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MTSS Part 2
2011 / 05 / 20 ( Fri )
Effects of Therapeutic Interventions
Moen, Tol, Weir, Steunebrink and Winter conducted a systemic review on the existing literature on MTSS including aetiology, biomechanics, histology, patient evaluation, diagnostic imaging, risk factors, therapy and prevention in 2009. In their search for the existing literature, they only found three randomized controlled trials that had ever been conducted on treatment of MTSS and all three of those studies were conducted among military populations. In this review, I was able to identify those three studies and two newer studies on the treatment of MTSS that actually demonstrated significant results, with no randomization.
Cyotherapy (i.e., icing) is by far the most common therapeutic intervention used for the treatment of any athletic injury, acute or chronic. Due to its high practicality and popularity, cryotherapy has been widely used to treat MTSS as well as other chronic injuries. However, the evidence of the effectiveness of icing for the treatment of MTSS is yet to be established.
In 1974, Andrish et al. conducted a study involving over 2,700 midshipmen. In the first part of their study, a total of 2,777 first-year midshipmen were randomly divided into five groups for the purpose of prophylactic regimens; 1) control group, normal physical activity with no prophylactic measure 2) normal physical activity with heel pads for running 3) normal physical activity, routine heel-cord stretching program 4) normal physical activity, routine use of heel pads and heel-cord stretching program 5) graduated running program two weeks prior to the start of training. The authors reported that there was no statistically significant difference in the incidence of MTSS (referred to as shin splints in the original article) between the five prophylactic groups.
In the second part of the study, 97 subjects who were diagnosed with MTSS were randomly assigned to one of the five treatment options; 1) no running until pain-free, apply ice 3 times/day 2) no running until pain-free, ice 3 times/day, 10g of aspirin 4 times/day for one week 3) no running until pain-free, ice 3 times/day, 100mg of phenyIbutazone 4 times/day for one week 4) no running until pain-free, ice 3 times/day, heel-cord stretching program 5) application of short walking cast for one week.
As a result, they found that the subjects with MTSS who were treated with combination of rest and ice (group I) showed statistically significant improvements compared to other groups of subjects who were treated with other treatment options. The success of treatment was measured by the average number of days lost from running. The average number of days lost in group I was 6.4 days and the overall average of all groups was 8.62 days (p<0.03).
Unfortunately, this study from 1974 is the only randomized controlled study available for review that studied the effectiveness of cryotherapy on this particular pathology (see table 2 for the PEDro scale rating). Since all treatment regimens were effective to varying degrees, it is difficult to say that there’s enough evidence on the effectiveness of cryotherapy for the treatment of MTSS. The fact that the two of the other treatment options (group II and III) also incorporated the application of ice combined with medication (aspirin in group II and phenyIbutazone in group III) yet failed to yield the same amount improvement as group I also raises a reasonable doubt as well. In fact, group II (ice and aspirin) showed the second least favorable result following group V (walking cast).
Another limitation of the study is that both their definition and diagnostic criteria for ‘shin splints’ were too broad and now outdated, deviating from the criteria for MTSS used in more current literatures, which leaves the findings of this study somewhat questionable. The majority (75%) of the subjects with shin splints reported the location of pain being anteromedial or anterolateral (22%), which contradicts one of the main diagnostic criteria today; pain along posteromedial tibial border. This deficit was never pointed out in any of the articles that cited this 1974 study by Andrish et al.
A problem with treating MTSS or tibial stress fractures with ice is that not only its effectiveness has never been well-established, but also it can possibly hinder the healing process of bone lesion by disrupting the balance between the osteoblastic and osteoclastic activities of the involved area of the bone. Beck (1998), Couture and Karlson (2002) suggested bone remodeling, or adaptation to mechanical properties in response to change in tibial loading, increases metabolic activity of osteoclasts. When osteoblasts fail to keep up with the increased activity of osteoclasts due to excessive bone stimulation, microfissures result, leading to the development of stress injury. Thus, the balance between the osteoblastic and osteoclastic activity is believed to be a key in treating these conditions. However, how the decreased tissue temperature affect the activity of osteoblasts and osteoclasts in the involved area of the bone was not investigated in any of the reviewed articles.
