Biomedical subjects

Thore Zantop

Publications and source records attributed to Thore Zantop.

At least 37 records · Page 2Linked to original sources

PubMed2005

Joint kinematics and in situ forces after single bundle PCL reconstruction: a graft placed at the center of the femoral attachment does not restore normal posterior laxity.

INTRODUCTION: Femoral tunnel placement has a great influence on the clinical outcome after PCL reconstruction. MATERIALS AND METHODS: Using a robotic/universal force moment sensor (UFS) testing system, we examined joint kinematics and in situ forces of human knees following soft-tissue single bundle PCL reconstruction fixed at the center of the femoral attachment. RESULTS: Posterior tibial translation significantly increased at all flexion angles after transsection of the posterior cruciate ligament (p<0.05). PCL reconstruction resulted in significantly less posterior tibial translation at all flexion angles when compared to the PCL deficient knee (p<0.05). The differences in the in situ force between the intact ligament and the reconstructed graft were statistical significant (p<0.05). CONCLUSION: Single bundle PCL reconstruction with a soft-tissue graft fixed at the center of the femoral attachment is able to reduce the posterior tibial translation significantly. However, it cannot restore kinematics of the intact knee and in situ forces of the intact PCL.

Aged↗

PubMed2005

A controlled prospective case control study of a prevention training program in female team handball players: the German experience.

BACKGROUND: Few authors have investigated the effectiveness of preventive intervention in European team handball. PURPOSE: The aim of the present study was to evaluate the effects of a prevention program on the incidence of injuries in female European team handball players. STUDY DESIGN: Prospective controlled study. METHODS: Ten female handball teams (134 players) took part in the prevention program (1. Information about injury mechanism, 2. Balance-board exercises, 3. Jump training) while 10 other teams (142 players) were instructed to train as usual. Over one season all injuries were documented weekly. RESULTS: Ankle sprain was the most frequent diagnosis in both groups with 11 ankle sprains in the control group and 7 ankle sprains in the intervention group (Odds ratio: 0.55, 95% confidence interval: 0.22-1.43). The knee was the second frequent injury site. In the control group 5 of all knee injuries were anterior cruciate ligament (ACL) ruptures (incidence: 0.21 per 1000 h) in comparison with one in the intervention group (incidence: 0.04 per 1000 h). Odds ratio was 0.17 with 95% confidence interval of 0.02-1.5. CONCLUSIONS: This study confirms that proprioceptive and neuromuscular training is appropriate for the prevention of knee and ankle injuries among female European team handball players.

Adult↗

PubMed2005

Primary stability of hamstring graft fixation with biodegradable suspension versus interference screws.

PURPOSE: During the early postoperative period, the stability of the fixation of a hamstring graft to the bone tunnel is the primary factor in limiting rehabilitation. The aim of this study was to evaluate if the initial fixation strength of a new suspension screw is comparable to that of the biodegradable interference screw fixation technique in the hamstring reconstruction of the anterior cruciate ligament (ACL). TYPE OF STUDY: Experimental laboratory study. METHODS: We evaluated the initial fixation strength of a biodegradable poly-L-lactide/tri-calcium phosphate (PLLA/TCP) screw that suspended the graft in the bone tunnel and compared it with the strength of an interference screw for fixation of hamstring grafts in ACL reconstruction using bovine knees. Single-cycle and cyclic loading tests were performed using a materials testing machine. RESULTS: The suspension screw provided a significantly higher yield load and ultimate failure load than the interference screw. There was no significant difference in the stiffness of both techniques. The typical failure mode for the suspension screw was fracture of the screw and for the interference screw it was slippage of the graft past the screw. In cyclic testing, both methods of fixation ran out to 1,000 cycles up to 250 N with a mean displacement of 2.6 mm (range, 1.8 to 3.3 mm) for the suspension screw and 4.1 mm (range, 2.3 to 6.0 mm) for the interference screw. Only the grafts fixed with the suspension screw survived a protocol with 1,000 cycles up to 400 N. CONCLUSIONS: Our biomechanical data suggest that hamstring graft fixation using a biodegradable PLLA/TCP suspension screw provides an alternative to interference screw fixation. CLINICAL RELEVANCE: Hamstring graft fixation using a suspension screw provides a reasonable alternative to interference screw fixation.

