Apophyseal Avulsion Fracture

Overview

Definition

An avulsion fracture Avulsion fracture Tearing away of the cortical bone fragment at the location of a strong ligament or tendon attachment. The bone fragment detachment site often occurs near a soft site (e.g., growth plate) at the base where ligaments; tendons; or joint capsules attach. Overview of Bone Fractures occurs when part of an apophysis is ripped off by the ligament due to a sudden forceful eccentric or concentric contraction of the muscle attached to it.

Epidemiology

• Age: common in adolescents
• Sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria distribution: predominantly affects males (78% incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency)
• Most commonly in association with contact and high-impact sports, such as soccer, football, and baseball
• Most commonly at the anterior inferior iliac spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy, anterior superior iliac spine Anterior Superior Iliac Spine Chronic Apophyseal Injury, and ischial tuberosity Ischial Tuberosity Chronic Apophyseal Injury

Anatomy

Apophyses exist on many bones and are the insertion site of a number of ligaments. Avulsion fractures can occur at any of these sites.

• Tibial tuberosity Tibial tuberosity Leg: Anatomy: attachment of patellar ligament Patellar ligament A band of fibrous tissue that attaches the apex of the patella to the lower part of the tubercle of the tibia. The ligament is actually the caudal continuation of the common tendon of the quadriceps femoris. The patella is embedded in that tendon. As such, the patellar ligament can be thought of as connecting the quadriceps femoris tendon to the tibia, and therefore it is sometimes called the patellar tendon. Osgood-Schlatter Disease on proximal tibia Tibia The second longest bone of the skeleton. It is located on the medial side of the lower leg, articulating with the fibula laterally, the talus distally, and the femur proximally. Knee Joint: Anatomy
• Anterior superior iliac spine Anterior Superior Iliac Spine Chronic Apophyseal Injury ( ASIS ASIS Chronic Apophyseal Injury): attachment of sartorius Sartorius Thigh: Anatomy muscle; seen most commonly in adolescent sprinters
• Anterior inferior iliac spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy (AIIS): attachment of rectus femoris Rectus femoris Thigh: Anatomy muscle
• Distal pole of patella Patella The flat, triangular bone situated at the anterior part of the knee. Knee Joint: Anatomy: patella Patella The flat, triangular bone situated at the anterior part of the knee. Knee Joint: Anatomy sleeve fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures; rare injury characterized by separation of cartilage Cartilage Cartilage is a type of connective tissue derived from embryonic mesenchyme that is responsible for structural support, resilience, and the smoothness of physical actions. Perichondrium (connective tissue membrane surrounding cartilage) compensates for the absence of vasculature in cartilage by providing nutrition and support. Cartilage: Histology sleeve from ossified patella Patella The flat, triangular bone situated at the anterior part of the knee. Knee Joint: Anatomy; may require surgery
• Ischial tuberosity Ischial Tuberosity Chronic Apophyseal Injury apophysis: hamstring insertion avulsion seen in adolescent sprinters; frequently misdiagnosed as acute hamstring tendon or muscle injury 
• Iliac crest: insertion of oblique muscles 
• Medial epicondyle of humerus: insertion of many muscles including the flexors of the forearm; variant of “little league elbow”
• Olecranon Olecranon A prominent projection of the ulna that articulates with the humerus and forms the outer protuberance of the elbow joint. Arm: Anatomy: insertion of tricep tendon

Clinical Presentation and Diagnosis

Acute apophyseal injuries are generally non-contact related, but rather due to a sudden explosive eccentric muscle contraction.

History and physical exam

Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with:

• Severe pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
• Swelling Swelling Inflammation
• Point tenderness Point Tenderness Chronic Apophyseal Injury
• Ecchymosis Ecchymosis Extravasation of blood into the skin, resulting in a nonelevated, rounded or irregular, blue or purplish patch, larger than a petechia. Orbital Fractures
• Sometimes, history of a “popping noise or feeling” precedes injury

Exam can reveal:

• Deformity Deformity Examination of the Upper Limbs of interested area
• Decreased range of motion Range of motion The distance and direction to which a bone joint can be extended. Range of motion is a function of the condition of the joints, muscles, and connective tissues involved. Joint flexibility can be improved through appropriate muscle strength exercises. Examination of the Upper Limbs
• Difficulty weight-bearing 
• Abnormally high patella Patella The flat, triangular bone situated at the anterior part of the knee. Knee Joint: Anatomy in cases of tibial tubercle Tibial Tubercle Osgood-Schlatter Disease avulsion fracture Avulsion fracture Tearing away of the cortical bone fragment at the location of a strong ligament or tendon attachment. The bone fragment detachment site often occurs near a soft site (e.g., growth plate) at the base where ligaments; tendons; or joint capsules attach. Overview of Bone Fractures
• Acute injury leads to swelling Swelling Inflammation, which limits examination; re-examination after 10–14 days may be necessary.

