a Departamento de Ortopedia, Santa Casa de São Paulo, São Paulo, SP, Brasil
b Serviço de Ortopedia e Traumatologia, Hospital Israelita Albert Einstein, Universidade Federal de São Paulo (Unifesp), São Paulo, SP,Brasil
c Instituto de Ortopedia, Hospital das Clínicas, Faculdade de Medicina, Universidade de São Paulo (USP), São Paulo, SP, Brasil
d Escola Paulista de Medicina, Universidade Federal de São Paulo (Unifesp), São Paulo, SP, Brasil
Introduction
Over recent decades, the number of people taking part insports activities around the world has progressively increased.A large part of this increase has occurred because of the exten-sive dissemination by the media of the benefits to health thatresult from regularly practicing exercise. Exercise providesimprovement of quality of life and reduction of the risk ofhaving many diseases.1-3
However, it is known that the benefits from practicingsports stand in contrast to the increase in the number of osteo-muscular injuries.4Almost 10 million sports-related injuriesoccur every year in the United States.5Most of them are notvery severe, but they are painful and often incapacitating,since they take people away from their physical and profes-sional activities.
Muscle injuries are the commonest of these and account for10-55% of all sports injuries. They consist mainly of bruises,sprains and lacerations.7Injuries due to sprains generallyaffect superficial and two-joint muscles (rectus femoris, kneeflexors and gastrocnemius) and they occur during the eccen-tric phase of contraction.8The causes are multifactorial andthere are some risk factors, such as age, previous muscleinjuries in the same region, ethnicity, overloading, force imbal-ance and alteration of the capacity to stretch the muscle groupin question.
However, little has changed over recent decades regardingthe way in which muscle injuries are understood andtreated. The aim of the present study was to evaluate theconceptualizations, diagnostic methods, treatment methodsand perspectives of specialist physicians through applying aquestionnaire among them, on muscle injuries in Brazil. Fromthese results, it will be possible to delimit national trends onthis little studied topic and guide subsequent new research inthis field.
Methods
This was a descriptive study with application of a question-naire to a sample formed mainly by sports physicians andorthopedists. This questionnaire was composed of 20 closedquestions and was drawn up by the present authors in a simpleand objective manner. It covered the main topic of the subjectof muscle injuries (Appendix 1).
The questionnaire was applied to physicians who routinelytreat muscle injuries who were attending the Second Brazilian Congress of Sports Arthroscopy and Traumatology (SBRATE),which took place in Fortaleza in 2013.
Thus, 168 questionnaires were filled out under guidancefrom one of the researchers for clarifications of any doubtsthat may have arisen.
From the data obtained through the questionnairesthat were filled out, descriptive statistics were calculatedon the variables involved, in order to characterize thesample.
The data were analyzed using the SPSS for Windows soft-ware, version 16.0, and the significance level was taken to be 5%.
Results
There were 168 completed questionnaires, filled out by physi-cians from 20 states in all the five regions of Brazil (Table 1):118 were orthopedists, 43 were orthopedists and sports physi-cians, five were sports physicians and two were from otherspecialties.
The mean length of time for which the professionals inter-viewed had been active in treating muscle injuries was 11years. Most of the interviewees dealt with muscle injuries inboth public and private services and saw more than 30 casesper year (Table 2).
Most of the injuries cited occurred in the lower limbs (97%):30% in the quadriceps, 28% in the thigh adductors and 21%in the sural triceps. These injuries most commonly occurredduring the eccentric phase of movement (in cases seen by 62%of the interviewees) and mostly affected the muscle-tendonjunction (53%) and the muscle body (45%) (Table 3).
The examination most often performed by the physiciansinterviewed, in order to aid in the diagnosis, was ultrasound(39%), but the majority of them (84%) considered that mag-netic resonance imaging was the best examination for makingdiagnoses (Table 4). Through the imaging examination, it waspossible to classify the injuries using the method preferred bythe majority of the interviewees (73%): the method that dividesinjuries into three grades according to the number of fibersinjured. On the other hand, 24% of the interviewees preferredto classify injuries only with a description of the anatomi-cal region injured. Moreover, 48% considered chronic muscleinjuries to be those that had been presented for more than sixweeks, 35% for more than three weeks and 15% for more than3 months.
The treatment of choice in the acute phase of theinjury for most of the interviewees was a combination ofrest, cryotherapy and medication. Regarding the options for
medications, the majority (35%) prescribed anti-inflammatorydrugs alone, followed by analgesics (25%) and an associa-tion of anti-inflammatory drugs and analgesics (12%). Formost of the interviews (56%), the treatment after the acutephase was composed of medication, rest and physiotherapy.In this case, the medication most prescribed was analgesics(Tables 5 and 6).
For injuries classified as grade I, the mean length of timeaway from sports activities was 13 days; grade II, 28 days; andgrade III,48 days. The main criteria used for determining thereturn to sport were comparison of muscle strength alone inthe injured limb with the contralateral limb and combinationevaluation of the pain scale and muscle strength in relation tothe contralateral limb, along with the patient's own degree ofconfidence (Table 7).
The interviewees were also asked about other possible ther-apies cited in the literature that could be used for treatingmuscle injuries: 52% believed that treatment with platelet-rich plasma (PRP) was efficient, but only 42% had already used
this therapeutic method, while 14% did not believe in any ofthe methods presented and 24% had never used any of thesetherapeutic methods (Table 8).
