Aim: Experimentally forming a frayed Achilles tendon rupture model in rabbit and repairing the ruptured site with different methods; after the tendon healing, with the help of biomechanical and histopathological analyses, to find out which repair method is the most ideal.

Material and Method: This study was carried out using 34 mature, female New Zealand type of rabbits with weights ranging 2200 to 2900 grams (2429,4 on average). The animals were divided into two groups named P and V, each with 17 rabbits. In each group, Achilles tendon on the right side was employed for the experiment (Pd and Vd) and the other side as a control (Pk and Vk). In the experiment groups, a frayed Achilles tendon rupture was performed. The control groups, however, received no procedures. After the primary repair, the Achilles tendons in the group Pd were augmented with the plantaris tendon. The Achilles tendons in the group Vd were primarily repaired after releasing gastrocnemius aponeurosis using “inverted-V” incision. In both groups, an above-knee cast was applied on the surgically procedured sides. After six weeks of observation, the repaired sites on tendons in the animals alive were analyzed biomechanically and histopathologically. 12 and 3 animals from each group were used respectively for the biomechanical and the histopathological analyses.

Results: The elongation at tendon to rupture was 3,02±0,47 mm for Pd and 2,86±0,35 mm for Vd. The difference between two groups, however, was not statistically significant (p> 0,05). The maximum load at rupture for Pd was 105,88±38,14 N, and it was 71,95±17,44 N for Vd, thus the difference was statistically significant (p< 0,05). The energy needed to initiate a damage to the tendon was 0,1979±0,0902 J for Pd, and 0,1309±0,0368 J for Vd, the difference was also statistically significant (p< 0,05). The elongation, maximum load and energy values were lower in Pd group than in Pk, and in Vd group than in Vk, and the differences between each groups were statistically significant (p< 0,05). In histopathological sense, the tendon healing process in group Pd was faster than in group Vd.

Conclusion: Although the repairs made with the augmentation of plantaris tendon yielded better results; the tendon, no matter which method is used, could not has its former strength. Results are bound to be better with stronger repair, and if the repair as much as supported by adjacent tendinous structures.

Key Words: Achilles tendon, rupture, primary repair, m. plantaris, rabbit

The pineal hormone melatonin was recently shown to have a free radical scavenging ability which reduces lipid peroxidation and has also been shown to scavenge the hydroxyl radical and other reactive oxygen species. Melatonin stimulates several antioxidative enzymes, which increases its efficiency as an antioxidant. Also, melatonin stimulates osteoblast differentiation and mineralization of matrix and it may regulate osteoclastic activity via superoxide dismutase in vitro. Therefore, the effect of melatonin in fracture healing depends in part on the free radical scavenging and osteoblastic-osteoclastic regulatory properties of melatonin.

In this study the effect of melatonin (MEL) on fracture healing in rat tibia model was studied by using biochemical, radiological and histopathologic methods.

Male Sprague-Dawley rats (n=80) were randomized into control and melatonin groups with 8 rats per group according to the day of sacrifice (Days 1, 3, 7, 14, 28). Group B (melatonin group) received 30 mg/kg melatonin intraperitoneally (i.p.) for the duration of the experiment.

Malondialdehyde (MDA) levels in MEL group decreased at days 3, 7, 14, and 28 compared to control values (p< 0.05). Superoxide dismutase (SOD) activity in MEL group decreased at days 3, 7, and 14, and returned to the first day value after 28 days. Myeloperoxidase (MPO) values in MEL group decreased at days 1, 3, and 7 (p< 0.001). Both radiologically and histopathologically fracture healing was significantly more advanced in the MEL group (p< 0.05, p< 0.05 respectively).

We conclude that exogenously administering a pharmacological dose of melatonin has a positive effect on fracture healing and may be beneficial as a supportive agent in fracture cases.

Aim: To biomechanically achieve both the most ideal and the strongest core and periferal suture method by combining 2 and 4 strand core sutures with the simple running and a new locking periferal suture techniques.

Materials and Methods: Fourty flexor digitorum pro-fundus tendons from sheep hindlimbs were studied. The tendons were then repaired using 4 different repair techniques: Group 1 – control, Group 2 – 2 strand modified Kessler’s core suture and simple running periferal suture, Group 3 – 2 strand modified Kessler’s core suture and a new multilocking loop periferal suture, Group 4 – 4 strand modified Kessler’s core suture and simple running periferal suture, Group 5 – 4 strand modified Kessler’s core suture and a new multilocking loop periferal suture. After tenoraphy all fresh sheep cadavers tendons were tested to failure using a distraction rate of 20 mm/min. Maximal strength, 2 mm gap formation force, load to failure, stiffness, method of failure and rate of tendon resistance were assessed. After and before tenoraphy, front – back and side sizes were measured.

