To determine the gross structural alterations of the nailed bone (femur or tibia) after the removal of an intramedullary nail (IMN).

Eighteen patients (14 femoral and 4 tibia nail) underwent an IMN removal from their femur or tibia. Every patient had a spiral computed tomography scan and a plain X-ray study, immediately after the nail removal and also at their latest follow-up (24–30 months). The 4 patients with a tibia nail were additionally examined using a peripheral quantitative computed tomography study at their latest follow-up. All patients were asymptomatic.

An intramedullary shell of compact bone was demonstrated around the nail track. This new bone was apparent on plain radiographs in all of the patients. Peripheral quantitative computed tomography study revealed that the density of the bony ring was similar to that of subcortical bone. The histologic examination of the intra-medullary shell of one of our patients suggested that the bony ring was made of cortical bone.

Intramedullary nailing may enhance new cortical bone formation within the bone marrow cavity. This “cortical bone” still exists more than 2 years after implant removal. Nail insertion also causes thickening of the normal cortex at the sites of nail–cortex contact where loads are transferred from the nail to the cortex. This new finding could probably lead the research of intramedullary nailing biomechanics toward new directions as to understand the body’s reaction to IMNs.

The evaluation of two methods for the placement of the tibial component of total knee arthroplasties in obese patients

Between December 2004 and October 2008 we studied 38 obese patients who underwent cemented total knee arthroplasty (using the rotating platform tibial tray) due to medial compartment osteoarthritis and consequent varus deformity. All patients had a body mass index (BMI)> 40. Functional outcome was assessed using the Knee Society Score (KSS). The study was based on the comparison between extramedullary (group A) and intramedullary (group B) instrumentation systems for the placement of the tibial prosthesis. The main endpoint was the immediate post-operative knee joint alignment.

There were 10 male and 28 female patients. The average follow-up period was 13.8 months (minimum follow-up of 6 months). There were 22 patients in group A whereas 16 patients comprised group B. In 5 of the 22 patients in group A there was an average varus malalignment of 40 and a mean KSS of 71.5 at the time of the latest follow-up visit. In the rest of patients of both groups there was a valgus alignment between 0 and 70 and a mean KSS of 86.4 respectively

Our experience suggests that the intramedullary instrumentation technique for the placement of the tibial component offers a more favourable post-operative alignment as well as better functional outcome in obese patients.

The timing of performing knee arthroplasties in bilateral osteoarthritic knees remains controversial. Our aim was to compare one-stage with two-stage bilateral knee arthroplasties (TKA).

Between November 2004 and April 2008, 128 patients (72 female and 56 male) underwent one-stage bilateral TKAs. Another group of 115 patients that underwent two-stage procedures during the same period formed the control group. All patients received the same type of anaesthesia. Study parameters included age, weight, medical co-morbidities, length of hospital stay, blood loss, post-operative complications and functional outcome.

There were no significant differences between the two groups. Co-morbidities and functional outcome based on the Knee Society Score were similar in both groups. In the one-stage group the length of hospital stay and blood losses were higher than the two-stage group; however less than double compared to the two-stage group. The early post-operative complications were higher but not statistically significant in the one-stage group.

Despite the fact that the early post-operative complications are slightly higher in the one-stage group, this particular method is an effective way of dealing with bilaterally osteoarthritic knees. It offers excellent functional outcome at a reduced cost

The evaluation of early results of combined percutaneous pedicle screw fixation and kyphoplasty for the management of thoraco-lumbar burst fractures

Between October 2008 and April 2009, 9 patients with thoracolumbar burst fractures underwent percutaneous short-segment pedicle screw fixation and augmentation kyphoplasty with calcium phosphate cement. All patients were selected according to the type of fracture (unstable type A3 fractures based on the Magerl classification) the absence of neurological signs and an intact posterior longitudinal ligament on the pre-operative MRI scan. Patient demographics, co-morbidities and complications were recorded. The main endpoints included Cobb angle correction, vertebral body height restoration and the length of hospital stay.

There were 3 male and 6 female patients with an average age of 43.6 years. The average follow-up was 2.4 months. The mean kyphotic angulation improved from 18.40 pre-operatively to 6, 80 post-operatively. The loss of vertebral body height improved from a mean of 38.7 % pre-operatively to 12.1 % post-operatively. The average duration of surgery was 40 minutes with insignificant blood loss. There were no post-operative complications. The average length of hospital stay was 3.2 days.

