Shoulder injuries from alpine skiing and snowboarding. Aetiology, treatment and prevention

Quality and stability of reduction of operated acromioclavicular dislocation using dual acromioclavicular and coracoclavicular stabilization

INTRODUCTION

Dual stabilization is advocated in acute acromioclavicular dislocation (ACD), but has been little assessed.

OBJECTIVE

This preliminary study performed clinical and radiological assessment of dual acromioclavicular (AC) and coracoclavicular (CC) stabilization in acute ACD. The study hypothesis was that dual stabilization allows satisfactory reduction that remains stable over time.

MATERIALS AND METHODS

A button was used under endoscopy for CC stabilization. For AC stabilization, a short approach was used; the joint was cleansed then stabilized by an anchored tape between the acromion and the clavicle to promote ligament healing. Clinical assessment was based on a visual analog pain scale (VAS), joint range of motion and Quick-DASH and Constant scores. Radiological reduction was assessed on the ratio of CC distance between the operated and healthy sides on two views. MRI was used in follow-up to screen for ligament healing: thickening and continuity.

RESULTS

Thirty-five patients with stage 3-5 acute dislocation were included. At a minimum 24 months' follow-up, mean clinical scores were very satisfactory, with recovery of motion and pain relief. Radiography showed 94% stable reduction in both vertical and horizontal planes. MRI confirmed CC and AC ligament healing. Postoperative complications mainly comprised 4 cases of reduction loss (11%). One clavicle fracture occurred, at 6 months.

CONCLUSION

Dual AC-CC stabilization provided very good radiographic reduction in both horizontal and vertical planes. Functional results were very satisfactory, and complications were few, with some cases of reduction loss. These good results encourage us to continue with dual stabilization in acute ACD.

LEVEL OF EVIDENCE

II; prospective cohort.

Austere Diagnosis and Reduction of Anterior Shoulder Dislocations: 10-Year Review of a Ski Patrol-Based Program with Emergency Medical Technicians

INTRODUCTION

Glenohumeral dislocations present a challenging management dilemma in austere settings where patient transport time may be prolonged. Expeditious reduction is preferable, but treatment is commonly expected to take place within a hospital or comparable facility. Through a novel shoulder injury program, professional ski patrollers trained as emergency medical technicians (EMTs) have diagnosed and reduced anterior shoulder dislocations using biomechanical techniques without sedation or analgesia for over 20 y. Summary records have been maintained to track the performance and safety of this program.

METHODS

Five hundred forty-six records of winter sports-related shoulder injuries from 2009-10 to 2019-20 were retrospectively analyzed to determine the assessment performance and dislocation reduction efficacy of EMTs, with the intent of ascertaining whether EMT-trained practitioners can reliably and safely diagnose and reduce anterior shoulder dislocations without premedication in a remote and resource-limited setting.

RESULTS

EMTs identified anterior shoulder dislocations with 98% sensitivity and 96% diagnostic accuracy. The overall success rate of reduction attempts was 86%, or 88% when limited to confirmed anterior dislocations. Two fracture-dislocations and 4 misdiagnoses were manipulated. No instances of iatrogenic harm were identified, and no patients who underwent successful reductions required ambulance transportation.

CONCLUSIONS

With appropriate education and within a structured program, EMT-trained practitioners can reliably and safely diagnose and reduce anterior shoulder dislocations using biomechanical techniques without premedication in remote and resource-limited environments. Implementation of similar programs in austere settings has the potential to improve patient care. Further, using biomechanical reduction techniques may reduce reliance on procedural sedation irrespective of care setting.

Acromioclavicular joint injuries at a Colorado ski resort

BACKGROUND

Acromioclavicular joint (ACJ) injuries are among the most common injuries in contact and non-contact sports. As winter sports become more popular, there has been an increase in shoulder injuries among recreational skiers and snowboarders.

METHODS

This was a retrospective analysis of all patients who presented to the Denver Health Winter Park Medical Center with ACJ injury from 2012 to 2017. We examined the incidence of ACJ injuries, the injury mechanism, demographics, and type of ACJ injuries among skiers and snowboarders treated at the clinic.

RESULTS

A total of 341 ACJ injuries (6.7% of total visits) were encountered during the study period. The majority of ACJ injures were type I (41.3%) and mainly occurred in men (86.5%). Most (96.8%) of the cases were primary ACJ injuries on the right shoulder (56.9%). The average age of patients with ACJ injuries was 30.0 years (range 10-72). More than half (62.2%) of ACJ injuries occurred while snowboarding. The most common mechanism of injury (93.5%) was fall to the snow while skiing/snowboarding. Women were more likely to have a type I ACJ injury than men (80.4% vs 35.4%; P < 0.001). Women with ACJ injuries were more likely to suffer the injury while skiing than snowboarding (71.7% vs 28.3%; P < 0.001), compared to men who were more likely to suffer the injury while snowboarding than skiing (67.5% vs 32.5%; P < 0.001).

