Hamstring Injury Site predicts return to sport

Hamstring muscle strain is one of the most common injuries in sports. Still, knowledge is limited about the progression of clinical and magnetic resonance imaging characteristics and their association with recovery time in athletes.

Eighteen elite sprinters with acute first-time hamstring injuries were examined, clinically and with MRI. All injuries occurred in the long head of the biceps femoris muscle. The results showed that injury to the proximal tendon, and closeness to the ischial tuberosity, were associated with longer time to return to pre-injury level.

CONCLUSION: Careful palpation during the first 3 weeks after injury and magnetic resonance imaging investigation performed during the first 6 weeks after injury provide valuable information that can be used to predict the time to return to pre-injury level of performance in elite sprinting.

Influence of a custom foot orthotic intervention on lower extremity dynamics in healthy runners.

Clin Biomech (Bristol, Avon). 2006 Jul;21(6):623-30. Epub 2006 Apr 5

• MacLean C,
• Davis IM,
• Hamill J.

Department of Exercise Science, University of Massachusetts-Amherst, 111 Totman Building, 30 Eastman Lane, Amherst, MA 01003-9258, USA.

OBJECTIVE: To investigate the influence of a custom foot orthotic intervention on the lower extremity dynamics in healthy runners. DESIGN: Three-dimensional kinematics and kinetics were collected on 15 female runners (>15 miles per week) while each performed the over-ground running trials in either a shoe only or a shoe+custom foot orthotic condition. Kinematic and kinetic variables were analyzed using Paired Sample t-tests. BACKGROUND: Custom foot orthotics are frequently prescribed treatment modality for the management of overuse running injuries. Although it is generally accepted that a custom foot orthotic intervention produces positive clinical outcomes, it remains unclear what influence this therapeutic modality has on the dynamics of the lower extremity. METHODS: Each subject performed five acceptable over-ground running trials (3.6 m s(-1) +/-5%) with and without the custom foot orthotic intervention in a running shoe. Selected maximum ankle and knee joint angles and moments were measured during the stance phase. RESULTS: While wearing the custom foot orthotic, subjects exhibited significantly decreased maximum values in rearfoot eversion angle, rearfoot eversion velocity and internal ankle inversion moment. CONCLUSIONS: In this sample of healthy female runners, the custom foot orthotic intervention led to significant decreases in maximum values for ankle dynamics in the frontal plane and in the sagittal plane of the knee joint. Relevance It remains unclear how a custom foot orthotic intervention influences lower extremity dynamics to produce positive clinical outcomes. Furthering our understanding of the dynamic influence will not only inform improved prescription and manufacturing practices but may provide insight into the mechanisms that cause overuse injuries.

The Role of Core Stability in Athletic Function

The Role of Core Stability in Athletic Function.

Current Opinion

Sports Medicine. 36(3):189-198, 2006.
Kibler, W Ben 1; Press, Joel 2; Sciascia, Aaron 1

Abstract:
The importance of function of the central core of the body for stabilisation and force generation in all sports activities is being increasingly recognised. 'Core stability' is seen as being pivotal for efficient biomechanical function to maximise force generation and minimise joint loads in all types of activities ranging from running to throwing. However, there is less clarity about what exactly constitutes 'the core', either anatomically or physiologically, and physical evaluation of core function is also variable.

'Core stability' is defined as the ability to control the position and motion of the trunk over the pelvis to allow optimum production, transfer and control of force and motion to the terminal segment in integrated athletic activities. Core muscle activity is best understood as the pre-programmed integration of local, single-joint muscles and multi-joint muscles to provide stability and produce motion. This results in proximal stability for distal mobility, a proximal to distal patterning of generation of force, and the creation of interactive moments that move and protect distal joints. Evaluation of the core should be dynamic, and include evaluation of the specific functions (trunk control over the planted leg) and directions of motions (three-planar activity). Rehabilitation should include the restoring of the core itself, but also include the core as the base for extremity function.

Intra-articular injection of a nutritive mixture solution protects articular cartilage from osteoarthritic progression..

