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PubMedDate not supplied

The effect of fibrin sealant on the strength of tendon repair of full thickness tendon lacerations in the rabbit Achilles tendon.

The influence of fibrin sealant on healing was investigated in the suture of Achilles tendons of 24 rabbits. The Achilles tendon cut through was anastomosed with a 4-0 prolene suture alone in one group and fibrin sealant was applied to the cut surfaces of the tendon prior to suture repair in the second group. After 17 and 27 days, five animals in each group were sacrificed. The repaired Achilles tendons were retrieved and the tensile strength of the repaired tendons measured using an Instron. One rabbit in each group was sacrificed at 3 weeks and 6 weeks and the repaired tendons were harvested and fixed for histologic study. At 17 and 27 days there was no significant difference between the tensile strength of the control and fibrin sealant groups. Histologically there was no distinct difference of the repair process of the tendons between the two groups.

Achilles Tendon↗
PubMed1976

[Experimental treatment of the lesion of the flexor tendon, by means of tendon sheath substitution using a vein and diphasic flexor tendon plasty. A new method for the reconstruction of peritendinous slipping surfaces (author's transl)].

In dog experiments the surgical treatment of flexor tendons is discussed by the authors: the lesions of the tendons have been repaired according to the method of Paneva-Holevitch, with biphasic flexor tendon plasty; and for the substitution of the injured tendon sheath and the peritendinous slipping surfaces freely transplanted, autologous vein has been used. In the preparations removed after 8 weeks both the macroscopic and microscopic examinations showed satisfactory vascularity of the vein used as tendon sheath and of the tendinous tissue, as well as normal tissue structure. Between the vein and the tendon only small, ligamentous adhesions developed. On the basis of the good results obtained in experimental examinations the method is applied by the authors also in men with satisfactory result.

Animals↗
PubMed2003

Anterior cruciate ligament reconstruction using semitendinosus and gracilis tendons, bone patellar tendon, or quadriceps tendon-graft with press-fit fixation without hardware. A new and innovative procedure.

BONE--PATELLAR TENDON: The "no hardware" technique for ACL reconstruction is a new method that offers many advantages and is straightforward to perform. Its main innovative feature is that it does not require bone-block harvesting from the patella. This reduces donor site morbidity and prevents patellar fractures. The bone tunnels are made using tube harvesters and compaction drilling. This minimizes trauma and obviates the risk of bone necrosis. The articular entrance of the tibial tunnel is completely occupied by the grafts. This prevents a windshield-wiper effect and synovial fluid ingress into the tunnel, and enhances graft incorporation. The fact that no hardware is used with both patellar tendon or hamstring grafts significantly reduces the overall cost of the operation and facilitates revision surgery. The quadriceps tendon is also a very good graft. It is thick and has good biomechanical properties and low donor site morbidity. Its disadvantages are: weakness of quadriceps after the operation, an unsightly scar, and some difficulty in graft harvesting [58]. Also, postoperative MRI is not fraught with the problem of metal artifacts. It is difficult to decide which of the methods currently available for ACL reconstruction is the best because most of them give satisfactory results. In the future, assessments of knee ligament reconstruction techniques should look at long-term stability combined with low complication rates. Ease of revision surgery and low cost should also be taken into consideration, given the large annual volume of knee ligament reconstructions (50,000 in the United States alone) [59]. We believe that our technique addresses most of these issues, and that it constitutes a useful alternative method for ACL reconstruction. SEMITENDINOSUS--GRACILIS: This technique, which was used with 915 patients from June 1998 to February 2002, shows a particularly low rate of postoperative morbidity. The reason is probably to be found in the "waterproofing" of the bone tunnels, which lead to less postoperative bleeding and swelling. No drains were used. Rehabilitation follows the same protocol as used for the reconstruction using patellar tendon grafts (accelerated/functional). As expected, there was no widening of the femoral tunnels and little widening of the tibial tunnels. Interestingly, tibial tunnel enlargement was significantly less in a nonaccelarated rehabilitation group than in the accelerated group [60] without affecting stability. The measured internal torque of the hamstrings, as well as their flexion force, already had returned to normal 12 months postoperatively. In a prospective randomized (unpublished) study comparing this technique with ACL reconstruction with BPT grafts with medial or lateral third with only one bone plug (from the tibial tuberosity, see technique described above), we found no significant difference between both groups in subjective scores, stability, KT-1000 values, Tegner activity score, and IKDC at 1-year follow-up. Only the results of kneeling and knee walking testing were significantly better in the hamstring group [61]. In summary, the advantages of this presented technique are: (1) the knot of the graft is close proximally to the anatomic site of the insertion of the ACL, thus avoiding the Bungee effect.; (2) the press-fit tunnel fixation prevents synovial fluid entering the bone tunnels, windshield-wiper effect, and longitudinal motion within the tunnel; the intensive contact between the bony wall of the tunnel and graft collagen over a long distance without any suture material results in quick and complete graft incorporation; and (3) no fixation material means no hardware problems, facilitates revision surgery, and lowers overall costs.

