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Konstantinos N Malizos

Publications and source records attributed to Konstantinos N Malizos.

At least 19 recordsLinked to original sources
PubMed2007

Patellar tendon length after anterior cruciate ligament reconstruction: a comparative magnetic resonance imaging study between patellar and hamstring tendon autografts.

Patellar tendon shortening after anterior cruciate ligament reconstruction may be associated with anterior knee pain or patellofemoral arthritis. The present study was designed to compare postoperative changes in patellar tendon length after anterior cruciate ligament reconstruction between patellar tendon and hamstring tendon autograft. Magnetic resonance images of both knees (operated and healthy) and functional outcome were documented at least 1 year postoperatively in 16 patellar tendon harvested patients and in 32 hamstrings harvested patients. Patellar tendon length, patella length and Insall-Salvati ratio were measured. The operated knee values were compared to the respective values of the non-operated control knees. A significant 4.2 mm or 9.7% patellar tendon shortening in patellar tendon group and a non-significant 1.14 mm or 2.6% shortening in hamstrings group was detected. No significant difference was detected in terms of major shortening-patella baja-(6% for the patellar tendon group vs. 0% for the hamstring group). There was no significant difference in anterior knee problems between the two groups as evidenced by the Shelbourne score (94 for the patellar tendon group vs. 98 for the hamstring group). Harvesting of the patellar tendon for anterior cruciate ligament reconstruction resulted in a significant shortening of the remaining tendon. In contrast harvesting of the hamstring tendons did not affect significantly the patellar tendon length. However, the incidence of patella baja and overall functional outcome was not significantly different between the two groups.

Adolescent↗
PubMed2006

Arthroscopic meniscal repair: a comparative study between three different surgical techniques.

The purpose of this prospective study was to evaluate and compare the results of arthroscopic meniscal repair using three different techniques. Between January 2002 and March 2004, 57 patients who met the inclusion criteria underwent an arthroscopic meniscal repair. The outside-in technique was used in 17 patients (group A), the inside-out in 20 patients (group B), while the rest of the 20 patients (group C) were managed by the all-inside technique using the Mitek RapidLoc soft tissue anchor (Mitek Surgical Products, Westwood, MA, USA). Anterior cruciate ligament (ACL) reconstruction was performed in 29 patients (51%). The criteria for clinical success included absence of joint line tenderness, locking, swelling, and a negative McMurray test. The minimum follow-up was one year for all groups. The mean follow-up was 23 months for group A, 22 months for group B, and 22 months for group C. All meniscal repairs were considered healed according to our criteria in group A, while 19 out of 20 repairs (95%) healed in group B. Finally 7 of 20 repairs (35%) were considered failures in group C and this difference was statistically significant in comparison with other groups. The time required for meniscal repair averaged 38.5 min for group A, 18.1 min for group B, and 13.6 min for group C. Operation time for meniscal repair in group A was statistically longer in comparison with other groups. There were no significant differences among the three groups concerning complications. According to our results, arhtroscopic meniscal repair with the inside-out technique seems to be superior in comparison with the other methods because it offers a high rate of meniscus healing without prolonged operation time.

Adult↗
PubMed2006

Low-intensity pulsed ultrasound for bone healing: an overview.

Low-intensity ultrasound is a biophysical form of intervention in the fracture-repair process, which through several mechanisms accelerates healing of fresh fractures and enhances callus formation in delayed unions and nonunions. The goal of this review is to present the current knowledge obtained from basic science and animal studies, as well as existing evidence from clinical trials and case series with the different applications of ultrasound in the management of fractures, delayed unions, nonunions and distraction osteogenesis. Low-intensity pulsed ultrasound is currently applied transcutaneously, although recent experimental studies have proven the efficacy of a trans-osseous application for both enhancement and monitoring of the bone healing process with modern smart implant technologies.

Animals↗
PubMed2006

Absence of linkage to chromosomes 6q and 16p in a Greek population with knee osteoarthritis.

Osteoarthritis (OA) is a common age-related debilitating disease of the joints characterized by degeneration of the articular cartilage which leads to joint pain, discomfort, and immobility. Several risk factors have been associated with OA including a genetic predisposition. Specific chromosomal regions have thus far been associated with susceptibility to OA, the strongest being on chromosomes 2, 6, and 16. We hereby report our data on 34 Central Greek knee OA families that were investigated for linkage to the chromosome 6q and 16p susceptibility regions. All affected members had undergone total knee replacement surgery (TKR) at a single large Orthopedics Unit in Central Greece. Nineteen microsatellite markers were selected, 15 for chromosome 6q and 4 for chromosome 16p at a distance of approximately 7 cm. Allele fragment sizes were determined by an automated DNA sequencer using the Fragment Analysis Software. Our results revealed a statistically significant difference in the ratio of affected females to males with knee OA and also showed that there is no evidence of linkage to regions 6q and 16p in a cohort of Central Greek pedigrees with knee OA.

