Shock waves in the treatment of stress fractures

Use of extracorporeal shockwave therapies for athletes and physically active individuals: a systematic review

OBJECTIVE

To determine the efficacy of extracorporeal shockwave therapy (ESWT) and investigate outcomes following the use of ESWT for athletes and physically active individuals.

DESIGN

Systematic review.

DATA SOURCES

We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses and searched four databases: PubMed (NLM), Embase (Elsevier), CINAHL Complete (EBSCO) and Web of Science (Clarivate).

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Included studies were randomised controlled trials, cohort and case-control studies, cases series and reports that evaluated outcomes following ESWT for athletes, physically active individuals and occupational groups requiring regular physical activity such as military cadets.

RESULTS

56 studies with 1874 athletes or physically active individuals were included. Using the Oxford level of evidence rating, included studies were 18 level I (32.1%), 3 level II (5.4%), 10 level III (17.9%), 13 level IV (23.2%) and 12 level V (21.4%). Based on the level I studies, ESWT may be effective alone in plantar fasciitis, lateral epicondylitis and proximal hamstring tendinopathy and as an adjunct to exercise treatment in medial tibial stress syndrome and osteitis pubis in athletes or physically active individuals. In most studies, athletes were allowed to continue activities and training and tolerated ESWT with minimal side effects.

CONCLUSION

ESWT may offer an efficacious treatment alone or as an adjunct to concurrent exercise therapy in selected sports-related injuries and without major adverse events. Further high-level research is needed to better define the role and clinical outcomes of ESWT.

Shockwave Treatment vs Surgery for Proximal Fifth Metatarsal Stress Fractures in Soccer Players: A Pilot Study

BACKGROUND

To compare the clinical, radiologic, and functional outcomes between shockwave and operative treatments for proximal fifth metatarsal stress fractures in soccer players in a pilot study.

METHODS

Between 2017 and 2019, 18 soccer players with fifth metatarsal stress fractures attended at Mutualidad de Futbolistas Españoles-Delegación Catalana were included. Patients were randomly assigned into 2 groups receiving either surgery with an intramedullary screw (group 1) or high-energy focused extracorporeal shockwave treatment (group 2 performed once a week for 3 weeks using 2000 impulses at an energy flux density of 0.21 mJ/mm2 and 4 Hz frequency). Clinical (pain), radiologic (bone healing), and functional (Tegner Activity Scale and American Orthopaedic Foot & Ankle Society [AOFAS] ankle-hindfoot scales) outcomes before and after receiving the treatment were compared between both groups. In addition, ability and time to return to play was also compared between groups.

RESULTS

No patients were lost to follow-up. There were no statistically significant differences at last follow-up between surgery and extracorporeal shockwave treatment for bone healing, pain relief, AOFAS ankle-hindfoot score, Tegner score, and time return to play. No complications were reported in either of the 2 groups.

CONCLUSION

In this pilot study, extracorporeal shockwave treatment and operative treatment were found to be equally effective at reducing pain, achieving bone healing, and allowing the soccer players to return to play after proximal fifth metatarsal stress fractures. This study suggests that ESWT may be a good option for the management of proximal fifth metatarsal stress fractures in soccer players. If this approach proves successful in larger trials, the shockwave approach might help avoid known complications of the surgical treatment like wound problems, nerve injury, and hardware intolerance. Further investigations with larger sample size should be conducted in order to confirm the present conclusions.

LEVEL OF EVIDENCE

Level II, therapeutic, pilot randomized controlled trial.

