Arthroscopic Treatment of Chondral Injuries and Osteochondritis Dissecans
Arthroscopic Treatment of Chondral Injuries and Osteochondritis Dissecans
DEFINITION
Osteochondritis dissecans (OCD) is a progressive form of osteochondrosis involving focal injury to the subchondral bone or its blood supply. It may occur in many different areas of the adolescent skeleton.
The knee is the most common location for OCD, but it may occur in several locations of the elbow, including the radial head, the trochlea, and the capitellum (the most common location within the elbow).
The injury to the subchondral bone results in loss of structural support for the overlying articular cartilage. As a result, degeneration and fragmentation of the articular cartilage and underlying bone occur, often with the formation of loose bodies.
The histopathology of the subchondral bone in OCD is consistent with osteonecrosis.
Articular cartilage injury may also occur anywhere in the elbow, especially after trauma. More common locations of nonarthritic chondral injury include the radial head and capitellum.
ANATOMY
Bony Anatomy
The bony anatomy of the elbow allows for two complex motions: flexion-extension and pronation-supination.
The ulnohumeral articulation of the elbow is almost a true hinge joint with its constant axis of rotation through the lateral epicondyle and just anterior and inferior to the medial epicondyle. This well-fitted hinge joint allows for little excessive motion or toggle.
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FIG 1 • A. Cross-section of the elbow showing the round, convex capitellum and the matching concave radial head. B. Anatomy of the medial elbow ligamentous complex. The ulnar collateral ligament complex comprises three ligaments: the anterior oblique, posterior oblique, and transverse ligaments.
The radius articulates with the proximal ulna and rounded capitellum of the distal humerus. The radiocapitellar joint and the proximal radioulnar joint allow for pronation-supination (FIG 1A). The ulnohumeral joint allows for flexion-extension of the elbow.
The ulnohumeral joint has 11 to 16 degrees of valgus. This results in increased compressive force in the lateral elbow (radiocapitellar joint) with axial loading.
Ligamentous Anatomy
The ligaments of the elbow are divided into the radial and ulnar collateral ligament complexes.
The lateral or radial collateral ligamentous complex provides varus stability. These ligaments are rarely stressed in the athlete.
The ulnar or medial collateral ligament complex consists of three ligaments: the anterior oblique, the posterior oblique, and the transverse.
The ulnar collateral ligament complex, particularly the anterior oblique ligament, resists valgus force, such as occurs with throwing, whereas the radiocapitellar joint is a secondary restraint to valgus force (FIG 1B).
Intraosseous Vascular Anatomy
There are two nutrient vessels in the lateral condyle of the developing elbow.
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Each vessel extends into the lateral aspect of the trochlea, with one entering proximal to the articular cartilage and the other entering posterolaterally at the origin of the capsule.
Although these two vessels communicate with each other, they do not do so with the metaphyseal
vasculature. The rapidly expanding capitellar epiphysis in the developing elbow thus receives its blood supply from one or two isolated transchondroepiphyseal vessels that enter the epiphysis posteriorly.
These vessels function as end arteries passing through the cartilaginous epiphysis to the capitellum.
Metaphyseal vascular anastomoses do not make significant contributions to the capitellum until approximately 19 years of age, placing this region at risk for vascular injury.
PATHOGENESIS
The cause of OCD is unclear and controversial.
OCD typically affects the dominant extremity of adolescents and young adults, with onset of symptoms between 11 and 16 years of age.
Most cases are seen in high-level athletes who experience repetitive valgus stress and lateral compression across the elbow (eg, overhead-throwing athletes, gymnasts, weightlifters).
The lesion usually affects only a portion of the capitellum.
Genetic factors, trauma, and ischemia have been proposed as causes.
Most authors believe that the primary mechanism of injury is repetitive microtrauma in a genetically predisposed individual’s developing elbow that results in vascular injury due to the tenuous blood supply.
The capitellum is softer than the radial head.
Repeated microtrauma, such as axial loading in the extended elbow or repeated throwing that produces valgus forces on the elbow, results in increased force in the radiocapitellar joint.
The repetitive microtrauma caused by these forces has been proposed to weaken the capitellar subchondral bone and result in fatigue fracture.
Should failure of bony repair occur, an avascular portion of bone may then undergo resorption with further weakening of the subchondral architecture. This is consistent with the characteristic rarefaction often seen at the periphery of the lesion.
The altered subchondral architecture can no longer support the overlying articular cartilage, rendering it vulnerable to shear stresses, which may lead to fragmentation.