Absorbable Implants↗

PubMed2005

Cyclic loading comparison between biodegradable interference screw fixation and biodegradable double cross-pin fixation of human bone-patellar tendon-bone grafts.

PURPOSE: The aim of this study was to compare ultimate load, yield load, stiffness, and displacement after cyclic loading of a cross-pin technique and an interference screw technique for the fixation of bone-patellar tendon-bone (BPTB) grafts in anterior cruciate ligament (ACL) reconstruction. TYPE OF STUDY: Biomechanical in vitro study. METHODS: The devices tested were 2 2.7-mm biodegradable pins (RigidFix; Ethicon, Mitek Division, Norderstedt, Germany) and biodegradable interference screws (Absolute; Innovasive Devices, Marlborough, MA). Each device was used for the fixation of 10 8-mm, 9-mm, or 10-mm sized human BPTB grafts in tunnels drilled in bovine knees. Ultimate load, yield load, stiffness, and displacement after cyclic loading (1,000 cycles between 50 and 250 N) were then evaluated. RESULTS: All 8-mm grafts that were fixed with cross-pins failed after a mean of 124 cycles of load. The 9-mm and 10-mm grafts survived the cyclic loading protocol. Yield load and maximum load of the 10-mm groups (cross-pin and interference screw) were significantly higher than that of the 9-mm groups. There was no significant difference in maximum load, yield load, and stiffness between the cross-pin and interference screw fixation technique for 1 graft size. CONCLUSIONS: The biomechanical data suggest that femoral fixation of 9-mm and 10-mm BPTB grafts using 2.7-mm biodegradable cross-pins leads to primary stability that is comparable to that of biodegradable interference screws. Fixation of 8-mm BPTB grafts using 2.7-mm biodegradable cross-pins had poor results. CLINICAL RELEVANCE: The diameter of the bone block is the limiting factor for the final fixation strength and the cyclical survival when using cross-pins. We strongly recommend not using this technique for bone blocks smaller than 9 mm in diameter.

Absorbable Implants↗

PubMed2005

Cyclic testing of flexible all-inside meniscus suture anchors: biomechanical analysis.

BACKGROUND: Flexible meniscus repair devices are designed to combine the benefits of rigid all-inside meniscus anchors with the biomechanical properties of sutures. HYPOTHESIS: Stiffness and pull-out strength of flexible all-inside suture anchors and conventional sutures under cyclic loading conditions will be comparable. STUDY DESIGN: Controlled laboratory study. METHODS: In 50 fresh frozen bovine menisci, artificial meniscus lesions were repaired with different meniscus fixation techniques: horizontal and vertical FasT-Fix, RapidLoc, and horizontal and vertical 2-0 Ethibond sutures. The specimens were cycled 1000 times between 5 and 20 N and then loaded to failure. RESULTS: All devices survived the cyclic loading protocol. There was no significant difference in the displacement between all repair techniques tested (horizontal FasT-Fix, 6.23 mm; vertical FasT-Fix, 5.34 mm; RapidLoc, 6.84 mm; horizontal 2-0 Ethibond, 6.03 mm; vertical 2-0 Ethibond, 5.61 mm (P > .05). Vertical and horizontal FasT-Fix suture anchors had a significantly higher stiffness and pull-out strength (94.1 N and 80.8 N, respectively) than did horizontal sutures (50.2 N) and RapidLoc devices (30.3 N) (P > .05). CONCLUSIONS: In this study, flexible all-inside meniscus anchors (FasT-Fix) had higher pull-out strength than did conventional vertical suture techniques. Biomechanical characteristics of the flexible RapidLoc are comparable to those of horizontal sutures. CLINICAL RELEVANCE: Flexible all-inside meniscus repair devices are an alternative to conventional suture techniques.