The combination of percutaneous short-segment pedicle screw fixation supplemented by balloon kypho-plasty for the management of thoracolumbar burst fractures with no neurological deficit offers correction of the normal thoracolumbar anatomy as well as augmentation of the anterior load-bearing column, using a minimally invasive technique. The early results are promising

The evaluation of results following posterior decompression and fusion for the management of cervical spondylotic myelopathy

Between July 2006 and May 2008, 68 patients with cervical myelopathy underwent posterior decompression with laminectomies and pedicle screw fixation of the cervical spine. All patients were selected based on the presence of multi-level degenerative disease and the correction of cervical lordosis on the pre-operative dynamic radiographs. Patient demographics, co-morbidities and post-operative complications were recorded and analysed. Functional outcome was assessed by using the Japanese Orthopaedic Association (JOA) score.

There were 37 male and 31 female patients with an average age 67.4 years. The average follow up period was 18 months. The mean pre-operative JOA score was 8.7, whereas the mean post-operative score was 12.1 on the latest follow-up visit. 9 patients had unsatisfactory clinical results and consequently underwent anterior procedures with significant improvement. Complications included 1 epidural haematoma, 2 superficial infections and 4 cases of myofascial pain. In three cases there was mild dysfunction of the C5 nerve root which resolved spontaneously with conservative measures.

In the present series of patients posterior decompression with laminectomies is an effective method for the management of cervical spondylotic myelopathy.

The circulatory effects of multilevel balloon kyphoplasty (BK) are not adequately addressed, neither the effectiveness of egg shell cementoplasty in preventing anticipated cement leakage in difficult cases. The purpose of this study was to evaluate

the effect of multilevel BK to blood pressure and arterial blood gasses;

Materials and methods: This is a prospective study of 89 patients (215 vertebral bodies-VBs) with osteoporotic compressive fractures (OCF), and 27 with osteolytic tumors (OT) (88 VBs). The mean age was 67.6 years. 27 patients with OCF were treated at one level, 26 at two, 21 at three, 7 at four, 6 at five, and 2 at six levels at the same sitting. Three patients with OT were treated at one level, 6 at two, 9 at three, 3 at four, 4 at five, and 2 at seven. Egg shell balloon cementoplasty to prevent cement leakage was performed in 10 patients with severe endplate fracture or vertebral wall lytic destruction. Arterial blood pressure and oxygen saturation were monitored during surgery. Arterial blood gases were measured before and 3 min after cement injection. Cement leakage was assessed by the postoperative x rays and computer tomography scans.

Results: A drop in blood pressure of more than 25mmHg during cement injection was observed in 6 patients, and was not associated with the number of VB treated. Blood pressure was dropped more than 40mm in 2 patients and the procedure was aborted after completing 1 level in the first and 2 levels in the second. Drop in arterial O2 saturation was noted in 4 patients. One patient treated for 5 levels developed fever and tachepnoea for 24 hours after surgery. Arterial O2 and chest x-rays were normal. Cement leakage was found in 9.7% (21/215) of VBs treated for OCF. Its incidence per location was: epidural, 0.9% (2 VBs); intraforaminal, 0.5% (1 VB); intradiscal, 3.2% (7 VBs); and through anterior or lateral walls, 5.1% (11 VBs). In the OT group cement leakage was found in 10.2% (9/88) of the treated VBs. Its location included 8 (9%) through the anterior or lateral walls and one (1.1%) intradiscal. Cement leakage had no clinical consequences. No cement leakage was observed in cases treated with egg shell balloon cementoplasty.

Conclusions: BK is a safe procedure when applied for multiple levels in the same sitting, and its rare circulatory effects are not related to the number of levels treated. The incidence of cement leakage in this study was 10%, which is far less than that reported with vertebroplasty using routine postoperative CT scan. Egg shell balloon cementoplasty can effectively minimize cement leakage in cases with fractured endplate or lytic destruction of VB walls.

Purpose: The purpose of this study is to evaluate the safety of methylmethacrylate cement balloon kypho-plasty (BK) when applied to five or six levels in the same sitting and the incidence and location of cement leakage.

Methods: Eighty nine patients (215 vertebral bodies-VBs) with osteoporotic compressive fractures (OCF), and 24 with osteolytic tumors (OT) (72 VBs) were treated with BK. Of patients with OCF, 27 were treated at one level, 26 at two, 21 at three, 7 at four, 6 at five, 2 at six levels. Of OT patients, 3 were treated at one level, 5 at two, 9 at three, 3 at four, and 4 at five.