In a recent British study, Moen et al. (2011) studied the effectiveness of shockwave therapy (extracorporeal shockwave therapy; ESWT) as a treatment for MTSS. ESWT is a relatively new treatment in which highly intensive acoustic waves are delivered in a very short duration to the injured area with or without a local anesthesia. They are characterised by an abrupt pressure increase, an exponential pressure drop and a prolonged flat negative pressure period. These features are different from the continuous waves of ultrasound. The therapeutic effect of shock waves are believed to be from the mechanical pressure and tension the wave exerts on the tissue (Brems, 1999). Although detailed knowledge on the effects of shock waves including side effects on different types of human tissue is not yet available, ESWT has been proved effective for a variety of musculoskeletal injuries including plantar fasciopathy, Achilles tendinopathy, shoulder calcific tendinitis, lateral epicondylitis, and greater trochanter pain syndrome (Rompe, Cacchio, Furia & Maffulli, 2010).
In this prospective observational controlled study by Moen et al., a total of 42 athletes who were diagnosed with MTSS were divided into two groups. The first group of patients was assigned a graded running program and the second group was assigned the same running program combined with ESWT treatment sessions over the course of 9 weeks. The running program performed by both groups consisted of six phases. In the first two phases of the program, the subjects ran on the treadmill and then progressed on to outside running in later phases. The running distance was determined individually in progression based on how long (how many meters) the individual can run without experiencing pain as a baseline. The subjects ran three days a week with at least one day between the sessions. The intensity and volume of the running assignments were determined using the 1-10 visual analog scale (VAS). If pain of 4 or more on VAS scale was experienced immediately after the completion of running session or one day after the session, then the next phase was not commenced and the next running session would start with the same load as the previous session but for less duration. The focused ESWT was administered on the second group in addition to the running programme. The ESWT device was used to deliver 1000 to 1500 shocks with an energy flux density of 0.10 to 0.25 mj/mm2 at a frequency of 2.5 shocks per second to the area along the posteromedial boarder of the tibia in which all subject had pain to palpation. This group started running program and treatment with ESWT in the same week. Outcome was primarily measured in the number of days from inclusion to completion of phase 6 of running schedule (i.e., full recovery). The result showed that in the first group (running program only) the duration to full recovery was 91.6 days (SD43.0) while the second group (running program and treatment with ESWT) returned to full running in 59.7 days (SD25.8). The two means were significantly different (p=0.008) with the treatment group recovering 17.5% faster. Since this was an observational study and there was no randomization or blinding used, the study is of a limited strength and therefore, the PEDro scale does not apply. However, this is one of the very few studies on treatment of MTSS that have ever been conducted and successfully found a significant difference on outcome measures between two different treatment options.
Moen’s findings are consistent with another study by Rompe et al., who compared shock wave therapy with a control group that performed a home exercise program (Rompe et al., 2010). A total of 94 subjects with chronic MTSS who had failed at least 3 forms of conservative treatments for a minimum of 3 months participated in this retrospective study in a secondary-care setting. Such conservative treatment measures consisted of relative rest, stretching and muscle strengthening, anti-inflammatory medications, cryotherapy, corticosteroid and/or local anesthetic injections, insoles and few others. The treatment group (N=47) was treated with shock wave treatment combined with the 12-week home training program (twice a day), relative rest and ice. The control group was treated the same except the shock wave treatment for 12 weeks. The home training program consisted of progressive slow repetitive exercises such as calf stretching, Thera-band resisted dorsiflexion, inversion and eversion, heel and toe raises. A low-energy shock wave treatment was performed to the treatment group at weeks 2, 3, and 4 using a radial shock wave device after the subjects started the home exercise program. With this device, each subject received 2000 shock waves with an energy flux density of 0.1mJ/mm2 at a frequency of 8 shocks per second 3 times a week in weekly intervals. The outcome was primarily measured by degree of recovery at 1, 4 and 15 months compared with baseline, which was measured on a 6-point Likert scale. Severity of pain was also self-reported by the subjects and recorded at those times compared with baseline. At all three points of time (1, 4, and 15 months after inclusion), the percentage of high scores on Likert scale rating (i.e., self-reported degree of recovery) was statistically greater in the treatment group than in the control group (p<.001 for each point). Positive results were also seen on the numeric pain scale ratings, with a statistically significant difference in the magnitude of the change in pain score between the two groups (p<.001 for each point). The fact that there was no randomization in this study and no placebo was used is certainly a limitation to this study and therefore, the PEDro scale does not apply here, either. Yet, the evidence is fairly strong and certainly supports positive findings from other controlled studies on the effectiveness of shock wave therapy for treatment of MTSS. Another weakness would be the fact that the subjects were not MRI or CT scan screened prior upon inclusion, but the diagnostic criteria used was well accepted and consistent with other studies. The authors concluded that low-energy radial shock wave is a safe and effective treatment for patients with chronic MTSS, and that satisfactory improvement is maintained for at least one year.
