Injuries of the distal phalanx can be a fingertip injury, which will be a different topic by itself. Fracture of the distal phalanx is the most common phalangeal fracture, and it can occur from a crushing injury that produces major soft tissue injury. It can involve the tuft, the shaft, or the base of the phalanx. If it involves the tuft, then it is usually a crush injury and may be associated with a nail bed injury. Usually it is associated with subungual hematoma. If the hematoma involves more than 25% of the nail, especially if there is a fracture, then you need to remove the nail, as well as explore and suture the nail bed. Most of the time the fracture is comminuted and probably will need a splint. In some cases, the fracture may need k-wire fixation. The fracture may fail to unite. Fracture of the distal phalanx shaft is usually stable and can be treated conservatively by a splint or buddy taping, and surgery is rarely needed. Distal phalanx nonunion, if symptomatic and painful, do reduction and internal fixation with bone graft. With fracture of the distal phalanx base, there are two types jersey finger and mallet finger. The patient that is unable to flex the DIP joint is the patient that has a Jersey finger, or volar base fracture. The patient with a mallet finger, or dorsal base fracture, is unable to extend the DIP joint. If the fracture is large, there may be a volar subluxation of the distal phalanx. Be aware of avulsion fracture at the base of the distal phalanx, because it must be evaluated thoroughly. It could be an avulsion of the insertion of the flexor or the extensor tendon, and the fracture appearing small and benign. If the fragment is large or if there is volar subluxation of the joint, then this can be treated by different techniques. K-wire utilization is a very common technique. The goal is to keep the DIP extended until the bone or the tendon heals. Some orthopaedic surgeons will continue to treat this injury by closed means (splint), even if there is a volar subluxation of the joint. The rationale is that a stiff finger that is treated by closed means is better than a stiff finger that is treated by surgery. When the tendon is avulsed with a bony fragment, the tendon with a piece of bone could be retracted at different levels, and it can be seen in the x-ray. In general, if the tendon is retracted to the palm, then the blood supply could be affected and surgery should be done within 10 days. If the fragment is large, then usually the retraction is limited to the DIP. The finger lies in extension relative to the other fingers, and the patient will not be able to do active DIP flexion. Seymour fracture is an epiphyseal fracture of the distal phalanx. It is a flexion injury that leads to physeal separation between the extensor tendon dorsally and the flexor digitorum profundus volarly. This flexion injury causes an avulsion of the nail from the nail fold with disruption of the nail matrix. The patient’s finger will appear flexed, which looks like a mallet finger, and the nail appears to be larger compared to the nail on the other side. This injury is really an open fracture and needs to be treated by antibiotics, removal of the nail, irrigation and debridement of the fracture, reduction and pinning of the fracture and nail bed repair.
The L5 nerve root is part of the lumbosacral plexus. It is an important component of the sciatic nerve. The L5 nerve root causes ankle dorsiflexion, which also comes from the L4 nerve root. The tibialis anterior is the primary dorsiflexor of the ankle, and the innervation comes from the deep peroneal nerve. Injury of the L5 nerve root can cause weakness of the tibialis anterior muscle, and this can lead to a foot drop. The L5 nerve root also causes dorsiflexion of the toes through innervating the extensor hallucis longus and extensor digitorum longus, and this innervation comes from the deep peroneal nerve. Of particular interest, is the extensor hallucis longus. Weakness of the big toes extension is usually present when disc herniation affects the L5 nerve root. So, when the L5 nerve root is affected, the extensor hallucis longus could become weak. The tibialis posterior is an important muscle that runs behind the medial malleolus, and its innervation comes from the posterior tibial nerve (L4-L5). The function of the tibialis posterior is to invert the foot, to assist in plantar flexion of the ankle, and to maintain the medial longitudinal arch. The L5 nerve root also innervates the muscles that cause hip extension, and the muscles are the hamstrings, which is innervated by the tibial nerve, and the gluteus maximus which is innervated by the inferior gluteal nerve. The hamstring muscles are also a major flexor of the knee. The L5 also innervates the hip abductors (gluteus medius and gluteus minimus), and the innervation comes from the superior gluteal nerve, injury of L5 nerve root can cause weakness of the hip abductors, and this can lead to Trendelenburg Gait. The L5 nerve root is really an important nerve root that supplies a lot of muscles. The L5 nerve root gives sensory innervation to the top of the foot. If you do not remember anything about the L5 nerve root, try to remember that injury to this nerve can cause weakness of the big toe extension, weakness of ankle dorsiflexion (foot drop), and weakness of the hip abductor muscles which will give you Trendelnburg Gait.
