When a shoulder dislocation occurs, the glenoid cavity may press on the humeral head, causing a Hill-Sachs lesion. This lesion corresponds to a pressure dent on the cartilage or bone of the humerus. Severe Hill-Sachs lesions must be corrected by surgical procedures.
What is a Hill-Sachs lesion?
Hill-Sachs lesion is also known as Hill-Sachs dent and corresponds to a pathologic condition at the head of the humerus. The lesion is usually a symptom of a dislocated shoulder and can affect both the cartilage and the bone at the humeral head. Two different forms of Hill-Sachs lesion exist. The ventral form affects the anterior segment. The dorsal form manifests on the posterior section. The type of Hill-Sachs defect is directly related to the direction of shoulder dislocation. The Hill-Sachs lesion corresponds to an impression fracture. Impression fractures are defined as those that cause displacement of bone parts or indentation of bone parts into other parts of the bone. Accordingly, the Hill-Sachs defect often manifests as an impressed area on the humerus and is almost never observed regardless of findings such as dislocated shoulder. In most cases, the lesion is preceded by an accidental event.
Causes
The shoulder joint is composed of parts of the humerus and scapula. The upper end of the humerus is located in the glenoid cavity on the lateral scapula. The socket is called the glenoid cavity and is the most important element of the shoulder joint. When the humerus slips out of this glenoid cavity, a dislocated shoulder is present. When a dislocated shoulder is found, the humerus may be partially depressed by the edges of the glenoid cavity. This results in severe pressure on the humeral head, which may manifest as a dent. Thus, shoulder dislocation is considered the cause of the Hill-Sachs lesion. In most cases, the defect does not occur until the shoulder has been dislocated several times. The defect is dorso-lateral to the humeral head in an anterior shoulder dislocation. In a posterior shoulder dislocation, the Hill-Sachs lesion is located ventrally and is sometimes referred to as an inverse Hill-Sachs lesion. Often, this pathologic phenomenon is associated with a Bankart lesion, which causes the anterior or posterior glenoid rim to shear.
Symptoms, complaints, and signs
Because Hill-Sachs lesion occurs predominantly in direct association with shoulder dislocation, patients suffer the typical symptoms of a dislocated shoulder. These include, first and foremost, limited or completely eliminated range of motion in the shoulder joint. In most cases, severe pain is the reason for the restricted mobility. Sufferers hold the affected arm in a slight abduction and move it as little as possible. Most patients complain of spontaneous pain in addition to pain on movement. The contour of the affected person’s shoulder appears somewhat angular. In addition, the head of the humerus can be palpated within the soft tissues outside the glenoid cavity. If the dislocated shoulder has damaged vessels, a bruise may be evident. Circulatory problems are also conceivable in this case. If, on the other hand, nerves have been damaged, sensory disturbances in the affected arm are often present in addition to motor deficits. These sensory disturbances can correspond to insensations or a general numbness. The Hill-Sachs lesion itself is not usually visible to the naked eye.
Diagnosis and course of the disease
The diagnosis of Hill-Sachs lesion is made along with the diagnosis of shoulder dislocation using radiographic imaging. The physician gathers initial evidence of the two phenomena during the history and physical examination. If anterior, inferior, and traumatic first shoulder dislocation is suspected, the physician must additionally look for a Bankart lesion, even if the radiograph shows no defects. Ideally, he or she will go on a search using MRI. Alternatively, diagnostic arthroscopy may take place.
Complications
Hill-Sachs lesion primarily results in severe limitation of the patient’s mobility. In most cases, pain and restrictions occur directly at the shoulder, making it difficult for the affected person to bend or lift.Due to the severe pain and the limited mobility of the patient, it is not uncommon for psychological complaints and depression to develop. Furthermore, irritability can develop in the patient, which can have a negative effect on the social environment. The pain in the shoulder caused by the Hill-Sachs lesion can also occur in the form of pain at rest, leading to sleep disturbances at night. The affected region swells considerably and in most cases a bruise also forms. Furthermore, due to pinched nerves or a circulatory disorder, paraesthesia or paralysis can also occur in the shoulder. This feels numb and often can no longer be moved to the usual extent. In most cases, the Hill-Sachs lesion must be treated surgically, with no further complications. After treatment, in some cases, the affected person cannot immediately subject the shoulder to high levels of stress.
When should you see a doctor?
A visit to the doctor should be made if there is any discomfort in the shoulders. If the irregularities are not due to short-term overuse, there is cause for concern. If the shoulder discomfort can be attributed to a jerky movement, impact or accident, it should be investigated and treated. If there is a restriction of movement, pain, or a decrease in physical strength, a doctor is needed. If symptoms persist for several days or increase in intensity, a physician should be consulted. Also unusual is a spreading of the symptoms or the development of new complaints. If disturbances of the blood circulation occur or there is muscle pain, a visit to the doctor is necessary. If the body is in a bad posture, one-sided physical strain, headaches or sleep disturbances occur, the symptoms should be clarified by a doctor. If a dislocated shoulder joint can be palpated or detected by visual inspection, the observations should be discussed with a physician. Numbness in the shoulder, arm or fingers, as well as sensory disturbances, should also be investigated. If the arm can no longer be loaded as usual or if there is tingling in the arms or fingers, a visit to the doctor is advisable. If changes in the appearance of the skin occur and discoloration occurs, a physician should be consulted.