Nissen, Astvad and Madsen (1994) conducted a randomized study on a military personnel which examined the effect of active laser treatment on a treatment group (N=23) who received a functional laser probe and a control group (N=26) who received a placebo treatment. The laser used in the study was a gallium-aluminum-arsenic laser of 830 nm wave-length (40 mW in 60 seconds/cm tender tibia edge). Each subject was asked to report their pain levels on a visual analog scale before every treatment. Both groups attended up to six treatment sessions total. After 14 days of treatment, 19 of 26 subjects (73%) in the placebo group and 18 of 23 subjects (78%) in the treatment group were able to return to duty based upon physical examination. The difference between the two groups was not significant. The analysis of visual pain scale scores revealed no statistical significance, either (see table 2 for the PEDro scale rating).
Therapeutic ultrasound is another commonly used modality for the treatment of MTSS. Although many clinicians employ the use of this modality to treat this condition, there was no study available that investigated the effect on MTSS.
Callison (2002) studied the effectiveness of acupuncture in patients with MTSS by comparing treatment results of acupuncture and sports medicine, which incorporated the use of therapeutic ultrasound as well as other conservative therapeutic measures. Since ultrasound was performed in combination with others, the contribution of ultrasound could not be estimated in this study. The results demonstrated that acupuncture was more effective conservative treatment in reducing pain associated with MTSS.
It is suggested by many authors that calf stretching should be part of the comprehensive management for treatment and prevention of MTSS or tibial stress fracture (Craig, 2002; Touliopolous & Hershman, 1999). Physicians, athletic trainers, physical therapists and coaches almost always seem to recommend calf stretching to athletes to treat and prevent ‘shin splints.’ However, currently there is no randomized control study available for review that studied whether calf stretching is effective in treatment for MTSS and stress fracture.
In the second part of Andrish’s 1974 study on 2,700 plus midshipmen, one of the five treatment groups were assigned heel-cord stretching as part of their treatment for MTSS. This groups of subjects who were diagnosed with MTSS (then termed shin splints) performed heel-cord stretching exercise three times a day every day until recovery (i.e., absence of pain and tenderness, or in the event of persistent mild symptoms, the ability to run approximately 500 meters comfortably). The outcome, as measured by the number of days lost from running, did not indicate heel-cord stretching was effective in treating MTSS, with the average number of days of all groups being 8.62 days and the group’s average being 8.8 days. Likewise, in the first part of the study which concerned itself with prophylactic measures, two of the five groups that were assigned heel-cord stretching exercises (one group stretching, the other group stretching and the use of heel pad) did not show any favorable results.
Thus, literature is very limited in terms of the effectiveness of calf stretching for either prevention or treatment of MTSS, even though in practice, calf stretching is “the gold standard.” The stretching exercised utilized in the study consisted of standing approximately 76 centimeters from a wall and bending forward, with the body kept straight and heels on the ground. Subjects were instructed to hold this position for 15 seconds, then to relax for 5 seconds, and repeat for 3 minutes. Since subjects were instructed to keep their knees straight, the gastrocnemics muscles was likely the one being stretch, not soleus. As concluded in more recent etiology studies, soleus appears to be the major contributor in development of MTSS. More specifically, it has been proposed that MTSS is a consequence of traction stress on the periosteum applied by the medially arising fibers of the soleus muscle or the posterior tibialis muscle (Beck & Osternig, 1994). Tight plantar flexors could cause the tibia to bend like a bow, creating a compressive load on the postero-medial surface of the tibia (Beck, 1998). Therefore, it would be very beneficial to investigate the outcome of a stretching program that focuses more on soleus (i.e., stretching with the knees flexed). No such study was found in current literature.
In the 1974 study by Andrish et al., one of the five groups wore a short walking cast for one week as their treatment, combined with the application of ice. The results showed no statistical difference between this group and others, as measured by the number of days lost from running. There was no other study available that concerned itself with the effect of a brace or cast in patients with MTSS.