Results: A drop in blood pressure of more than 25mmHg during cement injection was observed in four patients, and was not associated with the number of VB treated. The procedure was aborted in two patients. Otherwise no significant drop in arterial O2 was noted. One patient treated for 5 levels developed fever and tachepnoea for 24 hours after surgery. Arterial O2 and chest x-rays were normal. Pain significantly improved in 95% of patients with OCF and 98% of patients with tumors. In the osteoporotic group, kyphosis correction was achieved in 91% with a mean correction of 7.89°. Cement leakage occurred in 21/215 VBs (9.7%); Epidural: two (0.9%), intraforaminal: 1 (0.5%), intradiscal: 7 (3.2%) while through the anterior or lateral vertebral wall: 11 (5.1%). In the OT group leakage occurred in 6 VBs (8.3%), including 9 (7.0%) through the anterior or lateral wall and one (1.3%) intradiscal. None of the patients had any clinical consequences associated with cement leakage.

Conclusions: BK is a safe and effective procedure, even when applied for 5 or 6 levels. End plate fracture or vertebral wall lytic destruction can effectively be managed by eggshell balloon cementoplasty, thus minimizing the incidence of cement leakage. The incidence of cement leakage with KP (9.8%) is far less than that reported with vertebroplasty, (65.5% shown on CT scans).

Aims: In this study we assessed the results of the hemi-arthroplasty for shoulder fractures in patients with a follow-up 2 to 7 years. Methods: Twenty six patients (20 women and 6 men, mean age 64.7±8.2 years [range 41 to 78 years]), with a fracture of the upper humerus requiring hemiarthroplasty, were followed-up 2–7 years after surgery. Ten Coþeld, nine Global and seven Aequalis prosthesis were implanted, all cemented. All the procedures were performed 0–17 days after the injury (mean 5.5±4.6 days). The clinical outcome was assessed using the Constant-Murley scale. Results: The mean score, at their last follow up, was 70.4±16.4% (39–96%). The mean ßexion of the arm was 150û (30û–175û), the mean abduction was 145û (30û–170û), the mean external rotation was 30û (10û–45û) and the internal rotation corresponded with a position of the dorsum of the hand at the L3 vertebrae. The patients in our series achieved the optimum clinical result during the þrst 6 months after the operation. No statistical signiþcant improvement occurred after this period. Six months after the injury 20 out of the 26 patients (76.9%) had the same activity level as they had prior to the fracture. At their last follow up eighteen patients (69.2%) had no any pain and 7 (27%) patients had some mild pain at the end of their daily activities and 1 patient (3.8%) had pain even with mild activities. Conclusions: Shoulder hemiarthroplasty seems to be a worthwhile procedure in modern orthopaedic surgeonsñ armamentarium, giving predictable results presuming careful selection of the patients, restoration of the individual anatomy of the shoulder and aggressive rehabilitation program during the þrst 6 months after surgery.

Aims: The objective of this study was to assess whether anatomical placement of the prosthesis, in shoulder hemi-arthroplasty for fracture of the humeral head, is important to the clinical outcome. Methods: Sixteen patients, with a fracture of the upper humerus treated with hemi-arthroplasty, were followed-up 45.7±15.1 (20–72) months after surgery. The results were assessed using the Constant-Murley scale. The mean score was 75.8±15.7% (54–96%). At the time of their last follow up they underwent CT of the fractured and sound humerus, in order to be measured differences in humeral length and retroversion using special software. Correlation between these differences and the clinical outcome, as it was measured with the Constant-Murley scale, was performed. Results: The mean difference in retroversion was 8.7 degrees and the mean difference in length was 0.65cm, between fractured and sound humerus in our patients. We have achieved a very good þnal outcome (Constant score more than 71%) in patients with difference in retroversion less than 10 degrees and difference in length less then 14mm, between fractured and sound humerus. Conclusions: Restoration of the humeral length and retroversion is very important in shoulder hemiarthroplasty for fracture of the humeral head. Only small differences from the optimum length are well tolerated while only big differences from the optimum retroversion are likely to affect signiþcantly the clinical outcome. We attribute the very good clinical outcome in our series to the quality of the anatomical reconstruction that was performed despite the fact that our sample is small and we cannot have powerful statistics.