Anterior Cruciate Ligament↗
PubMed2001

A comparative study of the healing of tendon autograft and tendon-bone autograft using patellar tendon in rabbits.

In order to compare the healing of tendon to bone and the healing of bone to bone in a rabbit model, the lateral 4 mm of patellar tendons were detached from their insertion into the tibia either subperiosteally (group I) or with a bone block (group II) and implanted into drill holes in the proximal articular surface of the tibia. The histological and biomechanical features of the graft incorporation were observed at 2, 4, 8 and 12 weeks. Histological patterns similar to normal tendon-bone attachment were seen at the tendon-bone interface in group I by 12 weeks, while direct bony union was seen in group II by 8 weeks. The maximum tensile load and stiffness were significantly greater in group II at 4 and 8 weeks while the difference between the two groups was not significant at 2 and 12 weeks. These findings show that more rapid incorporation of the graft occurs in group II although no significant difference in biomechanical parameters was noted once healing was complete.

Animals↗
PubMed1986

[Reconstruction of flexor tendons following prognostically unfavorable injuries in the "no man's land" of the hand using transplantation of a tendon-tendon sheath unit--preliminary report].

For the reconstruction of injured flexor tendons with a bad prognosis in "no man's land", the authors used a composite flexor tendon graft from the foot. In one case, first in the literature, they carried out the transplantation with microvessel anastomosis. They modified the method proposed by Chacha in 1974 in several ways. On the basis of their favourable results they propose the method for reconstruction after flexor tendon injuries with a poor prognosis.

Adult↗
PubMed2005

[Reconstruction of the anterior cruciate ligament: comparison of patellar bone-tendon-bone and hamstring tendon graft methods. Part 1. Evaluation of patients treated by the patellar bone-tendon-bone graft technique].

PURPOSE OF THE STUDY: Reconstruction of the anterior cruciate ligament (ACL) by means of a patellar bone-tendon-bone (B-T-B) graft is currently one of the most frequent arthroscopic procedures. Progress in alternative techniques, particularly the use of hamstring tendon grafts and different methods for graft anchorage, was the reason for evaluation of our group of patients. The results were assessed at 18 months of follow-up. MATERIAL: We evaluated 137 surgically treated knees in 136 patients, 20 female and 117 male, on the basis of the Lysholm score system completed with a clinical examination of knee joint stability by Lachman's test and the pivot shift test and the ability of assuming a squatting position. We completed the evaluation with the patient's report on their satisfaction with the outcome and willingness to undergo the surgery again in the case of the other knee instability. METHODS: We carried out surgery under general anesthesia with the extremity in flexion and application of a tourniquet. Arthroscopy is performed from the anterolateral portal and graft is harvested, though a longitudinal incision, from the middle third of the patellar ligament and with the bony blocks from the patella and tibial tubercle. The graft width is 9 to 10 mm. Tibial or femoral tunnels are drilled by means of a tibial of femoral reamer and the inserted graft is fixed with metal interference screws. Cefazolinum with low-molecular heparin is administered during surgery. Rehabilitation of the extremity on a continuous passive motion (CPM) device begins on the first day. Full weight-bearing is allowed from the sixth week. RESULTS: The average Lysholm score of the group was 86.9. Excellent, good and satisfactory outcomes were achieved in 46.38%, 23.91% and 14.49% of the knees, respectively; 14.49% showed poor outcomes. Satisfaction with the outcome of surgery was reported by 90.5% of the patients, 75.18% complained of problems with knee-bend and pain at the donor site and scar. DISCUSSION The results of our evaluation are similar to those reported in the relevant literature. There are no differences in Lysholm scores from literature data or from the results recorded in a group of patients operated on with the use of the Rigidfix system and hamstring tendon grafts, in whom the average score was 84.3. The patients treated by the B-T-B technique, however, experience more problems at the graft harvest site, with subsequent femoropatellar complaints. CONCLUSIONS: ACL reconstruction with a patellar B-T-B graft is a surgical technique which resolves the patient's existing complaints due to knee instability, but may also have a preventive effect. This technique is suitable for sportsmen and sportswomen. Because of frequent postoperative complaints of pain at the donor site, it is not indicated for persons with femoropatellar problems, elderly persons and those who have kneeling jobs.

