We investigated the effect of the location and the number of distal screws in the efficiency of an intramedullary nail implementing the finite element method (FEM).

The left proximal femur of a 93-year old man was scanned and two series of full 3D models were developed. The first series, consisting of five models, concerned the use of a single distal screw inserted in five different distal locations. The second series, consisting of four models, concerned the use of four different pairs of distal screws. Each model was analyzed with the (FEM) twice, first considering that the femur is fractured and then considering that the femur is healed.

For nails with a single distal screw, stresses around the nail hole were reduced with proximal placement of the distal screw but the area around the nail hole where the lag screw is inserted is stressed more. Furthermore, for nails with a pair of distal screws, placing the pair of distal screws at a specific location is most beneficial for the mechanical behavior of the femur/nail assembly.

The distal area of the nail generally gets less stressed when a pair of distal screws is introduced, while the presence of two distal screws far away from each other results in lower proximal femoral head displacements. The stress field at the area of fracture is not influenced significantly by the presence of a single distal screw or a pair of distal screws.

To evaluate the clinical outcome of arthroscopic treatment of ACL with an Achilles tendon allograft in patient with acute rupture.

22 patients, between 2003 and 2006, with acute rupture of ACL, were treated with an Achilles tendon allograft. The mean age was 26 years. Patients were evaluated before and after surgery and at the latest follow-up with Noulis-Lahmann test and Pivot shift test. We also used IKDC score, Lysholm score and one leg stance test and functional reach test. Patients were also evaluated with Cybex II + and with plain radiographies.

The mean follow-up time was 3.5 years. 90% of the patients had a negative pivot shift test and 95% of the patients had a score at Noulis-Lahmann test +1. The mean value of IKDC score was 88 (62–100) and the mean time of Lysholm score was 91 (75–100). Until the latest follow-up there were no clinical sighs of inflammation or graft rejection. Radiologic evaluation revealed no sign of tunnel enlargement.

We believe that the use of a fresh-frozen allograft in the treatment of acute ACL ruptures is an effective procedure for the restoration of ligamentous stability of the knee.

In order to assess the effect of osteoporosis on healing time we retrospectively reviewed the files of 165 patients with femoral shaft fractures that were treated in our service by locked, intramedullary nailing. Patients were divided in two age groups; Group A (study group) consisted of patients over 65 years old with radiological evidence of osteoporosis and group B (control group) of patients between 18 and 40 years old with no signs of osteoporosis.

Sixty-six out of 165 patients fulfilled the inclusion criteria for this study. Patients with open fractures, pathological fractures, revision surgery, severe brain injuries, prolonged ITU stay and severe co morbidities were excluded. Twenty-nine patients were classified in group A and 37 in group B. All patients had been assigned the Injury Severity Score (ISS) and had been followed-up clinically and radiographically until fracture union.

In all patients the Singh Index Score for osteoporosis was assigned. In all group A patients Singh score 4 or less was assigned, suggesting the presence of installed osteoporosis, whereas group B patients were assigned with Sighn score 5 or 6. Fracture healing was significantly different between the groups.

Fractures of Group A healed in 19.38±5.9 weeks (12–30) and in group B 16.19±5.07 weeks (10–28) (P=0.02) Fracture healing of nailed femoral diaphyseal fractures significantly delays in older osteoporotic patients. Further studies are mandatory to clarify the exact impact of osteoporosis in the whole healing process and the possible future therapeutic strategies.

Introduction: Biodegradable systems releasing antibiotics are promising candidates for the management of chronic osteomyelitis. Gentamicin and fluoroquinolones are the commonest antibiotics applied with these systems. The effectiveness of a new system from polymerized dilactide (PLA) with incorporated linezolid has been investigated in a rabbit model for treating osteomyelitis by methicillin-resistant Staphylococcus Aureus (MRSA).

