Clavicle fracture

• Pain, particularly with arm movement or on the front part of upper chest • Swelling • Deformity of the clavicle area sometimes with a sharp bone end pressing up from below the skin creating the appearance of a tent held up by poles (skin tenting) • Often, after the swelling has subsided, the fracture can be felt through the skin • Sharp pain when any movement is made • Referred pain: dull to extreme ache in and around clavicle area, including surrounding muscles • Possible nausea, dizziness, and/or spotty vision due to extreme pain • Tachypnea (rapid breathing) if the underlying lung is affected (pneumothorax) • Arm weakness if the underlying neurovascular structures are damaged (brachial plexus injury) ==Mechanism==

Clavicle fractures are usually a result of injury or trauma. The most common mechanism involves a fall directly onto the shoulder (87%), with less common causes including direct impact to the clavicle (7%), or as a result of a fall onto an outstretched hand (6%). Newborns may present clavicle fractures following a difficult delivery involving shoulder dystocia. Due to the anatomy of the clavicle, 80% of fractures occur in the middle third of its length which is its weakest point. When a clavicle fracture occurs, the sternocleidomastoid tends to pull the proximal (near trunk) portion of the clavicle upwards toward the head while the conoid and trapezoid ligaments, pectoralis minor muscle, and overall weight of the arm pull the distal (near shoulder) portion of the clavicle downwards, away from the head. This creates the typical "S" shaped deformity most often seen with clavicle injuries. == Anatomy ==

The clavicle serves as a strut and the only bony attachment between the trunk of the body (axial skeleton) and the bones of arm which are otherwise connected to the trunk through a series of muscles and ligaments. A clavicle is located on each side of the front, upper part of the chest and it is located directly above the first rib. The clavicle consists of a medial end, a shaft, and a lateral end. The medial end connects with the manubrium of the sternum and gives attachments to the fibrous capsule of the sternoclavicular joint, articular disc, and interclavicular ligament. The lateral end connects at the acromion of the scapula which is referred to as the acromioclavicular joint. The clavicle forms a slight S-shaped curve where it curves from the sternal end laterally and anteriorly for near half its length, then forming a posterior curve to the acromion of the scapula. The clavicle widens and flattens at both ends while taking a hollow tubular shape through its middle segment with limited medullary bone resulting in a relative weak point where most fractures occur. ==Diagnosis==

If a clavicle fracture is suspected, the initial method to evaluate for a clavicle fracture is by an AP (anterioposterior; horizontal through the body from front to back) or PA (posterioanterior; horizontal through the body from back to front) X-ray of the affected clavicle to determine the fracture type and extent of injury. == Classification ==

A clavicle fracture can be classified and described based on its location, displacement, angulation, pattern, and comminution. The most common classification system for these fractures is the Allman classification system which broadly divides these fractures based upon their location along the clavicle divided into thirds along its length. Allman Classification Group I Fractures of the middle third of the clavicle. The most common type of clavicle fracture (80%) which both ends of the clavicle stablized and secured by muscular and ligamentous attachments. Group II Fractures of the distal third (closest to shoulder) of the clavicle. Second most common type of clavicle fracture (15%). Can be further subdivided based upon fracture relative location to coracoclavicular ligaments as this can inform the presense of involvement of the acromioclavicular joint surface, ligamentous involvement, and fracture stability. Group III Fractures of the proximal third (closest to neck/trunk) of the clavicle. These fractures need to be assessed for epiphyseal (growth plate) injury in pediatric patients. These fractures can be further subdivided based on displacement of the fracture, articular (joint) surface involvement, epiphyseal involvement, and comminution. ==Treatment==

The treatment of clavicle fractures depends on the type of fracture (Group I,II, or III) based upon which third of the clavicle length is affected, the degree of fracture displacement (distance fragments have moved out of their normal alignment), patient goals (speed of return to activity and activity level), and the presence of complications (open fracture, neurovascular compromise). Antibiotics and tetanus vaccination may be used if the bone breaks through the skin; however, this is uncommon. Nonoperative Current practice for simple fractures without great displacement is generally to provide a sling, and pain relief, and to allow the bone to heal itself, monitoring progress with X-rays every week or few weeks if necessary. Surgery is employed in 5–10% of cases. However, a meta-analysis of 2 144 midshaft clavicle fractures supports primary plate fixation of completely displaced midshaft clavicular fractures in active adult patients. There is a lack of consensus on nonoperative vs operative treatment for minimally displaced middle third clavicle fractures with operative treatment possibly leading to lower rates of nonunion and residual deformity but potentially leading to the need for future hardware removal. However, it seems that this does not affect the functional outcomes in most patients, indicated by recent systematic reviews. The evidence for different types of surgery for breaks of the middle part of the clavicle is poor as of 2023. Surgery may be considered when one or more of the following is presents • Comminution with separation (bone is broken into multiple pieces) • Skin penetration (open fracture) • Associated nervous and vascular trauma (brachial plexus or supraclavicular nerves) • Nonunion after several months (3–6 months, typically) • Displaced distal third fractures (high risk of nonunion) • Although shortening (as a result of overlap of fracture ends) has often been suggested as an indication for surgery, a review found that people treated without surgery for shortening of mid shaft clavicle fractures did not affect outcomes. A discontinuity in the bone shape often results from a clavicular fracture, visible through the skin, if not treated with surgery due to imperfect bone alignment or bony callous formation during fracture healing. Surgical procedures often call for ORIF|open reduction internal [plate] fixation where an anatomically shaped titanium or steel plate is affixed along the superior or anterior aspect of the bone by several screws. In some cases, the plate is removed after healing due to discomfort, to avoid tissue aggravation, osteolysis or subacromial impingement. This is especially important with a special type of fixation plate used in distal third fractures called a hook plate. With anatomical plates, plate removal is considered an elective procedure that is rarely necessary. An alternative to plate fixation is elastic TEN intramedullary nailing. These devices are implanted within the clavicle's canal to support the bone from the inside. Typical surgical complications are infection, loss of sensation below the incision on the chest due to inadvertent injury of one or several supraclavicular nerves (most common when using a horizontal surgical incision), and nonunion of the bone (failure of the bone to properly fuse together). The risk of injury to the supraclavicular nerves can be reduced by using a minimally invasive approach to the clavicle for middle third fractures. Major nerve injury to the brachial plexus or vascular injury is extremely rare. ==Prognosis==

Healing time varies based on age, health, fracture complexity, location of the break, fracture displacement, treatment course (operative vs nonoperative), and the presence/number of complications. For patients undergoing operative treatment, functional recovery and return to work often occurs early than those undergoing nonoperative treatment for the similar fractures although long-term results show no significant difference. Complication rates are relatively low but include infection (0.6-3.2% deep infections), hardware irritation requiring removal (approximately 10%), and wound-related issues. ==Epidemiology==

Clavicle fractures occur at 30–64 cases per 100,000 a year and are responsible for 2.6–5.0% of all fractures and 44-66% of fractures around the shoulder. Fractures of the middle third of the clavicle are the most common and make up 80% of all clavicle fractures. ==History==

Hippocrates, 4th century BC: From an ancient Egyptian text of approximately the 30th century B.C., in a copy known as the Edwin Smith papyrus, J. Breasted translation, case 35: All the cases in this text describe examination, prognosis, and (where applicable) treatment, in that order. == References ==