Discussion
Muscle injury is the commonest type of musculoskeletalinjury. It may represent up to 50% of all orthopedic complaints.In most cases, the patient is capable of returning to activi-ties at the same level as before the injury, without functionaldeficits.10,11Nonetheless, little is known about these injuries.There is no consensus on the best way of defining their sever-ity, the most appropriate treatment and the most efficientform of rehabilitation.
The present study evaluated the main topics involved inmuscle injuries and investigated them among a population ofhighly specialized physicians who were accustomed to dealingwith this pathological condition.
These questions were put to 168 sports physicians and/ororthopedists from all regions of Brazil whose mean level ofexperience of treating muscle injuries was 11 years.
When the number of muscle injuries treated per yearwas evaluated, it was seen that, independent of the sub-specialization of orthopedist or sports physician, these werethe injuries most frequently treated at the places where themajority of the interviewees attended patients. Independentof whether attendance was within the public or private sys-tem, the mean number of cases of injuries exceeded 30 peryear. The great majority of the physicians reported that thecommonest injuries were in the lower limbs, which is in linewith the sports practices that are most popular in our setting,i.e. soccer and athletics. The result was that greater numbersof injuries occurred in the muscles groupings involved, for example, in kicking movements: quadriceps, thigh adductorsand sural triceps.
In the literature, muscle injuries have been correlated witheccentric contraction.12-1562% of the interviewees also tookthe view that the majority of the injuries occurred during thisphase of the contraction, which should serve as informationfor correct physical preparation and injury prevention amongathletes practicing a variety of physical activities.
Although many classifications have been described withthe aim of better understanding of the types of muscle injury,we believe that there is still no consensus about the best wayof differentiating between them.16The difficulty in makingsamples homogenous makes comparison between differentinjuries very complex. Classifications may relate to anatomy,the region in which the muscle fibers are affected or the timeelapsed since the injury, among many others. In the presentstudy, the majority of the participants chose to define the typeof injury according to the number of fibers injured and theydivided these injuries into three types: grades I, II and III. How-ever, even though this classification depends on an imagingexamination, it is still very subjective and results from theopinion of the physician who makes the assessment. Even so,this is the classification that best led the professionals to thetype of treatment and the length of time for which the ath-lete will be away from his sport. It was seen that the higherthe grade of the injury was, the longer the time for whichthe study participants chose to keep the athletes from theiractivities was. In discussing the time required for defining aninjury as acute or chronic, there was also a very wide rangeof opinions. In the literature, there has been little scientifi-cally base description of what constitutes a chronic injury.16In the present study, 48% believed that these are injuries thatoccurred more than six weeks ago, 35% more than three weeksago and 15% more than three months ago.
In relation to the diagnostic method, there was concord-ance with the literature regarding the notion that magneticresonance imaging would be the ideal examination,17although the majority of the interviewees used ultrasound.This can be explained by the difference in costs between theexaminations, although this may no longer be the rule in othercountries, where the costs of magnetic resonance imaging arenot as high as it is in Brazil.
The treatment for muscle injuries is without doubt themost controversial item. Although the same treatment hasbeen used for more than 40 years, some therapies have beendescribed and have started to be used in our setting, eventhough in some situations there has been little basis for thisin the literature. In the acute phase, the great majority of theinterviewees mainly used analgesic and anti-inflammatorymedications, in association with rest and cryotherapy.
The subsequent treatment, which in most cases is guidedby the type of injury, was composed of physiotherapy, rest andmedication, according to 56% of the interviewees. This hasbeen the conventional trio of treatments for muscle injuriesfor many years. Over this time period, much has been saidabout adjuvant therapies that might accelerate muscle heal-ing and provide an earlier return to sport. We asked theparticipants whether they considered that treatments withPRP, shockwaves, local infiltration and gene therapy were effi-cient. Most of them believed that PRP treatment would beefficient, followed by shockwaves, gene therapy and infiltra-tion. However, when asked whether they were using thesetherapies, smaller numbers of participants affirmed this: 42%had already used PRP, 27% shockwaves and 21% infiltration.None of them mentioned using gene therapy.
For the return to sports practice, the main criteria usedby the participants were comparison of muscle strength withthe contralateral side, comparison of the combined resultsfrom the visual analog pain scale and muscle strength withthe contralateral side and the patient's confidence. The greatchallenge in treating muscle injuries probably relates to theexact time at which injured patients can return to their sportsactivities at a high performance level. Today, many criteriaare used to measure this capacity to return, but in mostcases these methods are still subjective, with little scientificevidence.
Although this was purely a descriptive study, with a lowlevel of evidence, it has great importance in that it analyzedthe way in which specialists deal with injuries that are so com-mon yet so little studied with regard to the main aspects of thispathological condition.
Conclusion
The number of muscle injury cases treated every year wasgreater than 30, independent of whether this was in thepublic or private sector. The injuries occurred mainly at themuscle-tendon junction, in the lower limbs and during theeccentric phase of muscle contraction. Ultrasound was theexamination most used, while magnetic resonance imagingwas considered to be ideal. The preferred treatment involvedrest, medication and physiotherapy, for the majority of theinterviewees. Moreover, 52% of the physicians believed thatPRP was efficient and 42% said that they had used it.
Conflicts of interest
The authors declare no conflicts of interest.
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