Overuse Injuries in Orthopaedics practice
Posted by Dr. Gourishankar Patnaik on Sunday, 12th September 2010
Overuse Injuries in Orthopaedics practice
INTRODUCTION
Overuse injuries are injuries of the musculoskeletal and nervous systems that may be caused by repetitive tasks, forceful exertions, vibrations, mechanical compression (pressing against hard surfaces), or sustained or awkward positions. It is also known as Repetitive Strain Injury or Cumulative Trauma Disorders. These are most commonly used to refer to patients in whom there is no discrete, objective, pathophysiology that corresponds with the pain complaints. Stress fracture is also a common overuse injury, which scientist already described it since 1855. Overuse injuries due to repetitive motion are common in occupational, recreational, habitual activities and elite athletes. [1] The examples of overuse injuries are Golfer's elbow, Tennis elbow, Baseball pitchers’ elbow, Javelin throwers’ elbow. These conditions have acquired names derived from activities in which they were encountered when they were first described.
PATHOPHYSIOLOGY
Normally, our tissues adapt to the stresses placed on them over time. Different types of stresses include shear, tension, compression, impingement, vibration, and contraction. Tendons, ligaments, neural tissue, and other soft tissues can undergo mechanical fatigue, resulting in characteristic changes depending on their individual properties. As a respond, the tissues attempt to adapt to the demands placed on them. In the process of adapting, they can incur injury unless they have appropriate time to heal. The rate of injury simply exceeds the rate of adaptation and healing in the tissue.
In stress fractures, it is resulted from recurrent and repetitive loading of bone. It differs from other types of fractures in that; most of them have no acute traumatic event preceding the symptoms. Usually, the patient has a history of an increase and/or change in the character of activity or athletic workouts, increase in frequency of doing activity, or change in posture during activity. Bones may be more prone to stress fractures if the bone is weakened, as in individuals with osteoporosis.
There are a lot of hypothesis as why does the injury happens in repetitive tasks. One of them is the depletion of adenosine 5’-triphosphate (ATP) in the muscle fibers, which leads to reduction of sarcoplasmic reuptake of Ca2+ resulting in high concentrations in the cytosol, allowing Ca2+ –dependent activation of phospholipase, the generation of free radicals, and damage to the muscle fibers involved. [1]
Other hypothesis involving Prostaglandin E2, which has been found to be present in high quantities in overuse tissues in rat and chicken models. [2] This mediator has been suggested to influence cell proliferation, increase collagenase, and decrease collagen synthesis. As the result of increasing loads on these tissues, nitric acid and prostaglandin amount are altered. However, a contradicting hypothesis based on rat-model observations shows that overuse of muscle may lead to an understimulation of tendon cells, rather than overstimulation.
In another study, alterations in regulation of genes within tendons undergoing overuse have been shown in the rat model, in which there is upregulation of genes associated with cartilage, and down-regulation of genes associated with tendon.[3] This might suggests that overuse may cause a morphologic alteration of tendon tissue, resulting in the cartilaginous changes in the tendons
From another point of view, psychosocial factors might play a role in overuse injuries for decades. This includes work satisfaction, perceived physical health, perceived mental health, coping mechanisms of the patient and his/her family, perception of work-readiness, and anxiety.
RISK FACTORS:
Risk factors for overuse injury are not only depends on the biomechanical changes of the action, but also intrinsic factor of the patient. Sex differences play a role in certain overuse injuries. For example, the incidence of carpal tunnel syndrome is higher among female compared to male. This has a variety of possible causes, including anatomical differences in the carpal tunnel, hormonal differences, differences in the activities performed by men and woman, biomechanical differences such as elbow carrying angles, Q-angles, femoral anteversion, and lean body mass. Stress fractures typically affect individuals who are more active, and the incidence probably increases with age due to age-related reduction in bone mineral density (BMD).
Although stress fractures result from repeated loading, some other causes such as menstrual disturbances and irregularities, lower dietary calcium intake, caloric restriction, less oral contraceptive use, muscle weakness, decreased testosterone level in male endurance athletes and leg-length differences are risk factors for stress fractures.[4] A study among military recruits has shown that recruits with stress fractures had significantly narrower tibiae and increased external rotation of the hip.