It has been suggested by multiple studies that the use of insole or orthotics should be incorporated as part of treatment program for MTSS (Craig, 2002; Touliopolous & Hershman, 1999). As mentioned previously, etiology studies do suggest that the amount of foot pronation and pes planus (flat feet) plays an important role in the development of MTSS and tibial stress fracture (Reinking and Hayes, 2006; Willems, Vi/itvrouw, DeCock and DeClercq, 2007). Reinking (2006) prospectively monitored 76 female college athletes for development of exercise-induced leg pain and found no differences between those who experienced leg pain and those who did not in terms of age, muscle length, eating behaviors, body mass index (BMl), menstrual function, or bone mineral density. However, athletes with exercise-induced leg pain did have significantly greater navicular drop values than those without. Williams et al. analyzed plantar pressure measurements and three-dimensional gait kinematics to characterize the running gait patterns of 400 physical education students. The subjects who developed exercise-related low leg pain demonstrated significantly greater pronation excursion and greater pressure on the medial portion of the foot during the stance phase of running gait. Therefore, it is reasonable to assume that supporting the medial arch of the foot by wearing an insole or orthotic would help alleviate the symptoms of MTSS. Craig (2002) argues that supporting the medial longitudinal arch to control pronation should decrease the magnitude of the eccentric load placed on the medial soleus and the rate at which is applied. Unfortunately, this assumption has not been confirmed but yet, the use of orthotics as treatment of MTSS is widely practiced with no evidence. To date, no study has been published that investigates the effect of orthotics on MTSS. What is known is, however, that using orthotics to increase medial arch support appears to be effective in preventing the development of MTSS, as demonstrated in a few studies (Shwellnu.s., Jordaan and Noakes, 1990; Larsen, Weidich & LeBoeuf-Yde, 2002).
Johnston (2006) presented data on the “Shin Saver” orthosis as a treatment for MTSS (then termed “shin splints” in the original article) in an active duty military population. In this randomized study, 25 active duty soldiers were divided into a shin orthosis group and traditional treatment group. The first group (experimental group) was instructed to wear a shin brace called ‘Shin Saver’ by Alimed on the involved shin during all daily activities excluding bathing and sleeping for 6 weeks, in addition to activity modification and ice massage biweekly. The control group received the same activity modification prescription as the experimental group as well as the application of biweekly ice massage. At day 7, subjects in both groups began walk-to-run program which involves graded walking to running. The program was performed until the subject was able to run 0.5 mile without experiencing pain, or until the end of the 6 week period. As an outcome measure, subjects were asked to mark their pain level before and after every session on a visual analog scale (VAS) for pain. The number of days to completion of the 0.5 mile run and the number of treatment sessions required were also recorded and analyzed statistically. Only 7 subjects in the experimental group and 6 in the control group were able to complete the study due to complications or failure to meet treatment schedule. VAS scores comparison between the two groups before and after the walk-to-run program revealed no significant difference, with only two subjects in the experimental group reporting some pain relief with the use of the orthosis. No statistically significant difference was seen in the days to completion of the 0.5 mile run (p>0.575), or in the number of treatment sessions required (p>0.578). 5 of the 7 subjects in the experimental group who completed the study reported no improvement or even worsening of the symptoms with the use of the orthotic device. Thus, this study fails to provide any strong evidence as to the effective or ineffectiveness of Shin Saver orthosis for the treatment of MTSS because of the small sample size, high dropout rate, and resultant low power (see table 2 for the PEDro scale rating).
The author suggests that further investigation and development of a treatment-based classification system may enhance clinicians’ ability to better manage this pathological condition. It is suggested in the discussion that there would be four different classification schemes for MTSS; 1) distal management 2) local treatment at the site of pain 3) proximal symptom management, and 4) systemic management. The first group would respond well to the treatment which involves accommodations for different foot types and running mechanics, such as overpronation. Such strategies would include the use of rigid or semi-rigid orthotic devices or shock-absorbing insoles. The second group would respond better to local treatment around the site of the pain including cryotherapy. The third group may respond best to proximal symptom management such as manual treatment of proximal joints (i.e., knee joint or hip joint) or core strengthening program. Lastly, some individuals may benefit the most from systemic management such as administration of NSAIDs in order to help reduce pain and inflammation. This classification can potentially be very useful in finding the treatment option that is most suited to each individual, if further investigation and case studies can match the characteristics of clinical findings and predict the best treatment option based on this proposed classification system.
