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At least 91 records · Page 5Linked to original sources
PubMed1997

Flexor tendon graft for late management of isolated rupture of the profundus tendon.

BACKGROUND: Late management options for the neglected flexor tendon injury include arthrodesis, tenodesis, tendon advancement, or tendon grafting. Although the clinical outcomes of single-stage and second-stage flexor tendon grafting are satisfactory, many controversies exist. The present study retrospectively reviewed the clinical outcomes of flexor tendon grafting for 15 patients with isolated profundus rupture. METHODS: Fifteen cases of isolated rupture of the flexor profundus tendon were treated by free tendon graft. The age of the patients ranged from 13 to 21 years (mean, 17.3 years). The time from injury to operation ranged from 4 to 14 weeks (mean, 8.3 weeks). All tendon grafts were passed through the intact superficialis tendon to repair the injured profundus tendon. These patient were followed up from 14 to 62 months after treatment mean, 31.3 months). RESULTS: All but one patient had less than 3.2 cm of flexion from fingertip to mid-palmar crease. Fourteen patients achieved active distal interphalangeal (DIP) joint flexion of more than 20 degrees. Four patients developed extension loss of the proximal interphalangeal (PIP) joint of more than 30 degrees after surgery. The mean active flexion after surgery was 33 degrees (range, 15-55 degrees) for DIP joints and 91.3 degrees (range, 80-100 degrees) for PIP joints. Three patients had combined extension loss of PIP and DIP joints of more than 40 degrees for the index and middle fingers. Twelve patients (80%) had satisfactory results, whereas treatment of the other 3 patients was considered unsuccessful. CONCLUSION: Flexor tendon graft can be used to reconstruct the isolated rupture of the profundus tendon and achieve satisfactory results for properly selected patients.

Adolescent↗
PubMedDate not supplied

Ex vivo strength comparison of bioabsorbable tendon plates and bioabsorbable suture in a 3-loop pulley pattern for repair of transected flexor tendons from horse cadavers.

OBJECTIVE: To test the failure strength and energy of 2 bioabsorbable implants applied to transected deep digital flexor tendons (DDFT) from adult horses. STUDY DESIGN: Ex vivo biomechanical experiment. SAMPLE POPULATION: Twelve pairs of deep digital flexor tendons harvested from the forelimbs of fresh equine cadavers. METHODS: Poly-L-lactic acid tendon plates were custom manufactured for application to the cylindrical surface of an adult equine deep digital flexor tendon. Twelve pairs of DDFTs were transected 2 cm distal to the insertion of the distal check ligament of the deep digital flexor tendon. One tendon of each pair was randomly selected for repair with a biodegradable plate or a 3-loop pulley method. Size 2 polydioxanone suture was used in both repairs. Repairs were tested in tension to failure, with peak force (PF) and total energy (TE) at repair failure recorded in Newtons (N) and Joules (J), respectively. A paired t-test was used for statistical evaluation with a significant level set at P< or = .05. RESULTS: Mean+/-SD PF for failure of plated tendons (1507.08+/-184.34 N) was significantly greater than for sutured tendons (460.86+/-60.93 N). TE was also significantly greater for failure of plated tendons versus sutured tendons. CONCLUSIONS: Plate fixation of transected cadaver DDFTs appear to have superior immediate failure strength than 3-loop pulley repairs. CLINICAL RELEVANCE: Whereas in vivo testing is required, a bioabsorbable tendon plate may provide initial increased strength to support tendon healing and decrease external coaptation requirements.

Absorbable Implants↗
PubMed2006

[Tendon holding capacities of the suture materials used in repairing Achilles tendon rupture].

OBJECTIVES: We evaluated tendon holding capacities of suture materials that are commonly used in repair of Achilles tendon ruptures. METHODS: Achilles tendons of 60 sheep were removed by incisions 2-cm proximal to the calcaneal insertion and 1-cm distal to the musculotendinous junction. The tendons were randomly divided into six groups and sutures were placed with the Kessler technique at the distal end of the tendons using one of the following suture materials: 2 polydioxanone (PDS), 1 PDS, 2 Vicryl, 1 Vicryl, 2 Ethibond, and 1 Prolene. The distal end of the suture material was left free. Each specimen was mounted in an Instron machine, with the tendon being placed proximally and the suture material distally. The system was loaded with a displacement rate of 20 mm/min. RESULTS: Failure of all the specimens was due to pull-out of the suture material through the tendon. There were no failures due to suture breakage. The highest and the lowest tendon holding capacities were found with 2 PDS and 2 Ethibond sutures, respectively. CONCLUSION: Following Achilles tendon repair, the healing period, in particular the first three weeks, is precarious for pull-out of the suture material through the tendon. Thus, tendon holding capacity of the suture material is an important factor for the strength of the repair. Among the tested suture materials, 2 PDS was found to have the highest tendon holding capacity.

