Biomechanical comparison of the simple running and cross-stitch epitenon sutures in achilles tendon repairs

BACKGROUND: Augmenting the strength of Achilles tendon repairs may allow for earlier active rehabilitation with less risk of adhesion formation and re-ruptures, leading to quicker and stronger healing. Building upon previous research that has (1) demonstrated strength gains in Achilles repairs upon addition of simple running epitenon sutures, and (2) shown the cross-stitch epitenon suture to be stronger than the simple running stitch in flexor tendons of the hand, this study compares use of these epitenon sutures in the Achilles tendon. MATERIALS AND METHODS: Ruptures were simulated in 7 matched pairs of fresh frozen human Achilles tendons and repaired with the two-tailed Krakow locking loop core technique using No. 2 nonabsorbable, braided, polyester suture. From each pair, one specimen was randomly selected to also receive the epitenon cross-stitch, the other receiving the simple running stitch. All epitenon repairs employed 4-0 nylon suture. Repaired tendons were loaded in tension to the point of failure on a Materials Testing Machine (MTS). RESULTS: Tendon repair augmented with the cross-stitch displayed a significant, 53% greater failure strength than those repaired with the simple running stitch. Increases in initial stiffness and resistance to 2-mm gap formation in the cross-stitch specimens were 3.1% and 3.6%, respectively. CONCLUSION: Gapping resistance and initial stiffness in Achilles tendon repairs were comparable between the cross-stitch and simple running stitch, but the cross-stitch significantly improved failure strength. CLINICAL RELEVANCE: Greater failure strength may translate clinically to lower rates of re-rupture and earlier mobilization following Achilles tendon repair.     

Biomechanical evaluation of arthroscopic rotator cuff repairs: double-row compared with single-row fixation

BACKGROUND: Recent studies have shown that arthroscopic rotator cuff repairs can have higher rates of failure than do open repairs. Current methods of rotator cuff repair have been limited to single-row fixation of simple and horizontal stitches, which is very different from open repairs. The objective of this study was to compare the initial cyclic loading and load-to-failure properties of double-row fixation with those of three commonly used single-row techniques. METHODS: Ten paired human supraspinatus tendons were split in half, yielding four tendons per cadaver. The bone mineral content at the greater tuberosity was assessed. Four stitch configurations (two-simple, massive cuff, arthroscopic Mason-Allen, and double-row fixation) were randomized and tested on each set of tendons. Specimens were cyclically loaded between 5 and 100 N at 0.25 Hz for fifty cycles and then loaded to failure under displacement control at 1 mm/sec. Conditioning elongation, peak-to-peak elongation, ultimate tensile load, and stiffness were measured with use of a three-dimensional tracking system and compared, and the failure type (suture or anchor pull-out) was recorded. RESULTS: No significant differences were found among the stitches with respect to conditioning elongation. The mean peak-to-peak elongation (and standard error of the mean) was significantly lower for the massive cuff (1.1 +/- 0.1 mm) and double-row stitches (1.1 +/- 0.1 mm) than for the arthroscopic Mason-Allen stitch (1.5 +/- 0.2 mm) (p < 0.05). The ultimate tensile load was significantly higher for double-row fixation (287 +/- 24 N) than for all of the single-row fixations (p < 0.05). Additionally, the massive cuff stitch (250 +/- 21 N) was found to have a significantly higher ultimate tensile load than the two-simple (191 +/- 18 N) and arthroscopic Mason-Allen (212 +/- 21 N) stitches (p < 0.05). No significant differences in stiffness were found among the stitches. Failure mechanisms were similar for all stitches. Rotator cuff repairs in the anterior half of the greater tuberosity had a significantly lower peak-to-peak elongation and higher ultimate tensile strength than did repairs on the posterior half. CONCLUSIONS: In this in vitro cadaver study, double-row fixation had a significantly higher ultimate tensile load than the three types of single-row fixation stitches. Of the single-row fixations, the massive cuff stitch had cyclic and load-to-failure characteristics similar to the double-row fixation. Anterior repairs of the supraspinatus tendon had significantly stronger biomechanical behavior than posterior repairs.     