Animals↗

PubMed2004

Soft-tissue graft fixation in posterior cruciate ligament reconstruction: evaluation of the effect of tibial insertion site on joint kinematics and in situ forces using a robotic/UFS testing system.

INTRODUCTION: Surgical reconstruction of the posterior cruciate ligament (PCL) is recommended in acute injuries that result in severe tibial subluxation and instability. The surgical outcome level may be affected by the tibial fixation site. In response to a 110-N posterior tibial load, kinematics and in situ forces of anatomical soft-tissue graft fixation in single-bundle PCL reconstruction using an interference screw fixation are significantly closer to those in the intact knee than with extracortical fixation with two staples. MATERIALS AND METHODS: Using a robotic/universal force moment sensor (UFS) testing system, we examined joint kinematics and in situ forces of porcine knees following single-bundle PCL reconstruction fixed at two different tibial fixation sites: anatomical interference screw and extracortical fixation. RESULTS: The site of the tibial graft fixation had significant effect on the resulting posterior displacement and in situ forces of the graft. Both PCL reconstruction techniques reduced the posterior tibial translation significantly. Proximal fixation techniques provided significantly less posterior tibial translation than extracortical fixation. Single-bundle PCL reconstruction with an interference screw showed higher in situ forces of the graft than the extracortical fixation. CONCLUSIONS: The kinematics and in situ forces of a single-bundle PCL reconstruction using an interference screw fixation technique are superior to the primary stability of an extracortical fixation with staples.

Animals↗

PubMed2004

Biomechanical evaluation of a new cross-pin technique for the fixation of different sized bone-patellar tendon-bone grafts.

To overcome the disadvantages of interference-screw fixation of bone-patellar tendon-bone (BPTB) grafts, new fixation techniques for anterior cruciate ligament (ACL) grafts using biodegradable pins have been developed. The hypothesis of the present study was that cross-pin fixation techniques provide a primary stability that is comparable to that of interference screws. A biomechanical in vitro study was discussed. Human BPTB grafts of 8, 9 and 10 mm diameter were fixed in bovine knees with biodegradable cross pins (diameter: 2.0, 2.7 or 3.2 mm) or biodegradable interference screws. Stiffness and ultimate load were evaluated. For 9 and 10 mm BPTB grafts, no statistically significant difference in maximum load and stiffness was found between the four fixation techniques tested. For 8 mm bone blocks the maximum load of the 3.2 mm pins (274.2 N) was significantly lower than for the 2.0 mm pins (479.8 N) and the interference screws (504.0 N). Predominant failure mode in this group was bone-block fracture. Thicker grafts (9 and 10 mm) fixed with the 2.0 mm pins predominantly failed by implant fracture. Femoral fixation of 8, 9 and 10 mm BPTB grafts using cross pins leads to biomechanical properties that are comparable to biodegradable interference screws when tested by a single-cycle load to failure. Cross pins provide a rigid fixation for 9 and 10 mm BPTB grafts.

Absorbable Implants↗

PubMed2004

Cyclic strain influences the expression of the vascular endothelial growth factor (VEGF) and the hypoxia inducible factor 1 alpha (HIF-1alpha) in tendon fibroblasts.

Neovascularization is involved in beneficial and detrimental processes of tendon pathology. We investigated the influence of repetitive motion on the expression of the most important angiogenic factor, the vascular endothelial growth factor (VEGF) in the 3T3 NIH fibroblast cell line and in cultures of rat Achilles tendon fibroblasts. Monolayers of subconfluently grown cells were stretched in rectangular silicone dishes with cyclic uniaxial movement. Strain was applied over 24 h varying the frequency (0.5-1 Hz). Fibroblasts (3T3 fibroblasts and rat Achilles tendon cultures) cultivated without the application of cyclic strain released measurable VEGF amounts into their culture supernatants. Cyclic stretching of the cells with a frequency of 1 Hz resulted in an increased expression of VEGF. A low frequency (0.5 Hz) reduced VEGF expression to control levels. RT PCR revealed VEGF 121 and VEGF 165 as the only splice forms that were induced by cyclic stretching. Western blot experiments could further show that cyclic stretching induced activation of the transcription factor HIF-1alpha. These results demonstrate that mechanical factors are involved in the regulation of VEGF expression in tendon tissue.