CONCLUSIONS

Most of the ACJ injuries were type I and occurred mostly in men. Snowboarders were more likely to have an ACJ injury than skiers.

LEVEL OF EVIDENCE

Level IV, Epidemeiology Study.

[Fractures of tibial shaft and tibial head in winter sports]

BACKGROUND

Injuries in alpine skiing often affect the lower extremities, in particular the knee joint and lower leg. In addition to conventional radiological diagnostics, CT and, in the case of fractures of the knee joint area, MRI also play an important role. In the case of tibial head fractures, especially if there has been a dislocation mechanism, there is an increased risk of vascular and nerve injuries. Lower leg fractures are predestined for the development of a compartment syndrome. For these reasons, an exact survey of the vascular-nerve status and a monitoring of the soft tissues should be carried out.

THERAPY

In the further therapy, whether conservative or surgical, the soft tissue situation must also be included in the planning. In the case of tibial head fractures in particular, the choice of the right approach is essential for a good result in surgical therapy. Angle-stable plate osteosynthesis and screw osteosynthesis play the most important role as osteosynthesis methods in the knee joint area. In the case of fractures in the shaft area, medullary nail osteosynthesis or angle-stable plate systems are primarily used. In the case of severely compromised soft tissue or unstable situations, it may be necessary to apply an external fixator first. The initiated therapy should enable functional follow-up treatment as early as possible.

PREVENTION

Good physical fitness, driving-specific training, but also good core stabilization have a preventative effect against injuries. In addition, the correct material coordination between ski boot, binding and ski is important for accident prevention.

Clinical Outcomes of Arthroscopy-Assisted Modified Triple Endobutton Plate Fixation in Rockwood Type III Acute Acromioclavicular Joint Dislocation: A Retrospective Study

Objective

The common triple Endobutton plate (CTEP) fixation is a lengthy procedure that is associated with high failure rates. Therefore, we used arthroscopy to improve the Endobutton fixation method by shortening the duration of surgery and reducing operative complications. This study explored the safety and effectiveness of arthroscopy‐assisted modified triple Endobutton plate (MTEP) fixation in Rockwood type III managing acute acromioclavicular joint (ACJ) dislocation.

Methods

This was a retrospective single‐center study involving 73 patients with Rockwood type III acute ACJ dislocation treated between January 2016 and January 2021. The 73 patients were classified into three groups, the acromioclavicular hook plate (ACHP) group (22 cases), CTEP group (24 cases) and MTEP group (27 cases), based on the type of surgical treatment they received. Clinical outcome data from the patient records, including the Constant–Murley score (CMS), American Shoulder and Elbow Surgeons score (ASES) and University of California at Los Angeles shoulder rating scale score (UCLA), were retrospectively reviewed. The scores were assessed before surgery and at the third and twelfth month after surgery. The clavicle‐coracoid (CC) distance on the affected side was estimated from imaging scans taken before surgery, on the second day after surgery, and within the third and twelfth month after surgery. The student's t‐test was used to compare normally distributed data for independent samples, while homogeneity of variance test was used to compare normally distributed data among multiple groups. Non‐normally distributed data were compared using Mann–Whitney rank‐sum tests.

Results

There were no differences in age, gender, body mass index (BMI), dislocated side, trauma etiology, and duration of follow‐up among the three groups. There was also no significant difference in the duration of surgery between the ACHP and MTEP groups, although the duration in the two groups was shorter than in the CTEP group (P < 0.05). The duration of hospitalization for the MTEP group was significantly shorter than for the CTEP group which was in turn shorter than for the ACHP group (both P < 0.05). There was no significant difference in postoperative CMS, ASES, and UCLA scores between the CTEP and MTEP groups but the score for the two groups differed significantly from those of the ACHP group (all Ps < 0.05). In addition, there was no significant difference in CC distance among the three groups after surgery (P > 0.05).

Conclusion

Arthroscopic reconstruction of the coracoclavicular ligament using MTEP fixation to manage acute Rockwood type III ACJ dislocation is minimally invasive, and is associated with rapid functional recovery, few complications and satisfactory early clinical results.

A 40-year Study of the Factors Associated with Diaphyseal Forearm Fractures in Skiers and Snowboarders

BACKGROUND

Skiing and snowboarding are popular sports that are associated with a high number of orthopaedic injuries. Diaphyseal forearm fractures are an important subset of these injuries. To our knowledge, factors associated with these injuries, the mechanisms that cause them, and their relative frequencies in skiers and snowboarders have not been described. In addition, it has been proposed that the use of wrist guards may increase the risk of sustaining a diaphyseal forearm fracture; therefore, we sought to explore the relationship between wrist guard use and diaphyseal forearm fractures.