Treatment and therapy
Therapy for a Hill-Sach lesion takes place on a case-by-case basis, depending on the nature of the injury. If it is the patient’s first shoulder dislocation, the Hill-Sachs defect is usually subtle and then does not require further therapy. If a Bakart lesion is present, this defect is corrected in an arthroscopic or open surgical Bankart repair procedure. If, on the other hand, there is recurrent or habitual shoulder dislocation with increasing instability, other procedures must be used. One such procedure may be Resch’s J-Span plasty. Equally suitable are operations according to Eden-Hybinette or subcapital derotation osteotomies according to Weber. If the Weber procedure is chosen, the physician moves the Hill-Sachs lesion out of the area of weight-bearing and at the same time tightens the posterior joint capsule by means of derotation. The tightening prevents recurrent dislocation to the anterior side. Posterior dislocation requires surgery to remove the imprinted lesion. A drill hole is made in the posterior aspect of the humeral head. Through this hole, the lesion is pushed outward using a ram and stabilized by autologous cancellous bone. In individual cases, the procedure is performed in combination with a posterior Bankart repair according to Scott and Kretzler. On the other hand, if an anterior Hill-Sachs defect is deep and imprinted, the small humeral tuberosity can be displaced into the defect. This procedure is equivalent to Neer surgery.
Outlook and prognosis
Many patients receive a good prognosis for Hill-Sachs lesion. If the shoulder joint is dislocated for the first time and is mild, correction can be performed with a few simple steps. Afterwards, the patient’s body should be adequately rested for some time and heavy loads on the upper body should be avoided. After a few days or weeks, the patient is completely free of symptoms. Late effects are not to be expected in these cases. If the shoulder has already been dislocated a number of times, the joint has already loosened.Therefore, recovery occurs only for a short time in these patients. The shoulder joint is unstable overall and requires additional strengthening. The treatment is carried out in a surgical procedure and is performed routinely with few risks. If no complications occur during the procedure, the patient normally experiences relief from his or her symptoms afterwards. However, complete resilience as with a natural joint is not achieved. In the event of complications during the surgical procedure or further damage to the surrounding areas, there may be permanent disturbances and irregularities in movement. Consequential damage is possible, a decrease in physical performance and likewise emotional distress may develop. The overall prognosis is thus considerably negatively affected. Nevertheless, the life of the affected person is not endangered by the disease.
Prevention
Hill-Sachs lesions can only be prevented by the patient preventing dislocations of the shoulder. Habitual dislocations due to tissue weaknesses can hardly be prevented. Prevention is also difficult in the context of accidents. However, if the affected person can relate the repeated dislocations of the shoulder to sports played, stopping activity in these sports, for example, would be equivalent to a preventive measure.
Follow-up
Individual follow-up of a Hill-Sachs lesion depends primarily on the respective duration of impairment, the severity of the paralysis associated with the lesion, and the type of previous therapy. In any case, however, extensive and individualized physiotherapy is recommended. The goal of such therapy is always to maintain and regain mobility, coordination, and strength. In addition to conventional physiotherapy with guidance from a therapist, home practice often proves extremely useful. If time is available, short exercise sessions of 10 to 30 minutes each are recommended throughout the day. Guided mobilization and exercise therapy should be started shortly after surgery. The shorter the time without movement, the easier it is to regain full resilience and mobility. In addition to physiotherapeutic work, rest periods should be observed. Everyday resilience can be expected after four to six weeks. Heavy physical and mechanical strain at work or during leisure time should be strictly avoided during the first four weeks. Elevation of the arm above the head and work performed in this position should be avoided until complete healing is achieved. In addition, regular attention should be paid to sensory disturbances or insensations in the shoulder and arm in order to prevent possible consequential damage such as circulatory disorders in good time.
What you can do yourself
In the case of Hill-Sachs lesion, surgical interventions are usually necessary to limit the symptoms and discomfort of the disease. Therefore, self-help options are rarely available to the affected person. In some cases, however, the disease can be prevented by avoiding dislocations of the shoulder. Particular attention should be paid to this if they occur during sporting activities. In the case of accidents or other illnesses, the Hill-Sachs lesion cannot be directly prevented. Should an accident occur, immediate medical treatment is advisable. Furthermore, the patient should naturally take care of his body and avoid performing strenuous activities and sports. After the treatment, the movement of the shoulder must be restored. Various therapies are suitable for this purpose, which can also be performed at home. The disturbances of the sensitivity or the insensations can possibly be limited by massages or by heat applications. As a rule, the circulatory disturbances are also treated. If the affected person suffers from psychological discomfort due to the movement restrictions, the support of friends or acquaintances is very helpful. Meeting other patients can also have a positive effect on the course of the disease.