Adolescent↗
PubMed1982

[Micro-constructive studies of human digital flexor tendon and tendon sheath--observation by scanning electron microscope and light microscope (author's transl)].

This report concerns a micro-construction of the human digital flexor tendon and tendon sheath. Using fresh human tendons and tendon sheaths, the specimens were prepared as continuous as possible, and observed under a scanning electron microscope. The results obtained from these observations were compared with the histological and histochemical findings and some interesting conclusions were obtained. The tendon and tendon sheath are organized to transmit the muscle contraction most effectively to the finger as a reasonable finger motion. The tendon consists of the bundles of dense collagen fibers, the endotenon which divides each tendon bundles, the epitenon which surrounds all the tendon bundles as a whole and the visceral synovial layer which bundles the top of the tendon. The fiber of the epitenon originates from the paratenon at the proximal reflexion of the synovial layer, and remain around the tendon bundle in the tendon sheath cavity. The epitenon thickens itself at the dorsal side of the tendon, and the longitudinal dorsal tendon vessels are included in the thickened epitenon. Both the epitenon and the endotenon consist of loose connective fibers and these fibers are in continuation from one to the other. The endotenon divides a tendon into bundles and includes the intertendinous longitudinal vessels inside it. It also relieves the strain of tendon aroused in the process of finger motion. The synovial tendon sheath cavity is considered as a bursa formed in the paratenon, and the volar sides of the parietal layer of the synovial tendon sheath act chiefly as the pulley in co-operation with the ligamentous tendon sheath. The dorsal sides of the parietal layer, especially in the area near the volar plate, the tendon anchoring area, the reflexion area of the synovial layer and the origin of the tendon vinculum, form the areolar-type of synovial layer, and are concerned in production of the synovial fluid. Some of the synovial cells in the synovial layer are stained metachromatically with the histochemical stains, and they are considered to produce the synovial fluid mainly composing of the hyaluronic acid. The synovial fluid gives a biological activity and a biomechanical lubrication to the tendon function. The paratenon, the mesotenon and the vinculum are all paratendinous tissues, which function as the tendon anchor and provide the paths for vessels to the tendon. These structures have been modified into the individual forms through the adaptation to the needs of function and to the environments surrounding them. The paratenon locates in the area where the tendon runs straight in the shortest excursion, and the mesotenon in the area of the curved long excursion as in the case for carpal tunnel or tarsal tunnel where is covered by the tendon sheath or the retinaculum. The vinculum exists in a highly differentiated narrow space such as the no-man's land of finger, and has remained as the minimum unit to maintain the blood supply to the tendon.

Adult↗
PubMed2002

Bridging tendon defects using autologous tenocyte engineered tendon in a hen model.