This is an interesting article, not yet fully published. Looking into intra-articular injections of dextrose based solutions and their effect on the protection of articular cartilage. I suspect there will be significant interest in this area in the months and years to come, it is very relevant to professional athletes and the question is, will we be using something like this prophylactically to prevent or minimise OA in later life ?
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Intra-articular injection of a nutritive mixture solution protects articular cartilage from osteoarthritic progression induced by anterior cruciate ligament transection in mature rabbits: a randomized controlled trial

Yoo-Sin Park , Si-Woong Lim , Il-Hoon Lee , Tae-Jin Lee , Jong-Sung Kim and Jin Soo Han

Abstract (provisional)

Osteoarthritis (OA) is a degenerative disease which disrupts collagenous matrix of articular cartilage, and is difficult to cure because articular cartilage is a nonvascular tissue. Treatment of OA has targeted macromolecular substitutes for cartilage components, such as hyaluronic acid or genetically engineered materials. However, the goal of this study is to examine whether intra-articular injection of the elementary nutrients restores the matrix of arthritic knee joints of mature animals. A nutritive mixture solution (NMS) was composed of elementary nutrients such as glucose or dextrose, amino acids and ascorbic acid. It was administered five times, at the 6th, 8th, 10th, 13th, and 16th weeks, into the unilateral anterior cruciate ligament transected (ACLT) knee joints of mature New Zealand White rabbits. It was compared to normal saline (NS)-injection effect. OA progression was histopathologically evaluated by hematoxylin & eosin (H&E) staining, by the Mankin grading method, and by scanning electron microscopy (SEM) at the 19th week. NMS-injection decreased progressive erosion of articular cartilage overall compared to NS-injection (p<0.01),>

full preliminary article pdf

Evaluation and Treatment of Acromioclavicular Joint Injuries

Augustus D. Mazzocca, MD, and James Bicos, MD

From the Department of Orthopaedics, University of Connecticut Health Center, Farmington, Connecticut, and JRSI Sports Medicine, Indianapolis, Indiana

Address correspondence to Robert A. Arciero, MD, Professor, Orthopaedics, University of Connecticut Health Center, 10 Talcott Notch, Farmington, CT 06034

Acromioclavicular joint injuries and, more specifically, separations are commonplace both in general practice and during athletic participation.


This article reviews the traditional classification as well as the clinical evaluation of patients with acute and chronic acromioclavicular joint separations. It also highlights many recent advances, principally in the anatomy and biomechanics of the acromioclavicular joint ligamentous complex. The concept of increases in superior translation as well as disturbances in horizontal translation with injuries to this joint and ligaments are discussed.

This information, coupled with the unpredictable long-term results with the Weaver-Dunn procedure and its modifications, have prompted many recent biomechanical studies evaluating potential improvements in the surgical management of acute and chronic injuries.

The authors present these recent works investigating cyclic loading and ultimate failure of traditional reconstructions, augmentations, use of free graft, and the more recent anatomic reconstruction of the conoid and trapezoid ligaments.

The clinical results (largely retrospective), including acromioclavicular joint repair, reconstruction and augmentation with the coracoclavicular ligament, supplemental sutures, and the use of free autogenous grafts, are summarized.

Finally, complications and the concept of the failed distal clavicle resection and reconstruction are addressed. The intent is to provide a current, in-depth treatise on all aspects of acromioclavicular joint complex injuries to include anatomy, biomechanics, benchmark studies on instability and reconstruction, clinical and radiographic evaluation, and to present the most recent clinical research on surgical outcomes.

Web 2.0 and the Concept of Open Sports Medicine

Open Sports Medicine is a web blog aimed at bringing together current and relevant articles from the Sports Medicine literature and from Surgeons, Physicians and Rehabilitation Specialists internationally.

You will see RSS links to the most common journals in SEM on the right of the screen and at the bottom pre prepared pub med searches of common injuries and links to latest research articles. These will all automatically update.

I am looking for some volunteers from the SEM community to become regular contributors to this blog.

Extract taken from BMJ Article on Web 2.0

The more we use, share, and exchange information on the web in a continual loop of analysis and refinement, the more open and creative the platform becomes; hence, the more useful it is in our work. What seems clear is that Web 2.0 brings people together in a more dynamic, interactive space. This new generation of internet services and devices—often referred to as social software—can be leveraged to enrich our web experience, as information is continually requested, consumed, and reinterpreted. The new environment features a highly connected digital network of practitioners (medical or otherwise), where knowledge exchange is not limited or controlled by private interests. For me, the promise of open access in Web 2.0—freed of publishing barriers and multinational interests—is especially compelling.