The sternoclavicular joint is composed of the proximal end of the clavicle and the manubrium of the sternum. Sternoclavicular joint injuries are uncommon shoulder injuries. In young patients, the injury is usually a physeal injury. Medial clavicle physeal fracture occurs in a patient less than 25 years old. Th epiphysis ossifies at the age of 18 and closes between 20-25 years of age. Anterior dislocation is more common than posterior dislocation. The AP x-ray is difficult to interpret, and we get what is called the Serendipity view X-ray, which is 40° cephalic tilt view with the beam focused on the manubrium, then you compare both clavicles. The serendipity view allows for identification of the anterior or posterior translation. In practice clinically, the anterior dislocation will be obvious. The posterior dislocation will not be obvious. The patient will have pain, order a CT scan. A CT scan is the best study to evaluate acute, traumatic injuries of the sternoclavicular joint. It will help determine what type of injury or dislocation (anterior or posterior). A Ct scan will show if the injury is a physeal injury or if it is a true dislocation. It shows the status of the mediastinal structures. Anterior dislocation is common. The patient will have pain, a bump, or swelling that is increased by abduction of the arm. Anterior dislocation is unstable if you reduce it, but it is benign. If it is acute, try to reduce it, otherwise accept the deformity. Observe the patient and treat the patient symptomatically. The anterior sternoclavicular dislocation is rarely symptomatic when left unreduced. Most of the time the patient will do very well, and it will not affect function or range of motion (resuming of unrestricted activity in 3 months). If the injury is chronic and symptomatic, then you will do surgery. The type of surgery that is done is a resection of the medial part of the clavicle. Resect less than 15 mm of the medical clavicle. Do soft tissue stabilization of the residual medial clavicle with costoclavicular ligament reconstruction. Reconstruction of the sternoclavicular joint utilizing tendon graft (allograft or autograft can be used). The hamstring tendon technique is popular, and the figure eight technique is commonly used because it provides great stability. The posterior sternoclavicular dislocation is less common and is a true orthopaedic emergency. 1/3 of the posterior dislocations may have compressive effect by exhibiting pressure on the great vessels, esophagus of the trachea. It may cause dyspnea, tachypnea, dysphagia, or paresthesia and it needs reduction. It has minimal, visible clinical findings. Sometimes the affected shoulder is shortened with forward thrust. The posterior sternoclavicular dislocation will be stable after reduction. You will have general anesthesia with thoracic surgeon backup. With a posterior sternoclavicular dislocation start with closed reduction with the hand or with a towel clip and lift the clavicle up. When you do closed reduction, the initial position for the extremity is the same for anterior and posterior dislocation. You will have general anesthesia and you will do abduction and extension of the shoulder. For the posterior dislocation, you will do abduction and extension. There will be a bump underneath the medial scapula. You will manipulate the medial clavicle with a towel clamp or with the fingers, lifting the clavicle up and reducing the joint. The posterior dislocation is usually stable, so give the patient a sling for 3-4 weeks. For the anterior dislocation, you will do direct pressure. If the reduction is stable, you will use a figure 8 strap or sling, and do therapy at 3-4 weeks. If posterior dislocation is unstable or irreducible, you will do reduction or excision of the medial clavicle plus stabilization of the soft tissue. If it is chronic, recurrent, or symptomatic, you will do excision of the medial clavicle plus soft tissue stabilization. Do not try to do closed reduction in late or chronic cases, because there are mediastinal adhesions that may cause problems inside the chest.
The triceps muscle is a powerful extensor of the elbow joint. The triceps muscle has three heads: the long head, the lateral head, and the triceps. All three heads of the triceps muscle share a common tendon that inserts into the olecranon process at the elbow. An injury to the triceps tendon can be missed. Rupture of the triceps muscle typically occurs in male athletes such as body builders, football players, and in athletes who lift heavy weights. The injury can also occur due to a fall onto an outstretched hand. The tear is usually seen in middle aged men. A rupture of the tendon can be either complete, or incomplete. The rupture occurs at the bony insertion of the tendon. The patient may have pain, swelling, and some ecchymosis around the posterior part of the elbow. Mechanisms of injury include stress from sudden increase in intensity of training, direct trauma to the tendon, and laceration of the tendon. Rupture of the tendon may also occur due to local steroid injection or it may be due to t a history of anabolic steroid use. Rupture may also occur due to systemic diseases such as renal disease, gout, or it may occur due to previous elbow surgery. Other risk factors include use of cipro (ciprofloxacin), diabetes mellitus, rheumatoid arthritis, osteoarthritis, and olecranon bursitis. There will be painful limitation of range of motion and the patient will not be able to extend the elbow against resistance. The patient may hear a “pop” and the tendon may retract upwards. A gap may be felt in the back of the elbow where the rupture occurs. There is a squeeze test for the distal biceps injury, achilles tendon injury, and also a squeeze test for the triceps injury. This test is completed when the patient is laying prone. The forearm will be hanging down with the elbow at the edge of the table and then squeeze the triceps. The inability of the patient to extend the elbow against gravity means that the patient has a complete tear of the triceps. X-rays may show a small bony avulsion. The “flake” sign identifies the avulsion and the position of the tendon on a lateral x-ray.