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From Sports Medicine Research: In the Lab & In the Field Blog Written by:  Stephen Thomas Reviewed by:  Kyle Harris The effects of Low-intensity Pulsed Ultrasound on tendon-bone healing in a transosseous-equivalent sheep rotator cuff model Lovric V, Ledger M, Goldberg J, Harper W, Bertollo N, Pelletier MH, Oliver RA, Yu Y, Walsh WR.  Knee Surg Sports Traumatol Arthrosc. 2012 Mar 31. [Epub ahead of print] Rotator cuff tears occur frequently and have a high rate of re-tears.  It has been very difficult to achieve effective rotator cuff healing not to mention reestablish the native tendon-bone interface following a cuff repair.  There has been attempts at optimizing the rehabilitation following cuff repair to improve success, however, no study has examined the application of low-intensity pulsed ultrasound (LIPUS) following cuff repair.  Therefore, the objective of this study was to examine the effects of LIPUS on the early phases of tendon-bone healing in a sheep model. Eight sheep underwent detachment and immediate reattach of the infraspinatus tendon.  The infraspinatus tendon in sheep is similar to the supraspinatus in humans.  Half (n = 4) of the animals were given LIPUS and the other half (n = 4) did not receive any treatment.  The LIPUS treatment was started the day following surgery and was administered 5 days a week for a duration of 20 minutes per day.  The LIPUS was delivered at 30 mW/cm2 in 200-µs bursts of sine waves at a frequency of 1.5MHz and a 0.2 duty cycle during each treatment.  Twenty-eight days post-surgery micro-CT, histology, and immunohistochemistry were performed on all animals.  They found increased bone mineral density at the rotator cuff footprint in the LIPUS group compared to the control group. They also found that the LIPUS group had an improved histological appearance compared to the control group.  They observed thicker regions of woven bone and increased osteoblast activity.  There was also more established Sharpey’s fibers in the transition region of tendon to bone.  The immunohistochemistry results found an increased amount of vascular endothelial growth factor (VEGF), RUNX2, and Smad4 in the LIPUS group.  Each of these proteins have been associated with improved bone healing. This is an interesting study that examines the use of LIPUS to improve rotator cuff tendon to bone healing following surgical repair.  LIPUS is a modality that has been seen frequently in sports medicine.  It has seemed to be most effective treating bone fractures but has been used to treat soft tissue injuries as well.  The rotator cuff insertion site is a unique location that incorporates soft tissue and bone.  These unique characteristics may optimize both the soft tissue and bone effects of the LIPUS to improve rotator cuff healing.  In addition, there are several studies demonstrating signs of degeneration in both the torn tendon and the bone of the rotator cuff footprint in chronically torn rotator cuff tendons.  This further suggests that LIPUS may have the potential to improve healing by increasing cell proliferation of both the bone and tendon.  Although it wasn’t examined in this study, the use of LIPUS preoperatively may be warranted in chronically torn tendons that undergo severe degeneration and have a poor prognosis.  However, due to the small sample size and the short time point of 28 days following surgery, there is clearly more research that needs to be done to fully understand the mechanisms through which LIPUS leads to improved rotator cuff healing.  Have you used LIPUS following rotator cuff repair?  Have you had success? To learn more about the latest research on healing and rehabilitation of rotator cuff tears look for our UQ/LQ course in a city near you!

From Sports Medicine Research: In the Lab & In the Field

Blog Written by: Jane McDevitt MS, ATC, CSCS

Reviewed by: Stephen Thomas

Rehabilitation of Concussion and Post-concussion Syndrome

Leddy JL, Sandhu VS, Baker JG., Willer B. Sports Health. 2012:4;147-154. (link to abstract)

The majority of athletes recover from a concussion within 10 days, however, at least 10% of athletes continue to have signs and symptoms (s/s) beyond 14 days. Post-concussion syndrome (PCS) occurs when patients display persistent s/s beyond normal recovery period (> 14 days). This systematic review found 564 studies that fulfilled their search criteria and utilized 119 articles that focused on pathophysiology, diagnosis, and treatment/rehabilitation of concussions and PCS. Acceleration-deceleration forces are the most common mechanisms that strain the neuron by causing the brain to move within the skull. The stretch of the neuron results in a neurometabolic cascade that causes an array of problems (e.g., hyperglycolosis, mitochondrial dysfunction, decreased blood flow) within neuronal tissue, which can last for 7-10 days. Researchers have described this period of time as a window of vulnerability that a second insult prior to healing could lead to a more severe injury. Magnetic resonance spectroscopy (MRS) can determine the concentration of brain metabolites such as lactate, which can characterize the state of the central nervous system. MRS imaging studies have shown that even after s/s subsided there is still an ionic imbalance (e.g., levels of calcium, sodium, and potassium are not within homeostatic levels in the neuronal cells) leaving the brain vulnerable for a secondary injury. Depression and migraine differential diagnosis is also important to evaluate because of the overlapping s/s. This review also notes that researchers found other physiological changes that can occur following a concussion are increased heart rate, autonomic dysfunction, and cerebral infarction, which can be exacerbated with exercise.

The differential diagnosis of PCS include depression, somatization, chronic fatigue, visual dysfunction, or a combination of these illnesses. The challenge is to determine whether the prolonged s/s implicate a concussion pathology or one of these secondary processes (e.g., migraine, depression). Initial concussion assessment should include concentration exam (e.g., counting down from 100 in 3’s), memory recall, cranial nerve exam, and vestibular-ocular exam including balance testing. An exertion test can help determine a concussion from psychological illness. If s/s occur during exertion but are alleviated with rest it is likely a concussion, however, if s/s are not relieved with rest it could indicate a psychological disorder. Another more broad definition used to define PCS is having 3 or more of the following s/s: headache, dizziness, fatigue, irritability, insomnia, difficulty concentrating, or memory difficulty. After diagnosis the clinician should provide treatment and rehabilitation for the concussion or PCS. There still is no therapeutic agent to accelerate recovery. Treatment includes primarily rest, however some therapeutic agents can be utilized. The most commonly prescribed medications for PCS are antidepressants. These therapeutic agents block serotonin from being taken up and can improve depression symptoms and cognition. In addition, glutamate blockers such as NMDA antagonists are used to help alleviate concussion s/s by preventing or limiting the ionic imbalance. Rest is necessary, however, prolonged rest especially for athletes can lead to physical deconditioning, metabolic disturbances, fatigue, and depression so implementing a gradual return to play after the concussive s/s have dissipated should be executed. Rehabilitation includes a gradual return to play. That is, starting when the athlete has been s/s free they can begin a treadmill test. If s/s develop during or following the treadmill test patients must return to the previous phase, and if no s/s are experienced patients progress through each of the phases of the return to play criteria. In children it has also been suggested that an information booklet on strategies for dealing with concussion s/s resulted in less behavioral changes and s/s. Other rehabilitation techniques include a neurocognitive portion that uses cognitive tasks to improve aspects of cognition such as attention, memory, and executive functioning. What have you done for athletes with prolonged s/s of concussions? Have any of your athletes developed an illness due to a prolonged concussion?

To learn more about the management of concussions and other sports related injuries check out the ACE/NASMI Foundations Course 

From Sports Medicine Research: In the Lab and In the Field

Blog Written by: Kyle Harris

Reviewed by: Jeffrey Driban

Clinical Results and Risk Factors for Reinjury 15 Years After Anterior Cruciate Ligament Reconstruction: A Prospective Study of Hamstring and Patellar Tendon Grafts

Leys T, Salmon L, Waller A, Linklater J, and Pinczewski L. Am J Sports Med. 2012; 40 (3). 595-605. (link to abstract)

