Elbow osteochondritis dissecans

The Problem

Osteochondritis dissecans (OCD) of the capitellum results from repetitive loading of the lateral compartment of the elbow and can result in profound arthritis of the radiocapitellar joint if left untreated.

Clinical Presentation

OCD commonly affects athletes aged 11-21 years (average 12-14) who participate in sports where repetitive overload of the elbow is common, such as baseball pitchers and gymnasts. Males are more commonly affected than females and the dominant arm more so than the non-dominant arm. Patients initially report activity-related lateral elbow pain, which is relieved with rest. Later in the disease process, patients may complain of locking or catching with the presence of loose bodies. Patients may also complain of a loss of motion, typically terminal extension.

Diagnostic Workup

Physical examination will often show tenderness over the radiocapitellar joint. Range of motion is typically decreased compared to the contralateral elbow, usually with a flexion contracture of 15-20 degrees. The active radiocapitellar compression test is performed by rotating the forearm in the midrange of flexion and extension, while applying an axial load to the radiocapitellar joint. Pain with this maneuver is suggestive of a capitellar OCD in the appropriate population. Posterolateral rotatory instability testing should be performed as well, to test for potential elbow instability as a cause of symptomatology.

Plain radiographs are the initial study of choice, but early OCD lesions may not be easily detectable on plain xrays. Plain radiographs should include 45 degree flexion AP and oblique views, in addition to standard AP and lateral radiographs (Figure 1). Imaging of the contralateral elbow may also be helpful to assess for subtle changes early in the disease course. The classic finding in capitellar OCD is a focal lesion in the anterolateral capitellum with irregularity of the articular surface. Loose bodies may also be evident later in the disease process. MRI is a useful imaging modality to assess early OCD lesions prior to any changes evident on plain radiographs. It is also useful to assess the integrity of the articular cartilage (Figure 2 and Figure 3). MR arthrography may provide additional accuracy when identifying unstable osteochondral fragments. While CT scans may not be routinely used in the evaluation of capitellar OCD, it may provide additional information regarding the bony anatomy of the lesion or presence and location of loose bodies.

Figure 1.

Figure 2.

Figure 3.

Non–Operative Management

Management of capitellar OCD is dependent on the age of the patient (status of the physis), integrity of the articular surface, and stability and size of the lesion. For patients with increased likelihood of healing their lesion (open physis, intact cartilage, stable lesion), non-operative treatment consists of activity modification with cessation of all sporting activity. The duration of rest is dependent on symptomatology, and involves complete cessation of sports for 3-6 weeks, with gradual return by 3-6 months. As pain subsides, stretching and strengthening exercises are incorporated into the physical therapy protocol. Anti-inflammatory medications and bracing may be used, although their efficacy is not supported by clinical evidence.

Non-operative management can be particularly successful early in the disease course. One study of 39 baseball players with a mean age of 12.8 years found 25 of 30 early lesions healed without surgery while only 1 of 9 lesions more advanced on presentation healed. Additionally, 16 of 17 athletes with open physis were noted to heal their lesion compared to 11 of 22 patients with closed physis. However, several long term studies have found high rates of residual discomfort and degenerative changes with non-operative treatment. Non-operative treatment is more likely to be successful in patients with an open capitellar growth plate, localized flattening or radiolucency of the subchondral bone, and good elbow motion (flexion contracture less than 20 degrees).

Indications for Surgery

The indications for surgical management of capitellar OCD lesions include: (1) presence of loose bodies, (2) mechanical symptoms, (3) unstable lesions, (4) and stable lesions that have failed a minimum of 6 months of non-operative treatment. Well-described surgical options include fragment excision, marrow stimulation, fragment fixation, and osteochondral autograft transfer.