Optimizing Achilles tendon repair: effect of epitendinous suture augmentation on the strength of achilles tendon repairs

BACKGROUND: Epitendinous suture augmentation has been shown to increase gap resistance and overall strength in flexor tendon repairs of the hand. The purpose of this study was to evaluate the effect of various suture augmentation techniques in Achilles tendon repair. MATERIALS AND METHODS: Eighteen fresh-frozen cadaveric Achilles tendons were transected and repaired with a 4-strand Krackow core stitch. Suture augmentation was performed with 3 figure-of-eight stitches in 6 specimens and a running cross-stitch weave in 6 specimens. The other 6 specimens were not augmented. Each tendon was loaded to failure on an MTS. Force to failure (defined as peak force or force at 5 mm gapping), gapping resistance, stiffness, and elongation were compared. RESULTS: Force to failure (p < 0.001), stiffness (p < 0.01) and gapping resistance (p < 0.05) were increased by suture augmentation. Additionally failure force and gapping resistance for the cross-stitch augmentation was higher than the figure-of-eight augmentation (p < 0.05). CONCLUSION: Cross-stitch augmentation of Achilles tendon repair yields a stronger and stiffer repair with greater resistance to gapping. CLINICAL RELEVANCE: Achilles tendon repairs augmented with a cross stitch weave will be able to withstand substantially higher forces than non-augmented repairs.     

Zone II tendon repairs augmented with autogenous dorsal tendon graft: a biomechanical analysis

We investigated the biomechanical properties of a new technique for tendon repair that reinforces a standard suture with an autogenous tendon graft. A dynamic in situ testing apparatus was used to test 40 flexor digitorum profundus tendons harvested from fresh-frozen cadaver hands. The tendons were cut and repaired using 1 of 4 suture techniques: 2-strand modified Kessler, 4-strand modified Kessler, 6-strand modified Savage, and 2-strand modified Kessler augmented with autogenous dorsal tendon graft. The augmented repair uses 1 slip of the flexor digitorum superficialis tendon secured to the dorsal surface of the repair site with a continuous stitch. Ultimate tensile strength, resistance to gap formation, and work of flexion were measured simultaneously on an in situ tensile testing apparatus. No significant difference in tensile strength was found between the augmented repair and the 6-strand Savage repair. The augmented repair and the 6-strand Savage repair showed significantly greater ultimate tensile strength than the 2- and 4-strand repairs. The augmented repair had significantly greater resistance to 2 mm gap formation than the other 3 repairs. We were unable to show a significant difference in work of flexion between the repairs with the numbers tested (n = 10). Our findings suggest that the augmented repair is strong enough to tolerate the projected forces generated during active motion without dehiscence or gap formation at the repair site.     

Flexor tendon repair using a stainless steel external splint. Biomechanical study on human cadaver flexor tendons

A stainless steel external tendon splint was used in repair of cadaver tendons and compared with standard tendon repairs with suture. The splint was combined with a Kessler repair and tested against the Kessler, Becker, and Savage repairs in fresh human cadaver flexor digitorum profundus tendons. Biomechanical testing was done on a tensile testing machine, and load-displacement curves were generated. The repairs using the external tendon splint demonstrated a range of improvement of 32 to 146% in mean maximal tensile strength and a 20 to 185% improvement of mean ultimate tensile strength compared with all other repairs. The external tendon splint is relatively easy to apply to a tendon. The repair is strengthened and becomes capable of withstanding early active range of motion exercises. In vivo testing will be needed to assess the potential clinical usefulness of such a device.     

Simplifying four-strand flexor tendon repair using double-stranded suture: a comparative ex vivo study on tensile strength and bulking

We have compared a simple four-strand flexor tendon repair, the single cross-stitch locked repair using a double-stranded suture (dsSCL) against two other four-strand repairs: the Pennington modified Kessler with double-stranded suture (dsPMK); and the cruciate cross-stitch locked repair with single-stranded suture (Modified Sandow). Thirty fresh frozen cadaveric flexor digitorum profundus tendons were transected and repaired with one of the core repair techniques using identical suture material and reinforced with identical peripheral sutures. Bulking at the repair site and tendon-suture junctions was measured. The tendons were subjected to linear load-to-failure testing. Results showed no significant difference in ultimate tensile strength between the Modified Sandow (36.8 N) and dsSCL (32.6 N) whereas the dsPMK was significantly weaker (26.8 N). There were no significant differences in 2 mm gap force, stiffness or bulk between the three repairs. We concluded that the simpler dsSCL repair is comparable to the modified Sandow repair in tensile strength, stiffness and bulking.     

