Table 1.

Musculoskeletal repair: surgical techniques and limitations

Long bone defects	Autologous bone graft	Allogeneic bone graft	Bone substitutes
	Donor-site morbidity, graft size, bone quality	Slower healing compared to autograft, risk of rejection	Mechanically inferior to bone-grafts
Osteonecrosis of femoral head	Decompression and autologous bone graft	Joint replacement
	Palliative treatment	Limited implant life-time, requiring replacement particularly for young patients
Articular cartilage defects	Microfracture	Autologous chondrocyte implantation	Joint replacement
	Formation of fibrocartilage with inferior mechanical properties, formation of subchondral bone cysts	Long healing process, ex vivo expansion and de-differentiation of chondrocytes, limited to focal cartilage defects, OA is contra- indication	Risk of complications including aseptic loosening, dislocation and infection
Meniscal tears	Meniscal suture (peripheral regions)	Partial meniscectomy (in central regions)	Meniscal allograft/ synthetic substitute
	Limited to small tears	Increased risk of OA	Do not match mechanical complexity
Volumetric muscle loss	Scar tissue debridement	Autologous innervated muscle tissue transfer
	Functional deficiency often remains	Donor-site morbidity, complex surgical procedure
Rotator cuff injuries	Subacromial decompression and tendon debridement	Suture and re-attachment of the tendon to the bone
	Creates more space, but does not treat the tear	Risk of re-tear, scar tissue and fibrosis may cause impingement
IVD degeneration	Resection of protrusions	Segmental fusion	Total disc arthroplasty
	Often causes imbalance of adjacent segments	Limited motion, increased risk of adjacent segment degeneration	Increased risk of adjacent segment degeneration

Abbreviations: IVD, intervertebral disc; OA, osteoarthritis