QUESTIONS/PURPOSES

(1) What are the relative frequencies and types of diaphyseal forearm fractures in skiers and snowboarders? (2) What factors are associated with these injuries? (3) Is the use of wrist guards associated with an increased risk of forearm fractures?

METHODS

This was an unmatched case-control study performed with an injury database from a university-run clinic at the base lodge of a major ski resort. Cases were injured skiers and snowboarders; controls were randomly selected uninjured skiers and snowboarders. Data were collected on the mechanism of injury; experience level; equipment; radiographs; skiing or snowboarding habits; and trail type, defined as green circle (easiest), blue square (intermediate), black diamond (difficult), and double black diamond (most difficult). From this database, we identified 84 patients with diaphyseal forearm fractures, one of which was a Monteggia fracture and was excluded. A logistic regression analysis was used to compare the injured and control groups to identify factors associated with diaphyseal forearm fractures, including wrist guard use.

RESULTS

When adjusted for participant days, diaphyseal forearm fractures were more common in snowboarders than skiers (0.03 injuries per 1000 person-days versus 0.004 per 1000 person-days). On multivariable analysis, factors associated with forearm fractures in skiers were younger age (odds ratio 1.08 [95% CI 1.05 to 1.14]; p < 0.01), being a man or boy (OR 11.9 [95% CI 2.5 to 57.2]; p < 0.01), lack of movement at the time of falling (OR 18.2 [95% CI 3.2 to 102.5]; p < 0.01), and skiing on green circle trails compared with black diamond trails (OR 3.6 [95% CI 1.4 to 12.5]; p = 0.04). Factors associated with forearm fractures in snowboarders were younger age (OR 1.08 [95% CI 1.02 to 1.15]; p = 0.01), decreased weight (OR 1.02 [95% CI 1.00 to 1.02]; p < 0.01), snowboarding on gentle terrain (OR 8.4 [95% CI 1.6 to 45.0]; p = 0.01), and snowboarding on groomed terrain compared with other (OR 7.2 [95% CI 1.9 to 28.0]; p < 0.01) or wet, heavy snow (OR 24.8 [95% CI 2.5 to 246.7]; p = 0.01). Wrist guard use was not associated with an increased odds of diaphyseal forearm fracture in skiers or snowboarders.

CONCLUSION

Diaphyseal forearm fractures occur more frequently in snowboarders than in skiers. Despite speculation in prior evidence that wrist guards may paradoxically increase the risk of sustaining these injuries, our study suggests that this is not the case and wrist guards are not unsafe to wear.

LEVEL OF EVIDENCE

Level III, prognostic study.

Closed Reduction of Anterior Shoulder Dislocations Performed by Ski Patrollers in the Alpine Prehospital Environment: A Retrospective Review Demonstrating Efficacy in a Canadian Ski Resort

INTRODUCTION

Shoulder dislocations are common ski hill injuries. Rapid reduction is known to improve outcomes; however, advanced providers are not always available to provide care to these patients. In 2017, nonmedical ski patrollers at Sunshine Village ski resort in Alberta, Canada, were trained to perform anterior shoulder dislocation (ASD) reductions. Program success was determined by a chart review after the 2020 ski season.

METHODS

This study retrospectively reviewed data on patients who presented to Sunshine Village ski patrol with a suspected ASD and who met the study inclusion criteria from November 2017 through March 2020. Data were collected from ski patrol electronic patient care records regarding general demographics, reduction technique used, analgesia administration, and reduction success rates.

RESULTS

Ninety-six cases were available for review after exclusions. Trained nonmedical ski patrollers successfully reduced 82 of these cases, resulting in an overall reduction success rate of 89%. Sixty-three (66%) of these patients had experienced first-time dislocations. Eighty-two (87%) patients were male, with a median age of 25 y. The most used technique was the Cunningham method (75%), and analgesia was administered to 70% of patients.

CONCLUSIONS

This retrospective study documents the results of a quality assurance review of the treatment of ASD at Sunshine Village ski resort. With a success rate of 89%, the evidence supports the conclusion that nonmedical ski patrollers can successfully perform ASD reductions. We believe training ski patrollers to reduce ASD improved patient care in our austere environment by providing early definitive treatment with a high success rate.