Imaging

• Plain X-rays X-rays X-rays are high-energy particles of electromagnetic radiation used in the medical field for the generation of anatomical images. X-rays are projected through the body of a patient and onto a film, and this technique is called conventional or projectional radiography. X-rays:
  • Soft tissue Soft Tissue Soft Tissue Abscess swelling Swelling Inflammation and joint effusion Joint Effusion Septic Arthritis are non-specific findings often seen.
  • Avulsed bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types fragments may be visible in acute injuries.
  • Subacute injuries may reveal areas of sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor.
  • Calcifications due to previous trauma may be visible.
• Computed tomography (CT) scan:
  • May be used to assess size of fragment and amount of displacement Displacement The process by which an emotional or behavioral response that is appropriate for one situation appears in another situation for which it is inappropriate. Defense Mechanisms
  • Can assist in perioperative planning
• Magnetic resonance imaging (MRI) scan: may be used to assess associated soft tissue Soft Tissue Soft Tissue Abscess injury

Management

Management of most acute avulsion injuries is non-surgical and based on the location and amount of displacement Displacement The process by which an emotional or behavioral response that is appropriate for one situation appears in another situation for which it is inappropriate. Defense Mechanisms of the avulsed bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types.

• Non-displaced or minimally displaced apophyseal avulsion fractures:
  • Rest
  • Protected motion, including partial weight-bearing
  • Appropriately staged physical therapy Physical Therapy Becker Muscular Dystrophy
• For displaced fractures: Amount of displacement Displacement The process by which an emotional or behavioral response that is appropriate for one situation appears in another situation for which it is inappropriate. Defense Mechanisms, size of fragment, and demands of athlete are important factors in surgical decision.

Clinical Relevance

Additional important pediatric skeletal injuries:

• Greenstick fracture Greenstick fracture The bones of growing children exhibit unique characteristics, which, combined with the unique mechanisms of injury seen in children, result in fracture patterns differing significantly from those common in adults. The greenstick fracture is an incomplete fracture usually seen in long bones. Greenstick Fracture: partial-thickness fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures involving a complete break of cortex and periosteum Periosteum Thin outer membrane that surrounds a bone. It contains connective tissue, capillaries, nerves, and a number of cell types. Bones: Structure and Types on only 1 side of the bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types. Termed “greenstick” as it resembles a break in a live, “green” twig, where 1 side of the stick remains intact. High risk for refracture and should be completely immobilized. Rarely requires reduction, but should be managed cautiously to prevent malunion Malunion Hip Fractures or angulation Angulation Buckle or Torus Fracture deformities, and often should be referred for orthopedic follow-up.
• Supracondylar fracture Supracondylar fracture Supracondylar fractures are the most common elbow fractures in the pediatric population. The most common mechanism of injury involves a fall on an outstretched hand, resulting in a fracture of the distal humerus. Patients frequently present with pain, visible deformity, and limited range of motion of the injured elbow. Supracondylar Fracture: complete fracture Complete Fracture Overview of Bone Fractures affecting distal humerus Humerus Bone in humans and primates extending from the shoulder joint to the elbow joint. Arm: Anatomy after falling on outstretched hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy (FOOSH). Commonly fractures of the elbow in children. Requires immediate orthopedic consultation as many cases are associated with neurovascular injury and require surgical intervention. 
• Buckle or Torus fracture Torus Fracture Buckle or Torus Fracture: fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures affecting growing metaphyseal bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types secondary to compression Compression Blunt Chest Trauma load, where bone Bone Bone is a compact type of hardened connective tissue composed of bone cells, membranes, an extracellular mineralized matrix, and central bone marrow. The 2 primary types of bone are compact and spongy. Bones: Structure and Types buckles or compresses. Generally considered a stable fracture Fracture A fracture is a disruption of the cortex of any bone and periosteum and is commonly due to mechanical stress after an injury or accident. Open fractures due to trauma can be a medical emergency. Fractures are frequently associated with automobile accidents, workplace injuries, and trauma. Overview of Bone Fractures. Treated by immobilization Immobilization Delirium, and has a good prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas.