PT Classroom - Posterior Lateral Rotary Instability of the Elbow  ׀ by Lauren Hogan, PT, DPT, OCS, ATC


Lauren Hogan, PT, DPT, ATC, graduated with her Doctor of Physical Therapy degree from Marquette University in May of 2010. She also received her bachelor of science degree in athletic training from Marquette University in 2008. Lauren works as a physical therapist at Froedtert and The Medical College of Wisconsin in outpatient orthopedics and has a special interest in the treatment of post-concussive syndrome.


Posterior Lateral Rotary Instability of the Elbow

Posterior lateral rotary instability (PLRI) of the elbow is usually the result of a lateral or radial collateral ligament injury. When this occurs, the proximal radioulnar complex can supinate or externally rotate away from the trochlea of the humerus. This will cause a subluxation of the humeroulnar and humeroradial joints (1). It is not the same as a radial head dislocation, as the annular ligament is generally intact. The mechanism of injury is often due to valgus stress, combined with axial loading and supination, which produces rotation at the humeroulnar joint (3). This usually occurs with a trauma, such as a fall resulting in an elbow sprain or dislocation. It may also occur with patients that do a lot of weight bearing through the upper extremities, such as gymnasts or those with prolonged crutch use (2).

Patients with PLRI will often report vague elbow discomfort, lateral elbow tenderness, or clicking, snapping or clunking that occurs with supination of the forearm. They may feel as though the elbow may “give out” when weight bearing, especially with the elbow flexed and forearm supinated (3). Evaluation and diagnosis can be challenging, as the symptoms are often unclear and the physical examination and imaging may appear normal. The clinician should rule out lateral epicondylalgia, radial tunnel syndrome, and referred pain from the cervical spine as the primary source of symptoms. Potentially, patients may experience secondary lateral epicondylalgia, neural inflammation or other symptoms as the result of PLRI and this should be fully explored (3).

The lateral pivot shift test is frequently used to diagnose PLRI. This can be falsely negative if only part of the LCL is disrupted, or with guarding of the surrounding musculature. Pain or apprehension with an active floor push up, the chair sign, or press up maneuver also indicates PLRI. The commonly used varus stress test of the elbow is not sensitive enough to identify mild PLRI, but may be able to assist with diagnosis of a more severe injury (3).

PLRI may be treated either operatively or non-operatively. Non-operative management should involve protecting and unloading the elbow to allow for healing of the injured structures. This usually involves use of a hinged elbow brace in pronation for 4-6 weeks. Upper extremity weight bearing and elbow motion with the shoulder abducted or internally rotated should also be avoided. These positions may lead to varus stress on the joint and affect healing (3).

LCL reconstruction or repair is considered with chronic instability. Like other surgeries, protocols vary based on the extent of the injury and surgeon preferences. Following surgery, the elbow is usually placed in a splint or hinged brace with the elbow locked around 90 of flexion and the forearm in neutral or slight pronation. Initially, modalities and elbow compression can be used to help with swelling and pain. In the first two weeks, protection of the elbow is important to allow for healing of the repaired structures. Exercises during this period can include gripping, shoulder isometrics and manual scapular exercises. After around two weeks, the patient can begin protected elbow ROM and gradually increase movement in a hinged brace with an extension block. The patient and PT should continue to protect the LCL, avoiding combined elbow extension and supination. Active supination may be added with the elbow in greater than 90 of flexion, as it places less strain on the repaired region. Shoulder and core exercises can be added with use of the elbow brace (3).

Around 8 weeks post-op, the patient can often be weaned from the brace once full ROM and pain free strengthening is achieved. Functional activities are progressed, but the patient should be educated to continue avoiding positions that strain the lateral elbow. Strengthening will often begin around week 10, with more sport-specific activities starting at week 16. Full return to sport can take up to 9 months following LCL reconstruction or repair (3).

Given the potential for underlying PLRI in patients with other elbow complaints, clinicians should be aware of this condition and evaluate patients thoroughly. During rehabilitation, clinicians should be careful to avoid positions and exercises that put undue strain on the lateral elbow to allow for proper healing and return of full function.

Last revised: November 17, 2013
by Lauren Hogan, PT, DPT, ATC


1) O’Brien, M. J., & Savoi III, F. H. (2011). Treatment & Rehabilitation of Elbow Dislocations. In S. B. Brotzman & R. C. Manske (Eds.), Clinical Orthopaedic Rehabilitation: An Evidence-Based Approach (3rd ed., pp. 63–65, 77). Philadelphia: Mosby, Inc.
2) Postero-lateral Elbow Instability. (n.d.). Physiopedia. Retrieved November 02, 2013, from
3) Sebelski, C. A. (2011). The Elbow: Physical Therapy Management Utilizing Current Evidence. In C. Hughes (Ed.), Current Concepts of Orthopaedic Physical Therapy (3rd ed., pp. 7–19). La Crosse, WI: Orthopaedic Section, APTA.

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