Surgical management of Rockwood type 3 acromioclavicular joint injuries: a retrospective comparison of outcomes of suture anchor fixation and double-button fixation techniques

The treatment of type 3 acromioclavicular joint injuries has still controversial issues. In this retrospective study, we aimed to compare the radiological and functional outcomes of the suture anchor and double-button fixation methods for the treatment of type 3 acromioclavicular joint injuries.This study included 20 patients who underwent suture anchor (9 patients) and double-button fixations (11 patients) for isolated type 3 acromioclavicular dislocation. Injuries were classified according to the Rockwood Classification System. Coracoclavicular(CC) distances and anterior translation have been measured pre-operatively and at the 12th month follow-up. Functional evaluation was performed using the DASH, and Constant-Murley scores of the patients were recorded at the12th-month follow-up.The mean age of the patients was 37 (22-50) years in Group 1(double-button group) and 39 (24-56) years in Group 2(suture anchor group). All of the patients were male. There was no statistically significant difference between the DASH and Constant-Murley scores of the 2 groups (P > .05). The mean DASH score of the patients evaluated at the postoperative 12th month was 6.65 (0-38.3) in Group 1 and 2.48 (0-4.2) in Group 2. The mean Constant-Murley score of the patients evaluated at the postoperative 12th month was 89,6 (50-98) in Group 1 and 93,6 (90-98) in Group 2. Comparison of the pre- and post-operative CC distances and pre- and post-operative anterior translation distances of both groups revealed that there was no statistically significant difference between groups regarding postoperative CC distances and anterior translation distances (P > .05).Suture anchor and double-button techniques are reliable treatment methods that are not superior to one another and can yield excellent functional outcomes.

Sternoclavicular joint

The sternoclavicular joint is a saddle shaped, synovial joint and is the only skeletal articulation between the axial skeleton and the upper limb. Here, a reviewis provided of the anatomy, biomechanics, traumatic and atraumatic conditions, and management options for the various conditions described.

BiPOD Arthroscopic Acromioclavicular Repair Restores Bidirectional Stability

Stabilizing the acromioclavicular joint in the vertical and horizontal planes is challenging, and most current techniques do not reliably achieve this goal. The BiPOD repair is an arthroscopically assisted procedure performed with image intensifier guidance that reconstructs the coracoclavicular ligaments as well as the acromioclavicular ligaments to achieve bidirectional stability. Repair is achieved with a combination of 2-mm FiberTape (Arthrex, Naples, Florida) and 20-mm Poly-Tape (Neoligaments, Leeds, England) to achieve rigid repair, prevent bone abrasion, and promote tissue ingrowth. This study is a prospective review of the first 6 patients treated for high-grade acute acromioclavicular injury with the BiPOD technique. The study included 6 men who were 21 to 36 years old (mean, 27 years). At 6-month follow-up, complications were recorded and radiographic analysis was used to determine the coracoclavicular distance for vertical reduction and the amount of acromioclavicular translation on the Alexander axillary view was used to determine horizontal reduction. One patient had a superficial infection over the tape knot. The difference in coracoclavicular distance between the operated side and the uninvolved side was 9±2 mm preoperatively and 0.3±2 mm at 6-month follow-up. On Alexander axillary view, all 6 patients showed stable reduction, which is defined as a clavicle that is in line with the acromion. The findings show that BiPOD acromioclavicular reconstruction restores bidirectional stability of the acromioclavicular joint at 6 months. [Orthopedics. 2017; 40(1):e35-e43.].

Injuries of the acromioclavicular joint and current treatment options

The acromioclavicular joint is involved in four out of ten shoulder injuries. The joint is prone to injury due to its anatomy and relative lack of soft tissue cover. Sportsmen involved in contact sports are likely to suffer damage to the joint during their professional careers. Most subluxations of the joint can be treated nonoperatively whilst dislocations are generally treated operatively except in those individuals at significant risk of re-injury, for example, rugby players. This article looks at the anatomy and physiology of the acromioclavicular joint, injury classification and presents the current evidence regarding treatment options for these injuries.

Management of acute acromioclavicular joint dislocation with a double-button fixation system

INTRODUCTION

Numerous static and dynamic techniques have been described for the management of acute acromioclavicular (AC) joint dislocation. To date, no standard technique has been established and several complications have been described for each of these techniques. The purpose of the present study was to evaluate the functional and radiographic outcomes of acute AC joint reconstruction after a mini-open technique using the double-button fixation system.

PATIENTS AND METHODS

Twelve patients with acute AC joint dislocation treated with the double-button fixation system by one surgeon were retrospectively reviewed. Functional assessment was performed by an independent reviewer using the DASH, Constant and the VAS scores. The coracoclavicular (CC) distance of the affected shoulder was assessed on a standard radiograph and compared with the contralateral normal one.