Outcomes Using Focused Shockwave for Treatment of Bone Stress Injury in Runners

Bone stress injury (BSI) is a common overuse injury that can result in prolonged time away from sport. Limited studies have characterized the use of extracorporeal shockwave therapy (ESWT) for the treatment of BSI. The purpose of this study was to describe the use of ESWT for the management of BSI in runners. A retrospective chart review was performed to identify eligible patients in a single physician's clinic from 1 August 2018 to 30 September 2022. BSI was identified in 40 runners with 41 injuries (28 females; average age and standard deviation: 30 ± 13 years; average pre-injury training 72 ± 40 km per week). Overall, 63% (n = 26) met the criteria for moderate- or high-risk Female or Male Athlete Triad categories. Runners started ESWT at a median of 36 days (IQR 11 to 95 days; range 3 days to 8 years) from BSI diagnosis. On average, each received 5 ± 2 total focused ESWT treatments. Those with acute BSI (ESWT started <3 months from BSI diagnosis) had an average return to run at 12.0 ± 7.5 weeks, while patients with delayed union (>3 months, n = 3) or non-union (>6 months, n = 9) had longer time for return to running (19.8 ± 14.8 weeks, p = 0.032). All runners returned to pain-free running after ESWT except one runner with non-union of grade 4 navicular BSI who opted for surgery. No complications were observed with ESWT. These findings suggest that focused ESWT may be a safe treatment for the management of BSI in runners.

Nonoperative Management of Tibial Stress Fractures Result in Higher Return to Sport Rates Despite Increased Failure Versus Operative Management: A Systematic Review

Purpose

To compare return to sport (RTS) rates and complications after nonoperative versus operative management of tibial stress fractures.

Methods

A literature search was conducted per the 2020 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines using EMBASE, PubMed, and Scopus computerized data from database inception to February 2023. Studies evaluating RTS sport rates and complications after nonoperative or operative management of tibial stress fractures were included. Failure was defined as defined by persistent stress fracture line seen on radiographic imaging. Study quality was assessed using the Modified Coleman Methodology Score.

Results

Twenty-two studies consisting of 341 patients were identified. The overall RTS rate ranged from 91.2% to 100% in the nonoperative group and 75.5% to 100% in the operative group. Failures rates ranged from 0% to 25% in the nonoperative groups and 0% to 6% in the operative group. Reoperations were reported in 0% to 6.1% of patients in the operative group, whereas 0% to 12.5% of patients initially managed nonoperatively eventually required operative treatment.

Conclusions

Patients can expect high RTS rates after appropriate nonoperative and operative management of tibial stress fractures. Treatment failure rates were greater in patients undergoing nonoperative management, with up to 12.5% initially treated nonoperatively later undergoing operative treatment.

Level of Evidence

Level IV; Systematic Review of level I-IV studies.

Outcomes in Pediatric Hip FAI Surgery: a Scoping Review

PURPOSE OF REVIEW

Femoracetabular impingement (FAI) is a common source of hip pain in children and adolescents. While nonoperative therapies and open surgical procedures can be effective, hip arthroscopy is a minimally invasive treatment option with substantial benefit. The purpose of this paper is to evaluate the current role of hip arthroscopy in treating FAI within the pediatric population. This article examines its efficacy through a review of hip arthroscopy outcomes in the contemporary orthopaedic literature.

RECENT FINDINGS

Morphologic changes in the acetabulum and proximal femur seen in FAI can be attributed to a multitude of etiologies-including idiopathic FAI, Legg-Calve-Perthes, and slipped capital femoral epiphysis. In general, arthroscopic treatment of FAI secondary to these conditions leads to statistically significant improvements in pain and patient-reported outcomes in the short and long term. In the pediatric athlete, repetitive stress on the hip perpetuates FAI and can drastically hinder performance. Hip arthroscopy allows for a high rate of return to sport with minimal morbidity in this population. Overall, pediatric hip arthroscopy is effective in treating FAI secondary to a wide variety of conditions. Despite its clinical benefits, patients and their families should be counseled regarding alternative treatments, potential complications, and return to play.

