Biomedical subjects

P N Soucacos

Publications and source records attributed to P N Soucacos.

At least 19 recordsLinked to original sources

PubMed2006

Electric stimulation and hyperbaric oxygen therapy in the treatment of nonunions.

Up to 10% of the fractures occurring annually in the U.S. end up in non-union or delayed union. Classical treatment with osteosynthesis and bone grafting is not always successful. Alternatives in treatment have long ago been considered. This article presents current concepts in treatment with electrical stimulation and hyperbaric oxygen, the mechanisms of action, experimental and clinical evidence of their application.

Animals↗

PubMed2006

Osteoid osteoma of the upper extremity. A diagnostic challenge.

Osteoid osteomas are benign tumors that may commonly mimic other entities in the upper extremity. The purpose of this study is to describe the clinical and imaging features of osteoid osteomas involving the upper extremity, highlight the difficulties in the diagnosis in the various areas and propose a diagnostic workup. Fourty-eight patients with histologically confirmed osteoid osteoma of the upper extremity treated at the authors' department from 1985 to 2000 were retrospectively reviewed. Data pertinent on the patients' history, lesion location, clinical and imaging characteristics as well as any unique features of individual patients were collected. There were 29 males and 19 females with a mean age of 28 years (range 20-42). The average duration of symptoms before definite diagnosis was 18 months (range 2-62). Pain was the presenting symptom in 46 of 48 patients, whereas swelling was the main complaint in 2 of the patients. Mean pre-operative visual analogue pain scale (VAS), was 8.8 ranging from 5.1 to 9.3. Eight lesions were located in the humerus, 4 in the ulna and 7 in the radius. In the carpal bones, 4 were located in the scaphoid, 4 in the capitate and 5 in the hamate. Seven lesions were located at the metacarpals and 9 lesions at the phalanges (5 proximal, no middle and 4 distal phalangeal lesions). Radiographs alone were sufficient to establish the diagnosis of osteoid osteoma in 32 cases. Bone scans identified a "hot spot" in 16 patients without previous radiographic evidence of a lesion and furthermore, computed tomography was performed in 32 patients to assist in the intraosseous localization of the lesion, and in the pre-operative planning. All patients underwent operative excision of the lesion and the diagnosis was confirmed by histology. Mean follow-up was 28 months (range 25-42). Fourty-three patients had an uneventful recovery. Mean post-operative VAS value was 1.8 ranging from 0 to 3. Osteoid osteoma of the upper extremity often mimics other etiologies and the complex anatomy of the upper extremity, as well as the tendency of patients to relate their symptoms to trauma are factors that easily lead to misdiagnosis or delay in the diagnosis. A high index of suspicion is essential and the diagnosis is based on an accurate clinical assessment and careful selection of imaging studies.

Adult↗

PubMed2006

The use of thoracoplasty in the surgical treatment of idiopathic scoliosis.

INTRODUCTION: Rib prominence on the convex side results from vertebral rotation. The cosmetic deformity of the back in scoliosis is only partially corrected by operations on the spine itself, whilst costoplasty addresses the problem directly, and improves the cosmesis. PURPOSE: Our experience in convex and concave side thoracoplasty is discussed. PATIENTS AND METHODS: The selection of the patients for thoracoplasty was done primarily taking into consideration the cosmetic disturbance of the rib hump and the consequences to the psychism of the patient. A total of 35 scoliotic patients (32 females and 3 males) with mean age 18.8 years underwent thoracoplasty in combination with posterior spinal fusion. In 23 patients (3 males and 20 females) convex side thoracoplasty (rib resection at the site of the hump) was done as a first stage procedure (18 patients) or a second stage procedure (5 patients). In the patients with spinal fusion at the same time, the resected ribs were used as bone graft. 12 female patients were treated with concave side thoracoplasty (osteotomies of the medial part of the ribs and elevation of the ribs on the instrumentation rod) as a first stage procedure combined with spinal fusion, while in one 22 female patient both side thoracoplasty was done as a second stage procedure. CONCLUSION: Either form of thoracoplasty was an effective and impressive way to improve the patient's appearance although it was not possible to quantify the results. The complications that were presented viz. 4 haemopneumothorax, 2 pneumothorax, 2 pneumonia) were treated successfully.

Adolescent↗

PubMed2006

Instrumentation loosening and material of implants as predisposal factors for late postoperative infections in operated idiopathic scoliosis.