The tenuous blood supply of the end arterioles in the capitellum may become injured with the repetitive microtrauma, resulting in OCD.
Although a genetic predisposition to OCD has been proposed in the literature, convincing scientific evidence of OCD as a heritable condition does not currently exist. Some individuals are more susceptible than others, and this may be genetically based.
NATURAL HISTORY
The natural history of capitellar OCD is unpredictable. No reliable criteria exist for predicting which lesions will collapse with subsequent joint incongruity and which will go on to heal without further sequelae.
If healing is going to take place, it usually occurs by the time of physeal closure.
If healing is not going to take place, repetitive microtrauma and shear stresses to the articular surface of a lesion that has lost its subchondral support may result in further subchondral collapse and deformation with joint incongruity as well as articular cartilage injury, fragmentation, and loose body formation.
In advanced cases, degenerative changes accompanied by a decreased range of motion are likely to develop.
PATIENT HISTORY AND PHYSICAL FINDINGS
The classic patient with OCD is an adolescent athlete who experiences repetitive valgus stress and lateral compression across the elbow (eg, overhead-throwing athletes, gymnasts, weightlifters).
The patient usually complains of the insidious onset of poorly localized, progressive lateral elbow pain in the dominant arm.
He or she may also note a flexion contracture.
The throwing athlete may note a reduction in throwing distance or velocity or both. Prodromal pain is not always present.
Typically, pain is exacerbated with activity and relieved by rest.
In advanced cases in which a fragment has become unstable or loose body formation has occurred, mechanical symptoms of elbow locking, clicking, or catching may be present.
Physical examination methods
On examination, there may be tenderness to palpation and crepitus over the radiocapitellar joint.
Effusion indicates intra-articular irritation and may be consistent with a loose or unstable OCD lesion or loose body.
Swelling, palpated in the posterolateral gutter (soft spot), may be appreciated. Crepitus may be present on range-of-motion testing.
Loss of 10 to 20 degrees of extension is common, and mild loss of flexion and forearm rotation may also be seen. Loss of pronation is less common.
Provocative testing includes the “active radiocapitellar compression test,” which consists of forearm pronation and supination with the elbow in full extension in an attempt to reproduce symptoms.
The examiner should rule out radiocapitellar overload as the result of ulnar collateral ligament insufficiency using the milking maneuver, modified milking maneuver, valgus stress test, or moving valgus stress test.
IMAGING AND OTHER DIAGNOSTIC STUDIES
Diagnostic evaluation of the elbow for OCD begins with plain radiographs—an anteroposterior (AP) view, lateral view, oblique views, and a 45-degree flexion AP view, which is particularly good at revealing the lesion.
Radiographs typically show the classic radiolucency (FIG 2A) or rarefaction of the capitellum (FIG 2B) in addition to irregularity or flattening of the articular surface.
The lesion frequently appears as a focal rim of sclerotic bone surrounding a radiolucent crater with rarefaction located in the anterolateral aspect of the capitellum.
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FIG 2 • A. Radiograph of a 15-year-old baseball pitcher with OCD of the capitellum of the dominant elbow. Clear lesion and sclerosis of the bony bed are shown. B. OCD in a 15-year-old gymnast with rarefaction of the capitellar lesion on oblique radiograph of the elbow. C. MRI of the elbow of a baseball pitcher, revealing OCD with loss of overlying articular cartilage and loose body.
Radiographs, however, may not reveal the osteochondral lesions in the earlier stages. They are not of much benefit for truly chondral lesions.
In advanced cases, articular surface collapse, loose bodies, subchondral cysts, radial head enlargement, and osteophyte formation may be seen.
Further diagnostic imaging of OCD lesions primarily consists of magnetic resonance imaging (MRI), although ultrasonography and bone scintigraphy have been used.
MRI is especially valuable in assessing the integrity of the articular cartilage overlying the OCD lesion as well as in diagnosing OCD in its early stages and identifying loose bodies (FIG 2C).
Controversy exists over the use of contrast-enhanced magnetic resonance arthrography. This technique, however, can potentially provide additional information regarding the status of the articular cartilage and identification of loose bodies.
Bone scintigraphy is very sensitive for identifying osteoblastic activity or increased vascularity at the site of an OCD lesion. However, it is nonspecific and has limited usefulness in diagnosis.
Computed tomography can help define bony anatomy and identify loose bodies.
Ultrasonography can also help in the assessment of capitellar lesions, including early stages, but ultrasound is technician dependent.