Adult↗
PubMed2006

Vascularized bone grafts from the palmar radius for the treatment of waist nonunions of the scaphoid.

PURPOSE: With their intrinsic vascularity vascularized bone grafts provide an alternative solution to the challenging problem of scaphoid nonunions. The union rate (after imaging evaluation including magnetic resonance imaging [MRI]) and functional outcome of using vascularized bone grafts pedicled on the palmar carpal epiphyseal artery for waist nonunions of the scaphoid are reported in this prospective case series. METHODS: The technique was applied to 9 waist nonunions resulting from fractures. The mean time elapsed from the initial injury to the procedure was 22 months and the mean follow-up time was 24 months. The graft was pedicled on the artery running at the distal edge of the pronator quadratus and was inserted in the nonunion as an intercalary graft. Six patients had postoperative MRIs to evaluate fracture healing and graft incorporation. RESULTS: Union was accomplished in all cases between 6 and 12 weeks. Postoperative MRI showed the viability of the graft (contrast-enhanced images) and confirmed union and graft incorporation. Complete absence of pain was noted in all patients. The Mayo modified wrist score increased from 63 to 92 after surgery and according to this score results were excellent in 5 patients and good in 4. CONCLUSIONS: Vascularized bone grafts from the anterior radius lead to rapid union and consolidation in cases of waist nonunion. Postoperative MRI confirms viability of the graft, union, and graft incorporation. The approach is limited to the distal radius and wrist and lacks donor site morbidity. The interposition of the graft from the palmar side allows correction of the humpback deformity and patients regain carpal height, grip strength, and painless motion. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.

Adolescent↗
PubMed2006

A capsular-based vascularized distal radius graft for proximal pole scaphoid pseudarthrosis.

PURPOSE: To evaluate the clinical results of the application of a capsular-based dorsal distal radius vascularized bone graft in scaphoid proximal pole nonunions. METHODS: Thirteen patients with symptomatic nonunion at the proximal pole of the scaphoid (10 with avascular necrosis) were treated and reviewed retrospectively. The vascularized bone graft was harvested from the distal aspect of the dorsal radius and was attached to a wide distally based strip of the dorsal wrist capsule. It was inserted press-fit into a dorsal trough across the nonunion site after scaphoid fixation with a Herbert screw. RESULTS: After a mean follow-up period of 19 months 10 of the 13 nonunions (8 of the 10 with avascular necrosis) achieved solid bone union. No complications other than the 3 persistent nonunions occurred. CONCLUSIONS: Results of the use of a capsular-based vascularized bone graft from the distal radius for proximal pole scaphoid nonunions compare favorably with the results of pedicled or free vascularized grafts. It is a simple technique that eliminates the need for dissection of small-caliber pedicle or microsurgical anastomoses. No donor site morbidity was observed. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic, Level IV.

Adult↗
PubMed2006

Guided ultrasound wave propagation in intact and healing long bones.

Ultrasonic evaluation of bone fracture healing has been traditionally based on the measurement of the propagation velocity of the first arriving signal (FAS). However, the FAS in general corresponds to a lateral wave that propagates along the bone's subsurface. In this work, we study guided ultrasound propagation in intact and healing bones. We developed a 2-D model of a bone-mimicking plate in which the healing process was simulated as a 7-stage process, and we also carried out ex vivo experiments on an intact tibia. Guided waves were represented in the time-frequency (t-f) domain of the signal by incorporating the Lamb wave theory. Three t-f distribution functions were examined, namely the reassigned Spectrogram, the smoothed-pseudo Wigner-Ville, and the reassigned version of it. For the intact plate case, we found that the S2, A3 Lamb modes were the dominant waves for a broadband 1-MHz excitation, and the S2, S0 for a 500-kHz excitation. During the simulated healing process, the mechanical and geometrical callus properties affected the theoretically anticipated Lamb modes. The propagation of guided waves throughout the thickness of the cortical bone and their sensitivity to both the mechanical and structural changes during healing can supplement velocity measurements so as to enhance the monitoring capabilities of ultrasonic evaluation. Nevertheless, the applicability of the Lamb wave theory to real bones has several limitations mostly associated with neglecting the inhomogeneity, anisotropy and irregular geometry of bone.

