Case report

Transplantation of tissue-engineered cartilage for the treatment of osteochondritis dissecans in the elbow: Outcomes over a four-year follow-up in two patients

The etiology and pathogenesis of osteochondritis dissecans (OCDs) lesions remain controversial.

This review presents the recent evolution about the healing, imaging, pathogenesis, and how to treat OCD of the capitellum in overhead athletes.

Compressive and shear forces to the growing capitellum can cause subchondral separation, leading to OCD, composed of 3 layers: articular fragment, gap, and underlying bone. Subchondral separation can cause ossification arrest (stage IA), followed by cartilage degeneration (stage IB) or delayed ossification (stage IIA), occasionally leading to osteonecrosis (stage IIB) in the articular fragment. Articular cartilage fracture and gap reseparation make the articular fragment unstable. The mean tilting angle of capitellar OCD is 57.6 degrees in throwers. Anteroposterior radiography of the elbow at 45 degrees of flexion (APR45) can increase the diagnostic reliability, showing OCD healing stages, as follows: I) radiolucency, II) delayed ossification, and III) union. Coronal computed tomography and magnetic resonance imaging with an appropriate tilting angle can also increase the reliability. MRI is most useful to show the instability, although it occasionally underestimates. Sonography contributes to detection of early OCD in adolescent throwers on the field. OCD lesions in the central aspect of the capitellum can be more unstable and may not heal. Cast immobilization has a positive effect on healing for stable lesions. Arthroscopic removal provides early return to sports, although a large osteochondral defect is associated with a poor prognosis. Fragment fixation, osteochondral autograft transplantation, and their hybrid technique have provided better results.

Further studies are needed to prevent problematic complications of capitellar OCD, such as osteoarthritis and chondrolysis.

Cartilage defects are treated with a wide array of non-operative and surgical procedures. Optimal choice of treatment depends on lesion depth and size.

To review and summarize current data on the management of cartilage injuries in joints as it relates to defect size.

MEDLINE, Cochrane Central Register of Controlled Trials & Cochrane Library, CINHAL.

Inclusion: (1) Studies investigating patients who underwent cartilage repair of the shoulder, elbow, hip, knee, and ankle. (2) Studies reporting outcome measures and treated lesion size. Exclusion: (1) No mention of defect size. (2) Joints not mentioned above. (3) <12 months clinical follow-up. (4) Unavailable full English or full texts.

Selection procedure and homogeneity of patient population and preoperative and postoperative care were examined. Attrition bias was scored based on the percentage follow-up of the primary outcome parameter. Level of evidence was determined according to the guidelines of the Oxford Center for Evidence-Based Medicine.

Small lesions sized 1.5 cm² are often either fixated or conservatively treated, lesions sized >1.5 cm² mostly addressed with cell-based therapies such as autologous cartilage implantation (ACI), or matrix associated cartilage implantation (MACI). Large lesions often are the domain of osteochondral autograft transfer system (OATS).

Prospective randomized controlled studies are not available for every joint and many studies represent case studies with limited implications for treatment decisions.

Evidence-based treatment selection based on cartilage defect size can be beneficial.

276559.

This Technical Note describes the full arthroscopic one-stage treatment of high-grade osteochondritis dissecans of the humeral capitellum of the elbow joint by means of minced cartilage implantation.

Osteochondritis dissecans is a multifactorial focal insult to the articular surface resulting in separation of the articular cartilage and subchondral bone. In the elbow, the most common location is the capitellum and generally occurs in younger (12 to 14 years old) athletes with a history of overuse. Most often patients present with pain and inability to participate in sports and radiographs are the initial study of choice. Treatment is based primarily on the stability of the articular cartilage but also on lesion size and location. Stable lesions can be treated nonoperatively, whereas unstable lesions typically require surgery. Arthroscopic debridement and microfracture is the treatment of choice except when the lesion involves over 50% of the articular surface or disrupts the lateral buttress. In these cases, or for smaller lesions in higher level athletes, open osteochondral autograft transplantation may have better results with regards to return to play.

To systematically evaluate the outcomes and complications of osteochondral autograft transfer (OAT) and osteochondral allograft transplantation (OCA) for the surgical treatment of capitellar osteochondritis dissecans (OCD).

A literature search was conducted across 3 databases (PubMed, Cochrane, and CINAHL [Cumulative Index to Nursing and Allied Health Literature]) from database inception through December 2019 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Individual study quality was assessed using the Methodological Index for Non-randomized Studies scale. Studies were published between 2005 and 2019.

Eighteen studies consisting of 446 elbow OCD lesions treated with OAT surgery were included. There was a single OCA study eligible for inclusion. Patient ages ranged from 10 to 45 years. Of the OAT studies, 4 used autologous costal grafts whereas the remainder used autografts from the knee. Outcome measures were heterogeneously reported. A significant improvement in Timmerman-Andrews scores from preoperatively to postoperatively was reported in 9 of 10 studies. Return-to-play rates to the preinjury level of competitive play ranged from 62% to 100% across 16 studies. Significant improvement in motion, most often extension, was noted in most studies. Reported complication, reoperation, and failure rates ranged from 0% to 11%, 0% to 26%, and 0% to 20%, respectively. When used, knee autografts resulted in low donor-site morbidity (Lysholm scores, 70-100).

OAT surgery for large, unstable OCD lesions of the capitellum reliably produced good outcomes, few complications, and a high rate of return to competitive play. Complications are relatively uncommon, and donor-site morbidity is low. Less is known about the performance of OCA given the paucity of available literature.

Level IV, systematic review of Level II to IV studies.

To assess the histological properties of cells from displaced fragments obtained from patients with advanced osteochondritis dissecans (OCD) of the elbow and to examine whether these displaced fragments could be used as cell sources for autologous chondrocyte implantation.

We harvested 6 displaced fragments from 6 patients who underwent osteochondral mosaicplasty for OCD of the elbow. The displaced fragments were examined histologically and digested to obtain chondrocytes. The cells obtained from young patients and skeletally matured cadaveric donors were examined using quantitative reverse transcription polymerase chain reaction analysis to quantify the expression of chondrocyte marker genes. The cells were cultured in atelocollagen, and the properties of 3-dimensional cultured cartilage were examined.

All 6 displaced fragments contained hyaline cartilage tissue. Chondrocyte marker genes were examined using cells from only 4 patients, because we obtained enough cells in only 4 patients. The relative expression levels of aggrecan, type II, Sox 9 were 2.61, 4.03, and 1.71, respectively. Three-dimensional cultured cartilage from all 6 displaced fragments contained 62.0 pg/cell (range, 22.8-91.3 pg/cell) of glycosaminoglycan and expressed type II collagen in the superficial and middle layer.

The chondrocytes obtained from the displaced fragments remained viable and exhibited chondrogenic features. These cells may potentially be a cell source of autologous chondrocytes implantation.

We have shown that displaced fragments from OCD of the elbow have potential for a cell source for generating 3-dimensional cultured cartilage.