Bone stress injuries

Bone stress injuries, including stress fractures, are overuse injuries that lead to substantial morbidity in active individuals. These injuries occur when excessive repetitive loads are introduced to a generally normal skeleton. Although the precise mechanisms for bone stress injuries are not completely understood, the prevailing theory is that an imbalance in bone metabolism favours microdamage accumulation over its removal and replacement with new bone via targeted remodelling. Diagnosis is achieved by a combination of patient history and physical examination, with imaging used for confirmation. Management of bone stress injuries is guided by their location and consequent risk of healing complications. Bone stress injuries at low-risk sites typically heal with activity modification followed by progressive loading and return to activity. Additional treatment approaches include non-weight-bearing immobilization, medications or surgery, but these approaches are usually limited to managing bone stress injuries that occur at high-risk sites. A comprehensive strategy that integrates anatomical, biomechanical and biological risk factors has the potential to improve the understanding of these injuries and aid in their prevention and management.

Effect of External Mechanical Stimuli on Human Bone: a narrative review

Bone is a living composite material that has the capacity to adapt and respond to both internal and external stimuli. This capacity allows bone to adapt its structure to habitual loads and repair microdamage. Although human bone evolved to adapt to normal physiologic loading (for example from gravitational and muscle forces), these same biological pathways can potentially be activated through other types of external stimuli such as pulsed electromagnetic fields, mechanical vibration, and others. This review summarizes what is currently known about how human bone adapts to various types of external stimuli. We highlight how studies on sports-specific athletes and other exercise interventions have clarified the role of mechanical loading on bone structure. We also discuss clinical scenarios, such as spinal cord injury, where mechanical loading is drastically reduced, leading to rapid bone loss and permanent alterations to bone structure. Finally, we highlight areas of emerging research and unmet clinical need.

A Narrative Review of Metatarsal Bone Stress Injury in Athletic Populations: Etiology, Biomechanics, and Management

Metatarsal bone stress injuries (BSIs) are common in athletic populations. BSIs are overuse injuries that result from an accumulation of microdamage that exceeds bone remodeling. Risk for metatarsal BSI is multifactorial and includes factors related to anatomy, biology, and biomechanics. In this article, anatomic factors including foot type, metatarsal length, bone density, bone geometry, and intrinsic muscle strength, which each influence how the foot responds to load, are discussed. Biologic factors such as low energy availability and impaired bone metabolism influence the quality of the bone. Finally, the influence of biomechanical loads to bone such as peak forces, load rates, and loading cycles are reviewed. General management of metatarsal BSI is discussed, including acute care, rehabilitation, treatment of refractory metatarsal BSI, and evaluation of healing/return to sport. Finally, we identify future research priorities and emerging treatments for metatarsal BSI.

Extracorporeal Shock Wave Treatment for Delayed Union and Nonunion Fractures: A Systematic Review

OBJECTIVES

Nonunions after bone fractures are usually treated surgically with risk of infections and failure of osteosynthesis. A noninvasive alternative is extracorporeal shock wave treatment (ESWT), which potentially stimulates bone regeneration. Therefore this review investigates whether ESWT is an effective and safe treatment for delayed unions and nonunions.

DATA SOURCES

Embase.com, MEDLINE ovid, Cochrane, Web of Science, PubMed publisher, and Google Scholar were systematically searched.

STUDY SELECTION

Inclusion criteria included studies with patients with delayed union or nonunion treated with ESWT; inclusion of ≥10 patients; and follow-up period ≥6 weeks.

DATA EXTRACTION

Assessment for risk of bias was conducted by 2 authors using the Cochrane tool. Union rates and adverse events were extracted from the studies.

DATA SYNTHESIS

Two RCTs and 28 nonrandomized studies were included. One RCT was assessed at medium risk of bias and reported similar union rates between ESWT-treated patients (71%) and surgery-treated patients (74%). The remaining 29 studies were at high risk of bias due to poor description of randomization (n = 1), nonrandomized allocation to control groups (n = 2), or absence of control groups (n = 26). The average union rate after ESWT in delayed unions was 86%, in nonunions 73%, and in nonunions after surgery 81%. Only minor adverse events were reported after ESWT.