Acoustics↗
PubMed2006

Rotator cuff interval reconstruction.

Five pairs of cadaveric shoulders underwent posterior and anterior drawer and inferior sulcus tests in five progressive conditions: intact, vented, following opening of the rotator cuff interval, reconstruction of the interval, and transfer of the coracoacromial ligament. The surgical treatments--vented, open rotator cuff interval, reconstruction, and coracoacromial ligament transfer--had an effect compared to the intact shoulders on the inferior stiffness (P = .00002) and on the anteroposterior stiffness (P = .00031). The difference between the stiffness of the reconstructed rotator cuff interval compared to the coracoacromial ligament transfer was significant for loading in the AP direction (P = .006) and for loading in the inferior direction (P = .005).

Adult↗
PubMed2005

Transosseous application of low-intensity ultrasound for the enhancement and monitoring of fracture healing process in a sheep osteotomy model.

The purpose of this study is twofold: (a) to investigate the application of transosseous low-intensity pulsed ultrasound (LiUS) on the enhancement of fracture healing and (b) to demonstrate the ability of transosseous ultrasound propagation to monitor the healing process. A midshaft tibial osteotomy model was used on 40 skeletally mature sheep, and an external fixator was applied to maintain the reduction and stabilization of the osteotomy. Two ultrasound transducers were implanted into the fracture site in contact with the bone. For investigating the efficacy of LiUS, the animals were randomly divided in two equal groups: the treatment group and the control group. The LiUS-treated animals received 200-micros bursts of 1-MHz sine waves with a pulse repetition rate of 1 kHz and average intensity of 30 mW/cm2, for 20 min daily. For monitoring purposes, an ultrasound dataset was constructed consisting of serial ultrasound measurements obtained from healing bones. Animals' sacrifice took place on the 100th post-operative day. The effect of LiUS on fracture healing was evaluated using radiographs, destructive three-point bending testing and quantitative CT-based bone mineral density (BMD) measurements. Survival analysis using Kaplan-Meier curves showed significantly higher probability of radiographic healing for the animals in the treatment group (P = 0.009). Statistical significance was also observed for callus BMD (P = 0.003, Wilcoxon nonparametric test), the breaking load (P = 0.001), extrinsic stiffness (P = 0.019), Young's modulus (P = 0.043) and ultimate strength (P = 0.051) in favor of the LiUS-treated limbs. Analysis of the obtained ultrasonic measurements showed that the propagation velocity across healing bones constitutes a significant feature able to early distinguish between healed and nonhealed bones (area under ROC curve was 0.810 and 0.841 on the 80th and 100th post-operative days, respectively). Both the LiUS application and the ultrasonic measurements are supported by an integrated telemedicine system which also incorporates an ultrasound wearable device and a patient management system.

Animals↗
PubMed2005

The healing potential of the periosteum molecular aspects.

The presence of pluripotential mesenchymal cells in the under surface of the periosteum in combination with growth factors regularly produced or released after injury, provide this unique tissue with an important role in the healing of bone and cartilage. The periosteum contributes in the secondary callus formation with cells and growth factors and should always be preserved and protected when surgery is performed for the management of a fracture. The current evidence about the cellular interactions, the stimulants and the signalling pathways related to osteogenesis and chondrogenesis is described. An essential knowledge of the basics related to the contribution of the periosteum in the healing of fractures, osteotomies, during the process of distraction osteogenesis and in some degree in the repair of cartilagenous defects, provides the surgeons with a better insight to understand the upcoming "biological" interventions in the management of skeletal injuries.

Cell Differentiation↗
PubMed2005

Vascularized periosteal flaps of distal forearm and hand.

BACKGROUND: Vascularized periosteal flaps (VPFs) are flexible osteogenic flaps, suitable for the reconstruction of small skeletal defects. Pedicled VPFs, harvested near the recipient site, minimize donor-site morbidity and procedure duration. The donor sites and the potential recipient sites for pedicled VPFs of the distal forearm-hand were identified in this study. METHODS: In 16 fresh cadaver upper extremities, the dimensions and arcs of rotation of the VPF pedicle(s) were studied. RESULTS: Pedicled VPFs with mean dimensions ranging between 0.5 x 3 cm and 2.5 x 4 cm could cover, after adequate mobilization, the distal half of the forearm, wrist, and hand to the proximal interphalangeal joints. CONCLUSION: The VPFs identified in this study can be used for the reconstruction of small skeletal defects and for the treatment of osteonecrotic lesions and nonunions of the distal forearm, wrist, and hand. The choice of the most suitable VPF will be based on the anatomic location and the dimensions of the recipient site.