DIFFERENTIAL DIAGNOSIS
Panner disease Infection
Lateral epicondylosis
Lateral epicondylar apophysitis Radial head osteochondrosis
Radial head or neck injury
Radiocapitellar overload and chondromalacia due to ulnar collateral ligament injury Posterolateral rotatory instability
NONOPERATIVE MANAGEMENT
The choice of conservative or surgical management depends on the patient’s age, symptoms, size of the lesion, and stage of the lesion, specifically the integrity of the cartilage surface.
The goal of treatment for OCD of the elbow is to prevent the progression of the disorder, detachment of the osteochondral lesion, and degenerative changes of the articular cartilage.
Small, nondisplaced lesions with intact overlying articular cartilage in younger (skeletally immature) athletes are best managed conservatively with relative rest and activity modification, ice, and nonsteroidal anti-inflammatories, particularly if the bone scan shows increased bony activity.
Activity modification consists of avoiding throwing activities and weight bearing on the involved arm. Short-term immobilization (less than 2 to 3 weeks, depending on symptoms) may be considered.
Serial radiographs, at 10- to 12-week intervals, are obtained to monitor healing.
Activity modification is continued until the radiographic appearance of revascularization and healing.
Radiographic findings of OCD may persist for several years. As a result, after conservative management, the most important issue in terms of an athlete’s ability to return to sports is symptom resolution.
Most patients can return to full activity after 6 months.
SURGICAL MANAGEMENT
The indications for surgical treatment include persistent symptoms despite conservative management, symptomatic loose bodies, articular cartilage fracture, displacement of the osteochondral lesion, and cold bone scan.
The surgeon must assess the size, stability, and viability of the fragment and decide whether to remove the fragment or attempt to surgically reattach it.
Most fragments cannot be reattached and therefore are excised, followed by local débridement.
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Arthroscopic abrasion chondroplasty or subchondral drilling may be performed to encourage healing.
Although symptoms usually improve, about half of all patients will continue to have chronic pain or limited range of motion.
In general, many athletes cannot return to their prior levels of competition.
Surgical indications for operative management of stable lesions with intact articular cartilage include radiographic evidence of lesion progression and failure of symptom resolution despite a 6-month trial of a conservative, nonoperative regimen.
Arthroscopic examination, débridement as needed, and drilling or microfracture of the OCD lesion (with or without in situ pinning) are usually the surgical treatments of choice.
Unstable lesions, characterized by overlying articular cartilage injury and instability as well as collapse or disruption of the subchondral bone architecture, and those with loose bodies are usually managed surgically.
These lesions are frequently flap lesions. They characteristically present with more advanced radiographic changes (including a well-demarcated fragment surrounded by a sclerotic margin).
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FIG 3 • A. Lateral positioning for elbow arthroscopy, including tourniquet placement. B. Setup in the operating room for the lateral position. C. Prone position of the patient. This is the preferred position, particularly due to the ease of posterior elbow access. The setup of the room is the same and the relative position of the elbow for the surgeon is similar between the prone and lateral positions. D. Supine position of the patient. Some surgeons prefer this position because it is easier to convert to open surgery and easier anesthesia management; however, posterior arthroscopic access is more difficult in this position.
There is controversy whether simple fragment excision or reduction (open or arthroscopic) and internal fixation is the preferred treatment. Many authors advocate excision of displaced fragments, often augmented by drilling or microfracture.
Critical considerations in operative planning include the size and integrity (viability) of the fragment, the subchondral architecture on the fragment and the opposing bony bed, the potential for anatomic restoration of the articular surface, and the method of fixation if attempted.
Internal fixation of the fragment may be performed using metallic screws, bioabsorbable screws or pins, Kirschner wire, bone pegs, and dynamic staple fixation.
There have been a few reports of osteoarticular autograft or allograft plugs in the treatment of more advanced lesions, but experience with this method is limited. The current recommendations are for lesions that involve the lateral column.
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FIG 4 • A. The elbow arthroscope is brought in from the proximal anteromedial portal that provides a direct view of the anterior capitellum and radial head. B. Position of the direct lateral soft spot portal.
Preoperative Planning
Before surgery, an MRI, preferably with contrast, can be used to assess the integrity of the articular cartilage to help determine whether débridement, loose body removal, and drilling may be needed or more advanced techniques, such as reduction and internal fixation or osteochondral transfer, may be needed.
The MRI of the joint is also inspected for loose bodies— their number and location (anterior vs. posterior elbow) (see FIG 2C).