3T3 Cells↗

PubMed2004

Expression of VEGFR-1 and VEGFR-2 in degenerative Achilles tendons.

Evidence suggests neovascularization is involved in the etiology of spontaneous Achilles tendon rupture. Therefore we investigated expression of the receptors of one of the most important angiogenic factors, the vascular endothelial growth factor in normal and pathologic human Achilles tendons by immunohistochemical and molecular biology methods. Light microscopy showed degenerative changes in all spontaneously ruptured tendons with a higher vascular density compared with controls of healthy tendons from a cadaver. The vascular endothelial growth factor receptors-1 and 2 could be immunostained in endothelial cells of ruptured and fetal tendons, but not in normal tendons. Reverse transcription-polymerase chain reaction showed messenger ribonucleic acid of both receptors are expressed in ruptured and fetal tendons but not in normal tendons. These results prove the reexpression of the major receptors for the angiogenic peptide vascular endothelial growth factor, the vascular endothelial growth factor receptor-1, and the vascular endothelial growth factor receptor-2 in ruptured and fetal tendons and support our theory that high vascular density is associated with the pathogenesis of tendon degenerations. Inhibiting angiogenesis could be a new approach in the therapy of degenerative Achilles tendon disease.

Achilles Tendon↗

PubMed2004

Effects of increasing tibial slope on the biomechanics of the knee.

PURPOSE: To determine the effects of increasing anterior-posterior (A-P) tibial slope on knee kinematics and in situ forces in the cruciate ligaments. METHODS: Ten cadaveric knees were studied using a robotic testing system using three loading conditions: (1) 200 N axial compression; (2) 134 N A-P tibial load; and (3) combined 200 N axial and 134 N A-P loads. Resulting knee kinematics were determined before and after a 5-mm anterior opening wedge osteotomy. Resulting in situ forces in each cruciate ligament were determined. RESULTS: Tibial slope was increased from 8.8 +/- 1.8 degrees to 13.2 +/- 2.1 degrees, causing an anterior shift in the resting position of the tibia relative to the femur up to 3.6 +/- 1.4 mm. Under axial compression, the osteotomy caused a significant anterior tibial translation up to 1.9 +/- 2.5 mm (90 degrees ). Under A-P and combined loads, no differences were detected in A-P translation or in situ forces in the cruciates (intact versus osteotomy). CONCLUSIONS: Results suggest that small increases in tibial slope do not affect A-P translations or in situ forces in the cruciate ligaments. However, increasing slope causes an anterior shift in tibial resting position that is accentuated under axial loads. This suggests that increasing tibial slope may be beneficial in reducing tibial sag in a PCL-deficient knee, whereas decreasing slope may be protective in an ACL-deficient knee.

Aged↗

PubMed2004

Initial fixation strength of flexible all-inside meniscus suture anchors in comparison to conventional suture technique and rigid anchors: biomechanical evaluation of new meniscus refixation systems.

