Research into tendon stem/progenitor cells / 中华创伤骨科杂志

Severe tendon injury will impair the mobility and quality of life of ordinary patients and come as a major blow to the career of professional athletes. As the current surgical treatment of tendon injury cannot achieve satisfactory results, the injury is still challenging for clinicians. The discovery of tendon stem/progenitor cells (TSPCs) and the continuous in-depth study of them provide a new direction for tendon repair and regeneration, and promote the continuous development of tendon tissue engineering. This article systematically summarizes the characteristics, aging, isolation and culture of TSPCs in tendon repair, and progress in their related applications as well. The research direction of TSPCs is also analyzed and prospected.

The Effect of Doxycycline on Achilles Tendon Repair in a Rat Model

@#Introduction: Doxycycline is a commonly used antibiotic that is also a potent inhibitor of matrix metalloproteinase (MMPs). The use of doxycycline in repairing tendon lesions has been previously investigated and conflicting findings have been reported on its effectiveness. In this study, we sought to evaluate the effects of exposure to doxycycline on Achilles tendon repair. Materials and Methods: Twenty healthy rats of the same breed and gender were randomly assigned to two groups of sham, and Doxycycline group therapy. The rats underwent a surgical intervention in which a 2mm incision was performed on the lateral sides of the right Achilles tendons. The treatment group received oral gavage administrations of 50mg/kg/day of doxycycline for 30 days. After this duration, tissue samples were taken from the site of the injuries, which were then histologically evaluated for alignment of the collagen fibres, inflammation reaction, cellular density, and fibroblastic activity. Results: The histological assessment of the tissue samples, revealed significant changes in the repaired tissues of the treatment group in comparison to the sham group; namely more irregularity in the alignment of the collagen fibres, increased cellular density, and increased fibroblastic activity. However, only the alignment of the collagen fibres reached the statistical significance. Conclusion: The results of this study indicate that exposure to doxycycline may result in the improvement of repair of the Achilles tendon injuries, especially collagen filament integrity

Evaluación biomecánica de reparación de roturas del tendón patelar: ¿es mejor doble Bunnell paralelo o perpendicular? / Biomechanical comparison of two patellar tendon repair techniques: is double Bunnell better parallel or perpendicular?

INTRODUCCIÓN: En tendón patelar, se ha probado que agregar un segundo punto Bunnell dispuesto perpendicular al punto clásico, es más resistente, sin embargo, esa técnica dispuesta paralelamente no ha sido evaluada. PROPÓSITO: Comparar la resistencia entre la técnica doble Bunnell dispuesta en perpendicular y en paralela. MÉTODO: 28 muestras frescas de tendones patelares porcinos, asignadas aleatoriamente a 2 grupos. Grupo 1: 14 muestras reparadas con doble Bunnell perpendicular. Grupo 2: 14 muestras reparadas con doble Bunnell paralelo. Todas realizadas con la misma sutura ultrarresistente. Con una máquina computarizada de tracción, se aplicó tracción axial continua hasta el fallo. Se registró el punto máximo de fallo (PMF) y el modelo de falla mecánica. Análisis estadístico con t-student (p < 0,05). RESULTADOS: Grupo 1: PMF = 342 ± 50,7 Newton. Todas las muestras sufrieron avulsión central, preservando fibras perimetrales. Grupo 2: PMF = 358 ± 34,1 Newton. Todas las muestras sufrieron un split longitudinal del tendón. Sin diferencia significativa entre los grupos (p = 0,340). CONCLUSIÓN: Este estudio no demostró diferencias significativas en la resistencia de una técnica de doble Bunnell paralelo versus perpendicular, aplicada en un modelo experimental de tendón patelar. RELEVANCIA CLÍNICA: Ambas técnicas tienen propiedades biomecánicas similares y dejan un remanente de tejido tendinoso luego del fallo que permitiría una segunda reparación directa, potencialmente sin necesidad de requerir el uso de injertos.

