Perform the operation with the patient under general anesthesia and in a supine position.

Preoperatively, palpate and mark the ipsilateral (fifth or sixth) rib and sterilely prepare and drape the rib area (Fig. 2). Use finger suspension to apply traction to the involved upper extremity and inflate the tourniquet to 250 mm Hg.

If loose bodies are identified, particularly on the anterior aspect of the elbow, remove them arthroscopically. When a nondisplaced large and progressed lesion is confirmed preoperatively, begin the arthrotomy without arthroscopy.

After the suspension is released, hyperflex the elbow maximally and use a posterolateral surgical approach (in an intermuscular and internervous plane between the anconeus [radial nerve] and extensor carpi ulnaris [posterior interosseous nerve], or anconeus muscle-splitting) (Fig. 3).

Resect detached (in osteochondritis dissecans IV, as classified with the system of the International Cartilage Repair Society [ICRS]) or unstable (in osteochondritis dissecans III) articular lesions and debride necrotic fibrous tissue completely.

Measure the lesion diameter. The procedure being described is indicated for a lesion with a diameter of ≥15 mm. If the lesion diameter is <15 mm, the procedure is possible after enlargement of the defect, although such a lesion can be generally treated with a less invasive procedure.

Perforate the sclerotic subchondral bone, and deepen the area of the cartilage defect cylindrically to a depth of about 15 mm using a high-speed surgical burr as perpendicular as possible to the articular surface.

Harvest the ipsilateral (fifth or sixth) rib at the osteochondral junction (Fig. 4; Video 1 [see Appendix]). We prefer to use the sixth rib because it is more round and fits more easily into the osteochondritis dissecans lesion. Use a transverse incision on the sixth rib. Incise the pectoral muscle and retract bluntly to explore the rib surface.

After making an H-shaped incision on the rib at the osteochondral junction, harvest the osteochondral graft. It is essential to elevate the graft carefully from the periosteum and perichondrium in this procedure to avoid damage to the pleura.

After harvest of the graft, suture the split periosteum to allow formation of new bone at the donor site. Careless management of the costal bone may also result in breakage at the osteochondral junction of the graft. In case of breakage of the graft at the osteochondral junction, replace the graft to the original position, repair the periosteum, and harvest the neighbor rib osteochondral junction.

Push and pack the graft into the prepared hole in the recipient site like a cork for a wine bottle. Never use a screwing motion; instead utilize gentle packing with a plastic rod and a hammer to avoid breakage of the osteochondral junction.

The articular defect of the elbow is usually oval-shaped, and one osteochondral rib provided suitable fit for the defect in many of the cases in our study¹² (eleven of twenty-six cases [mean recipient site cross section, 13.9 × 15.8 mm]). The packed graft is so stable in a press-fit fashion that no additional internal fixation is necessary during elbow motion in these cases (Fig. 6).

In cases with larger or round lesions (fifteen of twenty-six cases in our study¹² [mean recipient site cross section, 16.7 × 16.3 mm]), the piece of costal osteochondral graft is insufficient to fit the defect. In these cases, insert the sliced corticocancellous rib as a wedge into the space between the osteochondral graft and the posterolateral cortex of the recipient humerus (Fig. 7). Cancellous bone of the wedge fits stably between the graft and the recipient bone, so no internal fixation is necessary.

Multiple ribs can be used as grafts; however, most cases can be treated with one rib graft consisting of one osteochondral graft and one or two bone wedge grafts. One of the forty-three cases that we performed since 2006 required one and a half rib grafts because the defect was too large for a single graft.

After packing the grafts, shape and contour the cartilage surface to fit the radial head using a scalpel. This is an essential step, but it is not difficult because the costal cartilage in young patients is hyaline and shaving with a scalpel is easy (Video 3 [see Appendix]).

After irrigation of the wounds, tightly suture the incised elbow capsule and close the subcutaneous tissues and skin in layers. For the donor costal area, have the anesthetist apply positive pressure to the lungs through the endotracheal tube after filling the wound with sterile fluid to identify possible pleural leaks and pneumothorax. Also, close stripped periosteum and perichondrium, incised membrane of the pectoral muscles, and skin in layers at this site.

Immobilize the elbow with a splint in 90° of elbow flexion with the forearm in neutral rotation. Cover the costal wound with an adhesive dressing. Obtain postoperative anteroposterior and lateral elbow radiographs to identify the proper placement of the graft and an anteroposterior radiograph to rule out pneumothorax.

Two weeks postoperatively, the splint and sutures are removed and the patient starts active motion exercises. Most patients are able to perform normal daily activities in a few days or a week, but they are not allowed to play sports for three months.

Patients should make a step-by-step return to sports activities with some limitations once complete graft union (trabecular continuity) is seen on imaging studies. We advise patients to return to usual activities without limitation at six months postoperatively and allow baseball pitchers to start pitching while limiting the number of pitches per day and per week until twelve months postoperatively. Patients are subsequently followed every three or six months in the outpatient clinic.

Failure of more than six months of nonoperative treatment.

A large and advanced stage of osteochondritis dissecans of the humeral capitellum. An ICRS osteochondritis dissecans III or IV lesion with a diameter exceeding 15 mm is good indication for this procedure.

A patient with an open distal humeral physis at the capitellum.

Non-advanced or smaller lesions that can be treated with other, less invasive techniques. Non-advanced lesions should be treated by fixation of the lesion (e.g., bone peg grafting), and smaller lesions should be treated with a less invasive procedure (e.g., arthroscopic debridement).

Patients who ever experienced severe chest injury involving the costal area.

Complete debridement of the degenerated tissues is important to avoid recurrence of free bodies.

Too-thick donor cartilage may become necrotic and degenerated. After shaving of the surface, 1 to 4-mm-thick costal cartilage is suitable. For that purpose, precise preparation of the costal graft and the recipient hole is important.

Breakage of the osteochondral junction may occur while a graft is being harvested. Gentle stripping of the periosteum and the perichondrium is important to avoid not only pneumothorax but also breakage of the graft.

The overall results of cylindrical costal osteochondral autograft were generally good considering the severity of the lesions encountered, but long-term follow-up is clearly necessary.

Long-term donor-site morbidity also must be considered, especially for young athletes.

We used the fifth or sixth rib as a donor in this study; however, we do not know which rib is the best for the donor.