RESULTS

Eight patients were operated on for grade III AC joint dislocation and 4 for grade IV. The mean age of the patients at the time of surgery was 27.5 years. The mean follow-up was 18.25 months (range: 12-30 months). At the most recent follow-up, the mean Constant score was 94.8 (range: 84-100) showing a significant increase compared with the mean pre-operative value of 34.4 (range: 25-52) (p<0.001). The mean DASH score was significantly decreased from 19.6 (range: 14-28) preoperatively to 0.25 (range: 0-3) at the last follow-up (p<0.001). The mean VAS score showed a significant decrease from 5.75 (range: 4-7) to 0.2 (range: 0-2) (p<0.001). The mean CC distance on the operated shoulder was found to have no significant difference from the CC distance on the contralateral normal side (10.5 vs. 10mm) (p>0.05). There was no evidence of AC joint osteoarthrosis, CC calcification or osteolysis of the distal clavicle or the coracoid process.

CONCLUSIONS

The proposed mini-open technique provides adequate exposure of the base of the coracoid with minimal damage to the soft tissues surrounding the CC ligaments while ensures an excellent cosmetic result. We recommend this fast and relatively simple technique for all type IV injuries and for type III injuries in heavy manual workers and high-demand upper extremities athletes.

[Arthroscopic stabilization of acute acromioclavicular joint dislocation]

During the past few years arthroscopic and minimal invasive techniques for stabilization of acromioclavicular (AC) joint dislocations have gained increasing interest. Well established procedures for open surgery were modified and implemented to attain an arthroscopic level. Furthermore implants were developed which enable these reconstructive techniques to be performed arthroscopically without the disadvantages of open procedures. The short to mid-term results described so far concerning the clinical and radiological outcome of arthroscopic stabilization techniques show an at least equal outcome to those presented in open surgery.

Myths concerning alpine skiing injuries

There are many commonly discussed myths about ski safety that are propagated by industry, physicians, and skiers. Through a review of the literature concerning 12 such topics, this article demonstrates that the following are untrue: (1) Broken legs have been traded for blown-out knees. (2) If you know your DIN (a slang term for release indicator value), you can adjust your own bindings. (3) Toe and heel piece settings must be the same to function properly. (4) Formal ski instruction will make you safer. (5) Very short skis do not need release bindings. (6) Spending a lot of money on children's equipment is not worth the cost. (7) Children need plenty of room in ski boots for their growing feet. (8) If you think you are going to fall, just relax. (9) Exercise can prevent skiing injuries. (10) Lower release settings can reduce the risk of anterior cruciate ligament injury. (11) Buying new ski equipment is safer than renting. (12) Skiing is among the most dangerous of activities. It is important for the skiing public, physicians, and all those interested in improving skiing safety to verify the measures they advocate. The statements analyzed here are simply untrue and have the potential to cause harm if taken as fact by those exposed to these unsupported opinions.

The anatomic reconstruction of acromioclavicular joint dislocations using 2 TightRope devices: a biomechanical study

BACKGROUND

For the reconstruction of acromioclavicular (AC) joint separation, several operative procedures have been described; however, the anatomic reconstruction of both coracoclavicular ligaments has rarely been reported.

PURPOSE

The aim of this biomechanical study is to describe a new procedure for anatomic reconstruction of the AC joint.

STUDY DESIGN

Controlled laboratory study.

MATERIALS AND METHODS

Forty fresh-frozen cadaveric shoulders were tested. Cyclic loading and a load-to-failure protocol was performed in vertical (native, n = 10; reconstructed, n = 10) and anterior directions (native, n = 10; reconstructed, n = 10) on 20 AC joints and repeated after anatomic reconstruction. Reconstruction of conoid and trapezoid ligaments was achieved by 2 TightRope devices (Arthrex, Naples, Florida). Dynamic, cyclic, and static loading until failure in vertical (n = 5) and horizontal (n = 5) directions were tested in native as well as reconstructed joints in a standardized setting.

RESULTS

The native coracoclavicular ligaments in static load for vertical force measured 598 N (range, 409-687), elongation 10 mm (range, 6-14), and stiffness 99 N/mm (range, 67-130); static load for anterior force was 338 N (range, 186-561), elongation 4 mm (range, 3-7), and stiffness 140 N/mm (range, 70-210). The mean maximum static load until failure in reconstruction for vertical force was 982 N (range, 584-1330) (P =.001), elongation 4 mm (range, 3-6) (P < .001), and stiffness 80 N/mm (range, 66.6-105) (P = .091); and for anterior static force 627 N (range, 364-973) (P < .001), elongation 6.5 mm (range, 4-10) (P = .023), and stiffness 78 N/mm (range, 46-120) (P = .009). During dynamic testing of the native coracoclavicular ligaments, the mean amount of repetitions (100 repetitions per stage, stage 0-100 N, 100-200 N, 200-300 N, etc, and a frequency of 1.5 Hz) in native vertical direction was 593 repetitions (range, 426-683) and an average of 552 N (range, 452-683) load until failure. In vertical reconstructed testing, there were 742 repetitions (range, 488-893) (P = .222) with a load until failure of 768 N (range, 486-900) (P = .095). In the anterior direction load, the native ligament failed after an average of 365 repetitions (range, 330-475) and an average load of 360 N (range, 307-411), while reconstructed joints ended in 549 repetitions (range, 498-566) (P = .008) with a load until failure of 547 N (range, 490-585) (P = .008). In all testing procedures, a preload of 5 N was performed.