INTRODUCTION: In the patellar tendon, a second Bunnell stitch arranged perpendicular to the classic configuration has increased the resistance of the repair, however, the effect of a double parallel technique has not been evaluated. PURPOSE: To compare the resistance between a patellar tendon repair with Double Bunnell technique arranged in parallel or perpendicular. METHOD: 28 fresh porcine patellar tendon samples were randomly assigned to 2 groups. Group 1: 14 samples repaired with a perpendicular Double Bunnell technique. Group 2: 14 samples repaired with a parallel Double Bunnell technique. All performed with the same ultraresistant suture. The samples were fixed to a computerized traction machine, applying continuous axial traction, until failure. The ultimate failure point (UFP) and the mechanical failure model were recorded. Statistical analysis included student́s t-test (p < 0.05). RESULTS: Group 1: UFP = 342 ± 50.7 Newton. All samples suffered a central avulsion, preserving the perimetral tendon fibers. Group 2: UFP = 358 ± 34.1 Newton. All samples suffered a longitudinal split of the tendon. No significant difference was found among groups (p = 0.340). CONCLUSION: This biomechanical study showed no significant differences in the strength of a tendon repair using a parallel versus a perpendicular double Bunnell technique. CLINICAL RELEVANCE: Both techniques have similar biomechanical properties and leave a remnant of tendon tissue after the failure that would allow a second direct repair, potentially without requiring the use of grafts.

A Biomechanical Analysis of the Interlock Suture and a Modified Kessler-Loop Lock Flexor Tendon Suture

OBJECTIVE: In this work, we attempted to develop a modified single-knot Kessler-loop lock suture technique and compare the biomechanical properties associated with this single-knot suture technique with those associated with the conventional modified Kessler and interlock suture techniques. METHODS: In this experiment, a total of 18 porcine flexor digitorum profundus tendons were harvested and randomly divided into three groups. The tendons were transected and then repaired using three different techniques, including modified Kessler suture with peritendinous suture, interlock suture with peritendinous suture, and modified Kessler-loop lock suture with peritendinous suture. Times required for suturing were recorded and compared among groups. The groups were also compared with respect to 2-mm gap load, ultimate failure load, and gap at failure. RESULTS: For tendon repair, compared with the conventional modified Kessler suture technique, the interlock and modified Kessler-loop lock suture techniques resulted in significantly improved biomechanical properties. However, there were no significant differences between the interlock and modified Kessler-loop lock techniques with respect to biomechanical properties, gap at failure, and time required. CONCLUSIONS: The interlock and modified Kessler-loop lock techniques for flexor tendon sutures produce similar mechanical characteristics in vitro.

Biomechanical comparison of the four-strand cruciate and Strickland techniques in animal tendons

OBJECTIVE: The objective of this study was to compare two four-strand techniques: the traditional Strickland and cruciate techniques. METHODS: Thirty-eight Achilles tendons were removed from 19 rabbits and were assigned to two groups based on suture technique (Group 1, Strickland suture; Group 2, cruciate repair). The sutured tendons were subjected to constant progressive distraction using a universal testing machine (Kratos®). Based on data from the instrument, which were synchronized with the visualized gap at the suture site and at the time of suture rupture, the following data were obtained: maximum load to rupture, maximum deformation or gap, time elapsed until failure, and stiffness. RESULTS: In the statistical analysis, the data were parametric and unpaired, and by Kolmogorov-Smirnov test, the sample distribution was normal. By Student's t-test, there was no significant difference in any of the data: the cruciate repair sutures had slightly better mean stiffness, and the Strickland sutures had longer time-elapsed suture ruptures and higher average maximum deformation. CONCLUSIONS: The cruciate and Strickland techniques for flexor tendon sutures have similar mechanical characteristics in vitro. .

Analyses of Timing of Single Heel Raise and Muscle Power after Achilles Tendon Repair / 대한정형외과학회잡지

PURPOSE: The purpose of this study is to analyze the progress of muscle rehabilitation for patients with acute Achilles tendon rupture, who underwent Achilles tendon repair, checking capable time of single heel raise and isokinetic plantar flexion power. MATERIALS AND METHODS: From March 2006 to June 2011, 42 of 81 patients were excluded and the other 39 patients, who underwent surgery due to acute Achilles tendon rupture in our institute, were enrolled in this study. The operation and rehabilitation were constantly performed according to the author's method. Isokinetic plantar flexion power was measured at three months post-operation, capable time of single heel raise was assessed, and clinical results of the last follow up were measured and analyzed. RESULTS: Single heel raise was possible at an average of 14 weeks and three days, and repetitive single heel raise more than 10 times was possible at an average of 20 weeks. The peak torque of 30degrees/s plantar flexion was mean 69 Nm. The peak torque of 120degrees/s was 41 Nm. Assessment at three months post-operation showed 69% power, compared to the contralateral leg. The group of patients who were able to perform single heel raise within three months, showed better Achilles tendon total rupture score and foot and ankle outcome score at last follow up, and showed better plantar flexion power at three months post-operation. CONCLUSION: At the last follow up, we can expect better clinical results and muscle power in patients who are able to perform single heel raise early treatment of acute Achilles tendon rupture.