Tendon defects remain a major concern in plastic surgery because of the limited availability of tendon autografts. Whereas immune rejection prohibits the use of tendon allografts, most prosthetic replacements also fail to achieve a satisfactory long-term result of tendon repair. The tissue engineering technique, however, can generate different tissues using autologous cells and thus may provide an optimal approach to address this concern. The purpose of this study was to test the feasibility of engineering tendon tissues with autologous tenocytes to bridge a tendon defect in either a tendon sheath open model or a partial open model in the hen. In a total of 40 Leghorn hens, flexor tendons were harvested from the left feet and were digested with 0.25% type II collagenase. The isolated tenocytes were expanded in vitro and mixed with unwoven polyglycolic acid fibers to form a cell-scaffold construct in the shape of a tendon. The constructs were wrapped with intestinal submucosa and then cultured in Dulbecco's Modified Eagle Medium plus 10% fetal bovine serum for 1 week before in vivo transplantation. On the feet, a defect of 3 to 4 cm was created at the second flexor digitorum profundus tendon by resecting a tendon fragment. The defects were bridged either with a cell-scaffold construct in the experimental group ( n= 20) or with scaffold material alone in the control group ( n= 20). Specimens were harvested at 8, 12, and 14 weeks postrepair for gross and histologic examination and for biomechanical analysis. In the experimental group, a cordlike tissue bridging the tendon defect was formed at 8 weeks postrepair. At 14 weeks, the engineered tendons resembled the natural tendons grossly in both color and texture. Histologic examination at 8 weeks showed that the neo-tendon contained abundant tenocytes and collagen; most collagen bundles were randomly arranged. The undegraded polyglycolic acid fibers surrounded by inflammatory cells were also observed. At 12 weeks, tenocytes and collagen fibers became longitudinally aligned, with good interface healing to normal tendon. At 14 weeks, the engineered tendons displayed a typical tendon structure hardly distinguishable from that of normal tendons. Biomechanical analysis demonstrated increased breaking strength of the engineered tendons with time, which reached 83 percent of normal tendon strength at 14 weeks. In the control group, polyglycolic acid constructs were mostly degraded at 8 weeks and disappeared at 14 weeks. However, the breaking strength of the scaffold materials accounted for only 9 percent of normal tendon strength. The results of this study indicated that tendon tissue could be engineered in vivo to bridge a tendon defect. The engineered tendons resembled natural tendons not only in gross appearance and histologic structure but also in biomechanical properties.

Animals↗
PubMed2025

How Does Tendon Region, Donor, and the Presence of Disease Affect Protein Composition of the Achilles Tendon?

BACKGROUND: Response to treatment for tendinopathy is variable, which may reflect variability in underlying etiology and capacity for the tendon to respond to treatment. Understanding variability in tendon protein composition may help improve our understanding of the mechanistic underpinnings of painful tendon degeneration and inform treatment targets. QUESTIONS/PURPOSES: (1) What factors (tendon region, individual characteristics, presence of disease) contribute to protein compositional (proteomic) and structural variation in human Achilles tendons? (2) What compositional changes characterize tendinopathy, and what protein interactions might contribute to tendon degeneration? (3) How does diabetes influence tendon composition, and what mechanisms might underlie tendon dysfunction in individuals with diabetes? METHODS: In this exploratory, cross-sectional study, human Achilles tendon specimens were obtained from individuals with (diabetes group, n = 5) or without diabetes (control group, n = 5) undergoing lower extremity amputation and from individuals undergoing tendon debridement surgeries for tendinopathy (tendinopathy group, n = 8). Specimens were collected between 2019 and 2023. Protein abundances were quantified and analyzed using mass spectrometry, hierarchical clustering, and principal component analysis. To evaluate the role of tendon region and donor on tendon protein compositional variability, we assessed proteomic differences between three regions in nontendinopathic tendons from three individuals. To identify the contribution of disease (that is, presence of tendinopathy or diabetes) on protein composition, we compared tendons from the tendinopathy (n = 8 [2 males, 6 females], mean &#xb1; SD age 48 &#xb1; 11 years), diabetes (n = 5 [3 males, 2 females], age 54 &#xb1; 9 years), and control (n = 5 [3 males, 2 females], age 42 &#xb1; 12 years) groups. Proteomic differences associated with tendinopathy and diabetes were further examined using functional enrichment and protein-protein interaction network analysis. RESULTS: Variability in tendon protein composition was primarily from presence of disease, followed by donor and then tendon region. Protein composition distinguished tendons with tendinopathy from controls, with 311 proteins differentially expressed (152 overexpressed and 159 underexpressed; fold change &#x2265; 1.5, p < 0.05) and higher Bonar scores indicating greater degeneration (mean &#xb1; SD Bonar score tendinopathy group 8.6 &#xb1; 1.2 versus control group 2.1 &#xb1; 0.7; p = 0.01). Pathway analysis identified dysregulation in extracellular matrix remodeling (TIMP1, MMP3, MMP10), inflammatory response (TNF-&#x3b1;, EGFR1), and metabolic reprogramming. Tendons from individuals with diabetes exhibited minimal proteomic changes compared with the control group, with 66 differentially expressed proteins (31 overexpressed and 35 underexpressed; fold change &#x2265; 1.5, p < 0.05) with no histopathologic differences between diabetes and control group tendons (mean &#xb1; SD Bonar score diabetes group 3.4 &#xb1; 1.0 versus control group 2.1 &#xb1; 0.7; p = 0.19). Tendons in the diabetes group showed reductions in Type I collagen, enrichment of pathways associated with fibrosis and metabolic dysfunction, and inflammatory pathways associated with &#x3b1; 6 &#x3b2; 4 integrin. CONCLUSION: Our findings indicate that Achilles tendon composition primarily differs based on disease etiology, with tendinopathy showing extensive extracellular matrix disruption and inflammatory activity, whereas tendons from individuals with diabetes exhibit more subtle compositional changes. This distinction suggests that tendinopathy may require targeted interventions addressing tissue remodeling and inflammation, whereas diabetes may predispose tendons to injury but not directly result in degeneration. Understanding these protein compositional variations can help refine hypotheses about disease progression, treatment response, and potential therapeutic targets. CLINICAL RELEVANCE: While proteomic analysis is not currently a part of routine clinical assessment, these findings provide a framework for identifying protein markers that may aid in early diagnosis or patient stratification to improve treatment alignment. Future studies could determine whether these proteomic changes correlate with treatment response and further inform our understanding of early-stage degeneration from chronic disease. By bridging molecular findings with clinical presentation, this study lays the groundwork for future research on precision medicine approaches for tendon disorders, with the long-term goal of tailoring treatment based on both biological and symptomatic characteristics.

