Scot E. Campbell, MD

Mountaineering and climbing have been popular sports for many decades. The recent advent of artificial climbing walls and improved safety equipment have transformed the sport and brought it to a wider audience than ever. Such innovations allow individuals to climb safely in any weather conditions.

Today, an estimated five million people climb-indoors or outdoors-regularly.1,2 A survey of 1800 climbers found that approximately 82% had suffered a climbing-related injury. That's an average of 2.3 injuries per person.3 Due to the sport's growing popularity and its high frequency of associated injuries, it is increasingly important for physicians to be familiar with injuries sustained by participants.

Whereas injuries in traditional mountaineering result primarily from falls or falling objects, sport climbing injuries are typically caused by repetitive stress. Most of these occur in the upper extremity. Studies have shown that the majority of such injuries involve the fingers, ankles, elbows, and shoulders.3 Of these, 60% involve the hand and wrist, while the other 40% are divided equally between the elbow and shoulder.4 In this report, we will present cases of injuries sustained through rock climbing and alpine mountaineering.

As noted previously, the majority of rock climbing injuries involve the upper extremity, and about 60% of these involve the hand and wrist.5 In one survey, climbers reported 794 (about 55%) injuries to fingers or hands out of 1424 total upper extremity injuries.3 Most of these injuries were incurred in the fingers.3 The same survey found that these injuries are most frequently related to strain or overuse. Injuries and ruptures of dense annular structures of the fingers (designated A1 through A5) are unique to sport climbing. These structures prevent "bowstringing" of the flexor tendons, as the pulleys hold the tendons firmly against the phalanx. The traditional rock climbing grip, which involves hyperflexion of the proximal interphalangeal (PIP) joint and hyperextension of the distal interphalangeal (the "crimp position"), puts tremendous stress on these pulley structures. Such pulley injuries are the most common injuries in rock climbing and so characteristic of the sport that the most common pulley tear, an A2 tear, is known as climber's finger. Such an injury is demonstrated by a young rock climber in Figure 1.

The classic history of a pulley tear involves a rock climber who has fallen with his or her hand in the crimp position. The climber hears a loud pop and feels the PIP joint of middle or fourth finger lose flexion. Pain centered at the base of the finger generally follows. Clinical bowstringing can be detected, but usually only in the case of multiple pulley ruptures. It may also prove difficult to elicit on examination secondary to patient discomfort. Accurate imaging is thus crucial in the diagnosis of pulley injuries.

Initial evaluation of suspected pulley ruptures may begin with anteroposterior and lateral radiographs to rule out avulsion injuries or other fractures.6 MR imaging is considered the gold standard for diagnosing and establishing clinical management for pulley injuries. MRI can visualize such injuries directly or can demonstrate pulley defects indirectly by detecting a gap between the flexor tendon and bone on sagittal or transverse images. This finding is known as the bowstring sign (Figure 1).6,7 The size of such a gap increases proportionally with the number of disrupted pulleys.

The bowstring sign is best seen on T1 images, while T2-weighted images aid in distinguishing pulley ruptures from partial tears or tendinitis. Dynamic ultrasound has also proven highly accurate in diagnosis and staging of pulley injuries. Using a distance between flexor tendon and phalanx greater than 1 mm, Klauser et al achieved 98% sensitivity and 100% specificity in detecting pulley injuries with dynamic ultrasound.8

The primary advantages of ultrasound over MR imaging are cost and the ability to see the tendon bowstring in real-time. The primary disadvantage is operator dependence.

Imaging is used to grade pulley injuries on a scale developed by Schoffl et al.4 Grade 1 injuries are pulley strain with no bowstringing. Grade 2 injuries include complete A4 pulley rupture or partial rupture of A2 or A3, while grade 3 lesions involve complete ruptures of the latter. Multiple ruptures or single ruptures combined with lumbrical or collateral ligament trauma are grade 4 lesions.

Injuries graded 1 through 3 are initially treated conservatively, while grade 4 lesions are treated surgically.9 Conservative management consists of rest, ice, and nonsteroidal anti-inflammatory medications. No evidence-based guidelines exist as to how long climbing should be avoided, but generally the prognosis for these injuries is excellent. In fact, conservative treatment has been shown to result in no long-term strength deficit and a return to normal climbing levels within one year, even in cases of complete single pulley ruptures.10 The relative efficacy of surgeries to repair grade 4 lesions has not been determined.11 These surgeries aim for direct repair of the pulley with and without the use of various grafts. While these techniques are generally quite successful, complications such as joint contracture may occur. Prevention of future pulley injuries has traditionally been obtained by circular taping, though its usefulness is controversial. Newer H-taping methods appear to increase crimp grip strength and thus may prevent pulley injuries.12

CASE 2: BRACHIALIS TEAR WITH MYOSITIS OSSIFICANS

The patient is a 41-year-old male rock climber complaining of arm pain who was found on MRI to have a partial brachialis tear and concomitant myositis ossificans of the brachialis. The partial tear was acute in this patient, while the myositis ossificans was likely secondary to chronic microtrauma sustained by the muscle during rock climbing.