Purpose: To describe the percutaneous transpedicular biopsy technique as a novel way of approaching lesion of the thoracic and lumbar spine, to determine the amount of bone retrievable through the pedicle and its diagnostic yield. Material and Methods: Seventy-nine patients underwent 84 biopsies. Seventy-seven procedures were performed with ßuoroscopic guidance arid seven with CT guidance. Seventy-one biopsies underwent under local anesthesia and ten under general anesthesia. Age range of patient was from 3 to 81 years. Results: Adequate specimens for correct diagnosis were obtained in 80 of the 84 patients with the following diagnoses. Pyogenic spondylodiscitis 31, tuberculosis 4, coccidiomycosis 2, echinococcus cyst 1, blastomycosis 1, brucella 4, primary neoplasm 7, metastatic neoplasms 16, osteoporotic fractures 8, osseous repair for insufþciency fractures 5, Pagetñs disease 1. The 4 negative biopsies subsequently proven to be Ç false negative È and were related to faulty biopsy techniques. Conclusion: Pitfalls can be avoided when adhering to the details of our technique. These pitfalls can occur while retrieving the instrumentation without simultaneous withdrawal of the guiding pin; crushing pathological soft tissue against sclerotic or normal bone; or when encountering a sclerotic lesion distal to normal bone without using a sequential type of biopsy specimen-retrieval technique. Any type of bleeding is controllable. The approach is a safe, efþcacious and cost effective and avoids so the problems such low diagnostic yield nerve root injury, pneumothorax and hematoma encountered with conventional needle technique

Aim: The evaluation of the reliability of the Oswestry disability questionnaire in postmenopausal women with osteoporosis and chronic back pain

Patients and method: 104 postmenopausal women with osteoporosis and low or upper back pain with during at least three months have been included in our study. The disability caused by the pain was estimated using Oswestry questionnaire and the pain intensity was estimated using VAS. The reported general condition of health had five interpretations: bad, not so good, satisfying, good, very good, graded by 0,1,2,3,4, respectively.

Results: Statistical significant correlations was found to be between disability and pain intensity in the low back pain group (r = 0.44, P < 0.0001), pain intensity in the upper back pain (r = 0.32, P < 0.01), and the reported general condition of health (r = 0.4, P < 0.001).

Conclusions: The reported statistical significant correlations increase the reliability of Oswestry questionnaire, and it can be used in the evaluation of the disability due to chronic back pain in postmenopausal women with osteoporosis.

Aim: Presentation of the application of the transcervical system of posterior spinal fusion Varigrip in spinal infections showing its rapid and safe application and also its stability to the spinal level where it is applied to.

Patients and Methods: 22 patients (13 men / 9 women) with mean age 50, 6 years (18–79) and mean follow up time is 34,6 months (9–62) were included in our study. In 10 patients the level was in lumbar spine and in 12 in thoracic spine. In their admission 16 patients had neurological deficit and 22 mean pain score according to VAS 8, 4 (6–10). ESR was increased in 14 patients, CRP in 20 and 7 patients had also increased WBC. All 22 patients had increased signal of Tc” and 69Ga in the level of the lesion and also pathological signal in MRI (Tl, T2 and Tl with Gadolinium). All the patients underwent posterior spinal fusion using Varigrip system and 17 of these underwent in the same time somatectomy and anterior fusion.

Results: Pathologic organism was isolated to all the patients. In 20 patients the tissue culture of the lesion isolated the pathologic organism and the other 2 patients came to us with positive blood cultures from other hospitals. 6 months postoperatively 21 patients referred pain score according to VAS 2,4 (1–4) and 1 patient had no improvement (5–7). 1 patient died of PE, another of chest infection and one of head injury. 1 patient had recurrence of the infection in another level, 1 had herpeszoster and 1 had infection of the surgical wound. All the patients had neurological improvement postoperatively.

Conclusions: The method is characterized as safe because of avoidance of the neurological structures. It can be applied also safely to patients with osteoporosis. Its application is rapid so the surgical time is minimum and also it doesn’t need image intensifier during the surgical procedure. It can be applied easily either in thoracic or lumbar spine and it provides stability of the spine.

Aim: The aim of our study is to show if there is any relation between scoliosis in the lumbar spine and osteoporosis in postmenopausal women.