CONCLUSIONS

ESWT seems to be effective for the treatment of delayed unions and nonunions. However, the quality of most studies is poor. Therefore, we strongly encourage conducting well-designed RCTs to prove the effectiveness of ESWT and potentially improve the treatment of nonunions because ESWT might be as effective as surgery but safer.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Sesamoid osteonecrosis treated with radial extracorporeal shock wave therapy

Sesamoid osteonecrosis is a disabling condition resulting in severe forefoot pain, for which there are limited treatment options. We present a 52-year-old man with 1-year history of pain, aggravated by walking and playing tennis. On examination, pain was localised to plantar aspect of the first metatarsophalangeal joint. Imaging revealed evolving end-stage avascular necrosis of lateral sesamoid with early secondary degenerative changes. Previous exhaustive conservative treatment had been unsuccessful in alleviating his pain. As an alternative to surgery, radial extracorporeal shock wave therapy (rESWT) was proposed. Treatment protocol was 2000 pulses at frequency of 5 Hz, and pressure was varied from 1.2 to 1.8 bar according to patient tolerance. A total of eight sessions were delivered. At completion of treatment, the patient reported minimal discomfort to no pain and was able to return to playing tennis with no recurrence. We propose rESWT to be an effective novel conservative treatment for sesamoid osteonecrosis.

Tarsal navicular stress fractures

PURPOSE OF REVIEW

Navicular stress fractures are common in athletes and management is debated. This article will review the evaluation and management of navicular stress fractures.

RECENT FINDINGS

Various operative and non-operative adjunctive treatment modalities are reviewed including the relevance of vitamin D levels, use of shock wave therapy and bone marrow aspirate concentrate (BMAC), and administration of teriparatide. Surgical treatment may be associated with earlier return to sports. The author's preferred treatment algorithm with corresponding images is presented which allows for safe and rapid return to activities in the athletic patient. Future research is needed in evaluating the preventative effects of vitamin D and use of other adjunctive treatments to increase the healing rates of this fracture.

Foot and Ankle Stress Fractures in Athletes

The incidence of stress fractures in the general athletic population is less than 1%, but may be as high as 15% in runners. Stress fractures of the foot and ankle account for almost half of bone stress injuries in athletes. These injuries occur because of repetitive submaximal stresses on the bone resulting in microfractures, which may coalesce to form complete fractures. Advanced imaging such as MRI and triple-phase bone scans is used to evaluate patients with suspected stress fracture. Low-risk stress fractures are typically treated with rest and protected weight bearing. High-stress fractures more often require surgical treatment.

Stress Fractures of the Foot

Stress fractures of the foot and ankle may be more common among athletes than previously reported. A low threshold for investigation is warranted and further imaging may be appropriate if initial radiographs remain inconclusive. Most of these fractures can be treated conservatively with a period of non-weight-bearing mobilization followed by gradual return to activity. Early surgery augmented by bone graft may allow athletes to return to sports earlier. Risk of delayed union, nonunion, and recurrent fracture is high. Many of the patients may also have risk factors for injury that should be modified for a successful outcome.

Return to sports after stress fractures of the tibial diaphysis: a systematic review

INTRODUCTION

This review aims to provide information on the time taken to resume sport following tibial diaphyseal stress fractures (TDSFs).

SOURCES OF DATA

A systematic search of Medline, EMBASE, CINHAL, Cochrane, Web of Science, PEDro, Sports Discus, Scopus and Google Scholar was performed using the keywords 'tibial', 'tibia', 'stress', 'fractures', 'athletes', 'sports', 'non-operative', 'conservative', 'operative' and 'return to sport'.

AREAS OF AGREEMENT

Twenty-seven studies were included: 16 reported specifically on anterior TDSFs and 5 on posterior TDSFs. The general principles were to primarily attempt non-operative management for all TDSFs and to consider operative intervention for anterior TDSFs that remained symptomatic after 3-6 months. Anterior TDSFs showed a prolonged return to sport.

AREAS OF CONTROVERSY

The best time to return to sport and the optimal management modalities for TDSFs remain undefined.

GROWING POINTS

Management of TDSFs should include a full assessment of training methods, equipment and diet to modify pre-disposing factors.