HISTORY:
It is important to obtaining complete information on the onset, timing, and frequency of symptoms; any associated symptoms; and alleviating and exacerbating factors. Information about specific activity or technique problem is also essential. Other relevant symptoms may include a history of popping, clicking, rubbing, erythema, or vascular phenomena. In athlete, specific attention must be paid to training details, equipment fit, and technique. The most salient historical feature in the diagnosis of stress fracture is the insidious onset of activity-related pain. In early stage, the pain is usually mild and felt toward the end of the inciting activity. As the disease progresses, the pain may worsen and occur earlier, limiting participation in sports activities. Rest may relief the pain in the early stages, but as the injury progresses, the pain may persist even after cessation of activity. Other than that, night pain is a frequent complaint. Usually, the patient has no recent history of trauma to the affected area.
Long-bone fractures usually lead to localized pain, while pain from injury of trabecular bone is more diffuse. Possible risk factors that precipitated or contributed to the injury should be identify. These include details of the athlete's training history both in terms of volume and intensity, intensive sustained muscular activity, muscle fatigue, structural malalignments, biomechanical inefficiencies, concurrent injury, or poor bone health status. Diagnosis is usually based on clinical findings and high index of suspicion because fracture site or new bone formation is visible on radiography maybe only after several weeks.
PHYSICAL EXAMINATION
The examination in case of overuse injury follows the basic method of orthopaedic examination; consist of inspection (including alignment and anatomical structure), palpation, and passive (including athlete's flexibility) and active range of motion (ROM). Usually, tenderness and guarding are present. During ROM examination, crepitus; painful or painless usually can be appreciated. On local examination, erythema, swelling, and anatomic derangement raise the possibility of an acute injury or infection, as well as the presence of an inflammatory disease. Some special test or maneuvers can be applied to help in making diagnosis, such as “Hop test” and “Fulcrum test”, or Tinel and Phalen tests at the wrist.[5] But, no single physical examination test is sufficiently sensitive and specific to permit the unequivocal diagnosis of a stress fracture. So, the doctor should correlate the history with examination, together with high clinical suspicion to consider the overuse injury as one of the possible diagnosis.
CAUSES
The primary factor leading to overuse injury is repetitive activity, although the specific type of force leads to different outcomes. Repetition is part of the definition of overuse injury. The concept is that overuse injury is associated with repeated challenge without sufficient recovery time. Another terms to describe repeated activities are cycles and fundamental cycles. While cycle is a large-scale activity that is repeated throughout the day, fundamental cycle is a small component of a cycle that may be repeated several times during the performance of a cycle. Repetitiveness and force exerted are features of a task that increase the risk of sustaining an overuse injury.
However, some studies have shown that cycle times and repetitive motions do not specifically lead to overuse injury in the upper extremity, but as possible causes for injury.[1] It is shown that vibration; especially over long periods is a factor in increasing the risk of many injuries such as lower back pain, intervertebral disk injury, and wrist injury. Apart from the above, malpositioning of limbs away from their neutral position increases the risk for overuse injury.
DIFFERENTIAL DIAGNOSIS
Differential diagnoses vary and depend on location, symptoms, history and physical examination.
o Shin splints (medial tibial stress syndrome) can mimic stress fractures ot the tibia. Shin splint pain tends to be present at the start of activity, while overuse injury at the end. Tenderness to palpation over a wide region of the tibia and the tibialis muscle, whereas the pain from stress fractures tends to be localized to a specific area on the tibia.
o True fractures can be differentiated from overuse injury by an obvious history, with a traumatic event being recalled by the patient with acute onset of pain.
• Muscle strains; may be acute or chronic. Chronic muscle strains can be differentiated from overuse injury by the location and by factors that exacerbate or worsen the injury.
• Costochondritis may mimic the pain seen in stress fractures of the ribs. Rib stress fractures should be suspected in athletes who participate in rowing sports, such as crew rowing. The pain of costochondritis may be more diffuse or widespread than the pain from stress fractures of the ribs. .[4]
• Nerve entrapment syndromes can also mimic overuse injury, but can be differentiated by presence of numbness in the former.[4]
• Popliteal artery entrapment syndrome is another cause of lower extremity pain. This also present with increased pain and/or swelling with exercise, which is more diffuse than the pain associated with stress fractures. Measurement of ankle blood pressures before and during exercise or an angiogram may help with the diagnosis.