Commonly seen in young athletes, anterior cruciate ligament (ACL) rupture is often treated by surgical reconstruction of the ligament. The aims of this surgery are to restore the joint kinematics, limit episodes of instability, and return the patient to preinjury levels of activity. While the aims of ACL reconstructions are the same, the optimal graft type used in this reconstruction, is still a debated issue. Therefore, Leys and colleagues conducted a prospective cohort study to compare the outcomes of patellar tendon (PT) and hamstring tendon (HT) autografts assessed at 2, 5, 7, 10, and 15 years post-surgery. A total of 180 patients (90 consecutive patients in each group) were initially included in the study. At the 15-year follow-up visit, 51 patients with HT were available and 43 patients with PT were available for full assessment (subjective and clinical review, over 70 patients/group were available for just a subjective review at 15 years). The decision of which graft would be used was based on what time period (mid-October 1993: HT autograft, Oct 1993-Nov 1994: PT autograft) the patient’s initial consultation took place, with all surgeries being performed by one surgeon. The follow-up assessments included the International Knee Documentation Committee (IKDC) knee ligament evaluation (assesses signs and symptoms as well as knee function), Lysholm knee score (assesses knee function), clinical assessment (Lachman, anterior drawer, etc.), instrumented laxity testing, range of motion, kneeling pain using a visual analog scale, and single-legged hop test. Radiographs were also taken at each follow-up visit. Patients who received a HT autograft had superior outcomes at 15-years post-surgery compared to patients with PT autografts with respect to IKDC score, activity level (based on patient reports:, strenuous vs. moderate vs. light), kneeling pain, range of motion, single-legged hop test, and radiologic changes (using IKDC grading system). Since the 10-year follow-up visit, more patients with PT autografts may have developed extension deficits and patients with PT autografts experienced a decline in single-leg hop performance. Interestingly, the PT autograft was found to have better results with respect to clinical ligament stability measurements at 15 years post-surgery follow-up.

Overall, this study presents interesting insight into the long-term results comparing both HT and PT autografts. While the results of this study showed patient with HT autografts had significantly better results in function, pain levels, activity levels, and radiologic changes, the authors note that this change was seen primarily between 10 and 15 year follow-up. The authors suggest that these differences after long-term follow-up could be in part related to the onset and progression of osteoarthritis. Clinically, this study presents and interesting case for patients who are concerned about long-term knee outcomes to receive HT autografts as they appear to have less degenerative change and better functional outcomes at a 15 year follow-up. While this may be true, the PT autograft did show better performance (although not statistically significant) with respect to instrumental stability measures (once again showing a discordance between knee stability measures and other outcomes). How does this information change your current counseling strategy? Would you be more inclined to suggest a HT graft knowing that the long-term functional outcomes appear to be better?

From Sports Medicine Research: In the Lab & In the Field

Blog Written by: Mark Rice

Reviewed by: Stephen Thomas

Biceps Tenotomy Versus Tenodesis: Clinical Outcomes

Slenker NR, Lawson K, Ciccotti MG, Dodson CC, Cohen SB. Arthroscopy. 2012 Jan 25. [Epub ahead of print] (link to abstract)

Chronic inflammation of the long head of the biceps brachii (LHB) tendon can be a stubborn and complex condition. As with most chronic inflammatory conditions a course of rest, activity modification, nonsteroidal anti-inflammatory drugs (NSAIDs), rehabilitation, and even corticosteroid injection may be indicated. However, if conservative treatment fails there are two surgical interventions, biceps tenotomy (complete detachment of the LHB) or tenodesis (detachment with anchoring of the LHB in the bicipital groove). Slenker et al. conducted a systematic review to determine the clinical effectiveness of both surgical treatments. They conducted a systematic review of PubMed and were able to identify 16 studies with a total of 699 tenotomy procedures and 433 tenodesis procedures. Subjects ranged in age from 15 to 83 years of age and there was no mean age difference between the 2 treatment groups. Tenodesis resulted in a good to excellent outcome in 74% of the cases and yielded a cosmetic deformity (the Popeye sign) 8% of the time. After LHB tenotomy, 77% of the patients reported good to excellent outcomes, but cosmetic deformity was present in 43% of the cases. There was also less bicipital pain experienced post-op in the tenotomy group (19%) as compared to the tenodesis group (24%). The authors did analyze a subgroup of patients having either tenotomy or tenodesis performed along with concomitant rotator cuff pathology. The tenotomy subjects stated good to excellent outcomes 72 to 85% of the time. The subjects treated by tenodesis reported good to excellent outcomes 63 to 93% of the time. The Popeye sign was noted 27 to 62% and 0 to 9% respectively for tenotomy versus tenodesis.