Methods: The PLA – Linezolid system was made after thorough stirring 2gr of polymer with 100 mg of linezolid. Experimental osteomyelitis was established in 40 rabbits by a modification of the Norden model. Methicillin-resistant Staphylococcus aureus (MRSA) was applied as the test isolate. After drilling a hole in the upper right femur, the isolate was inoculated along with a thin needle working as a foreign body. After three weeks the needle was removed and cultured and PLA-Linezolid system was implanted in half of the animals. Animals were sacrificed at regular time intervals and tissue around the site of implantation was sent for histologic examination and quantitative cultures.

Results: At 2 – 4 – 6 – 8 – 10 weeks time after removal of the needle results (mean values) were as follows (Controls/PLA-Linezolid): Log10 (cfu/g) at infection site: 2.99/5.68 – 3.44/3.20 – 3.22/2.39 – 1.00/1.27 – 1.00/1.00 respectively and Δlog10 (cfu/g) compared to start: −0.05/−3.23 – 0.23/0.13 – 0.05/0.93 – 1.34/1.09 – 3.31/3.34 respectively. Histology confirmed the previous mentioned results, showing an early decrease following by late recurrence of the infectious reaction at the animals that PLA-Linezolid system was used.

Conclusions: It is concluded that the applied system achieved an early decrease of the tissue bacterial load which was not maintained until late on follow-up. This might be explained by the bacteriostatic mode of action of linezolid.

Purpose of study: To investigate and compare the characteristics of the reconstructed articular surface microscopically and histologically after a time period of 6 weeks following the treatment of a focal defect of the right femoral head with subchondral drilling and autologous osteochondral transplantation in rabbits

Material and method: A 2,5 mm diameter and 3 mm depth iatrogenic osteochondral defect in the anterolateral weight bearing area of the right femoral head was created in 12 rabbits. In a group of 6 rabbits the lesion was treated with autologous osteochondral transplantation. The donor site for the transplant was the lateral condyle of the ipsilateral knee joint. The other group of 6 rabbits was treated with subchondral drilling. Both groups were sacrificed after a time period of 6 weeks and specimens were evaluated histologically under the classification system of the ICRS. For statistical analysis we used the Mann – Wittney test

Results: According to the ICRS score statistical significance was found for all variables between the 2 groups (subchondral drilling 6 weeks vs autologous osteochondral transplantation 6 weeks).: articular surface (p=0,049), matrix (p=0,003), cell distribution (p< 0,0005), subchondral bone (p=0,010), cartilage mineralization (p=0,0) except cell population viability.

Discussion: In comparison to subchondral drilling, autologous osteochondral transplantation provided better results concerning the smoothness and continuity of the articular surface, the consistency of the matrix with dominance of the hyaline and mixed hyaline – fibrocartilage type of tissue, the normality of subchondral bone and the columna r distribution of cells. The viability of the cell populations was the same for both methods. The incorporation of the osseous part of the graft was successful in all cases and the surgical procedure did not produce any necrosis of the femoral head.

Conclusion: In cases of focal osteochondral defect of the femoral head in rabbits, reconstruction of the articular surface through autologous osteochondral graft transplantation gives superior macroscopical and histological results in comparison to subchondral drilling

AIM: Chronic osteomyelitis is a difficult to treat infection requiring prolonged antimicrobial therapy and involving systems of local antimicrobial delivery. Linezolid is a new antimicrobial agent with well documented in vitro activity against gram positive cocci when resistance to other antistaphylococcal agents is present. Few data are present regarding its embedding in local antimicrobial delivery systems and subsequent elution. The elution of linezolid by a polylactic acid (PLA) system was studied.

METHODS: Linezolid was dry-mixed with PLA at a ratio of 1:9, ie 50mg of linezolid were mixed with 450mg PLA. The mixture was diluted with 0,5mL of methanol and placed at the bottom of a cylindrical vial. Two replicas were created and one mL of Mueller-Hinton broth was added over the free solid surface of each mixture. Vials were transferred to a 37°C incubator and broth was replaced every 48h for 11 days. Concentration of linezolid was determined by an HPLC method using a Zorbax Eclipse XDB-C8 column and UV detection.

