Adams Bryan G, Tran Jeremy, Voinier Steven, Colantonio Donald F, Donohue Michael A, Kilcoyne Kelly G, Galvin Joseph W
Department of Orthopaedic Surgery, Landstuhl Regional Medical Center, Landstuhl, Germany.
Department of Orthopaedic Surgery, Walter Reed National Military Medical Center, Bethesda, MD, USA.
JSES Int. 2024 Jul 24;8(6):1157-1163. doi: 10.1016/j.jseint.2024.07.007. eCollection 2024 Nov.
Limitations to using the knee as donor cartilage include cartilage thickness mismatch and donor site morbidity. Using the radial head as donor autograft for capitellar lesions may allow for local graft harvest without distant donor site morbidity. The purpose of this study is to demonstrate the feasibility of performing local osteochondral autograft transfer from the nonarticular cartilaginous rim of the radial head to the capitellum. Additionally, we sought to determine the load to failure of the radial head after harvest.
Sixteen matched cadaveric elbows were used. A Kaplan approach was performed in half of the specimens and an extensor digitorum communis split in the other half. 6-mm and 8-mm capitellar cartilage defects were created. A donor plug was harvested from the rim of the radial head and transferred to the capitellum. In half of the specimens, the donor site was backfilled with autograft from the recipient plug. The other half was backfilled with calcium phosphate cement. The radial head was removed from the specimen and biomechanical analysis performed.
Both surgical approaches had adequate exposure to access the lateral two-third capitellar lesions in all specimens. The medial third of the capitellum was less accessible in extensor digitorum communis split approaches (1/8) compared to the Kaplan approach (6/8; = .01). The average cartilage thickness of the peripheral rim of the radial head and capitellum was 2.5 mm (range 1.8-3.2, standard deviation 0.4) and 2.2 mm (range 1.8-3, standard deviation 0.3), respectively. During the procedure, 2 of 8 radial heads fractured in the 8-mm plug group. No radial heads fractured in the 6-mm group ( = .47). Biomechanical testing demonstrated a mean load to failure of 1993N with no difference between groups when stratified by donor plug size or type of backfill.
This study demonstrates that the nonarticulating peripheral cartilaginous rim of the radial head could be a local harvest site for osteochondral autograft transfer for capitellar lesions up to 8 mm in diameter. The cartilage thickness of the radial head closely approximates the capitellum. Biomechanical analysis did not demonstrate a significant difference in load to fracture when backfilling the radial head harvest site with autograft bone or calcium phosphate cement. After harvest, the radial head could withstand forces much greater than those seen across the elbow when nonweight-bearing. Further investigation is needed to determine how to mitigate the risk of iatrogenic fracture with this operation.
将膝关节作为供体软骨存在局限性，包括软骨厚度不匹配和供体部位并发症。使用桡骨头作为自体移植供体治疗肱骨小头病变，可在局部获取移植物，而无远处供体部位并发症。本研究的目的是证明从桡骨头非关节软骨边缘向肱骨小头进行局部自体骨软骨移植的可行性。此外，我们试图确定取材后桡骨头的破坏载荷。
使用16对匹配的尸体肘部标本。一半标本采用 Kaplan 入路，另一半采用指总伸肌劈开入路。制作6毫米和8毫米的肱骨小头软骨缺损。从桡骨头边缘获取供体骨栓并移植到肱骨小头。在一半标本中，供体部位用取自受体骨栓的自体骨回填。另一半用磷酸钙骨水泥回填。从标本上取下桡骨头并进行生物力学分析。
两种手术入路在所有标本中都能充分暴露以处理外侧三分之二的肱骨小头病变。与 Kaplan 入路（6/8）相比，指总伸肌劈开入路处理肱骨小头内侧三分之一病变时暴露较差（1/8；P = 0.01）。桡骨头周边边缘和肱骨小头的平均软骨厚度分别为2.5毫米（范围1.8 - 3.2，标准差0.4）和2.2毫米（范围1.8 - 3，标准差0.3）。在手术过程中，8毫米骨栓组的8个桡骨头中有2个发生骨折。6毫米组中没有桡骨头骨折（P = 0.47）。生物力学测试表明，按供体骨栓大小或回填类型分层时，两组之间的平均破坏载荷为1993N，无差异。
本研究表明，桡骨头的非关节周边软骨边缘可作为直径达8毫米的肱骨小头病变自体骨软骨移植的局部取材部位。桡骨头的软骨厚度与肱骨小头相近。用自体骨或磷酸钙骨水泥回填桡骨头取材部位后，生物力学分析未显示骨折载荷有显著差异。取材后，桡骨头能承受远大于非负重时肘部所受的力。需要进一步研究以确定如何降低该手术导致医源性骨折的风险。