BACKGROUND: The newest generation of meniscus repair devices is designed to combine the benefits of the all-inside technique with the biomechanical properties of sutures. HYPOTHESIS: New flexible all-inside suture anchors have better fixation strength than rigid anchors, but there is no difference when compared to conventional horizontal and vertical mattress sutures. STUDY DESIGN: Controlled laboratory study. METHODS: In fresh-frozen bovine menisci, initial fixation strength, stiffness, and failure mode of different meniscus fixation techniques (FastT-Fix, RapidLoc, Meniscus Arrow, horizontal and vertical 2.0 Ethibond sutures) were evaluated in a computer-based materials testing machine at a rate of 12.5 mm/sec. RESULTS: The vertical and horizontal FastT-Fix suture anchors were the strongest devices with regard to pullout strength, with no significant difference compared to the vertical 2-0 Ethibond sutures. Horizontal sutures, Meniscus Arrow, and RapidLoc had significantly lower pullout strength. Vertical and horizontal FastT-Fix suture anchors showed significantly higher stiffness than the other devices. CONCLUSIONS: Biomechanical properties of flexible all-inside meniscus anchors (FastT-Fix) are comparable to conventional vertical suture techniques. Characteristics of the flexible RapidLoc are comparable to rigid anchors (Meniscus Arrow). CLINICAL RELEVANCE: From the biomechanical point of view, flexible all-inside meniscus refixation devices are an alternative to conventional suture techniques and rigid meniscus anchors.

Animals↗

PubMed2004

A prospective study of kitesurfing injuries.

BACKGROUND: To date, the pattern and rate of kitesurfing injuries are largely unclear. HYPOTHESIS: The pattern and rate of kitesurfing injuries are comparable to that of contact sports such as football and soccer. STUDY DESIGN: Prospective study. METHODS: The study was conducted over a 6-month period of 1 season and included 235 kitesurfers. RESULTS: The number of self-reported injuries was 124, for an overall self-reported injury rate of 7 per 1000 hours of practice. One fatal accident (polytrauma) and 11 severe injuries occurred during the study period (2 knee ligament injuries and 9 fractures at various sites). The most commonly injured sites were the foot and ankle (28%), skull (14%), chest (13%), and knee (13%). Fifty-six percent of the injuries were attributed to the inability to detach the kite from the harness in a situation involving loss of control over the kite. There was a tendency for athletes using a quick-release system to sustain fewer injuries than athletes without such a release system. CONCLUSION: Kitesurfing can be considered a high-risk sport. CLINICAL RELEVANCE: The use of a quick-release system that enables the surfers to detach the kite in case of an accident might aid in the prevention of injuries.

Adolescent↗

PubMed2003

A new rigid biodegradable anchor for meniscus refixation: biomechanical evaluation.

All-inside repair devices have been developed to overcome the disadvantages of conventional suture techniques (such as vein and nerve damage and increased OR time). The Contour Meniscus Arrow is a second generation of the first biodegradable all-inside implant, the Meniscus Arrow. The aim of this study was to compare the biomechanical properties of the Contour Meniscus Arrow to the first-generation Meniscus Arrow and vertical or horizontal suture techniques. In fresh frozen bovine menisci, initial fixation strength, stiffness and failure mode of four different meniscus refixation techniques (Meniscus Arrow, Contour Meniscus Arrow, vertical and horizontal 2-0 Ethibond suture techniques) were evaluated in a computer-based material-testing machine at a rate of 12.5 mm/s. Vertical meniscus sutures showed the highest initial fixation strength, followed by the horizontal suture technique and the Contour Arrow. The Meniscus Arrow showed inferior pull-out strength. Subjecting the different refixation techniques to cyclic testing decreased the fixation strength in all groups. The modified Meniscus Anchor (Contour Arrow) provides biomechanical properties that are superior (pull-out strength) or similar (stiffness) compared to the first biodegradable all-inside implant, the Meniscus Arrow. The pull-out strength of the Contour Arrow was comparable to the pull-out strength reported for horizontal meniscus sutures in the literature. These biomechanical characteristics of this new implant justify clinical use.

Absorbable Implants↗

PubMed2003

The splice variants 120 and 164 of the angiogenic peptide vascular endothelial cell growth factor (VEGF) are expressed during Achilles tendon healing.