内置十字交叉法肌腱缝合技术的生物力学研究及其在Ⅶ区伸肌腱修复中的应用

目的 报道一种新的肌腱缝合方法——内置十字交叉法的生物力学特性,及其修复Ⅶ区伸肌腱损伤的初步临床应用结果。方法 本研究采用33根猪后足的肌腱作为实验材料,随机等分成3组,分别用十字交叉法、内置十字交叉法及Halsted法进行修复。用Instron材料力学测定仪测定修复后肌腱的2-mm间隙形成负荷、断裂负荷、刚度和断裂功耗。用内置十字交叉法临床修复Ⅶ区伸肌腱断裂21例,共56指,术后均采用保护性主被动活动相结合的锻炼计划。采用Strickland标准进行功能评价。结果 等速直线拉伸模式下,内置十字交叉法的2-mm间隙形成负荷为(49.2±5.6)N,断裂负荷为(68.3±6.3)N,刚度为(6.9±0.7)N/mm,断裂功耗为(0.79±0.07)J,均优于十字交叉法和Halsted法(P<0.05)。术后平均随访26个月,内置十字交叉法修复的Ⅶ区伸肌腱(56指)无一例发生断裂,根据Strickland TAM标准,优50指,良4指,可2指,优良率96.4%。结论 内置十字交叉法具备良好的生物力学强度,外露缝线少,能满足伸肌腱早期保护性主被动活动的需要,是伸肌腱修复的理想选择。     

Biomechanical evaluation of flexor tendon repair techniques

Immediate active mobilization of repaired tendons is thought to be the most effective way to restore function of injured flexor tendons. Sixty human flexor digitorum profundus tendons were used to evaluate techniques for active tendon motion. The tendons were divided equally into six groups, and each group was assigned to one of the following techniques: Kessler core suture plus running peripheral suture, Kessler plus cross-stitch suture, Kessler plus Halsted suture, Tang core suture plus running peripheral suture, Tang plus cross-stitch suture, or Tang plus Halsted suture. Immediately after tendon repair, an Instron tensile testing machine was used to measure the 2-mm gap formation force, ultimate strength, elastic modulus, and energy to failure of the tendons repaired by these techniques. Ultimate strength, elastic modulus, and energy to failure were measured in load displacement curve. Results showed that the ultimate strength of the Tang plus Halsted or cross-stitch was, respectively, 116.8 +/- 9.6 N and 94.6 +/- 7.8 N; and 2-mm gap formation force was, respectively, 86.6 +/- 4.9 N and 71.9 +/- 5.1 N. The Tang plus Halsted or cross-stitch methods had a statistically significant increase in ultimate strength and 2-mm gap formation force as compared with the Kessler core suture or Tang plus running peripheral suture method. Elastic modulus and energy to failure of the Tang plus Halsted or cross-stitch suture were statistically higher than those of other techniques. The Tang plus cross-stitch or Tang plus Halsted sutures had the highest strength among the tested methods and are appropriate techniques for tendon repair in which the goal is immediate active tendon motion.     

Effect of suture locking and suture caliber on fatigue strength of flexor tendon repairs

The objectives of this cadaveric study were 2-fold: to determine the effect of different locking configurations on the cyclical fatigue strength of flexor tendon repairs and to assess the differences between each repair when a 3-0 or 4-0 suture is used. One hundred twenty flexor digitorum profundus tendons were cut and repaired using nonlocked, simple locked, and cross-stitch locked variations of 2- and 4-strand flexor tendon repairs. Using an incremental cyclical loading protocol we performed 10 trials of each repair with both 3-0 and 4-0 sutures and analyzed the number of Newton-cycles to failure using a 3-way ANOVA. The use of a 3-0 suture led to a 2- to 3-fold increase in fatigue strength in all repairs tested and the fatigue strength of the 4-strand repairs was significantly greater than the 2-strand repairs. All repairs performed with 4-0 suture failed by suture rupture. Of the 3-0 suture repairs, the three 2-strand repairs and the 4-strand cross-stitch locked repair failed by suture rupture. In contrast, 6 of 10 of the 4-strand simple locked and nonlocked repairs failed by suture pullout. There was no significant difference in fatigue strength between the 2 locked and the nonlocked 2-strand repairs using either 3-0 or 4-0 suture. There also was no significant difference in holding capacity or fatigue strength between the simple locked or nonlocked 4-strand repairs. However, the 4-strand cross-stitch locked repair with a 3-0 suture had significantly improved fatigue strength and holding capacity compared with the other repairs tested. Based on the consistently inferior biomechanical performance of 4-0 suture, we recommend that 3-0 suture be considered for 2- or 4-strand tendon repairs when early active motion is planned. The orientation of the transverse and longitudinal components of simple locked repairs did not significantly influence their holding capacity or fatigue strength. The cross-stitch type of locked repair provides better holding capacity and fatigue strength compared with simple locked or nonlocked 4-stranded flexor tendon repairs.     

