Osteoarticular Transplantation: Recognizing Expected Postsurgical Appearances and Complications

Abstract

Despite technologic advances in prosthetic joint replacement, young patients who have lost a large volume of bone or soft tissue because of a tumor or traumatic injury may not be good candidates for prosthetic implants, which have limited longevity relative to that of biologic tissue grafts. In recent years, the use of biologic materials in orthopedic surgery has increased. Such materials, known as allografts, consist of cadaveric bone, cartilage, and other soft tissues that can be transplanted into a living patient. Alternatively, osteochondral autografts, or autologous grafts of the patient's own bone and/or cartilage, can be harvested from one body site and transplanted to another. Surgical procedures range from the local implantation of small osteochondral plugs to the replacement of entire joints with allografts. The size of the allograft used depends on the amount of bone and soft tissue needed. The use of allografts in patients with large-volume bone loss often preserves limb function, obviating amputation, which makes it an attractive option for treatment of young patients. Advantages of using allografts include the similarity of graft materials to native tissues and the decreased patient morbidity in the absence of an autograft donor site; disadvantages include slower biologic remodeling and graft incorporation than are typical with the use of autologous grafts. Potential complications of allograft tissue implantation include graft nonunion, collapse, and failure; infection; and secondary osteoarthritis. The article discusses the indications for and basic steps involved in each type of transplant procedure, normal pre- and postoperative imaging appearances, and imaging features that may be indicative of transplant complications.

Talar Dome Osteochondral Lesions: Pre- and Postoperative Imaging

“…82 83 Regarding grafting, in the immediate and early postoperative period of OATS, the graft is often edematous, and the graft may be slightly proud of adjacent tissue due to differences in normal cartilage thickness between the knee and the ankle. 84 A 1-mm protrusion of the graft leads to a sevenfold increase in pressure on the graft. 85 In the delayed postoperative period, fissuring between the graft and native bone can be a sign of early failure, although perigraft cystic change is not, in itself, necessarily of clinical significance.…”

Surgical Correction of Articular Damage in the Knee: Osteoarticular Transplantation to Joint Reconstruction

“…Routine radiographic surveillance is performed at 6 weeks, 12 weeks, 6 months, and annually. 23 However, if there is clinical suspicion of graft failure or increasing pain for the patient, radiographs can be done sooner, followed by cross-sectional imaging such as CT or MRI. 24 Native bone-graft interface signal intensity, graft signal intensity, subchondral bone signal intensity, and articular surface contour are all imaging features that require scrutiny on MRI.…”

“…OATs come in numerous sizes including bone plugs, partial joint surface, whole joint surface, and whole joint with allograft. 23 Routine surveillance of OAT is done with radiographs. Similar to AOT, on radiographs the graft itself should be at the level of or above the native bone.…”

CT and MR Imaging of the Postoperative Ankle and Foot

“…Arthroscopic repair of OLTs is generally considered the reference standard for treatment, with many techniques available including chondroplasty, microfracture, grafting, and chondrocyte transplantation (51,54,55). Chondroplasty simply entails resection of injured tissue and mechanical smoothing of the subchondral bone to create a stable articular surface (Fig 18) (55).…”

“…CT and MR imaging are the preferred imaging methods for investigating patients with postoperative pain or clinical suspicion of graft failure (54). In the immediate and early postoperative period, there may be bone marrow edema in the graft itself, and the grafted bone may be seated slightly proud to the adjacent native bone (54). In the delayed postoperative period, fissuring may be seen between the graft and native bone as a sign of early failure.…”