AREAS TIMELY FOR DEVELOPING RESEARCH

Future prospective studies should aim to establish the optimal treatment modalities for TDSFs.

Exercise-induced leg pain

Exercise-induced leg pain is a common condition in athletes and in people involved in recreational sports. The diagnosis is not always straightforward: many conditions may cause exercise-induced leg pain. The aim of the present review is to provide a complete discussion of the most common pathologies related to this condition. Particular attention is dedicated to the history and the physical examination, which are fundamental for requesting the correct diagnostic tests or imaging techniques necessary for a precise diagnosis.

Overuse lower extremity injuries in sports

When athletes train harder the risk of injury increases, and there are several common overuse injuries to the lower extremity. Three of the most common lower extremity overuse injuries in sports are discussed including the diagnosis and treatments: medial tibal stress syndrome, iliotibial band syndrome, and stress fractures. The charge of sports medicine professionals is to identify and treat the cause of the injuries and not just treat the symptoms. Symptomatology is an excellent guide to healing and often the patient leads the physician to the proper diagnosis through an investigation of the athlete's training program, past injury history, dietary habits, choice of footwear, and training surface.

Fifth metatarsal fractures in the athlete: evidence for management

Shortest time to union, and to return to sporting activity, are the goals of management of fifth metatarsal fractures in the athlete. Whereas zone 1 injuries are largely treated conservatively, zone 2 and 3 injuries are best treated with surgical fixation in athletes, most commonly with intramedullary screw fixation. Fixation with the addition of bone graft has also yielded good results. In the chronic setting, good results have been shown with intramedullary screw fixation, surgical debridement and bone grafting alone, and tension band wiring. Shock wave therapy and pulsed electromagnetic fields may have a place in chronic and acute injury.

[Stress reactions in bones of the foot in sport: diagnosis, assessment and therapy]

Stress reactions and stress fractures are defined as structural damage to bone caused by repetitive stress or stereotypical loading. The balance between loading and unloading of bone is disrupted in stress reactions and stress fractures through the sport-specific demands and by the exogenous or endogenous risk factors present. In sports orthopedics the localization of stress reactions and stress fractures are subdivided into high risk fractures and low risk fractures. Conventional diagnostic radiology can initially be inconclusive. With symptoms persisting over 2 weeks further diagnostics using magnetic resonance imaging (MRI) should be performed. In the area of the foot stress reactions and stress fractures can often occur bilaterally or multifocally and most commonly affect the second metatarsals followed by the third metatarsals. Fractures of the fifth metatarsal, second metatarsal base, medial malleolus as well as navicular and sesamoid fractures are high risk fractures requiring special clinical and radiological monitoring. Basically, conservative treatment using the 2-phase model is the treatment of choice. In delayed union or severe pain surgical treatment is indicated.

Unfocused extracorporeal shock waves induce anabolic effects in osteoporotic rats

Unfocused extracorporeal shock waves (UESW) have been shown to have an anabolic effect on bone mass. Therefore we investigated the effects of UESW on bone in osteoporotic rats with and without anti-resorptive treatment. Twenty-week-old rats were ovariectomized (n = 27). One group was treated with saline and another group with Alendronate (ALN) 2.4 µg/kg, 3×/week. UESW were applied 2 weeks after ovariectomy. Thousand UESW were applied to one hind leg, the contra-lateral hind leg was not treated and served as control. With the use of in vivo micro-CT scanning it was shown that in saline treated rats trabecular bone volume fraction (BV/TV) was higher at 2 weeks follow-up in UESW treated legs compared to control legs. However, at 4 and 10 weeks no difference was found. In ALN treated animals UESW led to a pronounced anabolic response resulting in an increase in BV/TV at all time-points. Furthermore, UESW resulted in increased cortical volume (CtV), higher trabecular connectivity and, more plate-like and thicker trabeculae. Biomechanical testing showed that UESW lead to a higher maximum force before failure and higher stiffness in all treatment groups. With histology abundant areas of intramembranous bone formation along the periosteal cortex and within the bone marrow were observed. In conclusion this study shows promising results for the use of UESW in the treatment of osteoporosis, especially when this treatment is combined with an anti-resorptive treatment.