Biomechanical evaluation of arthroscopic rotator cuff stitches

BACKGROUND: The suture configurations in arthroscopic rotator cuff repairs have been limited to simple and horizontal stitches. Recent objective evaluations have demonstrated high failure rates of arthroscopic repairs of rotator cuff tears. A novel stitch for arthroscopic repair of the rotator cuff, the massive cuff stitch, was developed to increase the strength of the suture-tendon interface. The goal of this study was to determine the biomechanical properties of the massive cuff stitch and to compare it with other stitches commonly used for rotator cuff repair. METHODS: Eight pairs of sheep infraspinatus tendons were harvested and split in half to yield a set of four tendon specimens from each animal. Four stitch configurations (simple, horizontal, massive cuff, and modified Mason-Allen) were randomized and biomechanically tested in each set of tendon specimens. Each specimen was first cyclically loaded on an MTS uniaxial load frame under force control from 5 to 30 N at 0.25 Hz for twenty cycles. Each specimen was then loaded to failure under displacement control at a rate of 1 mm/sec. Cyclic elongation, peak-to-peak displacement, ultimate tensile load, and stiffness were measured with use of an optical motion analysis system and load-cell output. The type of failure (suture breakage or pull-out) was also recorded. A repeated-measures analysis of variance was performed on the results, with the alpha level of significance set at p < 0.05. RESULTS: There was no difference in cyclic elongation or peak-to-peak displacement among the four stitches. Ultimate tensile load was significantly higher (p < 0.05) for the massive cuff stitch (233 +/- 40 N) and the modified Mason-Allen stitch (246 +/- 40 N) than it was for either the simple stitch (72 +/- 18 N) or the horizontal stitch (77 +/- 15 N). There was no significant difference in the ultimate load between the massive cuff and modified Mason-Allen stitches. There was also no difference in stiffness among the four stitches. The simple and horizontal stitches failed by tissue pull-out, whereas the massive cuff and Mason-Allen stitches failed by a mixture of suture breakage and pull-out. CONCLUSIONS: The massive cuff stitch provides strength comparable with that of the modified Mason-Allen stitch commonly used in open rotator cuff repair. The ultimate tensile load before failure of the massive cuff stitch was significantly higher (p < 0.05) than that of the simple and horizontal stitches.     

Cross stitch peripheral tendon repair: a mechanical comparison with core stitch techniques

The purpose of this experimental study was to compare certain mechanical properties of a true epitendineal cross stitch suture with simple and double locking core tendon repairs. Using tensile strength and tendon lengthening until gap formation as measurement parameters, these three types of repair were tested in human flexor and extensor tendons from fresh cadavers. The peripheral cross stitch and the locked core repairs were found to have a greater lengthening capacity than the simple core suture, whereas the latter significantly better withstood axial load. Our findings established that, at least when used as a true epitendinous suture, the cross stitch technique alone was not suited for the repair of severed tendons. However, its design is particularly useful in preventing the suture site from potentially restrictive bulking.     

Embedded cross-stitch suture: an alternative to current cross-stitch peripheral suture

The cross-stitch peripheral suture has good strength, but the large amount of exposed suture on the tendon surface has restricted its clinical usage. We report a method of embedded cross-stitch that incorporates cross-stitches into peripheral sutures and reduces the amount of exposed suture on the tendon surface. Thirty-three fresh pig flexor tendons were divided equally into three groups and repaired with cross-stitch, embedded cross-stitch, or modified Halsted sutures. The tendons were tested in an Instron tensile machine to assess the mechanical performance of these repairs. With an identical number of strands across the repair site, the gap formation and ultimate forces of the embedded cross-stitch method were statistically greater than those of the cross-stitch and modified Halsted methods. The embedded cross-stitch method also had significantly greater stiffness and energy to failure than the cross-stitch method. The embedded cross-stitch method, with little suture exposure on the tendon and sufficient strength, presents an alternative to the current cross-stitch peripheral repair.     