INTRODUCTION: Instrumentation loosening and metal corrosion are predisposal factors under investigation for late Postoperative infections. PURPOSE OF THE STUDY: To investigate the contribution of the instrumentation material (stainless steel versus titanium implants) and the mechanical loosening in the development of late postoperative spinal infection. PATIENTS AND METHODS: The first group of patients involves 50 idiopathic scoliotic patients who were treated with first generation posterior stainless steel spinal segmental multihook instrumentation. The minimum post operative follow up was 4 years. Five patients presented with late infections 1 to 5 years post operatively. Removal of instrumentation was the effective solution to this problem. Common intraoperative findings were some degree of instrumentation loosening and corrosion. The second group involves 40 idiopathic scoliotic patients who were treated with newer generation posterior titanium spinal segmental multihook-multiscrew instrumentation system. More extensive use of pedicle screws was performed to the second group resulting in a more stable mechanical construct. Follow up ranged from 2 to 5 years. None of those patients presented late postoperative infection or any evidence of instrumentation loosening or failure. CONCLUSION: We believe that newer multihook-multiscrew titanium spinal instrumentation systems have smaller incidence of late postoperative infections because they provide a more stable construct (pedicle screws) with fewer tendencies for micro motion or failure, and they may give the advantage of greater bone adhesion on the implant resulting in the production of thinner biofilm, thus decreasing the chances of infection.

Adult↗

PubMed2005

Intraoperative Bier's block as supplement to insufficient axillary block anesthesia in upper extremity surgery.

The authors reviewed 52 patients who underwent Bier's block, as supplementary anesthesia for insufficient axillary block in upper extremity surgical procedures. Prior to proceeding to the Bier's block, the mean value of pain using the visual optical analogue scale (VAS) was 7.0. In 48 of the patients supplementation with the Bier's block was sufficient (mean VAS score of 1.0) and all patients were comfortable throughout the procedure. In the remaining four patients supplementation with narcotics and sedatives via the other i.v. line was required. Intraoperative Bier's block provides a safe and effective alternative way of successfully compensating for an insufficient axillary block in upper extremity surgical procedures.

Adult↗

PubMed2001

The presence of proprioceptive mechanoreceptors in the remnants of the ruptured ACL as a possible source of re-innervation of the ACL autograft.

This study investigated the presence of neural mechanoreceptors in the remnants of the ruptured ACL as a possible source of reinnervation of the ACL autologous graft. The remainder of the torn ACL was selected for further histological investigation from 17 patients during ACL reconstruction 3 months to 3.5 years after injury. Perioperatively two types of ACL remnant were identified. Fifteen patients had portions of ACL adapted at the PCL. In all of these patients we found mechanoreceptors (I and II). In five patients we found mushroomlike remnants which included either none or small numbers of mechanoreceptors. Free neural ends were found in both patient groups. There was a significant difference between the groups in regard to the mean number of mechanoreceptors I and II per slice. In conclusion, in patients with an ACL remnant adapted to the PCL, mechanoreceptors exist even 3 years after injury. If we accept that restoration of proprioception is the result of reinnervation of the ACL, leaving the ACL remnants as a source, if this is surgically possible without risk of Cyclop's lesion, may be of potential benefit to the patient.

Adolescent↗

PubMed2001

An MRI-based semiautomated volumetric quantification of hip osteonecrosis.

OBJECTIVE: To objectively and precisely define the spatial distribution of osteonecrosis and to investigate the influence of various factors including etiology. DESIGN: A volumetric method is presented to describe the size and spatial distribution of necrotic lesions of the femoral head, using MRI scans. The technique is based on the definition of an equivalent sphere model for the femoral head. PATIENTS: The gender, age, number of hips involved, disease duration, pain intensity, limping disability and etiology were correlated with the distribution of the pathologic bone. Seventy-nine patients with 122 hips affected by osteonecrosis were evaluated. RESULTS: The lesion size ranged from 7% to 73% of the sphere equivalent. The lateral octants presented considerable variability, ranging from wide lateral lesions extending beyond the lip of the acetabulum, to narrow medial lesions, leaving a lateral supporting pillar of intact bone. Patients with sickle cell disease and steroid administration presented the largest lesions. The extent of the posterior superior medial octant involvement correlated with the symptom intensity, a younger age and male gender. CONCLUSION: The methodology presented here has proven a reliable and straightforward imaging tool for precise assessment of necrotic lesions. It also enables us to target accurately the drilling and grafting procedures.