CONCLUSION

The anatomic reconstruction of the AC joint using TightRope is a stable and functional anatomic reconstruction procedure. The reconstruction technique led to favorable in vitro results with equal or even higher forces than native ligaments.

CLINICAL RELEVANCE

Through anatomic repair, stable function of the AC joint can be achieved in an anatomic manner.

Epidemiology and risk factors of humerus fractures among skiers and snowboarders

BACKGROUND

The incidence of humerus fractures while participating in snowboarding and skiing is undefined. Very little is known about the risk factors associated with these fractures.

HYPOTHESIS

Snowboarders are at increased risk for sustaining humerus fractures when compared with skiers. In addition, the types of fractures, laterality, and risk factors differ between the 2 groups.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

At a major ski area clinic, 318 humerus fractures were evaluated over 34 seasons. Radiographs were classified according to the AO and Neer systems. Patient data were analyzed and compared with that of a control population of uninjured skiers and snowboarders to determine incidence and risk factors.

RESULTS

The incidence of humerus fractures among snowboarders (0.062 per 1000 snowboarder days) was significantly higher than that of skiers (0.041 per 1000, P < .05). Skiers were more likely to sustain proximal fractures, and snowboarders were relatively more likely to sustain diaphyseal and distal fractures (P < .05). Of glenohumeral dislocations, 6.56% were associated with proximal humerus fractures among skiers (1.7% among snowboarders). Snowboarders who lead with their left foot were more likely to fracture their left humerus (P = .023). Helmet use and gender were not risk factors for humerus fractures among either skiers or snowboarders. Jumping was involved in 28.3% of humerus fractures among snowboarders and in 5.4% among skiers. Skiers with humerus fractures were more skilled, older, and fell less frequently than controls. Snowboarders were less skilled, younger, and fell at a similar rate compared with controls.

CONCLUSION

Snowboarders are at significantly higher risk of sustaining humerus fractures than skiers. In skiers, humerus fractures show no laterality and most often involve the proximal humerus. In contrast, snowboarders more often fracture the left humerus at the diaphysis.

Disorders of the sternoclavicular joint

The sternoclavicular joint is vulnerable to the same disease processes as other synovial joints, the most common of which are instability from injury, osteoarthritis, infection and rheumatoid disease. Patients may also present with other conditions, which are unique to the joint, or are manifestations of a systemic disease process. The surgeon should be aware of these possibilities when assessing a patient with a painful, swollen sternoclavicular joint.

Three-dimensional acromioclavicular joint motions during elevation of the arm

STUDY DESIGN

Descriptive laboratory study.

OBJECTIVES

To determine the 3-dimensional motions occurring between the scapula relative to the clavicle at the acromioclavicular joint during humeral elevation in the scapular plane.

BACKGROUND

Shoulder pathology is commonly treated through exercise programs aimed at correcting scapular motion abnormalities. However, little is known regarding how acromioclavicular joint motions contribute to normal and abnormal scapulothoracic motion.

METHODS AND MEASURES

Thirty subjects (16 males, 14 females) participated. Subjects with positive symptoms on clinical exam or past history of shoulder pathology, trauma, or surgery were excluded. Electromagnetic surface motion analysis was performed tracking the thorax, clavicle, scapula, and humerus. Subjects performed 3 repetitions of scapular plane abduction. Passive motion data were also collected for scapular plane abduction from cadaver specimens. Data were analyzed using within-session reliability and descriptive statistics as well as repeated measures analyses of variance (ANOVAs) to determine the effect of elevation angle from rest to 90 masculine humeral elevation. Reliability was determined from repeated trials in the same session without removing sensors or redigitizing landmarks.

RESULTS

Angular values were highly repeatable within session (ICC>0.94; SEM, < 2.3 degrees ). During active scapular plane abduction from rest to 90 degrees , average acromioclavicular joint angular values demonstrated increased internal rotation (approximately 4.3 degrees ), increased upward rotation (approximately 14.6 degrees ), and increased posterior tilting (approximately 6.7 degrees ) (P<.05). Passive motions on cadavers demonstrated similar kinematic patterns.

CONCLUSIONS

Significant motion occurs at the acromioclavicular joint during active humeral elevation, contributing to scapular motion on the thorax. This information provides a foundation for understanding normal acromioclavicular joint motion as a basis for further investigation of pathology and rehabilitation approaches.

