ANATOMY

Osteophytes build up in typical locations along the margins of the joint and in the fossae. Although the patient may have osteophytes on the posteromedial olecranon, osteophytes alone do not always cause impingement pain. The relationship between bony osteophytes and impingement pain poses an apparent dilemma. It is not unusual to see osteophytes that impinge at the limit of motion in patients who have no pain. The question is why some osteophytes are painful and others are not. Based on experience and unpublished research in progress, I think the usual cause for impingement pain in such circumstances is a fractured olecranon osteophyte that has typically progressed to nonunion by the time of referral to the orthopedic surgeon.¹³ Nonunion fractures are best visualized (Fig. 9-1) on sagittal and coronal computed tomography (CT) reconstructions. The loose fragment is easily missed during arthroscopy because it is very small or covered with cartilage and not obviously loose. In some patients, the loose fragment is removed during osteophyte excision without ever being recognized. Other causes for the pain include loose bodies or buildup of inflamed soft tissue posteriorly.

FIGURE 9-1 Impingement pain in hypertrophic osteoarthritis usually is caused by a painful nonunion of a fractured osteophyte, most commonly on the tip of the olecranon (arrow).

PATIENT EVALUATION

History and Physical Examination

The patient reports posterior pain at the end point of extension. An associated contracture of some degree is almost invariably present.

I have found that the diagnosis of posterior impingement due to fractured nonunited osteophytes can be confirmed with confidence on physical examination using the extension impingement test and the arm bar test.¹³ The extension impingement test is performed by starting with elbow near full extension and then quickly (but gently to prevent injury) snapping it into terminal extension. This maneuver reproduces the posterior or posteromedial pain experienced during provocative activities such as throwing. A simultaneous valgus load normally enhances the pain if the pathology is primarily posteromedial.

Diagnostic Imaging

CT with three-dimensional surface rendering provides excellent imaging of the bony pathology (Fig. 9-2A). The individual bones can be isolated from each other and spun around in three dimensions, demonstrating the location and structure of each osteophyte and loose body. Two-dimensional sagittal and coronal reconstructions are also necessary, because they reveal the fine details not available in the three-dimensional images (see Fig. 9-2B), including nonunited fractures, the original floors of the fossae, and small loose bodies embedded in the cartilage surfaces. Axial two-dimensional reconstructions complete the imaging protocol.

FIGURE 9-2 Three-dimensional surface rendering (A) and two-dimensional sagittal (B) computed tomographic reconstructions of the posterior compartment show osteophytes on the olecranon and in the olecranon fossa. The circles in A and B represent the arthroscopic fields of view in C and D, respectively. C, Step 1 is to get in and establish a view. The arthroscopic view is indicated by the circles, revealing the tip of the olecranon (Olec), which is just barely detectable within the surrounding scar tissue. D, Step 2 is to create a space in which to work by removing scar tissue, stripping the scar tissue and capsule off the bone, and inserting a retractor to elevate the soft tissues. A much larger view is then possible in which the olecranon (Olec) can be seen impinging on the marginal osteophyte on the trochlea (Troch). Above that area is scar tissue covering the floor of the olecranon fossa (Fossa). (Courtesy of Shawn W. O’Driscoll, PhD, MD, Mayo Clinic, Rochester, MN.)

TREATMENT

Indications and Contraindications

Arthroscopic osteocapsular arthroplasty is ideally indicated for symptomatic primary hypertrophic osteoarthritis of the elbow (with contracture and pain at the end range of motion) and for osteoarthritis resulting from osteochondritis dissecans. Relative indications include arthritis and contracture due to trauma or burned-out rheumatoid arthritis.

The main contraindication is questionable or inadequate expertise of the operating surgeon. The anterior capsulectomy portion of an arthroscopic osteocapsular arthroplasty may be relatively contraindicated in a patient with prior submuscular transposition of the ulnar nerve. Lying on the anterior capsule, to which it may be scarred, the nerve is theoretically at increased at risk for injury during anterior capsulectomy.

Relative contraindications include post-traumatic arthritis with severe joint surface irregularities and painful crepitus or non-hypertrophic osteoarthritis in the patients older than approximately 65 years.

Conservative Management

Nonsurgical treatment of hypertrophic arthritis with contracture is limited to symptomatic relief of pain by rest, activity modification, and nonsteroidal anti-inflammatory medications. Neither physical therapy nor splints have proved effective for established contractures.

Alternative Surgical Treatments

Alternatives to arthroscopic osteocapsular arthroplasty include arthroscopic or open Outerbridge-Kashiwagi, open column, and open Tsuge procedures.⁶^,⁸^–¹² In my experience, drilling a hole through the olecranon fossa does not adequately decompresses the coronoid fossa or the olecranon fossa, and it fails to address osteophytes in the radial fossa. It also eliminates the bony landmarks used to determine just how much bone should be removed from the fossa. The open column procedure does not permit as accurate and complete removal of osteophytes or contracted capsule (e.g., medial gutter) as the arthroscopic procedure. The Tsuge procedure has a high morbidity rate with no apparent advantages over arthroscopic osteocapsular arthroplasty.