RESULTS: Mean linezolid concentration at days 1, 3, 5, 7, 9 and 11 was 2778.54 mg/L, 2456.22 mg/L, 668.63 mg/L, 324.86 mg/L, 390.10 mg/L, and 155.28 mg/L respectively.

CONCLUSION: Elution of linezolid by a PLA local delivery system remains very high throughout the period studied. The results are promising for the therapy of staphylococcal chronic osteomyelitis with the use of a PLA local antimicrobial delivery system employing linezolid.

Aim: To evaluate the feasibility of Norian S.R.S in the treatment of comminuted distal radius fractures.

Material and methods: 24 patients with comminuted distal radius fractures were open reduced and preserved with external fixation. The bone gaps were filled with Norian S.R.S. The wrist was mobilized at the 3rd postoperative week and the external fixation was removed the 4th–6th postoperative week, when the fracture healing was radiologically confirmed. All the patients had regular clinical and radiological control the first postoperative date and the 1rd, 3rd, 4th postoperative week and monthly until the 9th postoperative month.

Results: In the postoperative follow-up we didn’t note any loss of reduction and the joint range of motion compared with the contralateral exceeded 50% in 3 months and came close to 85% in 6 months. There were no clinically significant adverse effects or complications.

Conclusions: We believe that the use of Norian S.R.S. offers the potential for filling bony voids, does not exhibit tissue reactions and is progressively absorbed. The results of this study are comparable with other therapeutic approaches. Additionally, the use of the Norian S.R.S offers the potential of earlier mobilization and as an implant is bioabsobable through osteoclastic activity. In conclusion we believe that use of Norian S.R.S in the filling of bony defects in the comminuted distal radius fractures is a reliable and safe method of treatment.

Aim: To compare two implants, the Gamma Nail and the ACE Trochanteric Nail in the treatment of pertrochanteric femoral fractures.

Patients and methods: Sixty patients were randomized on admission to two treatment groups. Thirty patients were treated with the Gamma nail implants , and thirty had intramedullary fixation with ACE Trochanteric NailI . The average age of these patients was 79 years. 22 patients were men and 38 women. 11 fractures were stable and 49 unstable. Patients were followed for 1 year and had a regular clinical and radiological review at 1, 3 and 6 months postoperatively. Operation time, intra-operative blood loss and blood transfusion and complications were recorded. The mobility score was used to assess the preinjury and postoperative mobility status. All the patients were operated within 24 hours after their accident and 39 of them within the first 6 hours.

Results: There were no complications during the surgery. All the patients were mobilized the first 24 hours post operatively irrespectively of the fracture’s type, and weight bearing was permitted as tolerated. The mean follow up time was 8 months (range 6 to 12 months). 3 patients were lost at the follow up and 2 died. Union of the fracture was achieved in all 55 patients. There was no statistically significant difference between the two groups with regard to intraoperative blood loss and the duration of the surgery. There was no mechanical failure of the implants despite the early patients mobilization. All the patients achieved mobility status similar to the preoperative at the latest follow up.

Conclusions: Based on our study, intramedullary nailing of pertrochanteric hip fractures represents a reliable method of treatment. We did not observe any differences in the two patient groups concerning the operation time, the intraoperative blood loss, the postoperative complications and the patients functional status at the latest follow up.