The data collected shows that biceps tenotomy and tenodesis have very similar success rates, whether there is rotator cuff involvement or not. The authors state that procedure selection should be based on a multitude of factors, including age and activity level. Biceps tenotomy has a much shorter recovery period due to the procedure being much less invasive than the tenodesis. However, the tenotomy treatment experiences greater incidence of cosmetic deformity. The tenodesis procedure typically takes longer to perform and recover from, and there is greater associated post-operative pain but less chance of cosmetic deformity. Prevailing thought dictates that for older and/or more sedentary patients, biceps tenotomy might be more appropriately indicated. Younger and/or more active (athletic/labor intensive careers) individuals might benefit more from biceps tenodesis. One item that remains unclear is if there is any true strength loss after either procedure. Some studies have shown as much as a 20% decrease in elbow flexion and supination strength after tenotomy, while others haven’t demonstrated any decreases. The authors set out to determine which procedure is clinically more effective; however, both procedures had similar clinical outcomes. As with any treatment or surgical procedure, the main factor to consider is the patient’s quality of life and function. Future studies are going to need to be conducted in an effort to clarify this topic, especially involving individuals that participate in vigorous overhead activity. What are your experiences with LHB surgical options? Should we consider either option at all, based upon the LHB’s role as shoulder dynamic stabilizer? Aside from the cosmetic differences, can you say whether one procedure has worked better than the other for your patients?

From Sports Medicine Research: In the Lab & In the Field

Blog Written by: Katherine Reuther

Reviewed by: Jeffrey Driban

Predictors of pain and function in patients with symptomatic, atraumatic full-thickness rotator cuff tears: a time-zero analysis of a prospective patient cohort enrolled in a structured physical therapy program.

 Harris JD, Pedroza A, Jones GL; MOON (Multicenter Orthopedic Outcomes Network) Shoulder Group. Am J Sports Med. 2012 Feb;40(2):359-66. Epub 2011 Nov 17. (link to abstract)

A high prevalence of functional asymptomatic rotator cuff tears exists, with symptoms commonly developing and progressing over time. Predicting which tears will become symptomatic and/or require surgery is a major clinical challenge. Identifying the factors that relate function and pain in symptomatic rotator cuff tears would be instrumental in helping to identify at-risk individuals and guide treatment strategies. Therefore, the purpose of this study was to determine the patient factors (modifiable and non-modifiable) associated with function and pain, based on the Western Ontario Rotator Cuff (WORC) index (a self-report questionnaire regarding quality of life) and American Shoulder and Elbow Surgeons (ASES) score (a self-report questionnaire regarding pain and function), in patients with symptomatic, atraumatic full thickness rotator cuff tears. 389 patients (18 to 100 years of age, unilateral full-thickness rotator cuff tear, significant weakness, pain with activities of daily living, impingement symptoms >3 months) who elected to participate in a non-operative physical therapy program were included in this study. Patients completed a self-administered outcome questionnaire that included their demographics, WORC index, and ASES scores. The minimal clinically important difference (MCID; the smallest change in scores that patients perceive) for the WORC index and ASES scores are 11.7 and 6.4 points, respectively. Additionally, patients underwent routine physical examination and determination of tear characteristics (i.e., tear size, tear retraction, and presence of scapulothoracic dyskinesis, humeral head migration, and/or muscle atrophy). The following variables were determined to be associated with higher WORC and ASES scores (reflecting increased function): female sex, higher education levels, increased active abduction range of motion (ROM), and increased strength in forward elevation and abduction. The modifiable parameters with greatest association (having MCID) were full muscle strength in forward elevation (increased WORC by 18.39 points compared to less strength) and abduction (increased WORC by 13.79 points compared to less strength), while increased active abduction and forward elevation ROM (every 10 degrees) were associated with increased ASES scores of only 0.78 and 0.85 points, respectively. The following variables were determined to be associated with lower WORC and ASES scores (reflecting decreased function): male sex, atrophy of the supraspinatus and infraspinatus, and presence of scapulothoracic dyskinesia. Specifically, the presence of scapulothoracic dyskinesis was associated with a decrease in the WORC index and ASES scores of 6.85 and 4.07 points, respectively. Additionally, tear size was not identified as a significant predictor unless comparing isolated supraspinatus tears to multi-tendon tears (i.e., involving the supraspinatus, infraspinatus, and subscapularis).