Achilles Tendon↗
PubMed1997

A low profile human tendon force transducer: the influence of tendon thickness on calibration.

An in vitro calibration method for human tendon force transducers using tendon thickness to predict the calibration factor has been previously proposed (An et al., 1990, J. Biomechanics 23, 1269-1271). However, changes in the calibration factor due to changing tendon geometry during repeated tendon loading are unknown. A new, low-profile transducer design that measures tendon thickness in the transducer, in situ, is developed. An empirical model estimating the transducer's calibration factor is developed using data from in vitro tension testing of 12 fresh frozen human finger flexor tendons. Each tendon is preseated with ten loading cycles before data collection. Using tendon thickness, the model predicts the measured calibration factor to within 0-15% (average 6%). During repeated loading of an in vitro tendon, the calibration factor changes 15% over the first ten cycles (0-50 N) due to the observed changing tendon thickness. After the first ten loading cycles the variability of the calibration factor is reduced to less than 1% for the next three loading cycles. Hence this new, modified in vitro calibration procedure with tendon preseating reduces the cycle-to-cycle variability caused by the associated change in the tendon thickness.

Calibration↗
PubMed1996

Ultrasonic properties of tendon: velocity, attenuation, and backscattering in equine digital flexor tendons.

Ultrasound velocity, attenuation, and backscattering were measured in vitro in samples of equine digital flexor tendon sandwiched between plane, parallel rexolite buffer rods. The buffer rods were coupled to transmitting and receiving transducers (nominally 10 MHz) mounted in-line and facing one another on the jaws of a digital caliper. Six superficial digital flexor (SDF) tendons and six deep digital flexor (DDF) tendons were measured in three orthogonal directions: along the long axis of the tendon (D), and across the tendon in the dorsal-volar (C), and lateral (L) directions. Substantial anisotropy was apparent in all the measured properties. The velocity data, which in both tendons showed a higher velocity along the fibers than across (e.g., in the DDF tendon at 0 degrees C: 1713 +/- 9 m/s in the D direction compared with 1650 +/- 5 m/s in the C direction), were consistent with a composite comprising stiff fibers embedded in a less stiff medium of lower speed. The apparent backscattering coefficient adjusted for the tissue's frequency-dependent attenuation (e.g., in the C direction of the DDF tendon at 0 degrees C: 7.4 x 10(-3) cm-1 sr-1), was independent of frequency in both transverse directions and larger than that measured along the long axis of the tendon (e.g., in DDF tendon at 0 degrees C: 1.2 x 10(-3) cm-1 sr-1 at 7 MHz) in which direction the apparent backscattering coefficient increased with frequency as f4.0 +/- 1.2. The frequency-independent backscattering was thought to be due to specular reflection from the boundaries between the fascicles, i.e., the bundles of fibers making up the tendon, while backscattering along the axis was due to structures of unknown origin, but of a size much smaller than 45 microns. Attenuation of ultrasound directed along the fibers was higher than that across (at 7 MHz in DDF tendon at 0 degrees C: 58 dB/cm in the D direction compared with 11.3 dB/cm in the C direction). Calculations indicated that the attenuation was primarily caused by absorption rather than scattering.

Animals↗
PubMed2003

[Morphological changes of collagen fibrils during the formation of autogenous tendon induced by human hair keratin artificial tendon].

OBJECTIVE: To observe the morphological changes of collagen fibrils during the formation of autogenous tendon induced by human hair keratin (HHK) artificial tendon. METHODS: Rabbit models of injured tendon were established in which implantation of HHK artificial tendon was performed to observe the formation of autogenous tendon under light microscope and electron microscope at 3, 6, 9, 12 and 16 weeks after HHK implantation. RESULTS AND CONCLUSION: During autogenous tendon formation induced by HHK artificial tendon, the tendon cells of the impaired end of the tendon and beneath the tendon membrane dedifferentiate and are capable of collagen secretion, followed by the formation of typesI,II and III collagen fibrils, and eventually, the majority of the tendon cells disappear with the collagenization of the tendon.

