Leung Kwok Sui, Qin Ling, Fu Lap Kun, Chan Chun Wai
Musculo-Skeletal Research Laboratory, Department of Orthopaedics & Traumatology, The Chinese University of Hong Kong, Clinical Sciences Building, Prince of Wales Hospital, Shatin, N.T., Hong Kong.
Clin Biomech (Bristol). 2002 Oct;17(8):594-602. doi: 10.1016/s0268-0033(02)00075-x.
To study the healing quality of bone to bone and bone to tendon repair in a patella-patellar tendon complex.
In vivo animal experiment in 60 mature 32-week-old female rabbits.
Injuries of patella-patellar tendon complex are not uncommon. However, no studies are available to compare the healing quality between bone to bone and bone to tendon surgical reconstructions used for repair of patella-patellar tendon complex.
A standard transverse osteotomy was performed at the distal one-third of patella of one hindlimb. Both patellar fragments were reattached for bone to bone group while the patellar tendon was reattached to the remaining patella after removing the distal one-third of patella for bone to tendon group. Patella-patellar tendon complex was harvested at 8, 12 and 24 weeks postoperatively for biomechanical and histological evaluations, with n=8 and n=2 at each healing time points in both groups. The contralateral knee served as a control.
No significant differences in the failure loads were found between two groups. However, greater ultimate stress was found in bone to bone group as compared with bone to tendon group at week 8 and 24 (both P<0.05). On average, the ultimate stress of the bone to tendon and bone to bone group only reached 20.6(4.2)% and 28.6(6.7)% of the control values at week 24, respectively. The discrepancy between findings in failure load and failure stress might be explained by an overall larger cross-sectional area of the healing interface in bone to tendon group as compared with bone to bone group. Histology revealed that the bone to bone healing was via endochondral ossification at the healing interface. In bone to tendon group, extensive scar tissue was formed to overbridge the healing interface and remodeled with healing over time. The structural integration at the tendon and bony healing interface was poor and no typical intermitted fibrocartilage zone as seen in normal bone to tendon junction was formed.
Failure load of bone to bone and bone to tendon healing interface did not differ during repair of patella-patellar tendon complex. However, the healing interface of bone to bone repair in terms of material properties as reflected by failure stress was superior to that of the bone to tendon healing.
The findings of this experimental study may suggest that the anatomical reconstruction of patella-patellar tendon complex injury may be the primary concern in decision making for selecting either bone to bone or bone to tendon repair. However whenever possible, to initial fracture (bone-to-bone) fixation for ensuring better and predictable repair at the healing interface.
研究髌骨-髌腱复合体中骨与骨及骨与肌腱修复的愈合质量。
对60只32周龄成熟雌性家兔进行体内动物实验。
髌骨-髌腱复合体损伤并不罕见。然而，尚无研究比较用于修复髌骨-髌腱复合体的骨与骨及骨与肌腱手术重建之间的愈合质量。
在一侧后肢髌骨远端三分之一处进行标准横向截骨术。在骨与骨组中，将两块髌骨碎片重新连接；在骨与肌腱组中，切除髌骨远端三分之一后，将髌腱重新连接到剩余的髌骨上。术后8周、12周和24周采集髌骨-髌腱复合体进行生物力学和组织学评估，两组在每个愈合时间点n = 8和n = 2。对侧膝关节作为对照。
两组之间的破坏载荷没有显著差异。然而，在第8周和第24周时，骨与骨组的极限应力高于骨与肌腱组（均P<0.05）。平均而言，在第24周时，骨与肌腱组和骨与骨组的极限应力分别仅达到对照值的20.6(4.2)%和28.6(6.7)%。破坏载荷和破坏应力结果之间的差异可能是由于与骨与骨组相比，骨与肌腱组愈合界面的横截面积总体更大。组织学显示，骨与骨愈合是通过愈合界面的软骨内成骨。在骨与肌腱组中，形成了广泛的瘢痕组织来跨越愈合界面，并随着时间的推移与愈合一起重塑。肌腱与骨愈合界面的结构整合较差，未形成正常骨与肌腱连接处所见的典型间断纤维软骨区。
在髌骨-髌腱复合体修复过程中，骨与骨及骨与肌腱愈合界面的破坏载荷没有差异。然而，从破坏应力反映的材料特性来看，骨与骨修复的愈合界面优于骨与肌腱愈合。
本实验研究结果可能表明，在选择骨与骨或骨与肌腱修复的决策中，髌骨-髌腱复合体损伤的解剖重建可能是主要考虑因素。然而，只要有可能，应进行初次骨折（骨与骨）固定，以确保愈合界面更好且可预测的修复。