This cross-sectional study identified several modifiable factors that related to function and pain in patients with symptomatic rotator cuff tears (e.g., scapulothoracic dyskinesis, range of motion in active abduction and forward elevation, as well as strength in abduction and forward elevation). The authors conclude that rehabilitation programs should address these factors to improve and/or eliminate symptoms in patients with atraumatic, full-thickness rotator cuff tears. However, before definitive recommendations can be made, it is important to consider the strength of the associations identified. In particular, the parameters of increased active abduction and forward elevation ROM were associated with minimal increases in ASES score and therefore, modifying these factors alone may not be sufficient to be perceived as a clinically important difference. Successful modification of a combination of several of these factors may be necessary to induce changes that patients may perceive as beneficial. Additionally, in order to determine if successful modification of these factors improves clinical outcome, longitudinal follow-up investigations (e.g., clinical trials) are necessary. Previous studies have identified rotator cuff tear size as a significant predictor of patient outcomes, with larger tears associated with both decreased shoulder function and patient satisfaction. Surprisingly, tear size was not found to be significantly associated with pain and function in this study. The cohort included only patients who elected non-operative rehabilitation treatment, excluding patients undergoing operative treatment. It is likely that patients with symptomatic larger tears may have elected operative management, which may account for the discrepancy observed. Nevertheless, this study has important clinical implications and it is likely that targeting these modifiable factors will improve patient pain and symptoms with the potential of converting symptomatic rotator cuff tears to asymptomatic tears. Do you currently target any of the factors identified in this study to treat patients with rotator cuff tears? Have you notice improved outcomes? Would the results of this study alter how you treat patients?

From Sports Medicine Research: In the Lab & In the Field

Blog Written by: Nicole Cattano

Reviewed by: Jeffrey Driban

The Prevalence of Radiographic Hip Abnormalities in Elite Soccer Players

Gerhardt MB, Romero AA, Silvers HF, Harris DJ, Watanabe D, & Mandelbaum BR. American Journal of Sports Medicine. 2012; 40: 584-588 (link to abstract)

Hip injuries (e.g., sports hernias, impingement, labral tears) have recently seemed to become more widely diagnosed and treated within the athletic population. Femoroacetabular impingement, and other radiographic hip abnormalities, may be a common source of hip pain and risk factor for hip osteoarthritis but unfortunately how common these radiographic abnormalities are remains unclear. Therefore, the purpose of this study was to identify the prevalence of radiographic abnormalities among 95 professional soccer athletes (75 males [on average 26 years old], 20 females [on average 24 years old]). All athletes were screened during routine preseason examinations. A portion of this screening included assessing for radiographic hip abnormalities. Fifty-five percent of the male and 25% of the female athletes reported a history of prior hip/groin injury. Seventy-two percent of the male and 50% of the female athletes had some evidence of abnormal hip radiographs, consistent with impingement. Radiographic abnormalities identified had extremely high incidences (76 to 100%) of bilateral hip involvement.