Sepsis and multiple-organ failure are common sequelae of multiple trauma. Although sepsis is considered to result from bacteria translocating through the gut mucosa, evidence for that is lacking. In order to define the chronic involvement of bacterial translocation, fracture was induced after crushing of the right femor on its mid in 11 rabbits. Blood was collected at regular time intervals for quantitative culture and for estimation of endotoxins (LPS) by the QCL LAL-assay, tumor necrosis factor-alpha (TNFalpha) by a bioassay in L929 fibrosarcoma cell line and malondialdehyde (MDA) by HPLC. After death, segments of liver, lung and spleen were cut for quantitative culture. Mean +/−SE of the log10 of viable cells in blood were 2.48 +/− 0.43, 3.16 +/− 0.46, 2.77 +/− 0.69 and 2.12 +/− 0.43 at 2, 4, 24 and 48 hours after fracture. Respective values for LPS were 1.50 +/−0.29, 1.54 +/− 0.44, 1.17 +/− 0.17 and < 1.00; for MDA 3.57 +/− 0.55, 7.50 +/− 3.00, 15.77 +/− 12.26 and 5.07 +/− 2.18 μM; and for TNFalpha 11.8 +/− 1.2, 36.7 +/− 25.9, 40.7 +/− 24.0 and 56.8 +/− 45.3 pg/ml. Positive tissue cultures for Serratia marscecens and Pseudomonas aeruginosa were found for six rabbits. Median survival for animals drawn positive tissue cultures was 1.00 days and 7.00 days for animals with negative tissue cultures (p: 0.0092). It is concluded that bacterial translocation is a process occurring early in a significant percentage in the field of multiple trauma. Its occurrence is accompanied by rapid progression to death. Further research is mandatory to clarify the reasons favoring that process in certain hosts compared to others.

Aims: The topographical measurement and representation of the ACL insertion on the tibial plateau, based on a greek population sample. Methods: Fourty eight tibial plateaus were explanted during TKA surgery in 33 female and 15 male patients (average age of 71.2 yrs) suffering from osteoarthritis and rheumatoid arthritis. By means of a calliper, measurements were conducted in order to determine the dimensions shown. Data were used for a topographical representation.

Conclusions: To the authors’ best knowledge, this is the first such anthropometric study on a greek population and its results provide a confirmation on the relatively wide base of ACL insertion on the tibial plateau. The biomechanical performance of this natural configuration for a full range of motion, is possibly not sufficiently reproduced by conventional ACL reconstruction techniques using just one bundle.

Aims: The evaluation of the results becoming from the use of demineralized bone matrix (DBM) in the bone defects. Methods: In the present study the above substance was implanted during the period 2000-2002 (28 months) to 24 patients, 11 males and 13 females average age 39,1 for the males and 60 for the females. As a cause was referred in 12 patients the fall, in 3 patients the car crash, in 5 patients the following the removal of osteosynthesis materials, in 2 patients the bone cysts, in 1 patient fracture of ankle joint following fusion and in 1 patient a pseudarthrosis. The implantation of DBM concerned 8 hips, 4 femurs, 6 knees, 1 humerus, 1 forearm, 1 ankle, 2 metacarpal and 1 phalanx. All the fractures as well the fusion were treated through internal fixation. There was a regular post op follow-up and concerned the clinical and x-ray examination per month until the total incorporation of the graft (12 weeks). Results: In all patients the total incorporation of the DBM was accomplished in a brief period of time, depended on the place of implantation without having local or systemic side effects. We have to remark the early signs of bone shadow around the 3rd week, as well the incorporation of the matrix around the 12th week in the x-ray findings. Conclusions: The use of DBM in bone defects could play an important role to the filling of bone defrects due to fractures or benign cysts as a result of its incorporation and without inducing local or systematic side effects.

Aims: The effectiveness of the local treatment of experimental osteomyelitis caused by MRSA (Methicillin Resistant Staph. aureus) performed with the implantation of acrylic bone cement (PMMA) mixture plus 4% grepaßoxacin into the femur of rabbits. Methods: 36 rabbits with chronic MRSA osteomyelitis of the right femur (Norden Model) were treated with a new local grepaßoxacin delivery system prepared by a mixture of PMMA plus 4% grepaßoxacin. Osteomyelitis was introduced by inoculating of the MRSA and the placement of a needle serving as a foreign body. The follow-up of the infection was performed by clinical, microbiological and x-rays þndings. On the 3rd week all animals were reoperated and the needle was removed followed by implantation of the mixture. One control and þve treated animals were sacriþced each week thereafter until the 6th week. Results: Osteomyelitis was induced in all rabbits. The in vitro grepaßoxacin levels were high for 6 weeks at least. Concerning the histological þndings serious tissue reactions were not observed. The lesions and the bone structure are progressively rehabilated after the implantation. The biomechanical study didnñt inßuence the mechanical properties of bone cement due to grepaßoxacin. Conclusions: The above mixture could be an approved supplementary method for the treatment of bone infections. In the chronic osteomyelitis itñs possible to replace the gentamycin PMMA beads. Furthermore could be use as a spacer in loosen arthroplasties due infection in combination with antibiotic administration.