Humans↗
PubMed1991

Matrix metabolism and healing in the flexor tendon. Experimental studies on rabbit tendon.

I. The rabbit flexor tendon within the synovial sheath contains segments with fibrocartilage-like areas. These segments have a higher proteoglycan and a lower collagen and non-collagen protein synthesis compared to the segment with "true" tendon tissue. Cell proliferation is also lower within the proximal segment than in the intermediate and distal segments. These regional variations should be considered when interpreting experimental data. They may also be of importance for the variable healing capacity of different flexor tendon regions. II. Recombinant human insulin-like growth factor, insulin and fetal calf serum stimulate matrix synthesis and cell proliferation in a dose dependent manner in flexor tendon explants cultured for three days. rhIGF-I was more potent than insulin in stimulating cell proliferation and matrix synthesis. rhIGF-I also stimulated matrix synthesis to a higher degree than FCS. III. In long-term culture of flexor tendon explants, the addition of rhIGF-I to the culture medium stimulates matrix synthesis, but does not influence turn-over rates. The total hexosamine and collagen contents in tendons cultured in medium with rhIGF-I remain at the same level, while non-collagen protein content decreases. There are no major differences in matrix metabolism between tendons cultured in medium supplemented with FCS or with rhIGF-I only. rhIGF-I may therefore be used as a growth factor supplement in serum-free culture of tendon tissue. IV. Dehydration inhibits in vitro matrix synthesis and cell proliferation in tendon explants. These effects are counteracted by keeping the exposed tendon segments moist with physiological saline solution during preparation. The sensitivity of tendon tissue to dehydration should be considered during tendon surgery. V. Tendon explants, cultured in a diffusion chamber, survive and exhibit an intrinsic capacity for healing. In healing tendon segments incubated for three weeks, protein synthesis remains unchanged and collagen synthesis decreases, whereas the rate of cell proliferation increases as compared with native tendons. VI. Endotenon cells of the rabbit flexor tendon can restore the injured tendon surface and bridge the tendon gap. The rabbit flexor tendon is a morphologically and biochemically heterogeneous tissue with an intrinsic capability for healing. Tendon tissue is susceptible to dehydration and during exposure quickly looses its viability. The metabolic and proliferative capacity of the tendon is stimulated by growth factors and rhIGF-I may be of importance in tendon healing.

Animals↗
PubMed2005

Hamstring tendon versus patellar tendon anterior cruciate ligament reconstruction using biodegradable interference fit fixation: a prospective matched-group analysis.