Adolescent↗

PubMed2001

Patellar fractures associated with medial-third bone-patellar tendon-bone autograft ACL reconstruction.

Patella fractures following anterior cruciate ligament (ACL) reconstruction are a recognized but rarely reported complication. To our knowledge, 24 reports of patella fractures after ACL reconstruction using the central-third patella-tendon autograft have been reported in the literature. Patellar fractures associated with the use of the medial-third bone-patellar tendon-bone autograft have not been reported. This article describes four cases of patellar fractures in 478 ACL reconstructions between 1992 and 1999, using the medial third of the patellar tendon graft. All of them were transverse fractures of the patella but only one was displaced. All patients suffered local injury to the donor knee between 2 and 4 months postoperatively. No significant differences in the final outcome were noticed between the cases complicated with patellar fracture and those with uncomplicated ACL reconstructions.

Adolescent↗

PubMed2001

Brachial plexus root avulsions.

The majority of adult brachial plexus palsies are posttraumatic injuries caused by high-energy forces, usually involving motor vehicles. In infants, brachial plexus palsies commonly represent obstetrical injuries following excessive traction on the plexus during complex or difficult delivery. Most adult injuries, and occasionally those in infants, represent brachial plexus root avulsion injuries that carry serious ramifications from the standpoint of permanent disability of a paralyzed extremity, prolonged recuperation, and significant socioeconomic impact. Modern-day management of root avulsions should focus on early, aggressive microsurgical reconstruction of the brachial plexus, combining various neurotizations with intraplexus and extraplexus ipsilateral and contralateral nerve donors, utilization of vascularized nerve grafts, and finally the use of free vascularized and neurotized muscles. When these multistage microsurgical management techniques are applied early (with complete avulsions) they may often result in significant return of neurologic function, especially in young patients. Amputation should be looked upon as an option only when these newer microsurgery techniques have failed.

Adolescent↗

PubMed2001

Longstanding nonunions of scaphoid fractures with bone loss: successful reconstruction with vascularized bone grafts.

Vascularized bone graft from the dorsum of distal radius was used to treat 22 nonunions of scaphoid fractures, with a mean delay of 4 years from the initial injury. Four of the eight patients with associated scapho-styloid arthritis also underwent a closing wedge osteotomy of the distal radius. Follow-up time ranged from 14 to 74 months. Union was accomplished in 6 to 12 weeks and wrist range of motion and grip strength improved postoperatively in all patients. Complete absence of pain was noted in 16 patients and the other six, all of whom had arthritic wrist changes or carpal collapse, only experienced pain with strenuous activities. The simple graft dissection, the avoidance of anastomoses and the lack of donor site morbidity are additional advantages to this surgical technique, which is successful even in cases with an avascular proximal pole.

Adult↗

PubMed2001

Indications and selection for digital amputation and replantation.

Even though replantation surgery has now become a routine procedure, it remains delicate and demanding surgery, requiring adequate training and expertise in microsurgical techniques. Well-defined selection criteria for replantation procedures have evolved over the past few years, including definitive guidelines for thumb, single digit, multiple digit and mid-palm amputations. For more complex cases, other techniques, including transpositional microsurgery and various secondary reconstructive procedures, such as toe-to-hand transfer, are now available. Although replantation procedures have been simplified, a second surgical team can save valuable surgical time by debriding and identifying the vessels in the amputated part, harvesting microvenous grafts, and performing bone fixation or tendon repair among other things, while the chief surgeon focuses on revascularization. Overall, the most significant guideline underlining the philosophy of digital replantation today reflects the aim of not only ensuring the survival of a digit, but its functional use as well. Experience dictates that this can be achieved only if the basic principles and indications of replantation surgery are adhered to.

Amputation, Traumatic↗

PubMed2001

Multimodal imaging quantitation of the lesion size in osteonecrosis of the femoral head.