Lesions with stable overlying cartilage on MRI, confirmed with arthroscopy, can be treated with retrograde drilling using intraoperative fluoroscopy. For small lesions with unstable cartilage caps or loose bodies, debridement of the osteochondral fragment is indicated, along with microfracture to stimulate a fibrocartilage healing response. Primary repair is often not amenable since the subchondral bone is abnormal and the displaced osteochondral lesion is also of poor quality. Unstable osteochondral fragments of sufficient size can be considered for fixation. Osteochondral autograft transfer (OATS) can be considered for contained lesions whose depth and diameter is significant. For lesions less than 10mm, a single osteochondral graft can be taken from the non-weight bearing portion of the lateral femoral condyle, superior to the sulcus terminalis. Larger lesions require mosaicplasty with multiple small osteochondral plugs.

Surgical Technique

Fluoroscopy-guided retrograde drilling

For a stable appearing lesion that has been persistently painful despite non-operative treatment for a minimum of 6 months, retrograde drilling may be considered. The patient is consented for a diagnostic arthroscopy and retrograde drilling versus microfracture, depending on the intraoperative determination of stability.

Our preference is to perform the diagnostic arthroscopy of the elbow in the lateral decubitus position with the patient stabilized on a short bean bag. All bony prominences are well padded and an axillary roll is placed. A nonsterile 18 inch tourniquet is applied to the proximal aspect of the arm, and the portion of the arm that has the tourniquet in place is then rested on an elbow arthroscopy arm holder. A diagnostic arthroscopy is performed first to confirm stability of the OCD. While viewing from a standard posterolateral portal, the mid-lateral soft spot portal is created after localization with a spinal needle. A motorized shaver is placed through the mid-lateral soft-spot portal and a synovectomy is performed in order to allow unobstructed visualization of the radiocapitellar joint. If the osteochondritis dissecans is unstable, then a debridement and microfracture may be performed. If the lesion is stable, then a retrograde drilling may be performed under fluoroscopy guidance.

The precise location of the osteochondritis dissecans lesion is confirmed with arthroscopy, fluoroscopy, and preoperative images. If necessary for additional confirmation with subtle lesions that are not clearly identifiable with fluoroscopy alone, the tip of the arthroscope can be placed on the site of the lesion while a fluroscopy image is taken. With the arm in the lateral decubitus position, a mini-C arm fluoroscopy machine is positioned and both an AP and lateral images are taken. A 0.625 Kirschner wire or a small diameter smooth Steinmann pin is placed percutaneously on the lateral border of the distal humerus in the metaphyseal region and aimed toward the capitellum osteochondritis dissecans lesion under fluoroscopic guidance. The goal is to place the tip of the K-wire up to the subchondral bone while taking precautions to avoid penetrating the cartilage. Check the trajectory of the K-wire in both the AP and lateral planes on the fluoroscope as the K-wire is directed toward the osteochondritis dissecans lesion. When the K-wire is close to the subchondral bone, visualization through the arthroscope may also be used to ensure that the cartilage is not penetrated, although this would require a skilled first assistant. Once the first K-wire has been successfully placed, then additional K-wires are may be inserted while using the first K-wire as a directional guide. After an appropriate number of K-wires have been placed to cover the volume of the osteochondritis dissecans lesion, then final fluoroscopy photos are taken and all K-wires may then be removed.

Arthroscopic microfracture

For small unstable lesions or larger lesions in a skeletally immature patient, arthroscopic debridement of the osteochondritis dissecans, removal of any loose bodies, and microfracture are performed. Positioning is as described above. For the microfracture portion of the procedure, the use of a distal ulnar portal as described by Steinmann and his colleagues is particularly useful. While viewing the capitellum en face by placing the arthroscope in the distal ulnar portal, a microfracture awl may then be placed through the mid-lateral soft spot portal (Figure 4).

Figure 4.

Osteochondral autograft transfer

For large unstable lesions or deep lesions, we prefer an open osteochondral autograft transfer from the non-weightbearing region of the ipsilateral knee. This is performed in the supine position with ipsilateral arm placed on a hand table. The ipsilateral lower extremity is also prepped and draped into the sterile field to allow for harvesting of osteochondral plugs.