Operative treatment of greater tuberosity fractures of the humerus--a biomechanical analysis

BACKGROUND

Fractures of the greater tuberosity of the humerus present with increasing frequency. However, no biomechanical data about the optimal fixation technique of greater tuberosity fractures is available. This biomechanical cadaver study compares the stability of three standard fixation techniques used for the treatment of greater tuberosity fractures of the proximal humerus.

METHODS

In 21 fresh frozen proximal humeri, standardized fractures of the greater tuberosity were created. The specimens were randomly assigned to one of three operation techniques: wire tension banding, two cancellous screws and transosseous sutures. These constructs were mechanically tested by applying an increasing force to the supraspinatus tendon. Load to 5mm displacement (load to 5mm yield point) and load to failure (maximum stretch strength) were measured in Newton (N).

FINDINGS

Load to 5mm yield point values showed no significant differences between tension banding (498 N, SD 153) and two cancellous screws (400 N, SD 174) (P>0.01). Both techniques showed significantly higher values than transosseous sutures (185 N, SD 132) (P<0.01). Load to failure values were significantly higher for tension banding (1054 N, SD 125) than screws (842 N, SD 140) and sutures (480 N SD 101) (P<0.01). The difference between screws and sutures was also significant (P<0.01).

INTERPRETATION

Tension banding and two cancellous screws provided the strongest fixation for isolated fractures of the greater tuberosity.

Autologous Tenocyte Therapy Using Porcine-Derived Bioscaffolds for Massive Rotator Cuff Defect in Rabbits

Large and retracted rotator cuff tendon tears fail to repair or retear after surgical intervention. This study attempted to develop novel tissue-engineering approaches using tenocyte-seeded bioscaffolds for tendon reconstruction of massive rotator cuff tendon defect in rabbits. Porcine small intestine submucosa (Restore) and type I/III collagen bioscaffold (ACI-Maix) were chosen as bioscaffold carriers for autologous tenocytes. Biological characterization of autologous tenocytes was conducted before the implantation. The tenocyte-seeded bioscaffolds were implanted as interposition grafts to reconstruct massive rotator cuff tendon defects in rabbits. In situ reimplantation of the autologous rotator cuff tendon, excised during defect creation, served as a positive control. Histological outcomes were analyzed and semi-quantitatively graded at 4 and 8 weeks after surgery. At 4 weeks, both tenocyte-seeded bioscaffolds displayed inflammatory reaction similar to bioscaffold-only cuff reconstruction, and the histological grading were inferior to control repair. However, at 8 weeks, inflammatory reaction of both tenocyte-seeded bioscaffolds were dramatically less than with bioscaffold alone. In addition, bioscaffolds seeded with tenocytes generated a histological appearance similar to that of the positive control. The implantation of autologous tenocytes on collagen-based bioscaffolds results in better rotator cuff tendon healing and remodeling than with the implantation of bioscaffold alone.

Alpine ski injuries and their prevention

Alpine skiing is a popular sport with significant risk of injury. Since the 1970s, injury rates have dropped from approximately 5 to 8 per 1000 skier-days to about 2 to 3 per 1000 skier-days. The nature of the injuries has also been transformed over the same period. Lower leg injuries are becoming less common while the incidence of knee sprains and upper extremity injuries is becoming more common. Much of this change can be attributed to advancements in binding technology, which effectively reduces lower leg injury, but does not adequately address the issue of knee sprains. Along with design, binding adjustment and maintenance are important preventative factors. Poorly adjusted bindings have been correlated with increased injury rates. Upper extremity injuries constitute approximately one-third of skiing injuries, with ulnar collateral ligament sprains and shoulder injuries being the most common. Strategies to prevent these include proper poling technique and avoidance of non-detachable ski pole retention devices. Spinal injuries in skiers have been traditionally much less common than in snowboarders, but this disparity is likely to diminish with the recent trend of incorporating snowboarding moves into skiing. Strategies to help reduce these injuries include promoting the development of terrain parks and focussing on proper technique during such moves. Head injuries have been increasing in incidence over recent decades and account for more than half of skiing-related deaths. The issue of ski helmets remains controversial while evidence for their efficacy remains under debate. There is no evidence to demonstrate that traditional ski instruction reduces injury frequency. More specific programmes focussed on injury prevention techniques are effective. The question of pre-season conditioning to prevent injuries needs further research to demonstrate efficacy.

Fractures and tendon injuries of the athletic shoulder

Athletic injuries in the shoulder range from a routine strain or sprain to a potentially disabling fracture or tendon rupture. The level of sports participation plays an important role in diagnosis and treatment. The nonprofessional athlete may be more likely to sustain injuries secondary to under-training or improper technique. The professional athlete may be capable of play under much higher velocities and applied loads and, therefore, may be subject to higher energy trauma than the amateur athlete. In addition to standard treatment considerations, return to play time must also be decided. Decisions regarding definitive treatment may be modulated depending on an athlete's desire to return to his or her previous level of competition.