All imaging studies are reviewed.
Examination under anesthesia is performed to assess range of motion and ligamentous stability, particularly valgus laxity, as injury to the ulnar collateral ligament in the athlete may increase the load on the radiocapitellar joint.
Positioning
Elbow arthroscopy can be performed in the supine, lateral, or prone position (FIG 3).
Prone positioning is preferred because it allows easy access to the elbow and reduces the risk of sterility breaks if the arm needs to be in a finger-trap device, as needed for supine elbow arthroscopy and arthroscopy.
The patient is positioned on chest rolls and padding under the knees and feet and ankles. The arm is placed on an arm holder.
A sterile tourniquet is placed after the arm is prepared and draped.
Approach
All cases are approached in the same manner initially.
Diagnostic arthroscopy of the elbow is carried out using a proximal anteromedial portal, a proximal
anterolateral portal, and two posterior portals. This allows for assessment of the entire joint to ensure that loose bodies are not missed.
The capitellum may be seen from the proximal anteromedial portal (FIG 4A) while the elbow is taken through a full range of motion.
A direct lateral portal (sometimes called the soft spot portal) is then used to allow direct access to the radiocapitellar joint and is needed to confirm the extent of the OCD or chondral lesion (FIG 4B).
TECHNIQUES
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Arthroscopic Débridement and Loose Body Removal
Elbow arthroscopy is begun in the prone (senior author’s preference), lateral, or supine position using the proximal medial portal to visualize the capitellum.
Complete elbow examination is mandatory to look for loose bodies: Proximal anteromedial portal
Proximal anterolateral portal
Posterior central portal Posterolateral portal Direct lateral portal
Loose bodies tend to hide:
In the proximal radioulnar joint anteriorly or the gutters
In the olecranon fossa or gutters posteriorly, particularly the lateral gutter
When looking at the capitellum from the proximal anteromedial portal, instrumentation (shavers, burrs, graspers, and curettes) may be accomplished using the proximal anterolateral portal.
Flexion and extension of the elbow allow for enhanced visualization of the capitellum.
Loose bodies and chondral fragments may be removed via the anterior portals (TECH FIG 1A,B). Then the arthroscope is brought in from the posterior portals to look for loose bodies.
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The direct lateral (“soft spot”) portal is used for complete evaluation of the capitellum.
This portal is mandatory to fully evaluate the extent of the lesion and to allow for adequate débridement of loose cartilage.
Often, loose bodies will be found using this portal.
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TECH FIG 1 • OCD of the capitellum. A. View from the proximal anteromedial portal reveals a flap of
cartilage from the capitellum (left) and a slightly deformed radial head (to the right). B. Probe on the flap of chondral tissue from the capitellum of this same patient. C. Grasper removing a loose body as viewed from the direct lateral portal.
Débridement is performed using shavers, curettes, graspers, and rongeurs to remove loose bodies and any loose, scaly, or fragmented cartilage (TECH FIG 1C).
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Microfracture and Abrasion Arthroplasty
When the OCD fragment is loose and it is not possible to fix the lesion back to the bony bed, then microfracture or abrasion arthroplasty may be indicated to stimulate a fibrocartilaginous growth in the bony defect.
The principle is to stimulate cartilage-like regeneration based on the formation of a superclot that is progressively invaded by multipotent cells from the marrow.
This is achieved by complete débridement of all unstable and damaged cartilage in the lesion and the preservation of the subchondral layer for chondral lesions based on experience of the treatment of knee chondral injuries.
Elbow arthroscopy is begun in the prone (senior author’s preference), lateral, or supine position using the proximal medial portal to visualize the capitellum.
Complete elbow examination using all four standard and the additional direct lateral arthroscopic portals is mandatory to look for loose bodies.
When looking at the capitellum from the proximal anteromedial portal, instrumentation (shavers, burrs, graspers, and curettes) may be done using the proximal anterolateral portal.
Flexion and extension of the elbow allow for enhanced visualization of the capitellum.
All underlying bone is débrided with an arthroscopic shaver or burr or manually with curettes or pituitary rongeurs.
Next, the arthroscope is brought in from the posterior portals to look for loose bodies. The direct lateral (soft spot) portal is used for complete evaluation of the capitellum.
This portal is mandatory to fully evaluate the extent of the lesion and to allow for adequate débridement of loose cartilage and may allow for a good direction for microfracturing the bed.
Abrasion is carried out from either anterolateral or direct lateral portals to the complete lesion. This may be done with a shaver on high speed or burr.
