Gelberman R H, Boyer M I, Brodt M D, Winters S C, Silva M J
Department of Orthopaedic Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
J Bone Joint Surg Am. 1999 Jul;81(7):975-82. doi: 10.2106/00004623-199907000-00010.
Elongation (gap formation) at the repair site has been associated with the formation of adhesions and a poor functional outcome after repair of flexor tendons. Our objectives were to evaluate the prevalence of gap formation in a clinically relevant canine model and to assess the effect of gap size on the range of motion of the digits and the mechanical properties of the tendons.
We performed operative repairs after sharp transection of sixty-four flexor tendons in thirty-two adult dogs. Rehabilitation with passive motion was performed daily until the dogs were killed at ten, twenty-one, or forty-two days postoperatively. Eight tendons ruptured in vivo. In the fifty-six intact specimens, the change in the angles of the proximal and distal interphalangeal joints and the linear excursion of the flexor tendon were measured as a 1.5-newton force was applied to the tendon. The gap at the repair site was then measured, and the isolated tendons were tested to failure in tension.
Twenty-nine tendons had a gap of less than one millimeter, twelve had a gap of one to three millimeters, and fifteen had a gap of more than three millimeters. Neither the time after the repair nor the size of the gap was found to have a significant effect on motion parameters (p > 0.05); however, the ultimate force, repair-site rigidity, and repair-site strain at twenty newtons were significantly affected by these parameters (p < 0.05). Testing of the tendons with a gap of three millimeters or less revealed that, compared with the ten-day specimens, the forty-two-day specimens failed at a significantly (90 percent) higher force (p < 0.01) and had a significantly (320 percent) increased rigidity (p < 0.01) and a significantly (60 percent) decreased strain at twenty newtons (p < 0.05). In contrast, the tensile properties of the tendons that had a gap of more than three millimeters did not change significantly with time.
Our data indicate that, in a dog model involving sharp transection followed by repair, a gap at the repair site of more than three millimeters does not increase the prevalence of adhesions or impair the range of motion but does prevent the accrual of strength and stiffness that normally occurs with time.
修复部位的延长（间隙形成）与屈肌腱修复后粘连的形成及功能预后不良有关。我们的目的是评估在一个具有临床相关性的犬类模型中间隙形成的发生率，并评估间隙大小对指关节活动范围和肌腱力学性能的影响。
我们对32只成年犬的64条屈肌腱进行锐性横断后进行手术修复。术后每天进行被动活动康复，直至犬在术后10天、21天或42天处死。8条肌腱在体内发生断裂。在56个完整标本中，当向肌腱施加1.5牛顿的力时，测量近端和远端指间关节角度的变化以及屈肌腱的线性偏移。然后测量修复部位的间隙，并对分离的肌腱进行拉伸直至破坏试验。
29条肌腱的间隙小于1毫米，12条肌腱的间隙为1至3毫米，15条肌腱的间隙大于3毫米。未发现修复后的时间和间隙大小对运动参数有显著影响（p>0.05）；然而，这些参数对20牛顿力时的极限力、修复部位的刚度和修复部位的应变有显著影响（p<0.05）。对间隙为3毫米或更小的肌腱进行测试发现，与术后10天的标本相比，术后42天的标本在显著更高的力（高90%）下破坏（p<0.01），刚度显著增加（增加320%）（p<0.01），在20牛顿力时应变显著降低（降低60%）（p<0.05）。相比之下，间隙大于3毫米肌腱的拉伸性能随时间未发生显著变化。
我们的数据表明，在一个先进行锐性横断然后修复的犬类模型中，修复部位间隙大于3毫米不会增加粘连的发生率或损害活动范围，但会阻止正常情况下随时间发生的强度和刚度的增加。