The brachialis is a flexor of the elbow joint originating from the lower anterior humerus and the intermuscular septa of the arm and inserting into the coronoid process and tuberosity of the ulna. Tendinitis of the brachialis is known as climber's elbow. This condition, originally thought to be a result of biceps tendinitis, is caused by brachialis overuse during elbow flexion and pronation, a position at which the biceps muscle is less efficient than the brachialis muscle at flexing the elbow.13

Isolated rupture of the brachialis is a poorly documented entity and an uncommon cause of elbow pain. MRI can demonstrate acute and chronic muscle tears. T1-weighted images may demonstrate disruption of the muscle or musculotendinous junction as well as hematoma formation (Figure 2A), while T2-weighted findings include increased signal related to edema (Figure 2B).14 Muscle strains are initially treated by rest, ice, compression, and nonsteroidal anti-inflammatory medications, followed by physical therapy as pain subsides.15 The long-term prognosis for such injuries is typically good.

Traumatic myositis ossificans is heterotopic ossification of muscle. There is little evidence describing the frequency of the condition, despite its early discovery (in 1741), but the majority of cases occur following trauma and are most commonly located in the anterior thigh muscles.16 The anterior arm is the second most common location, but a literature search revealed only a single reported case of myositis ossificans associated with rock climbing.

Pathophysiology is thought to result from an initial injury followed by prolonged macrophage invasion and osteogenic bone mediator release leading to osteogenesis.17 The predominant clinical feature is typically pain, but flexion contracture and a palpable mass may also be seen. Acute

treatment is with rest, ice, compression, and elevation. Surgery may be attempted to remove only mature ossified lesions as determined by plain films, ultrasound, or triphase bone scan.18,19

In radiographic studies, early-phase myositis ossificans may be confused with soft-tissue sarcoma, although extensive muscle edema is less pronounced in the latter.20 Conventional radiographic imaging of myositis ossificans follows the pattern of disease with often normal findings in the beginning, progressing to soft-tissue mass and finally to calcification (Figure 3).21 As demonstrated in this case, the calcification primarily occurs peripherally with a radiolucent center.

MRI evaluation of myositis ossificans is diminished by the modality's limited ability to demonstrate soft-tissue calcification with a high degree of conspicuity. Images obtained prior to the condition's visualization on plain radiographs may allow for early detection based on the demonstration of displaced fascial planes. The aforementioned edema is highlighted by increased signal intensity on T2-weighted images (Figure 2B). Gadolinium contrast may demonstrate rim enhancement in acute myositis ossificans.22 Other modalities, such as scintigraphy and ultrasound, may also be useful in detecting it.

This 32-year-old alpine mountaineer complained of chronic anterior knee pain, especially while climbing. MR examination showed increased signal within the patellar tendon on the proton density and T2-weighted images, along with thickening of the tendon (Figure 4).

Patellar tendinitis may be confused clinically with Osgood-Schlatter disease, Sindig-Larsen-Johansson disease, and prepatellar or infrapatellar bursitis. The former two conditions are found in adolescents and typically affect the junction between the patellar tendon and the tibial apophysis (Osgood-Schlatter) or the junction of the patellar tendon and the inferior pole of the patella (Sindig-Larson-Johansson).

This patient's clinical history and MR findings were highly suggestive of patellar tendinitis. The etiology of patellar tendinitis is likely related to either chronic repetitive strain on the patellar tendon secondary to repeated leg flexion and extension during climbing or to chronic trauma inflicted upon the tendon bumping on rock or ice.

The patellar tendon is the central continuation of the common tendon of the quadriceps femoris and extends from the patella to the tibial tuberosity. Patellar tendinitis is also known as jumper's knee and is a commonly encountered sports injury, with an incidence of 10% to 20% in athletes and military recruits.23 Risk factors include sports activity on hard play-ing surfaces, decreased quadriceps strength, increased training frequencies, and anatomical variations such as some deep knee flexion angles.23

Symptoms are staged by the Blazina classification, according to which stage 1 injuries involve knee pain only after sports activity, stage 2 lesions involve pain at warm-up that reappears at the end of the activity, and stage 3 is characterized by constant pain during activity that prevents attainment of previous performance levels.24 Stage 4 lesions involve complete rupture of the patellar tendon. Initial treatment for patellar tendinitis is conservative and based on elimination of inciting activity, NSAIDs, and steroid injections. Surgical treatment for the resection of degenerated or necrotic tendon tissue may be necessary with injuries not responsive to conservative measures.