DIAGNOSIS AND INVESTIGATIONS
Radiography
Stress fractures may not show up on radiographs for the first 2-4 weeks after injury. The first radiographic finding may be a localized periosteal reaction or an endosteal cortical thickening. The low sensitivity of radiographs for stress fractures gives advantage to bone scanning, magnetic resonance imaging (MRI), and computed tomography (CT).
Magnetic resonance imaging (MRI)
MRI not only provides information about bone integrity and fracture orientation, but also can demonstrate focal tissue damage and edema.
Technetium-99m bone scanning
It took 72 hours for Technetium bone scan findings to be positive in the case of a stress fracture. However, a positive bone scan finding is nonspecific, and it may be indicative of another diagnosis, such as an infection or a neoplastic process. In a study which compare conventional radiography and bone scanning for the initial detection of stress fractures, positive findings were reported in 96% of bone scans, whereas only 42% positive findings were reported on radiographs.
Electrodiagnostic testing
Electrodiagnostic testing (such as EMG, nerve conduction studies) can be very useful in cases of peripheral nerve compression or injury; such testing can provide evidence of the location and severity of the injury. However, EMG and nerve conduction studies are not tests with high specificity, although they can provide much-needed information when vague symptoms are the chief complaint. They are also very useful for documenting work-related injuries.
Laboratory Tests
These tests are relevant if the individual is discovered to have metabolic bone disease or another comorbidity such as inadequate nutritional status.
TREATMENT
Physical Therapy
Patient should have rest, particularly avoidance of the inciting activity. Total bed rest is virtually never advisable for these patients. Instead, participation in a carefully planned physical therapy program is important. The physical therapy program also offers the patient the chance to see that movement will not lead to ongoing tissue damage, thus preventing significant "sick behaviors" or kinesophobia. Ill-fitting equipment, overtraining, or technique flaws commonly cause overuse injury in athletes. So, specialized fitted equipments hould be provided, while sports psychology is worthwhile in combating overtraining, and sport-specific coaching is often invaluable. Coaches, athletes, and physicians must work together to correct these problems.
Occupational Therapy
Occupational therapists can help to identify workplace modifications. In cases of individuals who develop overuse injuries as a result of the interface with adaptive equipment, occupational therapy may be of great benefit. Simple modifications in the manner in which the patient performs activities of daily living or modifications in the equipment itself can provide relief.
Surgical Intervention
Surgical intervention is required only if conservative approaches fail, or if the injury is amenable to surgery. Most common problems that lead to surgery in overuse injury are decompression of nerves and repair of lax or failed ligaments. Surgical procedures most typically involve open-reduction internal fixation and pinning of the associated fracture sites. Surgeries that are performed solely to relieve pain in the absence of objective findings are notorious for suboptimal outcomes.
Medication
Combined injection of corticosteroids and local anesthetics is quite helpful in persons with overuse injury.[1] Pain relief enables more effective participation in therapy, and it may help to limit the likelihood that the patient will develop a chronic pain syndrome. Usually, injections should be performed after less invasive measures fail. In some rare condition, immediate relief of pain may be necessary to allow participation in an athletic or performing arts event, and this can be achieved through injection therapy.
Nonsteroidal anti-inflammatory drugs (NSAIDs) are mainstays in the treatment of overuse injuries. However, there are evidences that revealed that true inflammation is rarely a component of these disorders, especially tendinopathies. So, the use of simple analgesics has become more prevalent in the treatment of such disorders. Muscle relaxants, opiates, corticosteroids, tricyclic antidepressants, and sleep medications have a role in the specific treatment of individuals with overuse injury.
PREVENTION
Nutritional measures: calcium supplementation
A study by Schwellnus and Jordaan found that there is no benefit with calcium supplementation (500 mg/d) beyond the usual dietary intake in male military recruits.[6]
Biomechanical measures: orthotics and shoe inserts
The use of orthotic devices and shoe inserts has been studied as a preventive measure for lower-extremity stress fractures. It is found that the incidence of lower-extremity stress fractures was lower in the group using semirigid orthoses (15.7%) or soft biomechanical orthoses (10.7%) than in the control group (27%). Additionally, the recruits better tolerated the soft biomechanical orthoses than the semirigid orthoses.[7]
In a prospective study of stress fractures, shock-absorbing orthotic device worn within military boots decreases the incidence of stress fractures. [8] There is a statistically significant decrease in the incidence of femoral stress fractures in the orthotic device group.