Animals↗
PubMed1996

The tendon defect after anterior cruciate ligament reconstruction using the midthird patellar tendon--a problem for the patellofemoral joint?

Retrospective clinical and radiographic evaluation was performed on 41 patients seen at the Salzburg General Hospital Department of Traumatology on average 2 years following ACL reconstruction. In 26 patients (61%) clinical examination revealed pain trigger points over the donor site of the midthird patellar tendon and in the patellofemoral joint. Functional pain during kneeling activities was observed in 19 patients (46%). Objective measurement of the length of the patellar tendon in bilateral radiographs demonstrated exactly equal patellar tendon length in both knees in 11 patients (27%). The radiographs showed tendon shortening following harvesting of the midthird patellar tendon by 1-3 mm in 7 patients (17%), by 4-6 mm in 16 (39%), and by 6-9 mm in 7 (17%). Average length change in the patellar tendon on the donor side was -3 mm, representing a patellar tendon shortening of 9.8%. On the basis of the OAK score, however, good and very good results were recorded in 33 patients (80%). On the whole, these good overall results were compromised only be patellar tendon defect morbidity. In addition to the local scarring problems at the donor site, shortening of the patellar tendon was observed with changes to patella position and interference with the mechanics of the patellofemoral joint. Tendon shortening can be explained on the basis of cicatricial contraction in the process of autorepair to the tendon defect. The problems affecting the patellofemoral joint are inherent in the therapy and must be treated as a negative factor. In the case of patients whose work requires mainly a kneeling position and those who make significant functional demands of the extension system of the knee, a critical assessment is required of the use of the midthird patellar tendon for anterior cruciate ligament reconstruction.

Adult↗
PubMed1994

Tendon repair using flexor tendon splints: an experimental study.

Mechanical strength of tendon repair using Dacron tendon splints across the laceration site were evaluated in human cadaver profundus tendons; the splints were placed both on the dorsal surface and internally within the tendon substance. Comparison was made to modified Kessler, Becker, and Savage repair techniques. Ultimate tensile strength was 2.55 kgf for the Kessler, 3.00 kgf for the Becker, 8.29 kgf for the Savage, 8.46 kgf for the internal tendon splint, and 8.10 kgf for the dorsal tendon splint; the Savage and both Tendon Splints techniques had significant higher tensile strength than the Kessler and Becker. Gap strength was 1.44 kgf for the Kessler, 2.22 kgf for the Becker, 2.45 kgf for the Savage, 2.05 kgf for internal tendon splint, and 3.15 kgf for the dorsal tendon splint. The dorsal tendon splint technique showed significant greater gap strength than the other four techniques. There was no significant difference in the magnitude of the gap during cyclic testing of these techniques; however, three of seven Kessler repairs failed and one of six Becker repairs failed. The results of these cadaver studies suggest that both tendon splint repair techniques are comparable to the Savage and may have sufficient strength to allow postoperative active motion against minimal resistance. Further in vivo testing is in order.

Cadaver↗
PubMed2005

A comparison of bone-patellar tendon-bone and bone-hamstring tendon-bone autografts for anterior cruciate ligament reconstruction.