BACKGROUND: There are still controversies about graft selection for primary anterior cruciate ligament reconstruction, especially with respect to knee stability and functional outcome. HYPOTHESIS: Biodegradable interference screw fixation of hamstring tendon grafts provides clinical results similar to those achieved with identical fixation of bone-patellar tendon-bone grafts. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: In 1996 and 1997, primary isolated anterior cruciate ligament reconstruction using a bone-patellar tendon-bone autograft was performed in 72 patients. Since 1998, hamstring tendons were used as routine grafts. Matched patients with a hamstring tendon graft were selected from a database (n = 284). All patients were followed prospectively for a minimum of 2 years with KT-1000 arthrometer testing, International Knee Documentation Committee score, and Lysholm score. RESULTS: In the bone-patellar tendon-bone group, 9 patients were excluded because of bilateral rupture of the anterior cruciate ligament, 3 patients (4.2%) had a graft rupture, and 4 patients were lost to follow-up (follow-up rate, 92.1%), leaving 56 patients for a matched-group analysis. In the hamstring tendon database, the graft rupture rate was 5.6% (P = .698). The Lysholm score was 89.7 in the patellar tendon group and 94 in the hamstring tendon group (P = .003). The KT-1000 arthrometer side-to-side difference was 2.6 mm for the patellar tendon group and 2.1 mm for the hamstring tendon group (P = .041). There were significantly less positive pivot-shift test results in the hamstring tendon group (P = .005), and hamstring tendon patients showed lower thigh atrophy (P = .024) and patellofemoral crepitus (P = .003). Overall International Knee Documentation Committee scores were better (P = .001) in the hamstring tendon group (hamstring tendon: 34 x A, 21 x B, 0 x C, 0 x D; bone-patellar tendon-bone: 17 x A, 32 x B, 6 x C, 0 x D). CONCLUSIONS: In this comparison of anterior cruciate ligament reconstruction with bone-patellar tendon-bone and anatomical hamstring tendon grafts, the hamstring tendon graft was superior in knee stability and function. These findings are partially contrary to previous studies and might be attributable to the use of an anatomical joint line fixation for hamstring tendon grafts. Thus, hamstring tendons are the authors' primary graft choice for anterior cruciate ligament reconstruction, even in high-level athletes.

Adolescent↗
PubMed2004

[Histologic pattern and mechanical properties of tissue-engineered tendon implants for tendon defects].

This is a study on the histologic pattern and mechanical properties of tissue-engineered tendon implanted for treatment of tendon defects. Tendons were resected from Roman chickens. Tendon cells were isolated from the tendons and cultured in vitro. The 2nd-4th passages of tendon cells were seeded on the degradable polyglycolic acid mesh to form cell-scaffold composites, which were further cultured for 7-10 days to construct tissue-engineered tendons. The tendon defects, 0.5 cm-0.8 cm in length, were made in the second digit flexor tendon bilaterally in 20 Roman chickens and then bridged with the constructed tissue-engineered tendons. At 2 weeks, 4 weeks, 6 weeks, and 8 weeks post-operation, the samples of regenerated tendons were collected for gross examination, histologic staining and biomechanical test. After implantation of the tissue-engineered tendons, the wounds healed well. The gross appearance, the cells and collagen fibers arrangement of the regenerated tendons were similar to those of natural tendons, but there were relatively not many closely packed collagen fiber bundles organized in parallel with the tendons ("remodel"), so the maximum tensile force increased slowly and its value was 15.40+/-10.63 N at 8 weeks after surgery, reaching only 23% of that of natural tendon. The maximum strain was 22.49%+/-10.21% at 8 weeks, being 10% higher than that of natural tendons. Polyglycolic acid scaffolds are degraded in vivo so rapidly that the regenerated tendons lose the normal biomechanical stimulus and then are unable to be remodeled. As a result, the mechanical strength of regenerated tendons is much lower than that of natural tendons. These results suggest that the normal biomechanical stimulus may be an important factor for the regenerated tendons to remodel.

Animals↗
PubMed1995

MR imaging of Achilles tendon in patients with familial hyperlipidemia: comparison with plain films, physical examination, and patients with traumatic tendon lesions.