For chondral lesions, abrasion arthroplasty involves removal of the zone of calcified cartilage then use of a burr to lightly remove only a partial thickness of the subchondral bone to expose subchondral arterioles to bring blood into the lesion. The key is not to go too deep into the cancellous bone.
For OCD with a cartilage cap that is not intact, abrasion is done lightly to remove only a little bone to allow bleeding into the bony bed.
Microfracture or drilling can also be used to bring blood into the defect when the OCD or chondral lesion results in an exposed bony bed, with the theoretical benefit of microfracture being that less bone is lost and there is no heat production, which may be seen with drilling.
The bone is pierced every 3 to 4 mm for a 4-mm depth with an awl for microfracture or 0.062 Kirschner wire for drilling (TECH FIG 2).
If the anterolateral or direct lateral portals do not allow for adequate directionality of the drilling or microfracture, an additional outside-in portal may be made based on the known anatomy and using a spinal needle.
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TECH FIG 2 • A. Microfracture of the capitellum, making several small perforations within the capitellum about 4 mm apart and 4 mm deep. B. Intraoperative arthroscopic photograph from the direct lateral portal with a microfracture awl at the edge of the OCD lesion after removing the zone of calcified cartilage.
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Drilling for Intact Osteochondritis Dissecans Lesions
When the OCD lesion has an intact overlying chondral surface, then drilling may enhance or stimulate a healing response of the lesion, although this is not frequently needed.
The key is to try to prevent violation of the OCD cartilage cap, although some surgeons drill from outside-in, trying to avoid injury to the articular cartilage and some drill from the joint, which will perforate the articular cartilage.
Elbow arthroscopy is begun in the prone (senior author’s preference), lateral, or supine position using the proximal medial portal to visualize the capitellum.
Complete elbow examination using all four standard portals and the additional direct lateral arthroscopic portals is mandatory to look for loose bodies.
When looking at the capitellum from the proximal anteromedial portal, instrumentation (shavers, burrs, graspers, and curettes) may be done using the proximal anterolateral portal.
Flexion and extension of the elbow allow for enhanced visualization of the capitellum. Next, the arthroscope is brought in from the posterior portals to look for loose bodies. The direct lateral (soft spot) portal is then used for complete evaluation of the capitellum.
OCD lesions with intact articular cartilage, subchondral softening, fibrillated cartilage, or cartilage
character change may be identified visually or palpably using a probe (TECH FIG 3) or alternatively using fluoroscopic imaging.
Drilling through the cartilage and through the sclerotic subchondral bone is done in an effort to promote healing.
Attempts are made to limit the number of perforations through the intact cartilage, but the subchondral plate should be penetrated multiple times.
This may be accomplished by redirecting the drill in different directions from the same single (or a few) perforations through the articular cartilage.
The lesion is pierced with an 0.062 Kirschner wire for drilling.
If the anterolateral or direct lateral portals do not allow for adequate directionality of the drilling, an additional outside-in portal may be made based on the known anatomy and using a spinal needle.
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TECH FIG 3 • View from the direct lateral portal of an OCD lesion with intact articular cartilage. The probe is deforming the intact cartilage owing to the lack of subchondral support.
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Drilling for Intact Osteochondritis Dissecans Lesion: Outside-In Technique
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When the OCD lesion has an intact overlying chondral surface, then drilling may enhance or stimulate a healing response of the lesion.
The key is to try to prevent violation of the OCD cartilage cap, although some surgeons drill from outside-in, trying to avoid injury to the articular cartilage and some drill from the joint, which will perforate the articular cartilage.
Elbow arthroscopy is begun in the prone (senior author’s preference), lateral, or supine position using the
proximal medial portal to visualize the capitellum.
Complete elbow examination using all four standard and the additional direct lateral arthroscopic portals is mandatory to look for loose bodies.
When looking at the capitellum from the proximal anteromedial portal, instrumentation (shavers, burrs, graspers, and curettes) may be done using the proximal anterolateral portal.
Flexion and extension of the elbow allow for enhanced visualization of the capitellum. Next, the arthroscope is brought in from the posterior portals to look for loose bodies. The direct lateral (soft spot) portal is then used for complete evaluation of the capitellum.
OCD lesions with intact articular cartilage, subchondral softening, fibrillation of the cartilage, or cartilage character change may be identified visually or palpably (see TECH FIG 3) or alternatively using fluoroscopy.
Fluoroscopy is then brought in to identify the lesion.
