Yucheng Sun1, Jae-Man Kwak2, Erica Kholinne2,3, Youlang Zhou1, Jun Tan1, Kyoung Hwan Koh2, In-Ho Jeon2. 1. Department of Hand Surgery, Affiliated Hospital of Nantong University, College of Medicine, University of Nantong, Nantong, China. 2. Department of Orthopedic Surgery, ASAN Medical Center, College of Medicine, University of Ulsan, Seoul, Republic of Korea. 3. Department of Orthopedic Surgery, St. Carolus Hospital, Jakarta, Indonesia.
Abstract
BACKGROUND: Microfracture of the greater tuberosity has been proved effective for enhancing tendon-to-bone healing after rotator cuff repair. However, no standard diameter for the microfracture has been established. PURPOSE/HYPOTHESIS: This study aimed to assess treatment with large- and small-diameter microfractures to enhance healing during rotator cuff repair surgery in a rabbit model of chronic rotator cuff tear. It was hypothesized that a small-diameter microfracture had advantages in terms of tendon-to-bone integration, bone-tendon interface maturity, microfracture healing, and biomechanical properties compared with a large-diameter microfracture. STUDY DESIGN: Controlled laboratory study. METHODS: Bilateral supraspinatus tenotomy from the greater tuberosity was performed on 21 New Zealand White rabbits. Bilateral supraspinatus repair was performed 6 weeks later. Small-diameter (0.5 mm) microfracture and large-diameter microfracture (1 mm) were performed on the left side and right side, respectively, in 14 rabbits as a study group, and simple repair without microfracture was performed in 7 rabbits as a control group. At 12 weeks later, 7 of 14 rabbits in the study group were sacrificed for micro-computed tomography evaluation and biomechanical testing. Another 6 rabbits were sacrificed for histological evaluation. In the control group, 3 of the 7 rabbits were sacrificed for histological evaluation and the remaining rabbits were sacrificed for biomechanical testing. RESULTS: Significantly better bone-to-tendon integration was observed in the small-diameter microfracture group. Better histological formation and maturity of the bone-tendon interface corresponding to better biomechanical results (maximum load to failure and stiffness) were obtained on the small-diameter microfracture side compared with the large-diameter side and the control group. The large-diameter microfracture showed worse radiographic and histological properties for healing of the microfracture holes on the greater tuberosity. Additionally, the large-diameter microfracture showed inferior biomechanical properties but similar histological results compared with the control group. CONCLUSION: Small-diameter microfracture showed advantages with enhanced rotator cuff healing for biomechanical, histological, and radiographic outcomes compared with large-diameter microfracture, and large-diameter microfracture may worsen the rotator cuff healing. CLINICAL RELEVANCE: This animal study suggested that a smaller diameter microfracture may be a better choice to enhance healing in clinical rotator cuff repair surgery in humans.
BACKGROUND: Microfracture of the greater tuberosity has been proved effective for enhancing tendon-to-bone healing after rotator cuff repair. However, no standard diameter for the microfracture has been established. PURPOSE/HYPOTHESIS: This study aimed to assess treatment with large- and small-diameter microfractures to enhance healing during rotator cuff repair surgery in a rabbit model of chronic rotator cuff tear. It was hypothesized that a small-diameter microfracture had advantages in terms of tendon-to-bone integration, bone-tendon interface maturity, microfracture healing, and biomechanical properties compared with a large-diameter microfracture. STUDY DESIGN: Controlled laboratory study. METHODS: Bilateral supraspinatus tenotomy from the greater tuberosity was performed on 21 New Zealand White rabbits. Bilateral supraspinatus repair was performed 6 weeks later. Small-diameter (0.5 mm) microfracture and large-diameter microfracture (1 mm) were performed on the left side and right side, respectively, in 14 rabbits as a study group, and simple repair without microfracture was performed in 7 rabbits as a control group. At 12 weeks later, 7 of 14 rabbits in the study group were sacrificed for micro-computed tomography evaluation and biomechanical testing. Another 6 rabbits were sacrificed for histological evaluation. In the control group, 3 of the 7 rabbits were sacrificed for histological evaluation and the remaining rabbits were sacrificed for biomechanical testing. RESULTS: Significantly better bone-to-tendon integration was observed in the small-diameter microfracture group. Better histological formation and maturity of the bone-tendon interface corresponding to better biomechanical results (maximum load to failure and stiffness) were obtained on the small-diameter microfracture side compared with the large-diameter side and the control group. The large-diameter microfracture showed worse radiographic and histological properties for healing of the microfracture holes on the greater tuberosity. Additionally, the large-diameter microfracture showed inferior biomechanical properties but similar histological results compared with the control group. CONCLUSION: Small-diameter microfracture showed advantages with enhanced rotator cuff healing for biomechanical, histological, and radiographic outcomes compared with large-diameter microfracture, and large-diameter microfracture may worsen the rotator cuff healing. CLINICAL RELEVANCE: This animal study suggested that a smaller diameter microfracture may be a better choice to enhance healing in clinical rotator cuff repair surgery in humans.
Authors: Isabella T Wu; Michael C Gibbons; Mary C Esparza; Laura S Vasquez-Bolanos; Sydnee A Hyman; Shanelle N Dorn; Anshuman Singh; John G Lane; Donald C Fithian; Severin Ruoss; Samuel R Ward Journal: Front Physiol Date: 2022-03-08 Impact factor: 4.566