Aims: The effectiveness of the local treatment of experimental osteomyelitis by MRSA with a mixture of calcium phosphate bone cement and 3% teicoplanin into the femur of rabbits. Methods: Thirty-six male rabbits with chronic (3 weeks) MRSA (Methicillin Resistant Staph. aureus) osteomyelitis of the right femur (Model of Norden CW) were treated with a new local Teico-planin delivery system prepared by a mixture of calcium phosphate cement plus 3% teicoplanin. Osteomyelitis was introduced by inoculating 107 cfu/ml of the MRSA strain in a 2mm hole of the bone medula, placement of a needle serving as a foreign body and subsequent closure with a sterile bone wax. The follow-up of the infection was performed by clinical, microbiological, x-rays and histological þndings. On the third week all animals were reoperated and the needle was removed followed by implantation of the above mixture. One control and þve treated animals were sacriþced each week thereafter until the sixth week. Results: Cultures of the treated animals were positive during the þrst week but turned negative after the second week, while throughout the same period cultures from the controls remain positive. Clinical and histologic studies were in accordance. Conclusions: The above mixture could be approved as a supplementary method in the treatment of bone infections. It can be used by replacing the gentamycin polymethyl-methacrylate beads whose use demands reoperation to be removed. Finally it offers the possibility to contribute to the þlling of the bone gaps as it can be replaced by host bone.

Aims: The evaluation of the results becoming from the use of demineralized bone matrix (DBM) in the bone defects.

Methods: In the present study the above substance was implanted during the period 2000–2002 (28 months) to 24 patients, 11 males and 13 females average age 39.1 for the males and 60 for the females. As a cause was referred in 12 patients the fall, in 3 patients the car crash, in 5 patients following the removal of osteosynthesis materials, in 2 patients the bone cysts, in 1 patient fracture of ankle joint following fusion and in 1 patient a pseudarthrosis. The implantation of DBM concerned 8 hips, 4 femurs, 6 knees, 1 humerus, 1 forearm, 1 ankle, 2 metacarpal and 1 phalanx. All the fractures as well the fusion were treated through internal fixation. There was a regular post op follow-up and concerned the clinical and x-ray examination per month until the total incorporation of the graft (12 weeks).

Results: In all patients the total incorporation of the DBM was accomplished in a brief period of time, depended on the place of implantation without having local or systemic side effects. We have to remark the early signs of bone shadow around the 3rd week, as well the incorporation of the matrix around the 12th week in the x-ray findings.

Conclusions: The use of DBM in bone defects could play an important role to the filling of bone defects due to fractures or benign cysts as a result of its incorporation and without inducing local or systematic side effects.

Aims: The experimental application and biomechanical evaluation of a double – bundle ACL reconstructive technique(Ä plasty)

Methods: The reported technique suggests use of a pair of grafts, with common origin and different insertions. Experimental surgery was conducted on 25 porcine knee joints, divided as follows: Group A of 15 joints for the reported technique and group B of 10 joints for a single – bundle technique. Group A was divided in subgroups A1, A2 and A3, depending on different distances between insertion points. For surgery and testing a device was designed, with adaptors serving specimen alignment adjustments. A dial gauge was used for monitoring displacements caused by simulated drawer tests. Tests were carried out at knee flexion angles of 30, 60 and 90 degrees and with the natural ACL intact, ruptured and reconstructed. Measurements of Knee laxity were recorded

Results: In the intact condition, no statistical difference was found between specimens used to compare the two techniques (p-value equals 0,905). Overall, the double – bundle technique provided significantly lower laxity values, than the one – bundle technique (2.0 plus/minus 0.6 mm and 3.4 plus/minus 0.9 mm, respectively, with p – value less than 0.001). Laxity values obtained with the double – bundle technique were significantly lower, when adopting a large distance between insertions (p – value equals 0.016).