BACKGROUND: The Achilles tendon is one of the most common sites of tendon injury and rupture. One of the early events of wound healing is angiogenesis, in which neovascularization prompts delivery of inflammatory cells and fibroblasts to the wound site. Angiogenesis is controlled by a variety of mitogenic, chemotactic, or inhibitory peptides and lipid factors that act on invading endothelial and smooth muscle cells. One of the most important angiogenic factors is the vascular endothelial cell growth factor (VEGF), a glycosylated protein of 46-48 kDa composed of two disulfide-linked subunits. METHODS: We therefore investigated the expression of VEGF during healing of artificial lesions of the Achilles tendon in a sheep model by immunohistochemical, biochemical, molecular, and cell biology methods. Two groups were created, the Achilles tendon was tenotomized, and the animals were killed at 3 and 24 weeks. Each group consisted of 6 specimens. Six animals which did not undergo surgery served as controls. RESULTS: VEGF could be immunostained in tenocytes of ruptured but not in normal adult tendons. At microvessels, the receptors VEGFR-1 (flt-1) and VEGFR-2 (KDR) could also be visualized. High VEGF levels in ruptured and negligible levels in normal Achilles tendons could be confirmed and quantified by enzyme-linked immunoassay (ELISA). The highest VEGF concentrations were found in ruptured tendons, whereas the VEGF content in healthy adult tendons was negligible. Interestingly, the VEGF concentration of the original tendon stump was higher after 3 weeks than that of the newly regenerated tendon tissue. However, this difference was not significant (p>0.05). Reverse transcription-polymerase chain reaction (RT-PCR) showed that the splice variants VEGF(120 )and VEGF(164) are expressed at 3 weeks and 24 weeks, respectively. CONCLUSION: These results prove the presence of the splice variants VEGF(120 )and VEGF(164) in ruptured tendons during the healing process. The demonstrated up-regulation of VEGF in intrinsic tenocytes suggests a role for VEGF in mechanisms of angiogenesis and Achilles tendon repair. Further research is needed to evaluate if VEGF might be a possible tool to enhance the process of tendon healing.

Animals↗

PubMed2003

Quantitative assessment of blood vessels of the human Achilles tendon: an immunohistochemical cadaver study.

BACKGROUND: The pathogenesis of Achilles tendon rupture remains unclear, but vascular patterns may play an important role. Hypoxia is considered to be an important factor in the aetiology of tendon degeneration. METHODS: Statements from the literature regarding the vascularization of the Achilles tendon are controversial. We determined the vascular density of the Achilles tendon using a new method involving antibodies against laminin, a component of the basement membrane. RESULTS: The blood supply of the Achilles tendon mainly arose from the anterior paratenon of the tendon from which vessels run into the tendon. The proximal part of the tendon was supplied by a recurrent branch of the posterior tibial artery, while the distal part of the tendon was vascularized by the rete arteriosum calcaneare, supplied by the fibular and posterior tibial arteries. An avascular area could be seen close to the insertion of the tendon to the calcaneus. Three regions with different vascular density could be determined in the Achilles tendon. The distal part of the Achilles tendon had a vascular density of 56.6 vessels/cm(2). In the middle part of the tendon, the vascular density was much lower: 28.2 vessels/cm(2). The proximal part of the tendon had a vascular density of 73.4 vessels/cm(2). CONCLUSION: The reduced vascularization in the tendon waist may be a predisposing factor for degeneration and spontaneous rupture of the human Achilles tendon.

Achilles Tendon↗

PubMed2003

Hypoxia and PDGF have a synergistic effect that increases the expression of the angiogenetic peptide vascular endothelial growth factor in Achilles tendon fibroblasts.