Stress fractures of the pelvis and legs in athletes: a review

CONTEXT

Stress fractures are common injuries in athletes, often difficult to diagnose. A stress fracture is a fatigue-induced fracture of bone caused by repeated applications of stress over time.

EVIDENCE ACQUISITION

PubMed articles published from 1974 to January 2012.

RESULTS

Intrinsic and extrinsic factors may predict the risk of stress fractures in athletes, including bone health, training, nutrition, and biomechanical factors. Based on their location, stress fractures may be categorized as low- or high-risk, depending on the likelihood of the injury developing into a complete fracture. Treatment for these injuries varies substantially and must account for the risk level of the fractured bone, the stage of fracture development, and the needs of the patient. High-risk fractures include the anterior tibia, lateral femoral neck, patella, medial malleolus, and femoral head. Low-risk fractures include the posteromedial tibia, fibula, medial femoral shaft, and pelvis. Magnetic resonance is the imaging test of choice for diagnosis.

CONCLUSIONS

These injuries can lead to substantial lost time from participation. Treatment will vary by fracture location, but most stress fractures will heal with rest and modified weightbearing. Some may require more aggressive intervention, such as prolonged nonweightbearing movement or surgery. Contributing factors should also be addressed prior to return to sports.

Radial extracorporeal shock wave therapy (rESWT) induces new bone formation in vivo: results of an animal study in rabbits

The aim of this study was to investigate if radial extracorporeal shock wave therapy (rESWT) induces new bone formation and to study the time course of ESWT-induced osteogenesis. A total of 4000 impulses of radial shock waves (0.16 mJ/mm²) were applied to one hind leg of 13 New Zealand white rabbits with the contralateral side used for control. Treatment was repeated after 7 days. Fluorochrome sequence labeling of new bone formation was performed by subcutaneous injection of tetracycline, calcein green, alizarin red and calcein blue. Animals were sacrificed 2 weeks (n = 4), 4 weeks (n = 4) and 6 weeks (n = 5) after the first rESWT and bone sections were analyzed by fluorescence microscopy. Deposits of fluorochromes were classified and analyzed for significance with the Fisher exact test. rESWT significantly increased new bone formation at all time points over the 6-week study period. Intensity of ossification reached a peak after 4 weeks and declined at the end of the study. New bone formation was significantly higher and persisted longer at the ventral cortex, which was located in the direction to the shock wave device, compared with the dorsal cortex, emphasizing the dose-dependent process of ESWT-induced osteogenesis. No traumata, such as hemorrhage, periosteal detachment or microfractures, were observed by histologic and radiologic assessment. This is the first study demonstrating low-energy radial shock waves to induce new bone formation in vivo. Based on our results, repetition of ESWT in 6-week intervals can be recommended. Application to bone regions at increased fracture risk (e.g., in osteoporosis) are possible clinical indications.

Common leg injuries of long-distance runners: anatomical and biomechanical approach

CONTEXT

Long-distance running (greater than 3000 m) is often recommended to maintain a healthy lifestyle. Running injury rates increase significantly when weekly mileage extends beyond 40 miles cumulatively. With the development of running analysis and other diagnostic tests, injuries to the leg secondary to bone, musculotendinous, and vascular causes can be diagnosed and successfully managed.

EVIDENCE ACQUISITION

Searches used the terms running, injuries, lower extremity, leg, medial tibial stress syndrome, compartment syndrome, stress fractures, popliteal artery entrapment, gastrocnemius soleus tears, and Achilles tendinopathy. Sources included Medline, Google Scholar, and Ovid from 1970 through January 2012.

RESULTS

Tibial stress fractures and medial tibial stress syndrome can sometimes be prevented and/or treated by correcting biomechanical abnormalities. Exertional compartment syndrome and popliteal artery entrapment syndrome are caused by anatomic abnormalities and are difficult to treat without surgical correction.

