The shoulder is a biomechanically complex joint system. It is prone to injury resulting in joint pathology which is accountable for most of the musculoskeletal injuries in different countries of the world. There are different causes of shoulder injuries, one of which is posterior joint capsule contracture (PJCC).
What is Posterior Joint Capsule Contracture?
Posterior Joint Capsule Contracture (PJCC) is also known as posterior glenohumeral joint (GHJ) capsule contracture. It causes restricted internal rotation of shoulder and horizontal abduction accompanied with pain. It is observed that due to alteration in rotation of humeral axis, there is increased stiffness or contracture of the posterior GHJ, which leads to joint pathology characterized by loss of rotation of shoulder along with pain.
There are three types of posterior joint capsule contracture:
- Idiopathic Posterior Joint Capsule Contracture: The patient does not know/remember any prior trauma. Basically the cause is unknown.
- Posttraumatic Posterior Joint Capsule Contracture: After a low energy event the patient suffers from posterior joint capsule contracture.
- Post-operative Posterior Joint Capsule Contracture: Posterior Joint Capsule Contracture following surgeries such as after a posterior capsular shift for posterior instability.
Signs and Symptoms of Posterior Joint Capsule Contracture
The patient suffering from posterior joint capsule contracture experiences discrete and painful loss of internal rotation of shoulder. The symptoms include pain and difficulty with sleeping and reaching up the back.
Prognosis of Posterior Joint Capsule Contracture
Due to advanced medical technology and medical care facilities the prognosis for posterior joint capsule contracture is much better than earlier years. If posterior joint capsule contracture is immediately diagnosed and treated, it leads to better treatment outcomes.
Causes and Risk factors of Posterior Joint Capsule Contracture
- Causes of Posterior Joint Capsule Contracture in Athletes: Posterior joint capsule contracture is commonly seen among athletes involved in sports such as baseball pitchers, volleyball, tennis, cricket and swimming. These sports require repeated forward forceful movements of shoulder joint. The act puts tremendous physical challenges on glenohumeral joint (GHJ) causing posterior capsule tightness and increased risk of shoulder injury.
- Causes of Posterior Joint Capsule Contracture Causes in Non-athletes: Posterior joint capsule contracture is observed in non-athletes who have fallen or slipped, which in turn lead to forceful forward joint movement. However, apart from injuries there are some cases with unexplained reasons for this condition.
Pathophysiology of Posterior Joint Capsule Contracture
Posterior joint capsule contracture is a soft tissue alteration, which leads to stiffness of posterior muscles of shoulder resulting in joint pathology. The posterior capsule is a band of fibrous tissue. Four muscles and their tendons make up the rotator cuff of shoulder. This capsule interconnects with the tendons of the rotator cuff. They cover the outside of the shoulder to hold, protect and move the joint. Overuse of shoulder (as in case of athletes), leads to build up of tissue around posterior capsule which results in tightness and stiffness of the capsule and is called as posterior capsular contracture. This type of problem reduces the amount the shoulder can rotate inwardly.
Athletes are involved in continuous and excessive forceful forward movements while playing different sports. Overtime the effectiveness of posterior shoulder muscle becomes limited and fatigued which leads to increased tensile load on posterior GHJ capsule. This repetitive tensile load creates greater than normal mechanical input to the tissue, which becomes stiffer due to continuous connective tissue proliferation. Although this proliferation may take place as a protective mechanism for the capsular tissue, eventually it builds around posterior capsule and alters joint mechanics leading to joint pathology. Thus, it is been proposed that mechanical and cellular processes interact to increase the stiffness and decrease the compliance of the capsule. However, the exact processes that cause contracture have not yet been confirmed. It is not clear why only posterior capsule undergoes this process, while the anterior capsule remains unaffected. Since there is no clear understanding of the pathophysiology of posterior joint capsule contracture, both in vitro and animal studies, are required to examine the tissue's cellular and mechanical response to repetitive tensile loads which lead to pathophysiology of posterior joint capsule contracture.