Using an anterior cruciate ligament tibial guide or posterior cruciate ligament femoral guide can be useful to help aim the drill bit from outside the elbow toward the lesion.
Depending on the location of the lesion, the drill is brought from proximal and slightly anterior to the lateral epicondyle or posteriorly on the distal humerus.
A small incision is made at the proposed drilling entry site and blunt dissection is done to bone.
The lesion is drilled with a 0.062 Kirschner wire for drilling while watching with fluoroscopy or arthroscopy to ensure the articular cartilage is not violated.
Multiple passes with the Kirschner wire should be performed to enhance healing throughout the lesion.
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Internal Fixation
When the OCD fragment is partially detached or completely detached but not malformed and there is significant bone on the cartilage fragment, consideration for reattachment is recommended.
The principle is to stimulate healing and to stabilize the fragment within the bony bed.
Elbow arthroscopy is begun in the prone, lateral, or supine position, using the proximal medial portal to visualize the capitellum.
If it is likely the patient will need internal fixation of a partially detached OCD fragment, and there is a possibility that an arthrotomy is needed, the senior author has found that performing the surgery in the lateral position is a bit easier.
Complete elbow examination using all four standard and the additional direct lateral arthroscopic portals is mandatory to look for loose bodies.
When looking at the capitellum from the proximal anteromedial portal, instrumentation (shavers, burrs, graspers, and curettes) may be done using the proximal anterolateral portal.
Flexion and extension of the elbow allow for enhanced visualization of the capitellum.
All underlying bone is débrided with an arthroscopic shaver or burr or manually with curettes or pituitary rongeurs.
Next, the arthroscope is brought in from the posterior portals to look for loose bodies. The direct lateral (soft spot) portal is used for complete evaluation of the capitellum.
This portal is mandatory to fully evaluate the extent of the lesion and to allow for adequate débridement and preparation of the bed.
The osteochondral flap or undersurface of the fragment is elevated and the underlying sclerotic bone is
curetted and débrided of fibrous tissue (TECH FIG 4A). Drilling of the base is also performed to stimulate healing.
The abrasion and drilling are carried out from either anterolateral or direct lateral portals to the complete lesion. This may be done with a curette, a shaver on high speed, or a burr and a drill or Kirschner wire to gently débride the bed without removing much bone.
The flap is then replaced within the bed.
Retrograde pinning of the lesion with threaded or unthreaded wires can be performed with the wires exiting the lateral epicondyle for later removal (TECH FIG 4B,C).
The ends of the pins should be positioned below the articular surface so that the wires do not penetrate the joint space.
Bioabsorbable pins and bioabsorbable screws have been used as an alternative (TECH FIG 4D).
Further, some surgeons will place metallic screws for fixation. These can either be headless variable-pitched screws that are buried beneath the articular surface or regular-headed screws, which some prefer for better compression but must be removed.
If the anterolateral or direct lateral portals do not allow for adequate directionality of the drilling or microfracture, an additional outside-in portal may be made based on the known anatomy and using a spinal needle.
An arthrotomy may be necessary to perform the débridement or internal fixation.
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TECH FIG 4 • OCD of the capitellum. A. The humeral defect is above, and the osteochondral lesion fragment is opened like a trapdoor inferiorly. This allows for removal of fibrous tissue (already completed) to prepare for repair or fixation of this fragment. B. Schematic representation of internal fixation of the lesion with wires or pins. C. The lesion is reduced and a Kirschner wire holds the fragment. D. The lesion is fixed in place with an absorbable pin (three were used to fix this lesion).
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Osteochondral Autograft Implantation
When the OCD fragment is loose and it is not possible to fix the lesion back to the bony bed, and there is a large crater, particularly if it involves the lateral column, then consideration is given to inserting osteochondral autograft plugs into the defect to eliminate or reduce edge loading and loss of lateral support for the joint.
This is achieved by taking osteochondral plugs from the knee and implanting them into the capitellum.
Elbow arthroscopy is begun in the prone, lateral, or supine position, using the proximal medial portal to visualize the capitellum. Because insertion of the plugs often requires an arthrotomy and the grafts must come from the knee, the supine position is preferred.
Complete elbow examination using all four standard and the additional direct lateral arthroscopic portals is mandatory to look for loose bodies.
When looking at the capitellum from the proximal anteromedial portal, instrumentation (shavers, burrs, graspers, and curettes) may be done using the proximal anterolateral portal.
Flexion and extension of the elbow allow for enhanced visualization of the capitellum. A posterior or posterolateral approach may be used.