Comparison of modified Kessler tendon suture at different levels in the human flexor digitorum profundus tendon and porcine flexors and porcine extensors: an experimental biomechanical study

This study compared the biomechanical behaviour of repairs in the human flexor digitorum profundus tendon in zones I, II and III with repairs of different segments of the porcine flexor tendon of the second digit and the extensor digiti quarti proprius tendon, in order to assess the validity of porcine tendons as models for human flexor tendon repairs. These porcine tendons were selected after comparing their size with the human flexor digitorum profundus tendon. The tendon repairs were done in three segments of each porcine tendon and repairs in the human tendons were done in zones I,II and III. Ten tendons in each group yielded a total of 90 specimens. A modified Kessler repair was done with 3-0 coated braided polyester suture and subjected to uniaxial tensile testing. In human flexor tendons, the ultimate force was higher in zones I and II than in zone III. The porcine flexor digitorum profundus tendon from the second digit and the proximal segment of the extensor digiti quarti proprius tendon behaved similarly to the human flexor tendon in zone III and can be considered as surrogates for the human flexor tendon.     

Effect of circumferential sutures on tensile and gap strength of repaired canine flexor tendons

Sixty-four dog cadaver flexor digitorum profundus tendons in zone 2 were lacerated and repaired with a simple or a cross-stitch peripheral circumferential suture in combination with two-, four-, or six-strand core sutures. The tensile and gap strengths were compared. The range of tensile strengths with the cross-stitch circumferential suture in combination with various core suture techniques (4.28–9.37 kgf) was significantly higher than the range of values for the simple circumferential suture and similar core suture techniques (1.70–4.98kgf). The tensile strength with two-strand core suture plus the cross-stitch circumferential suture (5.29kgf) was as great as that of the six-strand core suture plus the simple circumferential suture (4.98kgf). Increased gap strength values were also observed with the cross-stitch (1.11–3.19 kgf) compared to the simple (0.84 to 1.76 kgf) circumferential sutures. The cross-stitch circumferential suture had a mechanical advantage in flexor tendon repair compared to the simple circumferential suture. No benefits in any form have been received or will be received from any commercial party related directly or indirectly to the subject of this article. This study was supported in part by Grant No. 15953 from the Shriner's hospital for Crippled Children (USA)     

Biomechanical evaluation of the Pulvertaft versus the 'wrap around' tendon suture technique

The purpose of this study was to compare the biomechanical properties of a novel wrap around tendon repair method with those of the standard Pulvertaft technique used for tendon reconstructions. Seventy-two porcine extensor tendons were used to create 36 reconstructions in six sets of six repairs, each using one of the two surgical techniques with differing lengths of the reconstructions. All the reconstructions were tested in?vitro by cyclic tensile loading, resulting in the time-zero strength. When only the size of the repair and the strength were compared, and length of the reconstruction was not taken in consideration, the 'wrap around' reconstructions were of similar strength but less bulky than the Pulvertaft repairs. In conclusion, the 'wrap around' technique gives a thinner reconstruction which is as strong as, or stronger than the Pulvertaft technique, depending on the amount of weaves.     

Flexor tendon-tendon sheath interaction after tendon grafting: a biomechanical study in a human model in vitro.

A human cadaver tendon sheath model was used to study the differences in excursion resistance of tendons that might be considered as sources of clinical tendon grafts. The flexor digitorum profundus and superficialis tendons, the extensor indicis proprius tendon used in its normal proximal-distal orientation, the extensor indicis proprius tendon used in a reversed distal-proximal orientation, and the palmaris longus tendon were studied in 7 fingers. The intrasynovial tendons (the flexor digitorum profundus and superficialis tendons and the reversed extensor indicis proprius tendon) produced less excursion resistance (p < .05) than the extrasynovial tendons (the normally oriented extensor indicis proprius tendon and the palmaris longus tendon). In contrast to studies measuring resistance against a single pulley, resistance within a complete tendon sheath may be affected by contact with other structures, particularly in joint extension.     