Results: Maximal strength was 496, 32, 94, 45 and 100 Newtons for Groups 1, 2, 3, 4 and 5 respectively. There was a significantly statistical difference between the groups (p< 0.0001). Load to 2 mm gap formation was 23, 63, 36 and 72 Newtons for Groups 2, 3, 4 and 5 respectively. There was a significantly statistical difference between the groups (p< 0.0001). Load to failure was 3,783 0,285 0,505 0,41 and 0,572 Joule for Groups 1, 2, 3, 4 and 5 respectively. There was a significantly statistical difference between the groups (p< 0.0001). Tendon stiffness was 42.6, 5.16, 11.2, 5.8 and 12.6 Newton/milimetre for Groups 1, 2, 3, 4 and 5 respectively. There was a significantly statistical difference between the groups (p< 0.0001). The rate of tendon resistance was 0.97, 0.8, 1.0 and 0.91 for Groups 2, 3, 4 and 5 respectively. There was no significantly statistical difference between these groups (p=0.747> 0.05). All the simple running repairs failed by suture pullout, while all the new multilocking loop periferal suture repairs failed by suture breakage.

Conclusion: The new multilocking loop periferal suture was the best performer overall, with greater ultimate strength, load to failure, 2 mm gap formation force and stiffness.

Aims: Immature articular cartilage has a different celularity from mature articular cartilage. Thus, the healing response may be different between these tissues. In this study, we investigated the role of IGF-I in full-thickness articular cartilage defects between immature and mature rabbits. Methods: This study used 36 immature and 36 mature New Zealand rabbits. Full-thickness articular cartilage defects in the medial femoral condyle were created. Spontaneous evolution occurred in 36 animals (18 immature and 18 mature). The other 36 animals were treated with a locally administrated IGF-I. The animals were killed in groups of eight at 4th, 8th and 12th weeks. Macroscopic, histopathologic and biochemical results were evaluated and analyzed statistically. Results: Serum IGF-I levels were signiþcantly higher in the immature group than the mature group (p< 0.001). Serum IGFBP-3 levels were signiþcantly higher in the mature group than the immature group (p< 0.05). Immunuhistochemical investigation showed chondrcyte proliferation in both groups, but duration of cell proliferation and healing process were shorter in the immature groups. The cell morphology was different between the groups. Local IGF-I treated groups had better histological scores than the control groups at all weeks (p< 0.001). Conclusions: The healing response in mature and immature cartilage were similar but the duration of this healing process was shorter in the immature group and repairing cell morphology was similar to that of the normal chondrocyte.

The purpose of this study was to evaluate the role of locked intramedullary nailing without reaming for the treatment of open tibial and femoral shaft fractures that has recently been widely used all over the world, and recently evaluated.

Seventy open femoral and tibial shaft fractures were treated by meticulous wound excision and early inter-locking nailing without reaming between 1996 and 1999 in our department. The average follow-up of the patients was 20.2 (12–36) months. Thirty-six were fractures of the tibia, and 34 of the femur. Ten (14.3%) were classified as Grade I., 32 (45.7%) as Grade II, and 28 (40%) as grade III according to Gustilo-Anderson. Most of the fractures were the result of high-energy trauma.

In patients fixed with locked intramedullary nails due to no immobilisation, rehabilitation began just after the operation. Hip, knee and ankle functions were regained rapidly. All fractures were united in an average of 17.1 (10.1–36.6) weeks. There were six (8.6%) delayed unions and four superficial infections (5.7%). One patient developed deep infection (1.4%) and required further surgical treatment. Locking screws broke in one tibia (1.4%) and two femurs (2.8%), but the breakage did not result in loss of reduction. Although there was no nail breakage observed, two (2.9%) had between eight and twelve degrees external rotation, four (8.5%) shortening of 1.1 to 2.5 cm., and three (4.3%) valgus seven to ten degrees. Of the seventy fractures, 52 (74.2%) were classified according to Folleras as excellent, 8 (11.4%) as good, 6 (8.5%) as fair and 4 (5.7%) as poor.

Early unreamed intramedullary interlocking nailing is a very effective and safe treatment method for open tibial and femoral shaft fractures.

We designed a prospective randomised trial to compare traditional conservative management with reaming, closed intramedullary nailing. Our aims were to compare early functional and the rehabilitation period between and of the two groups.

The trial had strict criteria for entry: Group A) All patients were skeletally mature, Group B) All fractures were at least 50% displaced or angulated at least 10° in any direction, Group C) All patients had a displaced fracture of the tibial shaft more than 5 cm away from either knee or ankle and with no other significant injury, Group D) Only grade I compound fractures were admitted; grade II and III compound fractures were excluded.

Group A was treated by manipulation of the fracture and the application of a long-leg plaster cast. Group B had closed intramedullary nailing of the fracture, with either dynamic or static locking as indicated. A total of 79 patients entered the trial: 37 in Group A and 42 in Group B. The criteria for fracture union was pain-free, unaided walking. There were two cases of non-union in Group A and none in Group B.

Mean time to union was significantly shorter in Group B, as was the mean delay before return to work. There was significantly more angular deformity and shortening in Group A. Two patients in Group B had been nailed in significant external rotation (8 degrees). Movement at the knee, ankle and hindfoot was regained in the final control. Group B spent longer in hospital than group A. Group A had no cases of infection or wound problems. There was failure of conservative treatment in five of the 37 patients. These patients required late operation. Group B had one case of deep infection. In one case the distal locking screw was broken but no problem was encountered during follow-up. Autogenous bone grafting was performed in one case with non-union.

We have concluded that displaced fractures of the tibial shaft are better and more efficiently treated by closed intramedullary nailing. This method has an acceptable complication rate when compared with conservative treatment.