Cadaver↗
PubMed2005

An ultrasound wearable system for the monitoring and acceleration of fracture healing in long bones.

An ultrasound wearable system for remote monitoring and acceleration of the healing process in fractured long bones is presented. The so-called USBone system consists of a pair of ultrasound transducers, implanted into the fracture region, a wearable device and a centralized unit. The wearable device is responsible to carry out ultrasound measurements using the axial-transmission technique and initiate therapy sessions of low-intensity pulsed ultrasound. The acquired measurements and other data are wirelessly transferred from the patient-site to the centralized unit, which is located in a clinical setting. The evaluation of the system on an animal tibial osteotomy model is also presented. A dataset was constructed for monitoring purposes consisting of serial ultrasound measurements, follow-up radiographs, quantitative computed tomography-based densitometry and biomechanical data. The animal study demonstrated the ability of the system to collect ultrasound measurements in an effective and reliable fashion and participating orthopaedic surgeons accepted the system for future clinical application. Analysis of the acquired measurements showed that the pattern of evolution of the ultrasound velocity through healing bones over the postoperative period monitors a dynamic healing process. Furthermore, the ultrasound velocity of radiographically healed bones returns to 80% of the intact bone value, whereas the correlation coefficient of the velocity with the material and mechanical properties of the healing bone ranges from 0.699 to 0.814. The USBone system constitutes the first telemedicine system for the out-hospital management of patients sustained open fractures and treated with external fixation devices.

Animals↗
PubMed2005

Diagnostic accuracy of a new clinical test (the Thessaly test) for early detection of meniscal tears.

BACKGROUND: Clinical tests used for the detection of meniscal tears in the knee do not present acceptable diagnostic sensitivity and specificity values. Diagnostic accuracy is improved by arthroscopic evaluation or magnetic resonance imaging studies. The objective of this study was to evaluate the diagnostic accuracy of a new dynamic clinical examination test for the detection of meniscal tears. METHODS: Two hundred and thirteen symptomatic patients with knee injuries who were examined clinically, had magnetic resonance imaging studies performed, and underwent arthroscopic surgery and 197 asymptomatic volunteers who were examined clinically and had magnetic resonance imaging studies done of their normal knees were included in this study. For clinical examination, the medial and lateral joint-line tenderness test, the McMurray test, the Apley compression and distraction test, the Thessaly test at 5 degrees of knee flexion, and the Thessaly test at 20 degrees of knee flexion were used. For all clinical tests, the sensitivity, specificity, false-positive, false-negative, and diagnostic accuracy rates were calculated and compared with the arthroscopic and magnetic resonance imaging data for the test subjects and the magnetic resonance imaging data for the control population. RESULTS: The Thessaly test at 20 degrees of knee flexion had a high diagnostic accuracy rate of 94% in the detection of tears of the medial meniscus and 96% in the detection of tears of the lateral meniscus, and it had a low rate of false-positive and false-negative recordings. Other traditional clinical examination tests, with the exception of joint-line tenderness, which presented a diagnostic accuracy rate of 89% in the detection of lateral meniscal tears, showed inferior rates. CONCLUSIONS: The Thessaly test at 20 degrees of knee flexion can be used effectively as a first-line clinical screening test for meniscal tears, reducing the need for and the cost of modern magnetic resonance imaging methods.

Adolescent↗
PubMed2004

Localized pigmented villonodular synovitis in the anteromedial compartment of the knee associated with cartilage lesions of the medial femoral condyle: report of a case and review of the literature.

Localized pigmented villonodular synovitis (PVNS) of the knee is an uncommon entity, presenting with different clinical signs and symptoms. We report on a case of a 42-year-old woman who presented with a 3-year history of knee pain and mechanical problems such as locking. On examination she was found to have a palpable and painful mass over the anteromedial joint line. Magnetic resonance imaging (MRI) revealed a soft tissue mass in the anteromedial compartment of the knee joint. The lesion was completely resected arthroscopically, and histologic examination confirmed the diagnosis of localized PVNS. The patient was free of symptoms, and MRI examination showed no evidence of recurrence at 1-year follow-up.

Adult↗
PubMed2004

MR imaging findings in early osteoarthritis of the knee.