Clinically, it appears that there are an extremely high number of radiographic hip abnormalities in a professional soccer population. The prevalence is more than tripled the rate that was found in a general population study. The number of abnormalities in this current study far exceeds the number of athletes that have had previous hip/groin injury. One hypothesis is that the repetitive functional activities associated with playing soccer may be putting these athletes at risk. It would be interesting to see a comparison of symptoms with the presence of radiographic abnormalities. The prevalence of radiographic abnormalities is only slightly lower than a collegiate football study previously posted on SMR, which also discussed the fact that there were abnormalities found in 95% of a collegiate football population despite being largely asymptomatic. If an athlete is asymptomatic, despite the presence of radiographic abnormalities, should this change our clinical action? It would also be interesting if the athletes with radiographic abnormalities were followed prospectively and their symptoms monitored at various time points. Within this population, evidence of hip osteoarthritic changes was found in 5 to 25% of the athletes. Specifically within hip osteoarthritis, bone shape may be one of the leading causes of osteoarthritis. Radiographic abnormalities may be precursors to hip osteoarthritis, ultimately providing a window of opportunity for early disease modifying interventions. Has anyone had patients who have had a hip injury or surgery and are trying any homeopathic interventions? Also, clinically, hip pathologies present very similarly to sports hernias. It may be important to take a look at all possible contributors to athletes’ symptoms prior to deciding on what the culprit is. Has anyone had any experiences with athletes who have had hip or sports hernia diagnoses?


From Sports Medicine Research: In the Lab & In the Field

 Blog Written by: Kathleen White

Reviewed by: Jeffrey Driban

Symmetry Restoration and Functional Recovery Before and After Anterior Cruciate Ligament Reconstruction

 Logerstedt D, Lynch A, Axe MJ, Snyder-Mackler L. Knee Surg Sports Traumatol Arthrosc. 2012 Feb 21. [Epub ahead of print] (link to abstract

Restoration of function after anterior cruciate ligament reconstruction (ACLR) is paramount for return-to-sport and long-term health of the knee joint. During rehabilitation, clinical measures of quadriceps strength and hop performance along with self-reported outcome measures have been used to evaluate improvements in function but we don’t know when these measures return to “normal” with rehabilitation before and after surgery. Furthermore, it is not clear how much improvement in limb symmetry, based on quadriceps strength and hop performance, is meaningful. Therefore, the purpose of this study was to identify how limb symmetry, based on using quadriceps strength and hop measures, changes during rehabilitation. Eighty-three athletes’ participating in sports involving cutting, pivoting and jumping activities were examined for this study. All athletes underwent pre-ACLR rehabilitation including strengthening and perturbation training (PERT). Functional measures of quadriceps strength, hop performance and self-reported outcome measures were collected at baseline (after injury but before pre-operative rehabilitation), after pre-operative PERT training (prior to surgery), as well as 6 and 12 months after ACLR. Quadriceps strength was tested through maximum voluntary isometric contraction with burst superimposition technique [Snyder-Mackler, 1995]. Four single leg hop tests, as previously described by Noyes et al, were used to evaluate limb symmetry (involved limb’s results divided by uninvolved limb’s results) with ?90% limb symmetry considered normal knee function, based on normal subject values [Risberg, 1995]. Self-reported questionnaires were used to evaluate the patients’ perception of knee function; Knee Outcome Survey-Activities of Daily Living (KOS-ADLs), International Knee Documentation Committee 2000 (IKDC 2000) and Global Rating Scale (GRS). Quadriceps strength measures of the involved limb (surgical limb) at baseline were weaker than the uninvolved limb (contralateral healthy limb). However, quadriceps strength improved overtime and there were no differences between limbs after baseline measures. The involved limb for all subjects hop scores, except the cross-over hop, improved more than the uninvolved limb and all scores improved from baseline to 12 months after ACLR. Despite the improvements, at 6 months after ACLR 19 to 23% of individuals did not achieve normal knee function based on ?90% limb symmetry on hop measures and 5 to 11% of individuals did not achieve this score at 12 months. Similarly, 25% and 13% of individuals had IKDC2000 scores below normal ranges at 6 month and 12-month post-ACLR; respectively. Small changes in all outcome measures occurred from 6 to 12 months after surgery.