OBJECTIVE: The purpose of this study was to evaluate the MR imaging characteristics of Achilles tendons in patients at risk for tendon xanthomas because of familial hyperlipidemia and to compare these findings with those seen on plain radiographs and physical examination. We also wished to determine if MR imaging could be used to differentiate xanthomas from traumatic tendinopathy in a second group of patients who had no history of hyperlipidemia but who had a history of trauma to the Achilles tendon. SUBJECTS AND METHODS: We evaluated the MR imaging studies of 26 Achilles tendons in 13 patients with heterozygous familial hypercholesterolemia (n = 11) and type III dysbetalipoproteinemia (n = 2). The size, shape, and signal characteristics of the Achilles tendon were recorded. A tendon was considered abnormal by MR if there was high signal, a convex anterior border, or an anteroposterior measurement greater than 7 mm. Findings on plain radiographs and physical examination of the Achilles tendons were evaluated in the same group of patients. In the group of patients with hyperlipidemia, palpable abnormalities of the Achilles tendon were present in 14 of 26 tendons. Plain radiographs were interpreted as showing abnormalities in 18 of the 26 tendons. In a second group of 21 tendons in patients with no history of hyperlipidemia but with traumatic tendinopathy, studies were evaluated for the size, shape, and signal characteristics of the Achilles tendon. RESULTS: On MR images, 24 of 26 tendons showed signal abnormalities, and 19 of 26 were enlarged. Abnormal signal was a diffuse stippled pattern with many low-signal round structures of equal size surrounded by high-signal material on all pulse sequences. Abnormal signal was seen in tendons of both normal and abnormal size. Bilateral and symmetric changes were found in all but one patient. Tendinopathy in patients without known hyperlipidemia appeared indistinguishable from tendon xanthomas in six (29%) of 21 tendons. The other tendons (71%) were distinctly different from xanthomas without a uniform stippled signal pattern. CONCLUSION: MR imaging of patients with familial hyperlipidemia showed an abnormal stippled signal pattern with or without enlargement or abnormal configuration of the tendon. MR imaging is a more sensitive method than physical examination and plain films for detecting abnormalities in Achilles tendons of patients with hyperlipidemia. Although the MR signal pattern of xanthomas is often different from that of partial tendon tears, tendon degeneration, or tendinitis, a significant overlap in appearance can be observed and the MR appearance of a xanthoma is not pathognomonic.

Achilles Tendon↗
PubMed2002

[Anterior cruciate ligament reconstruction: patellar tendon autograft versus four-strand hamstring tendon autografts. A comparative study at one year follow-up].

PURPOSE OF THE STUDY: The purpose of our study was to compare outcome at one year after anterior cruciate ligament reconstruction for chronic laxity using the patellar tendon autograft or four-strand hamstring tendon autografts. MATERIAL AND METHOD: This non-randomized study included 129 consecutive patients operated on between October 1996 and September 1998. Ninety patients were available for assessment at one year: 50 in the patellar tendon group and 40 in the hamstring tendon group. The two groups were comparable for all criteria except sex. A single operator assessed all patients using the IKDC 93 chart. Laxity was measured by comparison with the healthy knee using the KT1000 at maximal manual tension. Preoperative laxity was 8.0 +/- 3.0 mm in the patellar tendon group and 7.6 +/- 3.0 in the hamstring tendon group. All ligamentoplasties were performed arthroscopically using a blind femoral tunnel. The patellar tendon was fixed with two metallic interference screws and the four-strand hamstring autografts with two different methods: an RCI(R) interference screw or a cortical system associating a femoral Endobutton(R) and tibial fixation with a bicortical tibial screw. Lateral tendonesis was performed with the fascia lata in 60% of the patients in the patellar tendon group and in 45% of those in the hamstring tendon group. Rehabilitation exercises were initiated early and were the same in the two groups. RESULTS: Overall results were satisfactory in more than 80% of the patients in both groups. The final IKDC score was significantly better in the patellar tendon group and subjective patient satisfaction was better in the hamstrings group. Residual pain was significantly less pronounced in the hamstrings tendon group (p=0.004). Laxity was improved significantly better in the patellar tendon group: average residual laxity=2.7 +/- 2.1 mm versus 4.5 +/- 2.8 mm (p=0.03) in the hamstrings tendon group; hard stop at the Lachman test in 96% of the patellar tendon group and 78% in the hamstrings tendon group (p=0.007). Residual laxity was significantly less pronounced in the women in the patellar tendon group. There was no significant difference in laxity by type of fixation in the hamstrings tendon group. Recovery in terms of level of activity and type of sport was the same in the two groups. DISCUSSION: These two surgical techniques provide good functional outcome at one year with better control of laxity with patellar tendon autografts and better relief of pain with four-strand hamstrings autografts. Longer follow-up would be useful to assess laxity long after hamstring reconstruction. We compared the type of transplant and the fixation method together as a single unity, but progress in four-strand hamstring autograft fixation will certainly allow even more optimal results and improved correction of laxity. In our opinion, the patellar tendon autograft remains the gold standard for high-performance athletes practicing a contact-pivot sport, but both types of ACL reconstruction are most useful. We select patients for four-strand hamstring tendon reconstruction as a function of age, sex, and type of sports activities.

Adolescent↗