The radiocapitellar joint is approached anteriorly by splitting the intermuscular plane between the extensor digitorum communis and the extensor carpi radialis longus and brevis, exposing the anterior capsule, which is then incised.
The posterior approach uses a posterior longitudinal skin incision with the elbow in full flexion. Then the anconeus and posterior capsule are divided, providing direct access to the OCD lesion.
The posterolateral Kocher approach uses the interval between the anconeus and extensor carpi ulnaris. The lateral collateral ligament complex is protected and preserved, allowing exposure of the posterior radiocapitellar joint.
A commercially available osteochondral graft harvesting system is used.
The size of the lesion is assessed to decide how many grafts and of which size are necessary, although usually, less than 100% fill is achieved.
Recipient sockets are created in the lesion with the recipient graft harvesting tool.
Occasionally, the sclerotic bed makes it difficult to use the recipient harvesting tool and a cannulated drill is needed to make the recipient bed.
Drilling is carried out at the base of the socket before inserting the graft to allow for marrow stimulation and enhance healing potential.
Osteochondral grafts about 10 mm long are then harvested arthroscopically or with miniarthrotomy from the knee intercondylar notch or periphery of the non-weight-bearing portion of the lateral femoral condyle.
There are only a few case reports of this technique. Some use multiple 3.5-mm plugs and some use single larger osteochondral plugs.
Depth of the recipient socket is measured with a calibrated depth gauge or alignment stick. The length of the osteochondral autograft plug is matched to the depth of the recipient socket. The graft is seated flush with the surrounding intact cartilage.
Complete coverage of the lesion usually is not possible, although coverage of 80% to 90% of the lesion size should be achieved.
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PEARLS AND PITFALLS
Nerve injury
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The greatest risk of elbow arthroscopy, for OCD or any other diagnosis, is nerve injury. Knowledge of elbow neuroanatomy, particularly as it relates to the arthroscopic portals, is of paramount importance. It is safest to use the proximal medial portal and the proximal lateral portals anteriorly. Distending the joint, using the outside-in technique, and using blunt instruments after skin incision only all help to reduce iatrogenic nerve injury.
Direct lateral portal
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Familiarity with the direct lateral portal is critical for the evaluation and treatment of chondral and osteochondral lesions of the capitellum. The posterior radial head and capitellum are best seen with this portal, and loose bodies from OCD occasionally may only be seen from this portal. Full appreciation of the lesion cannot be made without the use of this portal.
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Converting to an open procedure
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Occasionally, synovitis or lack of working space makes visualization of the lesion difficult. Further, fixation of the lesion may be difficult arthroscopically. If visualization or fixation is difficult arthroscopically, there should be a low threshold to converting the procedure to open. The threshold of conversion to open should be based on experience and comfort with arthroscopy.
POSTOPERATIVE CARE
After elbow arthroscopy for débridement or loose body removal:
Early range-of-motion exercises are encouraged to prevent loss of elbow motion. Other early goals include reducing swelling, pain, and muscular atrophy.
As motion becomes full and the soft tissues are healing with minimal swelling, rehabilitation concentrates on strengthening and endurance of the joint as well as normalization of arthrokinematics of the elbow. This usually begins after 2 weeks.
After 4 weeks, the athlete is prepared to return to functional activities with more strengthening, endurance, and flexibility. However, some believe that individuals with OCD lesions who have a defect should not return to sports activities because of the risk of arthritic change in the elbow.
After in situ drilling, return to sports is usually delayed until 3 to 6 months postoperatively, when there is good radiographic evidence of bony incorporation and healing.
After microfracture or internal fixation:
Range of motion is encouraged, but some clinicians put their patients in a range-of-motion brace positioned in varus to reduce stress over the radiocapitellar joint.
Some also consider adding the use of continuous passive motion to help in cartilage nourishment to encourage the microfracture clot or the healing surface of a fixed lesion to reduce adhesions. In these scenarios, strengthening is usually not initiated for at least 6 weeks.
Return to gymnastics or throwing sports is delayed until 6 months postoperatively.
Following the autograft transfer procedure:
The joint is immobilized until 2 weeks postoperatively, when the cast or splint is discontinued. Beginning week 3, range-of-motion exercises are started.
Strengthening of the elbow and forearm is begun at 3 months postoperatively, and a throwing program is initiated at 6 months, with full return to participation at 10 to 12 months postoperatively.