While perturbation training and quadriceps strengthening was capable of improving limb symmetry in many patients not all individuals achieved ?90% limb symmetry at 6 and 12 months after surgery. Six months after surgery, when individuals are typically cleared to return-to-sport, up to 23% of individuals in this study did not achieve ?90% limb symmetry. Furthermore, at 12 months after surgery 5 to 11% of individuals still had not achieved 90% limb symmetry. This may be concerning since it is speculated that these asymmetries, tested during controlled dynamic hopping tasks, may be magnified during opposed athletic play. However, it is important to note that there is insufficient evidence to suggest that individuals that do not achieve this 90% cut-off have poorer outcomes. A recent systematic review determined that consistent return-to-sport criteria are lacking for this population [Barber-Westin, 2011]. Self-reported questionnaires and objective assessments of limb symmetry may become an important components for return-to-sport criteria. Based on normal values of ?90% [Risberg, 1995], not all individuals achieve limb symmetry at 6 and 12 months. Do you think this cut-off is sufficient to determine when return-to-sport is appropriate? Or is 90% not strict enough?

To learn more about ACL rehabilitation, functional movement and much more check out our great PT continuing education courses!

From PT In Motion News Now

Slower walking speed may be a marker for incident knee osteoarthritis (OA), say authors of an article published online last month in Arthritis Care & Research.

For this study, 1,858 noninstitutionalized residents age 45 years or older who lived at least 1 year in 1 of 6 townships in Johnston County, North Carolina, completed questionnaires and clinical examinations at baseline and at follow-up testing. Walking time was assessed using a manual stopwatch in 2 trials over an 8-foot distance. Walking speed was calculated as the average of both trials. For the hip and knee, researchers examined 3 outcomes per joint site—radiographic OA (weight-bearing anteroposterior knee radiographs, supine anteroposterior pelvic radiographs of the hip), chronic joint symptom, and symptomatic OA. Covariates included age, gender, race, education, marital status, body mass index, number of prescriptions, depressive symptoms, self-rated health, number of lower-body functional limitations, smoking, physical activity, and number of self-reported, health care provider-diagnosed chronic conditions.

Faster walking speed was consistently associated with lower incidence of radiographic (adjusted odds ratio [aOR]=0.88) and symptomatic knee OA (aOR=0.84). Slower walking speed was associated with greater incidence of these outcomes across a broad range of different clinical and radiographic OA outcomes.

APTA member Jama L. Purser, PT, PhD, is lead author of the study. APTA member Yvonne M. Golightly PT, PhD, is coauthor.

From PT In Motion News Now

People who have a cardiac arrest that can’t be helped by a defibrillator shock are more likely to survive if given cardiopulmonary resuscitation (CPR) based on updated guidelines that emphasize chest compressions, according to the American Heart Association (AHA).

AHA changed its CPR guidelines in 2005 to recommend more chest compressions with fewer interruptions. The emphasis on chest compressions continued in the 2010 guidelines update.

After the 2005 guidelines, several studies showed improved survival from shockable cardiac arrest.

However, new evidence shows that most cardiac arrests—nearly 75%— are due to conditions that don’t respond to shocks. Researchers identified 3,960 patients in King County, Washington, who had a type of cardiac arrest that doesn’t respond to shock from a defibrillator, or nonshockable cardiac arrest.