The Effects of Electroacupuncture on Achilles Tendon Rupture Repair in Rats / 日本温泉気候物理医学会雑誌

<B>Objective:</B> Histological and dynamic assessment to determine the effect of electroacupuncture on tendon repair in a rat model of Achilles tendon rupture.<br><B>Methods:</B> Sixty 12-week old male Wistar rats were used to prepare an Achilles tendon rupture model. The rats were randomly divided into an electroacupuncture group (EA group) and a control group. The EA group rats were restrained, and under mild anesthesia two acupuncture needles were inserted with the tip of one touching the ruptured tendon on the outer side, and the tip of the other touching it on the inner side. Using the needle on the inner side as the cathode and the needle on the outer side as the anode, electroacupuncture with intermittent direct current was performed (pulse width: 5 ms, stimulation frequency: 50 Hz, stimulation strength: 20 μA, stimulation time: 20 min). Electroacupuncture was performed every day from the day after model preparation until the days of assessment. Rats in the control group were retrained and mildly anesthetized only. Samples from the region of interest were taken 7 and 10 days after model preparation to assess tendon repair. Tissue imaging was performed, using HE staining to measure total cell count and immunohistochemical staining to measure the number of cells positive for TGF-<i>β</i>1 and b-FGF. Tension tests were also performed 10 days after model preparation to measure the maximum failure load of repaired tendon.<br><B>Results:</B> HE staining showed a significant difference between the assessment results on different days and between the two groups. A clear increase in the cell count was observed in the EA group (day 7: p<0.05, day 10: p<0.001). Immunostaining showed the strongest expression of both TGF-<i>β</i>1 and b-FGF inthe EA group 7 days after model preparation, and other significant difference were observed (TGF-<i>β</i>1: day 7 EA group vs. day 10 EA group: p<0.001, vs. day 7 control group: p<0.0001, vs. day 10 control group: p<0.0001) (b-FGF: day 7 EA group vs. 10 EA group: p<0.001, vs. day 7 control group: p<0.0001, vs. 10 day control group: p<0.0001). Maximum failure load of repaired tendon 10 days after model preparation was significantly higher in the EA group (p<0.01).<br><B>Discussion:</B> Examination in the early stages after Achilles tendon rupture showed an increased cell count and increased expression of growth factors in the EA group, as well as increased tendon strength. These results indicate the beneficial action direct current electroacupuncture has on cell growth and growth factor expression during tendon repair, and suggest it also increases the dynamic strength of repaired tendon. Direct current electroacupuncture is thought to be possibly useful method for promoting tendon repair.

The Effects of Electroacupuncture on Achilles Tendon Rupture Repair in Rats / 日本温泉気候物理医学会雑誌

Objective: Histological and dynamic assessment to determine the effect of electroacupuncture on tendon repair in a rat model of Achilles tendon rupture. Methods: Sixty 12-week old male Wistar rats were used to prepare an Achilles tendon rupture model. The rats were randomly divided into an electroacupuncture group (EA group) and a control group. The EA group rats were restrained, and under mild anesthesia two acupuncture needles were inserted with the tip of one touching the ruptured tendon on the outer side, and the tip of the other touching it on the inner side. Using the needle on the inner side as the cathode and the needle on the outer side as the anode, electroacupuncture with intermittent direct current was performed (pulse width: 5 ms, stimulation frequency: 50 Hz, stimulation strength: 20 μA, stimulation time: 20 min). Electroacupuncture was performed every day from the day after model preparation until the days of assessment. Rats in the control group were retrained and mildly anesthetized only. Samples from the region of interest were taken 7 and 10 days after model preparation to assess tendon repair. Tissue imaging was performed, using HE staining to measure total cell count and immunohistochemical staining to measure the number of cells positive for TGF-β1 and b-FGF. Tension tests were also performed 10 days after model preparation to measure the maximum failure load of repaired tendon. Results: HE staining showed a significant difference between the assessment results on different days and between the two groups. A clear increase in the cell count was observed in the EA group (day 7: p<0.05, day 10: p<0.001). Immunostaining showed the strongest expression of both TGF-β1 and b-FGF in the EA group 7 days after model preparation, and other significant difference were observed (TGF-β1: day 7 EA group vs. day 10 EA group: p<0.001, vs. day 7 control group: p<0.0001, vs. day 10 control group: p<0.0001) (b-FGF: day 7 EA group vs. 10 EA group: p<0.001, vs. day 7 control group: p<0.0001, vs. 10 day control group: p<0.0001). Maximum failure load of repaired tendon 10 days after model preparation was significantly higher in the EA group (p<0.01). Discussion: Examination in the early stages after Achilles tendon rupture showed an increased cell count and increased expression of growth factors in the EA group, as well as increased tendon strength. These results indicate the beneficial action direct current electroacupuncture has on cell growth and growth factor expression during tendon repair, and suggest it also increases the dynamic strength of repaired tendon. Direct current electroacupuncture is thought to be possibly useful method for promoting tendon repair.