Surgical Treatment of Tarsal Navicular Stress Fractures

Volume 14, Issue 4, Pages 248-251 (October 2006)

Lisa E. Choi, MD, Loretta B. Chou, MD

The tarsal navicular is part of the medial column of the foot. It articulates with the talus as well as the cuneiforms. The navicular can be injured with repetitive loading, such as in an athlete, resulting in a stress fracture. Patients complain of pain over the medial midfoot, especially with axial load. Plain radiographs may be normal, and MRI, CT or bone scan may be necessary to confirm the diagnosis. Nonoperative management can be successful with cast immobilization. For competitive athletes with delayed union or nonunion, surgical repair may be indicated. This is accomplished with interfragmentary screws and autogenous cancellous bone graft. Cast immobilization is important to prevent motion at the fracture site during the postoperative healing period. Nonweightbearing restrictions are used for eight to twelve weeks, or until radiographic bony union is verified. Using a comprehensive rehabilitative program, full motion and strength can be expected with eventual return to full athletic activity.

Operative Treatment of Stress Fractures of the Metatarsals

Volume 14, Issue 4, Pages 239-247 (October 2006)
G. Andrew Murphy, MD

A common presenting complaint in athletes and nonathletes alike, metatarsal stress fractures may be a source of persistent pain and loss of lower limb use, resulting in loss of recreational and vocational performance. Although most fractures respond to traditional conservative treatments, some may require more aggressive intervention on the part of the treating orthopaedic surgeon. The identification of these particular problem fractures and the search for associated conditions is important for the optimal outcome of these injuries. Attention to surgical technique is important; the options for adjunctive procedures are presented.

Pars Interarticularis Stress Lesions in the Lumbar Spine of Cricket Fast Bowlers

Medicine & Science in Sports & Exercise. 39(1):28-33, January 2007.
ENGSTROM, CRAIG M.; WALKER, DUNCAN G.

Abstract:
Purpose: This prospective magnetic resonance (MR) imaging study investigated the development of symptomatic pars lesions in the lumbar spine of adolescent cricket fast bowlers.

Methods: Annual MR examinations of the lumbar spine in male fast bowlers (N = 51) and swimmers (N = 20) without a prestudy history of symptomatic back injury were conducted to identify stress-induced pars injuries over 4 and 2 yr periods, respectively.

Results: Symptomatic L4 and L5 pars lesions developed in 11 of 51 and 1 of 51 of the bowlers, respectively. Preexisting L5 lesions were observed in both bowlers (10 of 51) and swimmers (4 of 20). No significant difference existed between the proportion of bowlers and swimmers with preexisting L5 lesions (P = 1.00, Fisher's exact test). In contrast, bowlers had a significantly greater proportion of L4 pars lesions compared with swimmers, with 22% of the bowlers developing L4 injuries during the study, whereas there were no L4 lesions in the swimmers (P = 0.027, Fisher's exact test). The symptomatic L4 lesions in the bowlers developed between 15 and 17 yr of age, and all were unilateral lesions lateralized to the nonbowling-arm side. The MR characteristics of the L4 pars lesions were consistent with a stress fracture through the cortical bone. Of the acquired L4 lesions in the bowlers, 4 of 11 and 7 of 11 developed in individuals with and without preexisting L5 defects, respectively. No significant association existed between the acquired L4 pars lesions and preexisting L5 defects in the bowlers (P = 0.216, Fisher's exact test).

Conclusion: Fast bowling was directly associated with the development of symptomatic pars lesions of the lumbar spine, particularly unilateral L4 stress lesions, in a significant proportion of the adolescent bowlers examined in this prospective MR study.