Materials and Methods: In 46 postmenopausal women who, according to WHO’s criteria (T-score < −2,5 ), had osteoporosis in lumbar spine and hip and in 40 post-menopausal women with established osteoporosis (T score < −2,5 and at least and vertebral fracture) was estimated clinical and radiological the presence or not scoliotic bow in the lumbar spine. The bone density was measured with DEXA method in the lumbar spine and in the hip and the scoliosis was measured radiologically with Cobb’s method. To all patients has been done full biochemical examination to exclude secondary osteoporosis cases. The radiological examination included face and lateral x-ray of the lumbar and thoracic spine and that was done to detect vertebral fractures and to exclude women with other degenerative lesions. Also were excluded from our study women with primary or metastatic tumors in the spine.

Results: Out of 46 women who had osteoporosis 32 (69%) had scoliotic lumbar bow and in 23 (50%) patients the bow was more than 10 degrees. Out of 40 women who had established osteoporosis 26 (65%) had scoliotic lumbar bow and in 22 patients (55%) the bow was more than 10 degrees. In contrast in the control group of 25 normal postmenopausal women 5 women (20%) had scoliotic lumbar bow and in 2 women (8%) the bow was more than 10 degrees. Also in the group with the 32 osteopenic women (34%) had scoliotic lumbar bow and in 8 women (25%) the bow was more than 10 degrees. Finally in the group of 32 postmenopausal women with degenerative lesions without osteoporosis 13 (31%) had scoliotic lumbar bow and only in 6 (18%) the bow was more than 10 degrees.

Conclusions: After the statistical analysis of the results is evident that postmenopausal women who have osteoporosis have also scoliosis in the lumbar spine.

Aim: Presentation of the technique, the mistakes and the results of a new minimal invasive surgical procedure for reduction and augmentation of pathological fractures of the vertebrae in spine.

Patients and Methods: 12 patients (2 men / 10 women) with mean age 68 years (54–73) with pathological vertebral underwent kyphoplasty. The mean pain according to VAS was 7, 3 (6–10) and the mean follow up time is 8 months (5–14). 11/12 patients (20 vertebrae) had osteoporotic vertebral and 1/12 (1 vertebra) had metastatic lesion. 8/21 vertebrae were in thoracic spine and 13/21 in lumbar spine. In 20/21 the procedure was transcervical to the vertebra and in 1/21 was out of the cervix. 11/12 patients had kyphotic deformity in the plain x-ray and 18/21 vertebrae had decreased their height. To all patients was spilled PMMA.

Results: 10/12 patients referred degrease of their pain in the first 48 hours and 2/12 in the 5th postoperative day. Correction of the kyphotic deformity was observed in 11/12 and reduction of the reduction of the fracture was occurred in 16/21 vertebrae. Leakage of PMMA was occurred in 5/21 vertebrae; in 2/5 the leakage was in the canal, in 1/5 in the intervertebral space and in 2/5 out of the vertebrae. 1/12 patient 2 moths postperatively had another vertebral fracture in a lower vertebra that was deled again with kyphoplasty. None of the patients had neurological deficit postoperatively. According to Oswestry questionnaire all the patients referred return to all their before fracture daily activities.

Conclusions: Kyphoplasty in pathological vertebral fractures has as a result the immediate decrease of the pain and the return of the patient to his/her daily activities. Also there is correction of the kyphotic deformity decreases the possibility of a new vertebral fracture and the establishment of chronic back pain.

Aim: The purpose of this prospective study was to assess the functional outcome of conservative treatment with early ambulation of thoracolumbar burst spinal fractures, using the Load Shearing classification.

Material – Methods: From 1997 to 2001, 60 consecutive patients with single-level thoracolumbar spinal injury, with no neurological impairment, were classified according to the Load Shearing scoring and were managed non-operatively. A custom-made thoracolumbosacral orthosis was worn by all patients for six months, and early ambulation was recommended. Several radiological parameters were evaluated; the Denis Pain and Work Scale was used to assess the clinical outcome. The average follow-up period was 42 months (range, 24 to 55 months).

Results: During this period the spinal canal occupation was significantly reduced. Other radiological parameters, such as Cobb’s angle and anterior vertebral body compression, showed loss of fracture reduction, which was statistically insignificant. However, the functional outcome was satisfactory in 55 of 60 patients with no complications recorded on completion of treatment. Conclusions: Load Sharing scoring is a reliable and easy-to-use classification for the conservative treatment and prognosis of thoracolumbar spinal fractures. Because of the three characteristics of the fracture site this classification can also predict the structural results of the spinal injury, such as posttraumatic kyphosis, and thereby the functional outcome in conservatively treated patients.