The Integrity after Arthroscopically Repairing the Rotator Cuff Tendon Using the Suture Bridge Technique / 대한정형외과학회잡지

PURPOSE: We evaluated the integrity after repairing the arthroscopic rotator cuff tendon using the suture-bridge technique in patients with full thickness rotator cuff tendon tears. MATERIALS AND METHODS: Forty two (males: 14, females: 28) consecutive shoulders that were treated with this index procedure and that had magnetic resonance imaging (MRI) taken at a mean of 9 months postoperatively were enrolled to estimate the postoperative intregrity of the repair. The mean age was 57 years (range: 44-75 years) and the mean follow-up period was 14 months (range: 12-16 months). The follow up MRI was evaluated using the Sugaya classification for postoperative cuff integrity. The clinical outcomes were evaluated by using the University of California Los Angeles (UCLA) score, the Korean Shoulder Scoring System (KSS) and Visual Analogue Scale (VAS). Significance was set at p values < 0.05 RESULTS: In the 42 cases with follow up MRI, the cuff integrity was graded as type I in 10 cases, type II in 28, type III in 2, type IV in 1 and type V in 1 case. Out of the 39 cases having a medium to large tear, the type I and II cuff integrity was 92.3% and two patients had type III cuff integrity postoperatively, while the rate of retear was 33.3% (1 of 3) in the cases with massive tear. The overall rate of retear was 4.8%. For the intact postoperative repair rate, the precent of cases with fatty degeneration of grade 3 or less seen on preoperative MRI was 92.7%. For 41 patients, except for 1 case of type V retear, the UCLA score and the KSS score were significantly improved (p < 0.05) from 17.2 to 31.4 and from 58.2 to 90.8 on average, respectively, which showed satisfactory clinical outcomes regardless of the type of repair integrity. CONCLUSION: The arthroscopic suture-bridge technique resulted in intact repair integrity in 90.4% of the cases and improved clinical outcomes, so we think this technique is one of the reliable procedures for treating full-thickness rotator cuff tear.

Loop Suture Technique for Flexor Digitorum Profundus Tendon Repair in the Insertion Site

PURPOSE: In the case of repair for far distal parts of FDP (Flexor digitorum profundus) division, the method of either pull-out suture or fixation of tendon to the distal phalanx is preferred. In this paper, the results of a modified loop suture technique used for the complete division of FDP from both zone 1a and distal parts of zone 1b in Moiemen classification are presented. METHODS: From July 2006 to July 2009, the modified loop suture technique was used for the 10 cases of FDP in complete division from zone 1a and distal parts of zone 1b, especially where insertion sites were less than 1 cm apart from a tendon of a stump. In a suture technique, a loop is applied to each distal and proximal parts of tendon respectively. Core suture of 2-strand and epitendinous suture are done with PDS 4-0. Out of 10 patients, the study was done on 6 patients who were available for the follow-up. The average age of the patients was 49.1 years (in the range from 26 to 67). 5 males and 1 female patients were involved in this study. There were 3 cases with zone 1a and distal parts of zone 1b. The average distance to the distal tendon end was 0.6 cm. There were 5 cases underwent microsurgical repair where both artery and nerve divided. One case of only tendon displacement was presented. The dorsal protective splint was kept for 5 weeks on average. The results of the following tests were measured: active & passive range of motion, grip strength test, key pinch and pulp pinch test. RESULTS: The follow-up period on average was 11 months, in the range from 2 to 20 months. There was no case of re-rupture, but tenolysis was performed in 1 cases. In all 6 cases, the average active range of motion of distal interphalangeal joint was 50.8 degree. The grip strength (ipsilateral/contralateral) was measured as 88.7% and the pulp pinch test was 79.2% as those of contralateral side. Flexion contracture was presented in 2 cases (15 degree on average) and there was no quadrigia effect found. CONCLUSION: Despite short length of tendon from the insertion site in FDS rupture in zone 1a and distal parts of zone 1b, sufficient functional recovery could be expected with the tendon to tendon repair using the modified loop suture technique.