Nonsterile tourniquets are placed on both the upper arm and thigh. The upper extremity tourniquet is inflated to 250 mmHg. Standard anteromedial and anterolateral portals are created and a diagnostic arthroscopy is performed. An arthroscopic synovectomy is performed with a 3.5mm shaver if there is significant synovitis. Any loose bodies are identified and removed, prior to addressing the osteochondral lesion. An arthroscopic removal of loose bodies is preferred because loose bodies located in the medial aspect of the elbow are difficult to access through the open lateral arthrotomy used for the OATS procedure.

Next, all instrumentation is removed from the elbow and a lateral surgical dissection is performed using the interval between the extensor carpi ulnaris and anconeus. A lateral arthrotomy is performed to allow for direct visualization of the OCD lesion. Inspection of the OCD lesion as well as the rest of the capitellum and radial head is performed (Figure 5). The size and depth of the lesion is measured and recorded. The appropriate sized OATS harvester is used to remove a cylindrical piece of subchondral bone to a depth of at least 10 mm (Figure 6). Since the elbow is a smaller joint than the knee, the depth of the plugs used in the elbow are typically shorter than the plugs used for knee osteochondral defects. The elbow wound is then packed with sterile gauze.

Figure 5.

Figure 6.

Attention is next turned to the lower extremity for graft harvest. The lower extremity tourniquet is inflated to 280 mmHg. A lateral parapatellar arthrotomy is made, with care not to injure the underlying articular cartilage. The non-weight bearing portion of the lateral femoral condyle is exposed with use of Z-shaped retractors. The appropriately sized OATS harvester is used to obtain a plug of the same depth as the recipient site. The osteochondral graft is subsequently implanted into the defect in the capitellum, such that the cartilage of the plug is flush with the native surrounding cartilage (Figure 7). The elbow is taken through a gentle range of motion.

Figure 7.

A back-fill cancellous allograft plug (Lifenet) is then implanted into the defect on the lateral femoral condyle, such that the plug is flush with the articular cartilage surface (Figure 8). The upper and lower extremity tourniquets are deflated and hemostasis is obtained. The wounds are irrigated and closed in layers. A sterile dressing is applied to the lower extremity. A well-padded plaster splint is placed in the upper extremity with the elbow flexed to 90 degrees and the forearm in neutral rotation.

Figure 8.

Pearls and Pitfalls of Technique

The lesion is usually located on the posteroinferior aspect of the capitellum. To prepare the lesion for OATS, the elbow must be flexed more than 90 degrees and forearm maximally pronated in order to be perpendicular to the lesion.

In order to avoid the weight-bearing portion of the lateral femoral condyle, the size of a single plug must be limited to a maximum of 10mm.

The cartilage on the lateral aspect of the lateral femoral condyle is down-sloping. This portion of the osteochondral plug should be rotated medially when placed in the capitellum for best congruence with the native cartilage.

Potential Complications

The most common complication following surgery for capitellum OCD is progression of the lesion with persistent pain and stiffness. Appropriate surgical indications are essential in order to appropriately treat the OCD lesion and minimize progression of osteoarthritis.

Post–operative Rehabilitation

Whether treating with an osteochondral autograft transfer to the capitellum, an arthroscopic microfracture or fluoroscopy guided retrograde drilling of an OCD lesion, the elbow is splinted at 90 degrees of flexion and neutral forearm rotation until the first post-operative visit. At the first post-operative visit, a hinged elbow brace is placed and physically therapy is initiated, focusing on passive and active-assisted range of motion. Resistance exercises are begun 3 months post-operatively. Repetitive loading exercises, such as overhead throwing or hand-stands are not permitted until 6 months post-operatively. A full return to athletic ability is expected to take 9 to 12 months.