Mouthguards in Sport Activities: History, Physical Properties and Injury Prevention Effectiveness

Review Article

Sports Medicine. 37(2):117-144, 2007.
Knapik, Joseph J 1; Marshall, Stephen W 2; Lee, Robyn B 1; Darakjy, Salima S 1; Jones, Sarah B 1; Mitchener, Timothy A 1; delaCruz, Georgia G 1; Jones, Bruce H 1

Abstract:
Three systematic reviews were conducted on: (i) the history of mouthguard use in sports; (ii) mouthguard material and construction; and (iii) the effectiveness of mouthguards in preventing orofacial injuries and concussions. Retrieval databases and bibliographies were explored to find studies using specific key words for each topic. The first recorded use of mouthguards was by boxers, and in the 1920s professional boxing became the first sport to require mouthguards. Advocacy by the American Dental Association led to the mandating of mouthguards for US high school football in the 1962 season. Currently, the US National Collegiate Athletic Association requires mouthguards for four sports (ice hockey, lacrosse, field hockey and football). However, the American Dental Association recommends the use of mouthguards in 29 sports/exercise activities.

Mouthguard properties measured in various studies included shock-absorbing capability, hardness, stiffness (indicative of protective capability), tensile strength, tear strength (indicative of durability) and water absorption. Materials used for mouthguards included: (i) polyvinylacetate-polyethylene or ethylene vinyl acetate (EVA) copolymer; (ii) polyvinylchloride; (iii) latex rubber; (iv) acrylic resin; and (v) polyurethane. Latex rubber was a popular material used in early mouthguards but it has lower shock absorbency, lower hardness and less tear and tensile strength than EVA or polyurethane. Among the more modern materials, none seems to stand out as superior to another since the characteristics of all the modern materials can be manipulated to provide a range of favourable characteristics. Impact studies have shown that compared with no mouthguard, mouthguards composed of many types of materials reduce the number of fractured teeth and head acceleration. In mouthguard design, consideration must be given to the nature of the collision (hard or soft objects) and characteristics of the mouth (e.g. brittle incisors, more rugged occusal surfaces of molars, soft gingiva). Laminates with different shock absorbing and stress distributing (stiffness) capability may be one way to accommodate these factors.

Studies comparing mouthguard users with nonusers have examined different sports, employed a variety of study designs and used widely-varying injury case definitions. Prior to the 1980s, most studies exhibited relatively low methodological quality. Despite these issues, meta-analyses indicated that the risk of an orofacial sports injury was 1.6-1.9 times higher when a mouthguard was not worn. However, the evidence that mouthguards protect against concussion was inconsistent, and no conclusion regarding the effectiveness of mouthguards in preventing concussion can be drawn at present. Mouthguards should continue to be used in sport activities where there is significant risk of orofacial injury.

ACLD - In the Skeletally Immature

Managing Anterior Cruciate Ligament Deficiency in the Skeletally Immature Individual: A Systematic Review of the Literature.

Thematic Issue

Clinical Journal of Sport Medicine. 16(6):457-464, November 2006.
Mohtadi, Nick MD *; Grant, John MD, PhD *+

Abstract:
Objective: To perform a systematic review of the literature to answer whether early ACL reconstruction for a skeletally immature individuals result in improved outcome compared with nonsurgical treatment or delaying the reconstruction until skeletal maturity in the pediatric athlete.

Data Sources: Articles were restricted to the English language, and 6 databases were searched (MEDLINE, CINAHL, EMBASE, ACP Journal Club, Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews). The following keywords were used: anterior cruciate ligament, ACL, child, immature, pediatric, pediatric, and young.

Selection Criteria: All studies examining the ACL reconstruction in skeletally immature individuals, including citations describing complications. Excluded were articles looking at ACL repairs and ACL avulsion injuries. All types of study design, including review articles, were included. Comparative studies were reviewed in detail and analyzed qualitatively.

Data Extraction and Synthesis: A total of 615 articles were identified. Sixty-six articles met the inclusion and exclusion criteria. There were no articles with levels of evidence better than level III. The majority of the articles represented case series and reviews with expert opinion.

Results: There were 7 articles that provided comparisons between surgical and nonsurgical treatment in order to answer the question.

Conclusions: The study designs are inadequate to answer the question of whether early or delayed ACL reconstruction results in the best possible outcome in skeletally immature individuals. Future prospective studies are required to answer the question adequately. A proposed algorithm was described to deal with the question.