Relevance of arm position and muscle activity on three-dimensional glenohumeral translation in patients with traumatic and atraumatic shoulder instability

BACKGROUND

No quantitative data on glenohumeral translation exist allowing one to distinguish insufficiency of the active or passive stabilizers in different forms of shoulder instability.

HYPOTHESIS

To determine whether 1) in traumatic or atraumatic shoulder instability an increase of glenohumeral translation can be observed in specific relevant arm positions, 2) muscle activity leads to recentering of the humeral head, and 3) there exist differences between traumatic and atraumatic instability.

STUDY DESIGN

Prospective clinical trial.

METHODS

In 12 patients with traumatic and 10 patients with atraumatic instability, both shoulders were examined in different arm positions-with and without muscle activity-by using open magnetic resonance imaging and a three-dimensional postprocessing technique.

RESULTS

At 90 degrees of abduction and external rotation, translation (anterior-inferior) was significantly higher in patients with traumatic unstable shoulders compared with their contralateral side (3.6 +/- 1.5 versus 0.7 +/- 1.6 mm). In patients with atraumatic instability, significantly increased translation (4.7 +/- 2.0 mm) was observed, with the direction being nonuniform. Muscle activity led to significant recentering in traumatic but not in atraumatic instability.

CONCLUSIONS

In traumatic instability, increased translation was observed only in functionally important arm positions, whereas intact active stabilizers demonstrate sufficient recentering. In atraumatic instability, a decentralized head position was recorded also during muscle activity, suggesting alterations of the active stabilizers.

CLINICAL RELEVANCE

These data are relevant for optimizing diagnostics and therapeutic strategies.

In-area and backcountry snowboarding: medical and safety aspects

Snowboarding is now a well-established winter sport and a popular mode of mountaineering. In-area and backcountry snowboarding are defined, as well as a new term, glisse, that refers to all types of skis and snowboards. New developments in equipment focus on boot and binding systems. Backcountry travel is highlighted, including ascent with snowshoes, skis, a splitboard, and crampons. Injuries are about 4-6 per 1000 snowboarding days. Upper extremity injuries are most often wrist sprains or fractures. Lower extremity injuries are primarily ankle sprains and are generally less severe than knee injuries in skiers. Fracture to the lateral process of the talus has been called snowboarder's fracture. Backcountry injuries include avalanche suffocation and trauma, deep snow immersion asphyxiation, hypothermia, frostbite, dehydration, fatigue, acute mountain sickness, and sunburn. Specific recommendations for prevention and safety are discussed.

Skiing injuries

Skiing is a winter sport enjoyed by approximately 200 million people worldwide. An overall injury rate of approximately 3 per 1000 skier-days means that skiing certainly is the riskiest sport undertaken by adults on a routine basis. However, the data suggest that one can anticipate years of enjoyable recreation free from injury. Many troubling injuries, particularly to the lower leg, have shown a steady decline over the past 20 to 30 years because of advances in boot design and binding capabilities. In addition, as information has been gathered regarding the importance of proper maintenance and adjustments, equipment now available can protect a skier more effectively than at any time in the past. Nevertheless, skiing continues to present inherent risks that can be minimized through the following strategies: 1. Enroll in a conditioning program before skiing that focuses on strength and endurance components particularly of the legs and back. 2. Have equipment that is compatible with the skier both from the standpoint of size and expertise. 3. Have equipment adjusted professionally. 4. Do routine testing of binding releases each day before beginning to ski. 5. Ski under control at speeds that are consistent with ability. 6. Stop skiing before fatigue becomes the limiting factor.

Snowboarding injuries: general patterns, with a focus on talus fractures

Injury patterns in snowboarding differ from those in Alpine skiing. Snowboarders tend to have fewer knee and thumb injuries than skiers but more upper-extremity trauma, fractures in general, and ankle injuries. Of particular concern in snowboarding is fracture of the lateral process of the talus (LPT), which masquerades as an inversion ankle sprain, is often missed, and can lead to significant disability. Signs are typically similar to those of inversion sprains, but pain on palpation of the lateral process can be helpful in diagnosis. Standard radiographs often do not show the fracture, so CT or lateral tomography may be required. The most minor, nondisplaced LPT injuries may heal with casting and rehab, but more severe fractures typically require surgery.

The downside of snowboarding. Common injuries in novices and those seeking 'hospital air'

Depending on where you live, you may never have treated a snowboarding injury. However, some of your patients (or maybe your own children) may return from a vacation in the Rockies sporting a snowboarding injury and needing immediate treatment or follow-up care. How familiar are you with the injury patterns specific to this increasingly popular sport? Read on for an introduction to the world of snowboarding and helpful guidelines on how to recognize and treat common snowboarding injuries.