The clinical diagnosis of patellar tendinitis is typically made based on knee pain and focal tenderness. Imaging of patellar tendinitis is somewhat controversial. Bone scintigraphy has been suggested as a test and has been found to be useful in detecting severe disease where surgery might be an option.25 The disadvantage of nuclear scintigraphy is its 29% false-positive rate.25

On MRI, the normal patellar tendon generally appears straight, smooth, and uniform. Findings of patellar tendinitis are traditionally described as increased signal intensity within the posterior aspect of a thickened proximal patellar tendon.25 Although MRI is thought to be effective at demonstrating patellar tendinitis, a recent controlled study showed only a 75% sensitivity and 29% specificity for patellar tendinitis. The authors concluded that the usefulness of MRI evaluation for patellar tendinitis is primarily in preoperative planning for stage 3 lesions.25

Ultrasound examination of patellar tendinitis demonstrates tendon enlargement and reduced echogenicity but, like ultrasound scanning of any tendon, it can be limited by operator dependence.26

Falls are the most obvious mechanism of injury in climbing. The prevalence of such injuries is not well established, but one survey found that they make up about 8% of all rock climbing injuries.3 Such falls may have severe results. One study found that of 113 safety harness-wearing individuals sustaining falls of 5 meters or greater, 11.5% sustained severe or critical multisystem trauma.27

Despite the potential seriousness of these injuries, their relative incidence and severity are likely decreased compared with similar injuries in the past secondary to the advent of improved safety equipment and the increased popularity of indoor climbing facilities.

Climbing-related falls appear to be less severe than near height equivalent falls outside the context of climbing.28 A prospective study examining rock climbers who presented to an emergency facility found most of their injuries were related to either outdoor climbs or climbs on indoor walls with inadequate safety mats.29 Fractures are a major complication of rock climbing falls. The study above also found that 12 of the 17 fall-related injuries they examined resulted in fractures.29 The majority of rock climbers reporting fractures from climbing localize these to the foot and ankle.3

The patient whose right foot is displayed on conventional radiography in Figure 5 is a rock climber who suffered a calcaneal fracture as a result of a fall while at a climbing gym. The calcaneous is the largest bone of the foot, bears the entire weight of the body with each step, and is also the most commonly fractured tarsal bone. Along with the talus, it is frequently injured in falls. Climbers sustaining calcaneal fracture as a result of a fall should be assumed to also have spinal fractures and should be transported under precaution.30

Calcaneus fractures present as painful swollen lesions, and while physical examination findings such as crepitus may be suggestive, confirmation of the diagnosis must be made radiographically. Conventional radiography is the initial investigation in suspected calcaneal fracture, but CT is often needed to characterize more complex fractures and to guide management. Bone scintigraphy is typically reserved for injuries highly suspicious for fracture but with negative radiographic and CT findings.

Using CT imaging, calcaneal fractures are divided into intra- and extra-articular varieties. CT findings help classify calcaneal fractures into the Sanders system, which largely dictates fracture management. Type 1 fractures are nondisplaced, Type 2 fractures are split into two parts, Type 3 fractures are depressed or split into three parts, and Type 4 fractures are comminuted. Type 2 and 3 fractures are further subdivided based on medial or lateral fracture line positioning, as medial fractures may be more difficult to visualize intraoperatively.

Based on the criteria set forth by Sanders et al, Type 1 fractures may be treated conservatively31 and generally have a good prognosis. Type 2 and 3 fractures are typically corrected via open reduction and internal fixation, with over 70% of patients experiencing good clinical results.31 Type 4 fracture repairs have been found to be rarely successful even with experienced surgeons.31 Extra-articular fractures are less common and do not involve the posterior facet. These injuries have a better prognosis than intra-articular fractures and are usually managed conservatively. Peroneal tendon injuries or ruptures as well as other tendinous or ligamentous injuries may complicate recovery from calcaneal fractures.

Despite the inherent risk that is present in climbing, the physical challenges, along with the beautiful scenery, make this an appealing sport. Familiarity with the various types of injuries that may be seen with climbing can be helpful in attaining an early diagnosis and can guide the rehabilitation experience. This early diagnosis and treatment may facilitate an earlier return to climbing activities.

Rock climbing and mountaineering are activities that are growing rapidly in popularity. The advent of indoor climbing walls has revolutionized the sport by allowing climbers to practice regardless of weather conditions and with unprecedented safety. As these sports continue to grow, physicians must be aware of the variety of injuries facing climbers. While most are simple overuse injuries, long-term consequences can be severe if the conditions are not recognized and effectively treated. Some of the conditions common in climbers are seldom seen in other types of sports, but some injuries classically associated with other sports (i.e., jumper's knee) may also be seen in rock climbers. Climbing is a growing sport that gives rise to its own commonly encountered set of injuries. Familiarity with these injuries will help to facilitate appropriate treatment.

Dr. Ly is a musculoskeletal radiologist, and Dr. Campbell is chief of musculoskeletal imaging, both at Wilford Hall Medical Center in Lackland, TX. Mr. Morelli is a fourth-year medical student, and Dr. Beall is section chief of musculoskeletal imaging, both at the University of Oklahoma College of Medicine in Oklahoma City.

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Scot E. Campbell, MD

Articles

As climbing popularity soars, so do musculoskeletal injuries