Outcomes/Evidence in the Literature

Iwasaki, N, Kato, H, Ishikawa, J, Masuko, T, Funakoshi, T, Minami, A. “Autologous osteochondral mosaicplasty for osteochondritis dissecans of the elbow in teenage athletes”. J Bone Joint Surg Am. vol. 91. 2009. pp. 2359-2366. (Nineteen teenage athletes with OCD of the capitellum underwent osteochondral mosaicplasty with 3.5 mm plugs from the lateral femoral condyle. At final follow-up, 18 of 19 patients were pain free and 17 had returned to previous level of sport. Elbow range of motion increased from 112 degrees preoperatively to 128 degrees postoperatively. All knees were graded as excellent based on the Lysholm scoring system.)

Mihara, K, Tsutsui, H, Nishinaka, N, Yamaguchi, K. “Nonoperative treatment for osteochondritis dissecans of the capitellum”. Am J Sports Med. vol. 37. 2009. pp. 298-304. (Thirty-nine adolescent baseball players with OCD of the capitellum treated non-operatively were retrospectively reviewed at a mean of 14.4 months. Early-stage lesions were found in 30 patients and advanced lesions in nine. Healing of the OCD lesion occurred in 25 of 30 patients with early-staged lesions and only 1 of 9 patients with advanced lesions. Lesion healing also occurred in 16 of 17 patients with open growth plates and only 11 of 22 patients with a closed capitellar growth plate.)

Takahara, M, Ogino, T, Sasaki, I, Kato, H, Minami, A, Kaneda, K. “Long term outcome of osteochondritis dissecans of the humeral capitellum”. Clin Orthop Relat Res. 1999. pp. 108-115. (Fifty-three patients with OCD of the capitellum were reviewed at an average follow-up of 12.6 years. Of 39 patients treated with fragment removal, 18 were symptomatic with activities of daily living. Seven patients were who underwent fragment removal had large osteochondral fragments and all seven did poorly. Seven of fourteen patients treated without surgery were also symptomatic at final follow-up. The authors concluded that poor outcomes are associated with advanced lesions, large osteochondral defects, and arthritis of the elbow on presentation.)

Takahara, M, Mura, N, Sasaki, J, Harada, M, Ogino, T. “Classification, treatment, and outcome of osteochondritis dissecans of the humeral capitellum”. J Bone Joint Surg Am. vol. 89. 2007. pp. 1205-1214. (Cases of capitellar OCD were reviewed retrospectively in 106 patients with an average age of 15.3 years. The authors classified lesions as stable or unstable, based on their likelihood to heal with non-operative treatment. Stable lesions must have an open capitellar physis, localized flattening or radiolucency of the subchondral bone, and good elbow motion. Unstable lesions, where surgery produced improved outcomes compared to non-operative treatment had one of the following: closed capitellar growth plate, fragmentation, or restricted elbow motion greater than 20 degrees compared to the contralateral elbow.)

Van den Ende, K. I. M., McIntosh, A. L., Adams, J. E., Steinmann, S. P.. “Osteochondritis dissecans of the capitellum: a review of the literature and a distal ulnar portal”. Arthroscopy?: The Journal of Arthroscopic & Related Surgery?: Official Publication of the Arthroscopy Association of North America and the International Arthroscopy Association. vol. 27. 2011. pp. 122-8. (Description of the distal ulnar portal used for en face visualization of the capitellum during arthroscopy. This portal is useful for visualization particularly during a microfracture procedure in which the microfracture awls are instrumented through the mid-lateral soft spot portal.)

Summary

Osteochondritis dissecans of the capitellum is primarily a condition of adolescent overhead athletes and gymnasts. Non-operative treatment is more likely to be successful in patients with an open capitellar growth plate, localized flattening or radiolucency of the subchondral bone, and good elbow motion. Surgical management is indicated in the presence of loose bodies, mechanical symptoms, unstable lesions, and stable lesions that remain symptomatic despite a minimum of 6 months of non-operative treatment. Surgical options include fragment excision, marrow stimulation, fragment fixation, and osteochondral autograft transplantation.

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