The Outcome after Arthroscopic Massive Rotator Cuff Repair according to the Repair Technique - Comparison of Tendon to Tendon Repair versus Tendon to Tendon and Bone to Tendon Repair - / 대한정형외과학회잡지

PURPOSE: We evaluated the functional outcomes after arthroscopic repair of a massive tear between the tendon to tendon (TT) repair technique and the tendon to tendon and bone to tendon (TTBT) repair technique. MATERIALS AND METHODS: From March, 2002 to January, 2007, 43 cases of arthroscopic massive rotator cuff repair were evaluated. 12 were repaired by TT repair and 31 were repaired by TTBT repair. At 1year follow-up, the functional results were assessed by the KSS, ASES, UCLA and Constant scoring system and the P-VAS (Pain visual analogue score). Post-operative integrity was evaluated by an ultrasound examination 6 months after the operation. RESULTS: In TTBT repair group, the improvement of the KSS, ASES, UCLA and Constant scores were 15.4 (50.5 to 65.9), 28 (55.6 to 83.6), 9.6 (21.1 to 30.7) and 11 (40.7 to 51.7), respectively. The pain improvement was 2.7 (VAS, 3.8 to 1.1) and the retear rate was 62%. In the TT repair group, the functional improvements were 29.2 (33.7 to 62.9), 42.7 (38.6 to 81.3), 13.4 (16.4 to 29.8) and 19.7 (29.6 to 49.3), respectively. The pain improvement was 4.2 (VAS, 5.5 to 1.3) and the retear rate was 75%. CONCLUSION: Arthroscopic repair of a massive tear could afford good functional results and pain relief in spite of a high retear rate. The TT repair technique was comparable to the TTBT repair technique.

The effects of intrinsic hand muscles training after digital flexor tendon repair: a clinical study / 中华物理医学与康复杂志

Objective To observe the effects of training on intrinsic hand muscles after digital flexor tendonrepair. Methods A total of 60 patients with digital flexor tendon repair were randomly assigned into an experimentgroup (n = 30) and a control group (n = 30). Patients in the experiment group received intrinsic hand muscles train-ing, in addition to the passive mobilization of the flexor tendons and active mobilization of the extensor tendons admin-istered to those in the control group. Minnesota manual dexterity test and Purdue pegboard test were adopted to as-sessment the outcome after 3 months of training. Results After 3 months of training, there were significant differ-ences between the two groups in terms of the results of Minnesota manual dexterity test and Purdue pegboard test( P < 0.01 ). Conclusion Intrinsic hand muscles training after digital flexor tendon repair can improve fine move-ment and coordination of hand.

Effect of Comprehensive Rehabilitation Therapy on Hand Function after Nerve and Tendon Repair in Wrist / 中国康复理论与实践

@#ObjectiveTo evaluate the efficacy of comprehensive rehabilitation therapy on hand function after nerve and tendon repair in wrist.Methods22 patients after nerve and tendons repaired in wrist accepted comprehensive rehabilitation treatment such as ultrasound therapy,electrical nerve stimulating and function training in the whole course.1,3,6 and 12 months after treatment,re-assessment of the involved hand were performed with digital movement,sensation function and Carroll upper extremities function test(UEFT).ResultsThe excellent rate of hand function recovery in all measures were 95% 12 months after treatment.ConclusionComprehensive rehabilitation therapy is effective significantly in the improvement of hand function after nerve and tendon repaired in wrist.

Effect of Comprehensive Rehabilitation Therapy on Hand Function after Nerve and Tendon Repair in Wrist / 中国康复理论与实践

@#ObjectiveTo evaluate the efficacy of comprehensive rehabilitation therapy on hand function after nerve and tendon repair in wrist.Methods22 patients after nerve and tendons repaired in wrist accepted comprehensive rehabilitation treatment such as ultrasound therapy,electrical nerve stimulating and function training in the whole course.1,3,6 and 12 months after treatment,re-assessment of the involved hand were performed with digital movement,sensation function and Carroll upper extremities function test(UEFT).ResultsThe excellent rate of hand function recovery in all measures were 95% 12 months after treatment.ConclusionComprehensive rehabilitation therapy is effective significantly in the improvement of hand function after nerve and tendon repaired in wrist.