Aim: The purpose of this prospective study was an evaluation of results in primary treatment of flexor tendon laceration in zone II. Special emphasis has been given to the postoperative rehabilitation program.

Material and Methods: Nineteen patients, (23 fingers), with laceration of the flexor tendons in zone II were treated operatively. Twelve males and seven females were included in the study. Their mean age was 28 (range, 16 to 50) years. In twelve cases a concomitant laceration of the digital nerve was present, hi all cases primary repair of all injured tendons and nerves was performed and a dorsal splint was applied. On third to fifth postoperative day an exercise program commenced involving passive flexion-active extension of the injured fingers. Eighteen (22 fingers) of 19 patients completed the follow-up.

Results: The results were estimated according to Strickland’s original classification system. In fifteen cases the result was excellent, in five good, and in two fair. Conclusions: After primary repair of injured flexor tendons, close follow-up, early protected motion and unrestricted motion of the interphalangeal joints affers the best chance of restoring optimal function to the hand.

Aim: The evaluation of the results of the posterior application of the combination of the implants Varifix (transcervical screws)/Varigrip (new generation under compression hook with middle line pedicle fixation) to the imstable thoracic and lumbar vertebral fractures.

Patients and Methods: During the years 1999–2001, 30 patients have been operated on with the combination of the implants Varifix/Varigrip to the unstable thoracic (T3–T10: 4), thoracolumbar (T11–L2:21) and lumbar (L3–L5:5) vertebral fractures. Mean age was 33, 5 years and sex variation was 22 men and 8 women. Road traffic accidents were the most common cause and the thoracic and lower limp injuries were the most common (17%) accompanied injuries. For the fracture type and the treatment indications the combination of Gertzbein & Gaines classification was used.

Results: The evaluation of the results was with radiological and clinical examination. Mean surgical time was 170 min (120–240) and the mean blood loss was 500ml (350–800). According to special questionnaire, 25 of the 30 patients (83, 5%) were free of pain and able to return to their previous activities. There was no deterioration in the 24 patients who were in Frankel E neurological condition and the mean post surgical improvement according to Frankel classification was 1, 4 points. In the radiological evaluation (compression percentage, Gardner ankle, conquest of the spinal canal) there was statistical significant difference (p < 0, 05, p < 0, 01, p < 0, 05) between pro and post surgical values. Two patients with acute infection were dealt with surgical cleaning, washing and closing of the wound in second time surgery. One failure of the hook in one patient with osteoporosis was dealt with removal of it.

Conclusions: TheVarifix/Varigrip combination has nearly the same surgical results with traditional partial implants. The satisfactory reduction during the operation in the 30 patients was preserved during the follow up time. The posterior Varigrip system acts with cross link splinting and provides multidirectional spinal stability when it is used alone or supporting the system Varifix for avoiding the detachment or break of the transcervical screws. We suggest the use of these systems for all the unstable thoracic and lumbar injuries because of their safe fixation and easy application.

Aim: Of Calveston (USA) and Crete (HELLAS). We studied immediate and long-term outcome of 50 patients who underwent subaxial lateral mass fixation of the cervical spine between January 1997 and March 2001.

Patients and Methods: Intraopeartive fluoroscopy and somatosensory evoked potential monitoring were employed in all patients. Immediate postoperative CT scans were performed to determine screw trajectory and placement. Follow up ranged from 1 to 5 years.

Results: Postoperative CT scans showed that 113 of 210 screws (54%) had unicorticate and 46% had bicorticate purchase. Forty-five screws (31 %) had suboptimal trajectory, but only 7 of these screws minimally penetrated the foramen transversarium without resultant vascular or neurological sequelae.

The overall fusion success rate in our series was 90%, while pseudoarthrosis occurred in 5 patients (10%), with screw breakage in 1 patient (2%). Two of these patients had bone graft supplementation and in other 2 patients was done anterior fusion.

Conclusions: Results of this study show that the recommended drilling technique and trajectory (15–25 degrees postal to the sagital plane, 20–30 degrees lateral I the axial plane), supplemented bone grafting and intraoperative SEP monitoring are all associated to good screw placement, fusion and neurological outcome and are recommended for all lateral mass fusion procedures.