Use of cadaver models is an efficient method to examine the effect of increased posterior GHJ capsule stiffness on motion and pathology. Similarly, imaging in the form of magnetic resonance (MR) and ultrasound (US) imaging is used to identify and quantify the change in joint pathology. Both methods provide additional information on mechanisms of posterior joint capsule contracture.
Complications in Posterior Joint Capsule Contracture
In shoulder joint pathology, the postero-inferior capsule contracture is the primary condition. Untreated or unattended posterior joint capsule contracture, results in a SLAP lesion with subsequent development of dead arm syndrome.
Diagnosis of Posterior Joint Capsule Contracture
Range of Motion (ROM) measurements performed during physical examination may help in the diagnosis of posterior joint capsule contracture by identifying loss of internal rotation, cross-body adduction and to a lesser extent, forward flexion while maintaining external rotation. It is necessary to measure both active and passive range of motion because the presence of pain may limit the patient's ability to actively rotate the internal joint of shoulder to the physical limits of range of motion.
During diagnosis one should be careful to differentiate posterior joint capsule contracture from adhesive capsulitis, which is characterized by global loss of motion. Patients with adhesive capsulitis show diminished external rotation with increased loss of flexion of the shoulder than is encountered in posterior joint capsule contracture patients.
Treatment of Posterior Joint Capsule Contracture
There are two main types of treatment:
- Nonsurgical Management of Posterior Joint Capsule Contracture: The initial management of posterior joint capsule contracture is nonsurgical, which emphasizes on stretching exercises for increasing range-of-motion with goal of restoring normal motion. This approach is sometimes successful for the patient with posterior capsular tightness. Physician or therapist supervises and advises for the following procedure while posterior capsular stretching.
- The patient performs gentle stretches five times per day.
- Patient performs each stretch until patient feels pull against shoulder tightness such that no pain is experienced.
- Every stretch is performed for 1 min. Every day the patient performs stretching exercise for 30 minutes.
- Although improvement occurs within the first month, however 3 months may be required to completely eliminate the condition.
The athlete patients (baseball pitchers and throwing athletes) with chronic painful loss of internal rotation are usually nonresponsive to nonsurgical treatment; they may have to undergo surgical treatment in form of Arthroscopic posterior capsular release.
- Surgical Management of Posterior Joint Capsule Contracture: For patient with increased glenohumeral joint capsule stiffness, surgery in form of Arthroscopic posterior capsular release is used. While in case of overhead throwing athletes, most of the times the posterior-inferior aspect of capsule is tight for which a selective Postero-inferior Capsulotomy may be performed. Both types of operations result in improved motion and pain relief.
After surgery, the patient has to undergo post-operative management. Patient is advised passive motion exercises twice in a day and encouraged for self-assisted motion exercises. Soon after surgery, the arm is placed in an arm sling and the shoulder is kept in a cryotherapy sleeve. Patients are advised to use operative arm for daily activities as soon as possible after surgery. The post-operative patients are also suggested to swim between 2-4 weeks. As observed in majority of cases, surgery yields good result as there are no post-operative complications and no posterior instability.
Prevention of Posterior Joint Capsule Contracture
Patient, especially an athlete, needs to take care of treated shoulder injuries. Post-surgery and treatment, they should be diligent while performing exercises and playing sports since continued strenuous activities will lead to the fatigue of shoulder joints and the problem may persists or may result in complications.
Posterior capsular contracture is a painful condition accompanied with loss of internal rotation of the joint of shoulder. If untreated it leads to complications such as dead arm shoulder. When rightly diagnosed, patient should be treated with either nonsurgical or surgical treatment. Post treatment enough care has to be taken to prevent recurrence of posterior joint capsule contracture. Due to advance medical technology, posterior joint capsule contracture patients can be treated very well and may have good prognosis.