They compared survival rates among patients who had nonshockable cardiac arrests from 2000-2004—before the 2005 guidelines changes—to those who had nonshockable arrests from 2005-2010 and found:

The likelihood of survival to discharge from the hospital improved from 4.6% before to 6.8% after the new guideline changes.

The proportion of patients who survived with good brain function increased from 3.4% to 5.1% between study periods.

One-year survival almost doubled from 2.7% to 4.9%.

Free full text of the study is available online in Circulation.

From Sports Medicine Research: In the Lab and In the Field

Written by: Jeffrey Driban

Reviewed by: Stephen Thomas

The lumbar spine of the young cricket fast bowler: An MRI study

Crewe H, Elliott B, Couanis G, Campbell A, Alderson J. J Sci Med Sport. 2011 Dec 21. [Epub ahead of print] (link to abstract)

Medical imaging (e.g., radiographs, magnetic resonance [MR] imaging, ultrasound) is commonly used to diagnose pathology; however, it is unclear what MR imaging findings are common among junior cricket fast bowlers in cricket (a population at high risk for lumbar pain). Therefore, Crewe et al described the prevalence and nature of MR-identified lumbar spine abnormalities among 46 asymptomatic adolescent cricket fast bowlers. MR imaging scans were performed before the start of the season. All of the athletes were injury free at the time of the MRI and reported not experiencing low back pain in the preceding three months. The MR images were assessed by two experienced musculoskeletal radiologist who primarily assessed the pars interarticularis and intervertebral discs. The authors found that 15 (33%) athletes had at least one lumbar pars abnormality (9 unilateral, 5 bilateral, and one subject had a bilateral defect at L5 and a unilateral defect at L4). Typically the pars abnormalities occurred at the L5 vertebra (19 out of 22 abnormalities; where we often observe spondylolysis and spondylolisthesis). Thirteen of the 22 abnormalities were subtotal stress fractures. Other abnormalities included 3 chronic stress reactions, 5 chronic stress fractures, and 1 acute stress fracture. Among 11 participants with acute stress injuries, 4 admitted to symptoms during clinical history questions after they were informed of the MR imaging results and on clinical examination 3 others were found to have pain with extension, single-legged extension, quadrant testing, or direct palpation. Sixteen (35%) athletes were found to have degeneration of at least one lumbar disc (six with multiple lumbar discs having abnormalities). Most of the disc abnormalities were L4/L5 or L5/S1.


This study has two very interesting findings: 1) 33% of young cricket fast bowlers who reported being asymptomatic for 3 months had evidence of lumbar abnormalities on MR images, and 2) on closer examination 7 of 11 patients with signs of acute stress injuries ended up reporting being symptomatic or had positive findings during clinical examination. The athletes who ended up having positive clinical findings often attributed their symptoms to “general soreness” or as insignificant. The authors suggest that this is further support for “thorough clinical questioning” to elicit the difference between acceptable soreness and pain that warrants further evaluation. SMR had a post last year that stressed the importance of not rushing through asking about a patient’s medical history. The authors also advocate for providing more education to our athletes about the potential risks of playing through pain (something we can apply to all of the injuries we treat). The other aspect of this study that was intriguing and relevant to other aspects of sports medicine is whether some of these imaging findings represent structural changes that precede symptoms or a normal sign of the body adapting to the stress of mechanical loading. Most likely these findings reflect normal adaptation to mechanical loading but if adequate recovery is not provided then these findings progress to changes that induce symptoms (e.g., stress fracture). In osteoarthritis research, for example, structural changes are sometimes perceived as risk factors for developing joint symptoms. The authors note that it’s not financially feasible to order MR imaging for all of our high-risk athletes but instead suggest that young athletes should undergo regular physical exams (including a thorough questioning) and be educated about the importance of reporting pain to avoid a delayed diagnosis; which if you think about it could hold them out of play even longer. Do you find that young athletes sometimes can’t distinguish pain from exercise-induced soreness?