stress fracture was significantly associated with years of experience of participants, military sector, and residence area in the kingdom.

Hubungan Sikap Kerja dan Beban Kerja Dengan Keluhan Muskuloskeletal pada Nelayan

Musculoskeletal complaints are complaints that occur in the skeletal muscles that are felt with complaints ranging from very mild complaints to very painful complaints. Musculoskeletal complaints can occur due to static and repetitive loading on the muscles that occurs for a long time. Musculoskeletal complaints can damage joints, ligaments and muscles. This can cause work stress due to the wrong working conditions. The purpose of this study was to determine the relationship between work attitude and workload with musculoskeletal complaints in fishermen. The type of research used is quantitative with a cross sectional stady design. This research was conducted in the Fisherman of Pasia Nan Tigo, Koto Tangah District. The number of samples is 30 people. This study uses primary data and secondary data. The measuring instrument used is a questionnaire. The data were analyzed univariately and bivariately using the Chi Square test. Based on the results of the study, it was known that there was a relationship between ape's attitude (p value: 0.23) and workload (p value: 0.009) with musculoskeletal complaints.

Bivalves rapidly repair shells damaged by fatigue and bolster strength

ABSTRACT Hard external armors have to defend against a lifetime of threats yet are traditionally understood by their ability to withstand a single attack. Survival of bivalve mollusks thus can depend on the ability to repair shell damage between encounters. We studied the capacity for repair in the intertidal mussel Mytilus californianus by compressing live mussels for 15 cycles at ∼79% of their predicted strength (critically fracturing 46% of shells), then allowing the survivors 0, 1, 2 or 4 weeks to repair. Immediately after fatigue loading, mussel shells were 20% weaker than control shells that had not experienced repetitive loading. However, mussels restored full shell strength within 1 week, and after 4 weeks shells that had experienced greater fatiguing forces were stronger than those repetitively loaded at lower forces. Microscopy supported the hypothesis that crack propagation is a mechanism of fatigue-caused weakening. However, the mechanism of repair was only partially explained, as epifluorescence microscopy of calcein staining for shell deposition showed that only half of the mussels that experienced repetitive loading had initiated direct repair via shell growth around fractures. Our findings document repair weeks to months faster than demonstrated in other mollusks. This rapid repair may be important for the mussels’ success contending with predatory and environmental threats in the harsh environment of wave-swept rocky coasts, allowing them to address non-critical but weakening damage and to initiate plastic changes to shell strength. We highlight the significant insight gained by studying biological armors not as static structures but, instead, as dynamic systems that accumulate, repair and respond to damage.

What does ‘toughness’ look like? An examination of the breakdown of young and mature leaves under cyclical loading

The material property of leaf toughness is considered the crucial mechanical challenge facing folivorous primates. Mature leaves have higher recorded toughness values than young leaves on average, leading to many assumptions about the patterning of food breakdown that follow a tough/not-tough dichotomy. We tested three hypotheses about how leaves break down under repetitive loading cycles, predicting that mature leaves (i) experience more force during simulated occlusal loads, (ii) more effectively resist fragmentation into small pieces, and (iii) show a more gradual decline in resistance over consecutive cycles than young leaves. Under displacement control using a mechanical testing system, we subjected young and mature leaves to 20 cycles of axial loading using interlocking steel wedges, then collected and quantified the size of the leaf fragments. While we found that mature leaves experienced more overall force than young leaves ( p < 0.001), they also shattered into smaller pieces ( p = 0.004) and showed a steeper decline in their resistance to the cycles over the course of a test ( p < 0.01). These results suggest that putatively ‘tougher’ foods (i.e. mature versus young leaves) do not necessarily resist fragmentation as commonly assumed. The current tough/not-tough paradigm of primate foods may not accurately reflect how leaves break down during masticatory behaviour.

Injuries in Muscle-Tendon-Bone Units: A Systematic Review Considering the Role of Passive Tissue Fatigue

Background: Low-cycle fatigue damage accumulating to the point of structural failure has been recently reported at the origin of the human anterior cruciate ligament under strenuous repetitive loading. If this can occur in a ligament, low-cycle fatigue damage may also occur in the connective tissue of muscle-tendon units. To this end, we reviewed what is known about how, when, and where injuries of muscle-tendon units occur throughout the body. Purpose: To systematically review injuries in the muscle-tendon-bone complex; assess the site of injury (muscle belly, musculotendinous junction [MTJ], tendon/aponeurosis, tendon/aponeurosis–bone junction, and tendon/aponeurosis avulsion), incidence, muscles and tendons involved, mechanism of injury, and main symptoms; and consider the hypothesis that injury may often be consistent with the accumulation of multiscale material fatigue damage during repetitive submaximal loading regimens. Methods: PubMed, Web of Science, Scopus, and ProQuest were searched on July 24, 2019. Quality assessment was undertaken using ARRIVE, STROBE, and CARE (Animal Research: Reporting In Vivo Experiments, Strengthening the Reporting of Observational Studies in Epidemiology, and the Case Report Statement and Checklist, respectively). Results: Overall, 131 studies met the inclusion criteria, including 799 specimens and 2,823 patients who sustained 3,246 injuries. Laboratory studies showed a preponderance of failures at the MTJ, a viscoelastic behavior of muscle-tendon units, and damage accumulation at the MTJ with repetitive loading. Observational studies showed that 35% of injuries occurred in the tendon midsubstance; 28%, at the MTJ; 18%, at the tendon-bone junction; 13%, within the muscle belly and that 6% were tendon avulsions including a bone fragment. The biceps femoris was the most injured muscle (25%), followed by the supraspinatus (12%) and the Achilles tendon (9%). The most common symptoms were hematoma and/or swelling, tenderness, edema and muscle/tendon retraction. The onset of injury was consistent with tissue fatigue at all injury sites except for tendon avulsions, where 63% of the injuries were caused by an evident trauma. Conclusion: Excluding traumatic tendon avulsions, most injuries were consistent with the hypothesis that material fatigue damage accumulated during repetitive submaximal loading regimens. If supported by data from better imaging modalities, this has implications for improving injury detection, prevention, and training regimens.

An In-Vivo Model For Overloading-Induced Soft Tissue Injury

This proof-of-concept study demonstrates that repetitive loading to the pain threshold can safely recreate overloading-induced soft tissue damage and that localised tissue stiffening can be used as a marker for injury. This concept was demonstrated here for the soft tissue of the sole of the foot where it was found that repeated loading to the pain threshold led to long-lasting statistically significant stiffening in the areas where pressure was most intense. Loading at lower magnitudes did not have the same effect. This method can shed new light on the aetiology of overloading injury in the foot to improve the management of conditions such as diabetic foot ulceration and heel pain syndrome. At the same time, the presented concept can also enable the direct assessment of subject-specific thresholds for overloading in other soft tissues which are sensitive to pain, accessible for imaging and can be loaded in a clinically relevant manner.

Snapping thumb: a rare case of stenosing tenosynovitis of the extensor pollicis longus tendon

Tenosynovitis of the extensor pollicis longus (EPL) is rarely reported in patients without rheumatoid arthritis but may lead to thumb snapping as a consequence of EPL stenosing tenosynovitis.This case presents painful thumb snapping that developed after a wrist trauma and repetitive loading. Ultrasound and MRI were used as diagnostic tools, before surgical release of the EPL in the third extensor compartment was performed. Neither EPL tenosynovitis nor thumb snapping were found at follow-up.