Conclusions: As the two techniques were compared on a uniform specimen population, results of in vitro biomechanical testing advocate that the reported double- bundle technique offered ACL reconstructions of superior stability. This is a promising technique which is deserved biggest study in vivo.

Aims: The topographical measurement and representation of the ACL insertion on the tibial plateau, based on a greek population sample.

Methods: Fourty eight tibial plateaus were explanted during TKA surgery in 33 female and 15 male patients (average age of 71.2 yrs) suffering from osteoarthritis and rheumatoid arthritis. By means of a calliper, measurements were conducted in order to determine the dimensions shown. Data were used for a topographical representation.

Conclusions: To the authors’ best knowledge, this is the first such anthropometric study on a greek population and its results provide a confirmation on the relatively wide base of ACL insertion on the tibial plateau. The biomechanical performance of this natural configuration for a full range of motion, is possibly not sufficiently reproduced by conventional ACL reconstruction techniques using just one bundle.

Purpose: The aim of this paper is to present a new surgical method for the reconstruction of the recurrent sprain of the ankle.

Material – Methods: From 1980 until 1997, 17 patients 3 females and 14 males, average age 25.53 (19 – 44) underwent surgery suffering recurrent sprain of the ankle. In 11 patients the right ankle was involved and in 6 patients the left ankle. The cause of the injury was: athletic activities in 9 cases, weekend activities in 7 cases and daily activities in 1 case.

The patients were suffering from ankle instability 4–15 years prior the operation. All the patients underwent reconstructive surgery of the anterolateral elements (capsule and ligaments) according to senior author’s method. This included shortening of the anterolateral elements, capsule and ligaments, overlaping the anterolateral part over the anterolateral one in such a way, that the anterior drawer and varus tests were negative with the patient under anaesthesia.

Results: The follow up is 2–12 years. A patient underwent for a second time surgery, because of a new injury. In 2 patients early signs of ankle osteoarthritis. In the rest of them, restoration of the function of the ankle joint was excellent, obtaining full activities 3 months postperatively.

Conclusion: This surgical method for the reconstruction of the recurrent sprain of the ankle is considered satisfactory and when indicated allows young patients and athletes to participate in a rather short period of time, in their previous level of activities.

Aims: The effectiveness of the local treatment of experimental osteomyelitis by MRSA with a mixture of calcium phosphate bone cement and 3% teicoplanin into the femur of rabbits.

Methods: Thirty-six male rabbits with chronic (3 weeks) MRSA (Methicillin Resistant Staph. aureus) osteomyelitis of the right femur (Model of Norden CW) were treated with a new local Teicoplanin delivery system prepared by a mixture of calcium phosphate cement plus 3% teicoplanin. Osteomyelitis was introduced by inoculating 107 cfu/ml of the MRSA strain in a 2mm hole of the bone medula, placement of a needle serving as a foreign body and subsequent closure with a sterile bone wax. The follow-up of the infection was performed by clinical, microbiological, x-rays and histological findings. On the third week all animals were reoperated and the needle was removed followed by implantation of the above mixture. One control and five treated animals were sacrificed each week thereafter until the sixth week.

Results: Cultures of the treated animals were positive during the first week but turned negative after the second week, while throughout the same period cultures from the controls remain positive. Clinical and histologic studies were in accordance.

Conclusions: The above mixture could be approved as a supplementary method in the treatment of bone infections. It can be used by replacing the gentamycin polymethylmethacrylate beads whose use demands reoperation to be removed. Finally it offers the possibility to contribute to the filling of the bone gaps as it can be replaced by host bone.