Biomechanical analysis of a step-cut technique for flexor tendon repair.

We compared the strength of a new step-cut technique for flexor tendon repair with that of the widely used Kessler-Tajima technique, giving special attention to the relative contributions of the core and epitendinous sutures. 36 flexor digitorum profundus tendons from human cadavers were used. Corresponding digits from the same donor were paired, and the two tendons of each pair were placed in the Kessler-Tajima and step-cut groups, respectively. Each group had three subcategories of repair: (1) core repair alone; (2) epitendinous repair alone; and (3) full repair. In the Kessler-Tajima repair, the core stitch contributed more to ultimate tensile strength, while the epitendinous stitch contributed more to gap formation resistance. In the step-cut repair, however, the epitendinous stitch contributed more to both measures of strength. The full step-cut repair was 65% stronger in resisting gap formation and had 84% more ultimate tensile strength than the full Kessler-Tajima repair. We attribute the greater strength of the step-cut repair to the additional number of epitendinous loops, which lie perpendicular to the long axis of the tendon.     

Biomechanical study on the suture strength of ligament in cruciate ligament reconstruction

Objective: To test the suture strength on the tendon or ligament end and evaluate the stitch in the reconstruction of cruciate ligament and its clinical application. Methods: Twenty-four specimens of patellar tendon with free ends were divided into 3 groups: Group I (3 Krackow stitches ), Group H ( 2 Krackow stitches ) and Group HI (2 Krackow stitches with the first stitch passing through the tendon tissue as a modified Krackow stitch).These 3 groups were further divided into 6 subgroups according to different suture materials, No 1 Ethilon or stainless steel wire (φ = 0.4 mm ). Tensile test was undertaken to f‘md out the least stitches with efficient suture pattern. Results: Two Krackow locking stitches had stronger strength than 0.4 mm-diameter stainless steel wire. The fixation strength of 2 stitches with No 1 Ethilon was more than 80 N, superior to the failure strength of the material itself. The same strength was maintained if the first stitch was across the tendon tissue transversely. There was no statistically significant difference in the suture strength between 2 and 3 Krackow locking stitches. Conclusions: The suture strength is greater than the failure strength of the suture material. Less suture exposure can be achieved when the first stitch is across the tendon tissue while maintaining a comparable strength to other sutures. To attain higher suture strength, stronger materials or multiple strands rather than more stitches are preferred. Therefore, a rapid early rehabilitation of range of motion (ROM) is possible and reliable in practice.     

卡锁环肌腱缝合法在伸指肌腱修复中的作用

目的：以改良Kessler法作为参照，研究卡锁环缝合法在修复伸指肌健中的抗拉力作用效果。方法：术中随机对50根断裂伸指肌腱平均分为两组，分别采用卡锁环（Locking loop）法和改良Kessler法进行修复，然后进行屈指活动抗拉力测试观察。结果：两组肌腱出现拉松和缝线拉脱的例数分别为：卡锁环法组2，0，改良Kessler组7，5。结论：卡销环法抗拉力作用显，适合于伸指肌腱的修复。     

膝十字韧带移植重建术中韧带末端缝合固定的生物力学研究及临床应用

目的研究膝十字韧带移植重建术中韧带末端缝合固定的方法及固定强度。方法将24条带髌骨的髌韧带标本分为3组,对其末端分别采用Krackow双锁边缝合法缝合2针、3针,缝合材料为Ethilon缝线及直径0.4mm钢丝,对样本分别进行拉伸力学检测以比较强度,探讨最佳的缝合针数和方法并应用于临床。结果Krackow双锁边缝合法缝合2针,缝合点固定强度超过钢丝材料的破坏强度;用缝线缝合2针的强度达到80N以上,超过缝线材料的破坏强度;将第一针贯穿韧带缝合,不降低固定强度。根据实验结果,将改良的Krackow双锁边缝合法临床应用17例,加速了术后早期康复,取得良好效果。结论Krackow双锁边缝合法缝合2针或3针的固定强度差别不大,差异无显著性意义,第一针贯穿韧带,可减少缝线裸露但不降低固定强度,均超过缝合材料破坏强度。若想增加固定强度,应从改进缝合材料强度和增加缝线数目着手,此缝合法临床应用可加速康复,固定可靠。