BACKGROUND: Angiogenesis, the formation of new blood vessels from pre-existing vessels, is an essential step in the process of tendon healing and tendon graft remodelling, e.g. after anterior cruciate ligament reconstruction. To address the question of whether platelet-derived growth factor (PDGF) could influence vascular endothelial growth factor (VEGF) expression in tenocytes, we challenged primary cultures of rat tenocytes with different stimulators (hypoxia, PDGF) and measured their VEGF secretion. METHODS: To measure the VEGF secretion and the effect of PDGF, we used cell culture and stimulation of rat tenocytes (2-5 days old), immunohistochemistry as well as enzyme-linked immunosorbent assay (ELISA). RESULTS: Tenocytes cultivated under normal oxygen pressure released measurable amounts of VEGF into their culture supernatants. Stimulation with PDGF, a cytokine that activates mitogen-activated protein kinases, raised VEGF secretion 2-fold. Hypoxic conditions alone (5% O(2)) raised VEGF secretion only 2-fold. However, the combination of cytokines and hypoxia increased VEGF production 5-fold, apparently a synergistic effect. CONCLUSION: These data are useful to further our understanding of angiogenesis in tendon healing and tendon graft remodelling after ACL reconstruction.

Achilles Tendon↗

PubMed2003

Structure of the human tibialis posterior tendon.

BACKGROUND: The most common site of rupture of the posterior tibial tendon is the retromalleolar region where the tendon changes its direction of pull. The aim of this study was to characterize the tissue of the gliding zone of the tibialis posterior tendon to gain further knowledge about possible structural causes for spontaneous tendon rupture. METHODS: Light microscopy, transmission electron microscopy and immunohistochemical methods were used to describe the structure of the human tibialis posterior tendon. RESULTS: In the region where the tendon wraps around the medial malleolus, the structure of the tissue changes from the typical structure of a traction tendon. The superficial zone which was directed towards the pulley tissue had the structure of fibrocartilage with a specific three-dimensional collagen fibril texture. Transmission electron microscopy showed chondrocytes with a felt-like pericellular matrix that increased in size towards the gliding surface. The extracellular matrix of the fibrocartilage was rich in acid glycosaminoglycans and stained intensively with alcian blue at pH 1. Immunohistochemical staining of cartilage-specific extracellular matrix components such as type II collagen, chondroitin-4-sulphate, chondroitin-6-sulphate, keratan sulphate and aggrecan was positive. CONCLUSION: The location of the fibrocartilage corresponds to the region where the tibialis posterior tendon wraps around the medial malleolus, which serves as a pulley. According to the theory of 'causal histogenesis', the stimulus for the development of fibrocartilage within dense connective tissue is intermittent compressive and shear stress. The fibrocartilaginous region is the region where most spontaneous ruptures of the tibialis posterior tendon occur. Due to its structure, the fibrocartilaginous region may be more vulnerable to repetitive tensile microtrauma; degeneration may occur due to the poor repair response of the avascular fibrocartilaginous tissue.

Adult↗

PubMed2003

Intra-articular ganglion cysts of the cruciate ligaments: case report and review of the literature.

BACKGROUND: A ganglion can arise as a cystic lesion from a tendon sheath or a joint capsule and contain a glassy, clear, and jelly-like fluid. They can occur within muscles, menisci, and tendons. Intra-articular ganglion cysts of the knee joint are rare. We report on three ganglion cysts of the cruciate ligaments: Two were intercruciate, and one was located around the posterior cruciate ligament. METHODS: The clinical diagnosis was established using magnetic resonance imaging. All patients were treated successfully using arthroscopic debridement by basket punch and shaver. Subsequent histological examination confirmed the diagnosis. RESULTS: All three patients were asymptomatic at the postoperative follow-up of 16-36 months. CONCLUSION: A review of the literature reveals a controversial discussion about the clinical significance as well as the etiology of ganglion cysts arising from the cruciate ligaments. These case reports show that an intra-articular ganglion cyst of the cruciate ligaments is difficult to diagnose. A cyst does not necessarily have to be associated with specific clinical symptoms or a previous trauma. Preoperatively, MRI is essential when diagnosing ganglion cysts of the knee joint. An intra-articular ganglion cyst of the knee joint can be successfully treated by arthroscopy.

Adult↗