CONCLUSION

Leg pain due to bone, musculotendinous, and vascular causes is common among long-distance runners. Knowledge of the underlying biomechanical and/or anatomic abnormality is necessary to successfully treat these conditions.

Optimal intensity shock wave promotes the adhesion and migration of rat osteoblasts via integrin β1-mediated expression of phosphorylated focal adhesion kinase

To search for factors promoting bone fracture repair, we investigated the effects of extracorporeal shock wave (ESW) on the adhesion, spreading, and migration of osteoblasts and its specific underlying cellular mechanisms. After a single period of stimulation by 10 kV (500 impulses) of shock wave (SW), the adhesion rate was increased as compared with the vehicle control. The data from both wound healing and transwell tests confirmed an acceleration in the migration of osteoblasts by SW treatment. RT-PCR, flow cytometry, and Western blotting showed that SW rapidly increased the surface expression of α5 and β1 subunit integrins, indicating that integrin β1 acted as an early signal for ESW-induced osteoblast adhesion and migration. It has also been found that a significant elevation occurred in the expression of phosphorylated β-catenin and focal adhesion kinase (FAK) at the site of tyrosine 397 in response to SW stimulation after the increasing expression of the integrin β1 molecule. When siRNAs of integrin α5 and β1 subunit were added, the level of FAK phosphorylation elevated by SW declined. Interestingly, the adhesion and migration of osteoblasts were decreased when these siRNA reagents as well as the ERK1/2 signaling pathway inhibitors, U0126 and PD98059, were present. Further studies demonstrated that U0126 could inhibit the downstream integrin-dependent signaling pathways, such as the FAK signaling pathway, whereas it had no influence on the synthesis of integrin β1 molecule. In conclusion, these data suggest that ESW promotes the adhesion and migration of osteoblasts via integrin β1-mediated expression of phosphorylated FAK at the Tyr-397 site; in addition, ERK1/2 are also important for osteoblast adhesion, spreading, migration, and integrin expression.

Extracorporeal shock waves in articular cartilage defects in the rats

Thirty adult Sprague-Dawley rats were used to assess the nature of healing tissues in hyaline cartilage defects and to compare the healing in defects treated with shock waves, with those in defects without treatment. A 2 × 2 mm cartilage defect with exposed cancellous bone was created in a nonweight-bearing area of each medial femoral condyle. Each right knee defect was received extracorporeal shock waves (Swiss Dolorclast) of 500 impulses in 5 min at 2 bar (comparative to 0.09 mJ/mm(2)), and the left knee defects were assigned as controls. The rat groups were sacrificed at 6 and 12 weeks postsurgery. Sections from each knee were stained with hematoxylin-eosin to analyze synovial adhesion, synovial thickness, bone maturation, and chondroid metaplasia and with masson trichrome to analyze collagen fiber intensity. There was not a significant difference found between the study and control groups (P > 0.05). Extracorporeal shock waves did not effect healing of the chondral defects.

Reduced local perfusion after shock wave treatment of rotator cuff tendinopathy

A marked neovascularity has been demonstrated in tendinopathies, due to the inflammatory-degenerative process. The aim of this study was to assess the effect of extracorporeal shock wave therapy (ESWT) on tissue perfusion in the treatment of tendinopathy. An observational clinical study was made of 30 patients undergoing ESWT for tendinopathy of the rotator cuff. A clinical improvement was obtained in 65.6% of patients at 2 and 6 months. This was associated with a statistically significant reduction in the oxygen tissue saturation, measured by oxymetry that was apparent already during treatment, as well as at subsequent follow-up visits. The reduced perfusion achieved with ESWT supports the hypothesis that this treatment can regulate the inflammatory process and offset increased vascularization, restoring physiologic tendon conditions.