Early diagnosis of osteonecrosis of the femoral head is important for initiating early treatment, which is associated with a more favorable outcome for patients. Confusion in evaluating the severity of the disease, and the clinical outcome after treatment partially is attributed to the use of various staging systems that are based on qualitative rather than quantitative criteria. At the authors' institution, 45 patients (77 hips) with osteonecrosis of the femoral head were evaluated using a multimodal imaging approach that included conventional radiography, bone scintigraphy, and magnetic resonance imaging. A computerized image analysis program that allowed quantification of the lesion size on radiographs and magnetic resonance images was used. Measurements of the extent of involvement on radiographs and selected serial magnetic resonance images were compared in 33 hips (42.9%) before collapse versus 44 hips (57.1%) after collapse. The size of the necrotic lesion varied significantly according to the specific stage of disease. Quantification of the lesion during the course of the disease provided a record of the progression of osteonecrosis, despite a spurious stability in staging. In general, conventional radiography closely approximated measurements of the lesion size obtained by magnetic resonance imaging. Bone scintigraphy and magnetic resonance imaging were well suited for detection of osteonecrosis at an early stage. Finally, precise quantification of the lesion size was an optimal preoperative means for evaluating the extent of involvement of the femoral head in the early and advanced stages of osteonecrosis.

Adolescent↗

PubMed2001

Optimizing free fibular grafting in femoral head osteonecrosis: the Ioannina aiming device.

The extracapsular placement of a vascularized fibular graft in the subchondral region of the femoral head now is a widely accepted method for treating patients with osteonecrosis of the femoral head. The effectiveness of the fibular graft seems to be dependent on precise placement in a biologically and anatomically relevant site within the femoral head. The current authors present the Ioannina technique for application of a new computer-aided design and computer-aided manufacturing process in the treatment of osteonecrosis of the femoral head using free vascularized fibular transplantation. The objective was to develop a computer-assisted design and manufacturing system for an accurate and easier approach to the necrotic area in the femoral head. The Ioannina technique uses serial computed tomography scans of the proximal femur to identify the configuration of the proximal femur, and the size, location, and configuration of the lesion using a computer-aided design and computer-aided manufacturing process. Optimal graft placement is determined and a guide wire canal is drilled into an patient-specific aiming device. In this process, identification of the optimal graft location is related to achieving that location surgically. The more arbitrary placement of the graft during conventional fibular graft surgery leads to accurate graft placement in only 55% of the patients, whereas the use of the patient-specific Ioannina aiming device resulted in optimal graft placement in 89% of the patients.

Bone Transplantation↗

PubMed2001

Cementless hip arthroplasty in the treatment of patients with femoral head necrosis.

Treatment of patients with osteonecrosis of the femoral head focuses on pain relief and improved function of the hip. Total hip arthroplasty remains an effective tool for the treatment of patients with end-stage osteonecrosis with collapse of the femoral head, although there is a greater risk for failure. The aim of the current study was to assess the long-term survival of cementless total hip arthroplasties in 28 patients (36 hips) with osteonecrosis of the femoral head (Steinberg Stage V and Stage VI) with an average followup of 11.2 years (range, 10-15 years). There were 19 women and nine men with an average age of 51.4 years (range, 28-65 years). A threaded titanium cup CST (Conical Screwed Titanium) was used in all patients and different cementless femoral components were used depending on the optimal fit in the femoral canal as assessed during preoperative templating. No serious complications were encountered postoperatively. The patients were evaluated preoperatively and postoperatively with the Merle d'Aubigné and Postel scale. After cementless total hip arthroplasty, the average pain score improved 3.6 points, walking ability improved 1.6 points, and range of motion improved 1 point. Two patients had thigh pain. Radiographic evaluation on anteroposterior and lateral radiographs of the proximal femur was excellent in 10 hips postoperatively. No heterotropic ossification was observed, although proximal femoral atrophy was seen in 15 hips. Clinical and radiologic findings did not correlate. There were two revisions of the acetabular implants in one patient with bilateral idiopathic osteonecroses and total hip replacement. Overall, survival of the prostheses was 93.4% at the average followup of 11.2 years.

Adult↗

PubMed2001

Treatment of avascular necrosis of the femoral head with vascularized fibular transplant.