OUTCOMES
Reports in the literature on follow-up of the conservative and surgical management of OCD are difficult to compare and interpret because there is a lack of a universally accepted classification system, the numbers of patients in most series is limited, and there are disparities in age at presentation, symptoms, lesion size, location, stability, and viability. Further, there are differences in the method of diagnostic imaging used, surgical technique, and length of follow-up.
A consensus exists in the literature on the need to limit continual high-stress loading of the radiocapitellar joint in patients treated (even successfully) with OCD to prevent the deterioration of the frequently obtained short-term favorable results. As a result, most pitchers are counseled to move to other positions and gymnasts are advised of the difficulty in returning to continued high-level competitive gymnastics.
Conservative treatment of OCD does not provide uniformly successful results.
Takahara et al6,7 presented the results of nonoperative management of early OCD lesions with an average follow-up of 5.2 years and reported that more than half of these patients had pain with activities and fewer than half of the lesions showed radiographic improvement.
Surgery also does not result in uniformly good outcomes.
In one of the longest follow-up studies available in the elbow OCD literature, Bauer et al1 presented the results of 31 patients (23 of whom were treated surgically with lesion or loose body excision) with capitellar OCD followed for an average of 23 years. At follow-up, the most common complaints were decreased range of motion (average 9 degrees of flexion loss, 2 degrees of extension loss, and 6 degrees of pronation-supination loss) and pain with activity. Radiographic evidence of degenerative changes involving the elbow joint was present in 61% and radial head enlargement in 58%.
McManama et al4 presented data on 14 adolescents with radiocapitellar OCD lesions treated with excision via a lateral arthrotomy with average follow-up of 2 years. Lesions were not sized, but 93% had good or excellent results.
Jackson et al3 reported on the roughly 3-year follow-up of OCD lesions in 10 female gymnasts treated primarily with curettage of loose cartilage, drilling, and loose body excision. All of the patients reported symptomatic relief, but only 1 patient returned to competition, and she did so with discomfort. Average loss of extension at follow-up in this series was 9 degrees, which is consistent with other reports.
Ruch et al5 presented the follow-up at an average of 3.2 years after arthroscopic débridement alone for management of
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elbow OCD in 12 adolescents. The average flexion contracture improved 13 degrees (23 degrees preoperatively to 10 degrees postoperatively). All patients had capitellar remodeling on follow-up
radiographs, and approximately 42% had associated radial head enlargement. Ninety-two percent of the patients in this series were highly satisfied, with minimal symptoms. Of note, 5 patients (42%) had a
triangular lateral capsular avulsion fragment (seen radiographically but not at arthroscopy), which had a
statistically significant association with a worse subjective outcome.
Baumgarten et al2 presented an average 4-year follow-up (range 24 to 75 months) on 17 elbows with OCD treated in 16 patients. Their results showed that the average flexion contracture improved 14 degrees, approximately 24% had pain, 7 of 9 (78%) throwers and 4 of 5 (80%) gymnasts were able to return to sport, and no patient had demonstrable degenerative joint disease.
COMPLICATIONS
The complications seen with OCD treated surgically or not include flexion contracture, elbow pain, arthritis, and inability to return to sports.
Loose bodies may develop in elbows treated nonoperatively.
Surgical intervention, particularly arthroscopy, has the added risk of nerve injury because the neural structures are so close to the usual elbow arthroscopy portals.
REFERENCES
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Bauer M, Jonsson K, Josefsson PO, et al. Osteochondritis dissecans of the elbow: a long-term follow-up study. Clin Orthop Relat Res 1992;284:156-160.
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Baumgarten TE, Andrews JR, Satterwhite YE. The arthroscopic classification and treatment of osteochondritis dissecans of the capitellum. Am J Sports Med 1998;26:520-523.
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Jackson D, Silvino N, Reimen P. Osteochondritis in the female gymnast’s elbow. Arthroscopy 1989;5:129-136.
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McManama GB Jr, Micheli LJ, Berry MV, et al. The surgical treatment of osteochondritis of the capitellum. Am J Sports Med 1985;13:11-21.
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Ruch DS, Cory JW, Poehling GG. The arthroscopic management of osteochondritis dissecans of the adolescent elbow. Arthroscopy 1998;14:797-803.
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Takahara M, Ogino T, Fukushima S, et al. Nonoperative treatment of osteochondritis dissecans of the humeral capitellum. Am J Sports Med 1999;27:728-732.
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Takahara M, Ogino T, Sasaki I, et al. Long-term outcome of osteochondritis dissecans of the humeral capitellum. Clin Orthop Relat Res 1999;363:108-115.