PURPOSE: To carry out a modern diagnostic survey among patients with a clinical and radiological diagnosis of early osteoarthritis of the knee. MATERIALS AND METHODS: A magnetic resonance imaging survey was performed on 70 patients (82 knees) with a mean age of 59 years. (range, 40-71 years) who had chronic knee pain, clinical diagnosis of early osteoarthritis of the knee and conventional knee radiographs classified as 1 and 2 on the Kellgren-Lawrence scale. RESULTS: A variety of different disorders was found; degenerative meniscal lesions with or without ruptures of the anterior cruciate ligament in 70.7% of the knees, osteonecrosis of the femoral and tibial condyles in 9.75%, osteophytes and degenerative articular cartilage lesions in 8.54%, transient osteoporosis in 2.44% and benign neoplasms and cysts in 6.1%. CONCLUSIONS: The existence of such a heterogenous group of disorders in these "early osteoarthritic knees" may explain failures in treatment and it may justify a modern MRI imaging approach to proper diagnosis.

Adult↗
PubMed2004

Evaluation of meniscal repair with serial magnetic resonance imaging: a comparative study between conventional MRI and indirect MR arthrography.

OBJECTIVE: To prospectively investigate the healing process of meniscal repair with plain magnetic resonance imaging (MRI) and indirect MR arthrography and to compare the two methods. MATERIALS AND METHODS: Twenty patients with an arthroscopic meniscal repair without clinical symptoms underwent conventional and indirect MR arthrography of the affected knee, 3, 6 and 12 months after the index operation applying a T1-w Spin Echo sequence in three planes. The size of the tear gap was measured on transverse images. The signal-to-noise ratio and the configuration of the abnormal signal were evaluated in the coronal images. RESULTS: All patients demonstrated abnormal signal intensity at the side of the meniscal repair. The size of the gap at the previous tear side, reduced significantly by 45 and 40% on conventional MRI and indirect MR arthrography respectively, from 3 months to 1 year (P < 0.05). The signal-to-noise ratio of the intrameniscal abnormal signal reduced significantly and approximately 50% from 3 to 6 months, and from 6 to 12 months postoperatively, as demonstrated with indirect MR arthrography. However, as opposed to normal meniscus, the signal-to-noise ratio of the abnormal area remains 5.5 times higher 12 months postoperatively. In contrast, the reduction of signal-to-noise ratio of the abnormal area at conventional MRI was not significant even from 3 to 12 months. In 90% of the cases, the indirect MR arthrography showed the intrameniscal abnormal signal on plain MRI, to extend to the articular surface as opposed to 25% on plain MRI. CONCLUSION: With indirect MR arthrography, the natural process of meniscal healing can be evaluated. Significant reduction of the size of the tear gap and significant reduction of the signal-to-noise ratio of the abnormal signal as well as its configuration are the main parameters interpretating the normal healing process.

Adolescent↗
PubMed2004

MR imaging findings in transient osteoporosis of the hip.

PURPOSE: The authors sought to describe the magnetic resonance (MR) imaging findings including perfusion imaging, in association with the course of acute bone marrow oedema syndrome (aBMEs), in a group of patients with acute hip pain and a final diagnosis of transient osteoporosis of the hip (TOH). MATERIALS AND METHODS: From 217 patients referred with a probable diagnosis of avascular necrosis (AVN) of the femoral head, we identified 42 patients who had clinical and radiographic findings not relevant to AVN. MR imaging examinations were performed on a 1.0T scanner. Perfusion imaging was performed in 20 patients. The bone marrow oedema (BME) was classified in four stages. In addition, the presence or absence of oedema in the subchondral area and the presence of other subchondral lesions were recorded. Acetabular bone marrow was also assessed for the presence of oedema. The quantitative measurements included: maximum size of the effusion, percentage of enhancement (PE) and time of peak enhancement of abnormal marrow compared to the first pass, on the perfusion images. RESULTS: Osteopenia was present on plain radiographs in 87% of cases. The most common pattern of BME was extending to the femoral head and neck. Acetabulum was involved in 16.6%. In 22.6% the BME spared the subchondral region of the femoral head. There were two cases (4.7%) with subchondral changes. A joint effusion was noted in 33 of the 42 patients. On perfusion imaging, a delayed peak enhancement was noted in 20 patients between 40 and 65 s after the first pass of contrast. No patient had any evidence of femoral head collapse or change in sphericity on follow-up MRI. None of the patients developed avascular necrosis in a time frame of 18 months from the onset of the acute hip pain. CONCLUSION: The aBMEs MR imaging pattern varies and is most commonly appearing on X-rays as osteopenia. Absence of subcondral lesions, delayed peak enhancement of the abnormal marrow on perfusion images, and sparing of subchondral zone from marrow oedema are MR imaging findings highly correlated to TOH.

Adult↗