Bone Peg Grafting for Capitellar Osteochondritis Dissecans in Adolescent Baseball Players
Authors: Oshiba Hiroyuki , Itsubo Toshiro , Komatsu Masatoshi , Uchiyama Shigeharu , Kato Hiroyuki 
Published: March 2018

Background:
Capitellar osteochondritis dissecans (OCD) is a focal injury of the articular cartilage involving separation of a segment of cartilage from the subchondral bone that is infrequently encountered in the dominant-side elbow of adolescent throwing athletes
1,2
. The literature suggests that patients may achieve better short and mid-term results when treated with certain types of surgical procedures
3,4
. Selection of the appropriate surgical method should be based on the International Cartilage Repair Society (ICRS) OCD classification system
5
. For lesions involving ≤50% of the surface area of the capitellum, debridement with microfracture and/or loose body removal have shown excellent results. For lesions involving >50% of the surface area of the capitellum and classified as ICRS OCD III or IV, autologous osteochondral grafting may be the most suitable treatment
6–8
. Bone peg grafting (BPG) has been shown to be an effective treatment option for early-stage capitellar OCD that can preserve the local hyaline cartilage
9,10
.

Description:
Using direct vision and with arthroscopy, the continuity of the capitellar surface and the stability of the capitellar lesion were evaluated according to the ICRS OCD classification
5
. BPG was indicated for adolescents with ICRS OCD I or II. The elbow was opened between the extensor carpi ulnaris and the anconeus muscle (Kocher interval). Another skin incision of 3 cm in length was made at the posterior aspect of the metaphysis of the ipsilateral olecranon. Three, 4, or 5 bone pegs of approximately 20 mm in length were harvested from the posterior ulnar cortex. A Kirschner wire of 3 mm in diameter was used for drilling holes in the lesion, and then the bone pegs were inserted with tweezers to a depth of 10 mm. Next, a flat-surfaced rod was placed on the head of each bone peg to press it to a depth slightly lower than the articular cartilage surface. Postoperatively, the elbow was immobilized for 3 weeks. Throwing was allowed at 6 months, and a return to competitive baseball at preinjury levels was permitted at 8 months after BPG.

Alternatives:

Arthroscopic debridement of the lesion.Arthroscopic bone marrow stimulation or microfracture.Fragment fixation using metal implants or biodegradable materials.Use of autologous osteochondral graft from the distal aspect of the femur or from a rib.

Rationale:
Our follow-up study after BPG revealed that 10 of 11 patients with ICRS OCD I or II capitellar OCD could return to their preinjury baseball ability and that 8 of the 11 lesions completely healed as seen radiographically
11
. Radiographic and magnetic resonance imaging (MRI) findings showed that BPG could secure the lesion to the osseous floor as a physiological scaffold. Fragment fixation with metal implants or biodegradable materials carries a risk of damaging cartilage surfaces, and autologous osteochondral grafting is too invasive for this early-stage lesion. BPG is indicated for ICRS OCD I or II lesions, especially with central positioning and/or occupying <75% of the size of the capitellum in the coronal plane
11
.