If conservative treatment fails, a surgery may be indicated in rare cases. Yates, Allen, and Barnes (2003) conducted a postoperative follow-up study on 46 patients (athletes) who underwent surgical treatment of MTSS after seeing no improvement with conservative treatment for a minimum of 6 months. The outcomes of the surgical intervention were assessed by comparing preoperative and postoperative pain levels as marked on a visual analog pain scale and ascertaining the ability of the athletes to return to presymptom levels of activity. All surgical procedures were performed at Leicester General Hospital, Leicester, United Kingdom by one of the authors. The procedure includes a deep posterior compartment fasciotomy and partial removal of periosteum from along the inner tibial border by means of periosteal elevator. The patients are allowed to start walking with crutches between 24 to 48 hours after the operation. The patients return to full weight bearing in two weeks, and non-to-partial weight bearing exercises such as biking and swimming in six weeks. Gradual running is permitted at three months, and return to full activity may take up to 12 months. The participants were followed-up for an average duration of 30 months. The result clearly indicated that surgical intervention reduced pain significantly by an average of 72% (ranged 20% to 100%), as reported on visual analog scale (p<0.001). Despite the successful results in pain reduction, only 19 (41%) of the 46 participants returned to their presymptom level of sports activity. The reason for not going back to their pre-injury activity level varied between individuals. For example, 10 individuals remained symptomatic after the surgery, some chose not to due to the fear of reproduction of symptoms with activity, and some for not having enough motivation or time.
This study appears to be the most meaningful study on the outcome of surgical interventions for MTSS to date, involving the largest number of patients. The absence of a control group would add to its limitations, but the evidence is still very valuable considering the fact that the majority of studies on treatment for MTSS are inconclusive as for their effectiveness. The diagnostic criteria utilized were also reliable and consistent with recent studies.
Acupuncture, an alternative medicine originating from China that treats an injury or disease by inserting needles to the body, is another potential treatment option for MTSS. The effectiveness of acupuncture has been recognized widely in treating a variety of conditions including various musculoskeletal injuries. There was one interesting study by Callison (2002), which compared treatment results from acupuncture and sports medicine in patients with MTSS. In this study, forty athletes were divided into three groups; 1) sports medicine group, who received standard forms of treatment often used in the athletic training setting such as pulsed ultrasound, cryotherapy and proprioceptive neuromuscular facilitation (PNF) stretching of the involved leg and foot muscles 2) acupuncture group and 3) a combination of sports medicine and acupuncture. As the outcome measurement, participants were asked questions concerning their pain (intensity, duration and how much it affects their performance) during and after activities, as well as dosages taken of anti-inflammatory medications (NSAIDs). Participants in each group received a minimum of 2 treatments per week over a 3-week period.
The results indicated acupuncture is an effective treatment for reducing pain associated with MTSS. As demonstrated in the questionnaire, severity of pain during activity at the time of follow-ups was significantly lower in the acupuncture group than in the other two, so was the severity of pain present. All athletes (100%) in the acupuncture group reported a reduction in pain, while 72.7% of the combination group and only 41.2% of the sports medicine group did. Another important factor addressed in the questionnaire as part of the outcome measurement was the effect of different treatment on the athlete’s sports performance, which can be the single most important aspect for some of the athletes. 100% of the athletes in the acupuncture group reported less hindrance by pain during their sports activity, 72.7% in the combination group, and 35.3% in the sports medicine group. The difference was also significant between the groups of athletes when asked about dosage of anti-inflammatory medications (amount taken per day). Throughout the course of the 3-week study, athletes in the acupuncture group and combination group reported taking significantly less amount of NSAIDs (decreased by 80% and 60%, respectively) compared to the sports medicine group, who reported taking the same amount over the course of the study.
Due to the small sample size, these results can only be interpreted as preliminary tendencies. The author used a number of Chinese medical terminologies when describing the acupuncture treatment method and manual therapy utilized in the study (i.e, motor points) which makes it difficult to visualize what had been performed to the involved areas. The author does not provide explanation on many of the Chinese medical practice, such as “tuina massage” that was performed on all athletes in the acupuncture group for 5 minutes at the end of every treatment session, which could have affected the outcome directly. The fact that all treatments were performed by either certified athletic trainer, athletic training students or acupuncture interns as well as diagnosis of MTSS upon inclusion adds to its weaknesses due to a possible inconsistency between these practitioners at varying levels. As for diagnosis of MTSS, the diagnostic criteria was not clearly stated which is an essential information when assessing the study for its clinical relevance. It was also unclear how those practitioners were able to rule out stress fracture or exertional compartment syndrome without the use of imaging. However, despite its limitations, this is the only study that examined the effectiveness of acupuncture treatment for patients with MTSS. Their positive findings suggest that acupuncture is an effective modality for relieving pain associated with MTSS and for reducing reliance on NSAIDs. Acupuncture should be considered as a treatment option if the patient fails to respond to conservative treatments (i.e., treatments received by the sports medicine group). A larger sample size would be necessary in order to conclude validity (see table 2 for the PEDro scale rating).
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