Two hundred twenty-eight hips in 187 patients with avascular necrosis of the femoral head were treated with vascularized fibular transplant from March 1989 to March 2000. The etiologic factors associated with the disease included corticosteroids in 84 patients (44%; 101 hips, trauma in 25 patients (13%; 29 hips), alcohol abuse in 24 patients (12%; 28 hips), and 41 hips (18%) were classified as idiopathic. Systemic disorders, including systemic lupus erythematosus, sickle cell anemia, inflammatory bowel disease, pregnancy, and dysbaric disease were observed in 12, nine, four, three, and one hip(s), respectively. Of the 228 hips operated on, 184 hips (152 patients) were assessed postoperatively with followup ranging from 1 to 10 years (mean, 4.7 years). Using the Steinberg classification system, 39 hips (21%) were in Stage II; 45 hips (25%) were in Stage II; 77 hips (42%) were in Stage IV; and 23 hips (12%) were in Stage V. Of the 184 hips treated, 101 (54%) remained stable postoperatively, whereas 69 (38%) had progression, and 14 hips (8%) were converted to total hip arthroplasty. Of the 69 hips that had progression, 44 (64%) did not progress until 6 to 10 years after the procedure, whereas 25 (36%) progressed within the first 5 years postoperatively. The best results were obtained in patients with Stage II osteonecrosis in whom 95% of the hips did not progress postoperatively. In contrast, only 39% of the hips in patients with Stage V osteonecrosis remained stable. Preoperative and postoperative clinical evaluation using the Harris hip score showed an increase from 85 to 96 points in hips with Stage II disease; from 74 to 91 points in hips with Stage III disease; from 69 to 85 points in hips with Stage IV disease; and from 61 to 76 in hips with Stage V disease. The current results show that the vascularized fibular graft is an excellent procedure for the precollapse stages and a valuable alternative for patients with Stages III, IV, and V of the disease.

Adolescent↗

PubMed2001

Three-dimensional computerized selection of hip prostheses in patients with congenital dislocated hips.

This study assessed the effectiveness of the combined use of computed tomography (CT) and computer-aided design (CAD) in the preoperative evaluation and implant selection in 20 patients (20 hips) with congenital dislocation of the hip who were scheduled to undergo total hip arthroplasty. Computerized selection of the femoral implant with optimum fit and fill was made after a three-dimensional reconstruction of the femoral canal using CT data and CAD. Implantation of all sizes of 5 noncemented and 2 cemented femoral implants was simulated using CATIA software (IBM, Kingstone, NY). When patients underwent surgery, 18 of 20 preselected prostheses agreed by type and size with the prostheses implanted. The remaining 2 preselected implants agreed by type only. In patients with dislocated and dysplastic hips, combined use of CT and CAD allows effective preoperative planning by providing the surgeon with vital information about the proximal femoral canal geometry and the possible femoral implant with optimum fit and fill to be used.

Aged↗

PubMed2001

Back pain caused by benign tumors and tumor-like lesions of the thoracolumbar spine.

Twenty-two patients with benign tumors or tumor-like lesions of the spine (vertebral echinococcal cysts, eosinophilic granuloma) presented with back pain and deformity. The duration of pain ranged from 1 to 6 years. Five patients had incomplete paraplegia at admission. Spine deformity was observed in patients with osteoid osteoma, osteoblastoma, hemangioma, and vertebral echinococcal involvement. All patients underwent clinical evaluation, laboratory studies, and histologic studies. Electromyogram studies were performed in patients who had a neurologic deficit or nerve root irritation. Imaging evaluation consisted of plain films, bone scans, computed tomography scans, and magnetic resonance imaging scans. Fifteen patients had lumbar involvement; 7 had thoracic involvement. For 18 patients, management included tumor excision and thorough debridement of the lesion. Spinal instrumentation and fusion were used to correct the deformity and treat the instability in 5 patients. Patients were followed for 1 to 8 years. Of the 5 patients with incomplete paraplegia, 4 recovered completely, and the fifth (who had spinal cord hemangioma) improved 2 grades on Frankel's scale. The remaining patients were disease free and returned to routine daily activities. Benign tumors or tumor-like lesions of the thoracolumbar or lumbar spine are very rare and easily misdiagnosed in patients with persistent back pain. Patients whose symptoms progress or fail to respond over an appropriate period of time should be evaluated further. Complete excision of the tumor followed by spinal instrumentation in the presence of deformity or instability is the treatment of choice.

Adolescent↗

PubMed2001

Mesenchymal chondrosarcoma of soft tissues of the calf.

Mesenchymal chondrosarcomas are distinct from conventional and dedifferentiated chondrosarcomas and are quite rare, making up less than 2% of all chondrosarcomas. We describe a mesenchymal chondrosarcoma of the soft tissues of the calf and review the differential diagnosis of this poorly understood entity.

Chondrosarcoma, Mesenchymal↗