BACKGROUND: Most of the previous comparative studies between patellar tendon and hamstring tendon anterior cruciate ligament grafts compared grafts of different constructs fixed with different methods. PURPOSE: To compare patellar tendon and hamstring tendon grafts with the same fixation method used to reconstruct the anterior cruciate ligament. STUDY DESIGN: Randomized controlled trial; Level of evidence, 1. METHODS: During the reconstructive procedure, the hamstring tendon graft was prepared as a bone-hamstring-bone graft; both bone-patellar tendon-bone and bone-hamstring-bone grafts were fixed with interference screws. Eighty consecutive patients who underwent anterior cruciate ligament reconstruction were randomly assigned to either bone-patellar tendon-bone or bone-hamstring-bone groups. Follow-up examinations were performed for at least 5 years postoperatively. Seventy-two of the 80 patients (37 patients in the bone-patellar tendon-bone group and 35 in the bone-hamstring-bone group) were evaluated, with a mean follow-up period of 87.0 and 80.8 months, respectively. Follow-up examinations were performed using the International Knee Documentation Committee knee ligament standard and subjective knee forms. RESULTS: The mean KT-1000 arthrometer evaluation results showed no significant difference between the bone-patellar tendon-bone and bone-hamstring-bone groups (1.2 +/- 2.1 mm and 1.7 +/- 1.4 mm, respectively; P = .24). However, symptoms related to graft harvest (anterior kneeling pain) were more frequently observed in the bone-patellar tendon-bone group, and unsatisfactory results were correlated with severe kneeling pain in 3 patients from this group (P = .0056). Significant hamstring muscle weakness without complaint of functional deficit was found in the bone-hamstring-bone group (P = .0045). CONCLUSION: Bone-hamstring-bone grafts were shown to reduce the risk of problems at the graft harvest site compared to bone-patellar tendon-bone grafts, with comparable results in the remaining clinical parameters tested.

Adolescent↗
PubMed1999

Treatment of posterior tibial tendon dysfunction with tendon procedures from the posterior muscle group.

The use of tendons from the posterior muscle group, specifically the FDL, as a means to repair PTTD is useful for the early stages of the deformity. Once the patient has reached the later stages and the foot becomes rigidly deformed with loss of the medial longitudinal arch, however, any attempt to reconstruct the area with tendon work alone fails. Tendon repair, tenodesis, and tendon transfer are attractive treatment options for PTTD, but care should be taken in choosing the correct patient for these procedures. Some authors note that side-to-side tenodesis does not address arch realignment. Other procedures combined with tendon work perhaps can help to reduce the shortcomings of isolated tendon procedures. Subtalar joint arthroeresis in combination with the tendon work seems to solve this problem. The authors have begun to explore this option and have performed this procedure on some patients. It is premature to address the effectiveness of this combined procedure. Similarly, tendon procedures augmented with other soft-tissue-type procedures also remains an option and is mostly ignored in the medical literature. Deland et al experimented with reconstruction of the spring ligament in a cadaver study, and believed that it should be considered in any reconstructive flatfoot surgery. Likewise, Myerson used some capsular reefing of the talonavicular joint in his tendon reconstruction to aid the correction of the forefoot-to-rearfoot relationship. The treatment of the patient with PTTD remains driven by the surgeon's preference, with little scientific research to guide him or her. There is much controversy regarding the efficacy of tendon procedures and the specific surgical technique of each procedure. Some variations may prove inconsequential, whereas others may prove revolutionary. The authors believe that the use of the tendon work as a means of treatment for PTTD is viable alone or in combination with other procedures. Much research is still needed to identify the best technique for each stage of the deformity. Wiekland has attempted to do this, but unfortunately has not offered any long-term follow-up to justify his treatment algorithms. Foot and ankle specialists should strive for clinical research, which allows better understanding of the appropriate treatment options for each progressive stage of PTTD.

Ankle↗
PubMed1992

[An experimental study on the healing of the digital flexor tendon and restoration of gliding function--Part XII--Shortening and changes of physical properties of morphological and functional changes of severed tendons].

The present investigator has sequentially studied gross, histological findings and serial changes of physical properties of severed flexor tendons in young chickens in order to provide information on a primary direct suture of the tendon. In these chickens, the distal portion of the profundus tendon of the third toe was severed then these chickens were divided into two groups. In group 1, the tendon was left in situ (vincula intact). In group 2 (vincula disrupted), the tendon was pulled out proximally to its trifurcation in order to disrupt the vincular system and returned to the original sheath. In group 1, shortening and physical changes were limited to the portion distal to the anchoring of the vinculum and the physical properties were well preserved and remained almost normal. In group 2, the tendon became short and thick. The physical properties were also degenerated markedly. From these results, it was concluded that the vincula greatly effects changes of the physical properties of severed flexor tendons. When vincula was not ruptured, the physiological properties remained almost unchanged resulting in primary suture. When vincula was ruptured and also marked shortening of tendon occurred, primary suture was completed 3 weeks from the restoration of shortened tendon and 2 weeks from degenerating shortened tendon. Combined the above results with such histological changes as thickening of epitenon and tendon and also adhesions, an ideal primary suture appeared to be within one week after severance.

Animals↗