COMPLICATION
High-risk stress fractures
Even though nonunion of stress fractures is uncommon, but it can occur. To prevent this, stress injuries should be closely followed up for early surgical intervention. These include stress fractures of the neck of the femur, the anterior cortex of the tibia, the tarsal navicular, and the bases of the second and fifth metatarsals. Other high-risk stress fractures include stress fractures of the patella and medial malleolus.
Low-risk stress fractures
Low-risk stress fractures include most upper-extremity stress fractures, except for the fractures through the physis of the humeral head (little leaguer's shoulder) and fractures through the medial epicondyle (little leaguer's elbow), which may have complications due to the involvement of the growth plate.[9] Other low-risk stress fractures include stress fractures of the ribs, pelvis, femoral shaft, fibula, calcaneus, and the metatarsal shafts.
REFERENCES:
1. eMedicine. Scott R Laker, MD. Overuse Injury, Mar 12, 2008.
2. Flick J, Devkota A, Tsuzaki M, et al. Cyclic loading alters biomechanical properties and secretion of PGE2 and NO from tendon explants. Clin Biomech (Bristol, Avon). Jan 2006; 21(1): 99-106.
3. Archambault JM, Jelinsky SA, Lake SP, et al. Rat supraspinatus tendon expresses cartilage markers with overuse. J Orthop Res. May 2007; 25(5): 617-24.
4. eMedicine. John M Martinez, MD. Stress Fractures, Apr 17, 2008.
5. eMedicine. Vincent N Disabella, DO, FAOASM. Elbow and Forearm Overuse Injury, Feb 12, 2008.
6. Schwellnus MP, Jordaan G. Does calcium supplementation prevents bone stress injuries? A clinical trial. Int J Sport Nutr. Jun 1992; 2(2): 165-74.
7. Finestone A, Giladi M, Elad H. Prevention of stress fractures using custom biomechanical shoe orthoses. Clin Orthop. Mar 1999;360: 182-90
8. Schwellnus MP, Jordaan G, Noakes TD. Prevention of common overuse injuries by the use of shock absorbing insoles – A prospective study. Am J Sports Med. December 1990; 18:636-641.
9. Boden BP, Osbahr DC, Jimenez C. Low-risk stress fractures. Am J Sports Med. Jan-Feb 2001; 29(1): 100-11.
N.B. This article is excerpted from the Book : OVERUSE INJURIES IN ORTHOPEDIC PRACTICE: Diagnostic Enigma and Mananagement Principles
Editorial Reviews
Product Description
Overuse injuries are injuries of the musculoskeletal and nervous systems that may be caused by repetitive tasks, forceful exertions,vibrations,mechanical compression,or sustained or awkward positions.It is also known as Repetitive Strain Injury or Cumulative Trauma Disorders. These are most commonly used to refer to patients in whom there is no discrete,objective,pathophysiology that corresponds with the pain complaints.Physical activity is a great way for kids to build bone strength, prevent obesity and stay healthy,when paired with safety and prevention practices. With youth sports injuries rising at alarming rates,overuse injuries such as sore bones and muscles, and swollen or injured joints need prompt attention in child athletes to prevent chronic musculoskeletal problems later in life. Understanding overuse injuries can guide you to designing your training to reduce the risk of injury and help you to recognize and treat them as they inevitably occur.Overuse injuries can be defined as the product of "too much,too fast,too soon." The topics discussed in these chapters are conditions commonly seen by the author in his long stint as an orthopedic and sports medicine consultant.
About the Author
Prof Gourishankar Patnaik is internationally renowned orthopedic and Spinal surgeon. A topper throughout he has over two decades of teaching and research experience at various medical colleges in India, Oman, USA and Malaysia. A globe trotter he has authored many books. A gifted Surgeon his research interests include diabetes, Neurotrauma and E-learning.
Rate It
Why we are No. 1 › 
Category (
Views (