Re-repture after primary flexor tendon repair of the hand / 대한정형외과학회잡지

In the treatment of flexor tendon injury of the hand, re-rupture after primary tendon repair is one of complications which occurs occasionally and so impose burden on both the patient and the surgeon. Authors experienced twelve cases of re-rupture after primary flexor tendon repair of 274 patients from Mar. 1989 to Mar.1996. The incidence of re-rupture after primary flexor tendon repair was 4.4% in author's series. One case happened with slip down injury, and in six cases re-rupture occurred during physical therapy with snapping click sound. However in five cases, the patients conldnt recognize any related causes. In majority of cases, re-ruptures were identified between three and five weeks after primary repair by the surgeon and the patient, so it could be suggested that the attention should be paid for the high possiblity of re-rupture during this period. Operative findings were the resorption and friability of repaired end with insecure suture fixation in two cases, rupture of suture material in four cases and loosening of the knot in six cases. From this study, the authors suggest the importance of knot, and recommend to make more than four knots on suture tie with attention to the tie direction, and advise careful physical therapy according to each patients' different situation. In the treatment of re-rupture, end-to-end re-anastomosis was available in seven cases (59%). In five cases (41%), tendon graft was needed. The clinical result of the re-rupture cases was evaluated by the Stickland evaluation method, and it was satisfactory in 67% of the patients who had the complication of re-rupture.

Experimental study of the Tensile Strength and Morphology on Tendon Repairs / 대한정형외과학회잡지

Many injuries of the hand have been occurred in these days because of frequent industrial hazards and frequent handling of tools in modern civilizing life. A voluminous amount of literature has been recently concerned with many problems and questions posed by tendon surgery. Many investigations have been devoted to discussion of suture materials, tendon suturing, grafting, healing, rate of healing, nutrition and related clinical and laboratory endeavors. Whatever the material, the aim of tendon suture is not only restoration of a strong mechanical union but also sliding function of the tendon. Thus the question has always been after what delay active mobilization can be allowed or encouraged. If immobilization allows fibroblasts to invade the tendon extremities and form a scar mass, its prolong leads to adhesion and loss of normal sliding. On the other hand, one can admit that early passive or active mobilization, even if only over a short distance may distend the adherences and transform them into a kind of mesotenon assuring a better sliding function. Before permiting early motion, several factors must be considered such as tensile strength of the suture material, holding power of the suture for the tnedon, bulkiness of the repair and stress that must be withstood. Thus it is the purpose of this study to analysis and comparing of tensile strength and morphological changes in the healing process of tendon tissues by different suturing methods. For this study deep flexor tendon on third toe of adult chicken with an initial weight of about 2Kg was used. The animals were divided into 4 sutured groups which including different suturing methods. Suturing methods used were interrupted suture, Bunnels lace suture, Kessler suture and end-weave anastomosis, which have been applied frequently in tendon surgery. All suture material used were the same size 4-0 Ethilon which has least tissue reaction but high strength. In the animals, after the sharp dissection of the distal portion of the deep flexor tendon on third toe, the tendon stumps were approximated and sutured by 4 different methods. Then a long leg cast in the position of flexion of the foot and ankle joint was applied. On operation day and fifth, tenth, fourteenth and twenty-first postoperative day; the animals were sacrified and the specimens were gained. The measurement of the tensile strength of the sutured tendon was performed through the use of force transducer with the recording of polygraph for permitting continous monitoring of a progressively increasing load until the failure of tendon repair. Specimens stained with hematoxylin-eosin and Massontrichrome stain were observed during 42 days after operation. The findings are as follows. 1. The tensile strength of sutured tendon groups using interrupted suture, Kessler suture, and end-weave anastomosis were reduced maximally on fifth postoperative fay and the tensile strength of Bunnel's lace suture group was reduced maximally on tenth postoperative day. Thereafter the strength was increased progressively on entire experimental groups. 2. The tensile strength of end-weave anastomosis group was the strongest among all experimental groups during experimental period. 3. Just after the repairs of injured tendon, the order of strength was Bunnel. Kessler and inerrupted suture but the strength was nearly approximated on 21st day. 4. The morphological healing process of interrupted and Kessler suture were better than that of Nunnel and end-weave suture. From these morphological and physical results, it is suggested that Kessler suture is better suturing method in tendon repair.