Shock wave therapy as a treatment of nonunions, avascular necrosis, and delayed healing of stress fractures

Shock wave therapy (SWT) stimulates angiogenesis and osteogenesis. SWT is commonly used to treat soft tissue musculoskeletal conditions such as fasciopathies and tendinopathies. Recent basic science and clinical data suggest that SWT can also be used to treat disorders of bone. Nonunions, avascular necrosis, and delayed healing of stress fractures have all been successfully treated with SWT. Success rates with SWT are equal to those with standard surgical treatment, but SWT has the advantage of decreased morbidity. The procedure is safe, well tolerated, yields few complications, and, typically, can be performed on an outpatient basis. SWT is a viable noninvasive alternative to stimulate healing of bone.

Extracorporeal shockwaves versus surgery in the treatment of pseudoarthrosis of the carpal scaphoid

The peculiar anatomical characteristics and precarious vascularization of the carpal scaphoid are responsible for a difficult healing of fractures and a fairly frequent subsequent evolution to pseudoarthrosis. Recently, extracorporeal shockwaves therapy (ESWT) has yielded encouraging results in the treatment of pseudoarthrosis of various bone segments. We report a retrospective study comparing the results of application of three sessions of shockwaves therapy (SW) with energy flux density (EFD) impulses of 0.09 (SD = 0.02) mJ/mm(2) ESWT emitted by an electromagnetic generator in 58 patients (group I) affected by pseudoarthrosis of the carpal scaphoid, with the results of surgical treatment consisting of stabilization and bone graft according to the Matti-Russe technique, performed in 60 subjects (controls, group II). There were no statistically significant differences in the mean duration of the pseudoarthrosis (p = 0.46), sex distribution (p = 0.41) and mean age at recruitment (p = 0.95) between the two patient groups. Posttreatment clinical-functional assessment, based on the Mayo Wrist Score, showed a significantly improved score, rising from 28-74.6 in group I already after 2 mo (p < 0.001), with 86.3% of the results judged as satisfactory or excellent; in group II the mean score rose from 27.5-74.2 after 2 mo, with 83.4% of the results judged as satisfactory or excellent (p < 0.001). At the same two-months follow-up (FU), radiographic consolidation was shown in 75.9% of patients in group I and 76.7% in group II. These improvements persisted at the subsequent controls at six and 12 mo in both groups. The Mayo Wrist Score and X-rays did not show statistically significant differences at the various FU visits in the two groups (p > 0.05). On the basis of our data, we can conclude that the results of ESWT are comparable with those of surgical stabilization and bone graft in the treatment of scaphoid pseudoarthrosis. In view of their minimal invasiveness, shockwaves should therefore be considered the treatment of choice of this disorder.

The effect of variable waveform low-intensity pulsed ultrasound in a fourth metacarpal osteotomy gap model in horses

The objective of this study was to evaluate the effects of variable waveform low-intensity ultrasound on the healing of a fracture gap of the fourth metacarpal bone in horses. A randomized, blinded, controlled trial was conducted in eight healthy adult horses. In each horse, a 1-cm osteotomy of the fourth metacarpal bone was created. One randomly selected metacarpal gap was treated daily with a 40-min session of ultrasound and the opposite gap was managed similarly with an inactive transducer. The fourth metacarpal bones were radiographed weekly. Fluorescent markers were administered at 14, 28, 56 and 70 d. At the completion of the study at day 84, the bones were harvested and evaluated with peripheral quantitative computed tomography (pQCT) and histology. There were no significant differences between treated and control bones for any of the radiographic, pQCT or histologic parameters evaluated. These findings suggested that low-intensity ultrasound did not affect bone formation in a fracture gap model in the horse.

Stress fractures in athletes

Stress fractures that occur in the young active population typically represent an overuse injury, and may lead to prolonged periods of restriction from play if they are not treated appropriately. Several risk factors have been identified and must be addressed when treating these patients. Low-risk stress fractures can be successfully treated with activity restriction and a stepwise return to sport. Several pharmacologic and nonoperative treatment modalities have been described. However, high-risk stress fractures are more difficult to treat because they may have an increased rate of delay and nonunion, and often require surgical stabilization. When treating an athlete with a stress fracture, the objective is a safe and quick return to sport; therefore, special considerations must be made in this population, particularly when dealing with the in-season athlete.