Hallux anatomy: much ado about shoes-an attempt to prove that constrictive V-shaped toe-box shoes deform the hallux.

PURPOSE: A question still remains as to whether constrictive toe-box shoes (TBS) cause disability only due to pain on pressure points or if they can cause permanent changes in the hallux anatomy. The aim of this study is to compare the hallux morphology in 3 groups classified according to their use of constrictive or open TBS. METHODS: 424 patients were classified into 3 groups: group A used open TBS daily; group B used constrictive TBS daily; group C used both open and constrictive TBS. Hallux's angles, presence of exostoses and shape of the distal phalanx (DP) were analyzed on dorsoplantar weight-bearing radiographs and compared amongst groups. RESULTS: The intermetatarsal (IMA), metatarsophalangeal (MTPA), DASA, PASA, interphalangeal (IPA), obliquity (AP1), asymmetry (AP2) and joint deviation (JDA) angles for group A were 10°, 8°, 5°, 4°, 9°, 3°, 5°, 3°; for group B were 9°, 19°, 5°, 6°, 12°, 2°, 8°, 2°; and for group C were 10°, 10°, 4°, 4°, 12°, 3°, 8°, 1°. Only the differences in the MTPA, IPA and AP2 were statistically significant (p < 0.05). The prevalence of exostoses on the tibial side of the DP was 22, 36, and 29% in groups A, B and C, respectively (p < 0.05). We found similar distributions of the different DP shapes in the three groups. CONCLUSIONS: Our results suggest that the use of constrictive TBS, even if used only occasionally, could change hallux anatomy from a young age increasing MTPA, IPA and AP2. Moreover, we have found that DP exostoses are present as a "normal variation" in patients who wear an open TBS, but their prevalence is higher in those wearing constrictive toe-box shoes. This could be due to a reactive bone formation secondary to the friction caused by the inner border of the shoe. LEVEL OF CLINICAL EVIDENCE: 3.

Osteoid osteoma in the ankle and foot. An overview of 50 years of experience.

BACKGROUND: The literature published about osteoid osteoma (OO) in the ankle-foot consists mainly on case reports. METHODS: We performed a retrospective study in which we analyzed demographic parameters, pain characteristics, treatment options and functional outcomes measured using the AOFAS and the SEFAS scales. RESULTS: We treated 17 patients with OO around the ankle-foot. Eighty-eight percent of patients had night pain that was relieved with NSAIDs. The bones most often affected were the talus and calcaneus. OO was diagnosed 21 months after the onset of symptoms. Mean follow-up was 17.3 years. The surgical techniques most used were curettage and curettage and bone grafting. There was a significant increase in AOFAS and SEFAS scores after surgery. CONCLUSIONS: Suspicion is the base of a prompt and a correct diagnosis of OO. The OO should be especially suspected in patients who present night pain that can be relieved with NSAIDs.

Akin osteotomy: Is the type of staple fixation relevant?

BACKGROUND: Although different fixation techniques for the Akin osteotomy have been described in the literature, there are no many studies trying to analyze the differences between the types of fixation available. The aim of this study is to analyze if there are any differences between three types of staple fixation available in the market. METHOD: We present a retrospective study of 145 cases in which an Akin osteotomy was performed and fixed with three different kinds of implants staple A (28%), staple B (45%), and staple C (27%). Staple A is made out of stainless steel, and the surgeon mechanically controls the compression applied. Staple B increases the compression when heat is applied to it. Staple C has an intrinsic elastic memory that closes the osteotomy. In all cases, distal articular set angle, interphalangeal joint obliquity angle, and metatarsophalangeal angle were measured pre-operatively and 1.5 months post-operatively on dorsoplantar weight-bearing radiographs. Other details such as post-operative complications, implant migration, osteolysis, or fracture of the lateral cortex during surgery were also recorded. RESULTS: Clinical and radiological results show no relevant differences between the three types of fixation. The mean angular corrections of DASA, interphalangeal joint obliquity angle, and metatarsophalangeal angle were 5, 12, and 21, respectively, for staple A; 4, 10, and 19, respectively, for staple B; and 7, 10, and 23, respectively, for staple C. The rates of intra-operative and post-operative complications were similar for all groups. There was one case of infection per group. We had five cases of delayed union two with staple A and three with staple C. In four cases, there was a loss of correction, two of them fixed with staple A and two with staple C. Seven cases developed a Südeck's syndrome, four of them fixed with staple A and three with staple C. Fifteen patients suffered an uncontrolled fracture of the lateral cortex of the phalanx when performing the osteotomy (3, 8, and 4 cases fixed with staples A, B, and C, respectively), and 87.5% of the patients that developed a plantar displacement of the osteotomy had an uncontrolled fracture of the lateral cortex (p < 0.05). All three staples achieved a rigid internal fixation and minimal periosteum damage and provided a good bone-bone contact. CONCLUSIONS: According to our results, the radiological differences are minimal, and although the thermal compression staple had less complication, clinical differences were also not statistically significant. This means the choice of implant could be left to the surgeon's preferences or made according to cost.

The efficacy of an intramedullary nitinol implant in the correction of claw toe or hammertoe deformities.

INTRODUCTION: A multitude of procedures has been described in the literature for the treatment of lesser toe deformities and there is currently no general consensus on the optimal method of fixation. The aim of this study is to assess the clinical and radiological outcomes of an intramedullary nitinol implant for the correction of lesser toe deformities, and to determine if the distal interphalangeal (DIP) joint and metatarsophalangeal (MTP) joint are modified during patient follow-up after correction of the PIP joint. MATERIALS AND METHODS: A prospective analysis of 36 patients with claw toe or hammertoe who were treated with an intramedullary nitinol implant. Clinical manifestations and angulation of the metatarsophalangeal, proximal and distal interphalangeal (MTP, PIP, DIP) joints were evaluated in radiographic studies preoperatively, at first medical revision post-surgery, and after a minimum of 1 year of follow-up. Complications such as non-union rate, implant rupture, and implant infection were also evaluated during follow-up. RESULTS: All patients were women with an average age of 65.5 (range 47-82) years. The average follow-up time was 2.4 (range 1-5.7) years. Fifty intramedullary nitinol implants were used. The MTP joint extension and PIP joint flexion decreased by 15.9° (95% CI - 19.11 to - 12.63) and 49.4° (95% CI - 55.29 to - 43.52), respectively, at the end of follow-up. Moreover, the DIP joint flexion increased progressively during follow-up (13.7° pre-surgery versus 35.6 in last medical check-up, 95% CI 13.24-30.57). There were four (8%) asymptomatic implant ruptures. The rate of fusion was 98%. CONCLUSION: The reduction of the PIP joint using an intramedullary nitinol implant is a good option in lesser toe deformities, with few complications and a high rate of arthrodesis. Moreover, the PIP joint reduction affects both the MTP and DIP joints.

Local and systemic diffusion of antineoplastic drugs following vertebroplasty using acrylic cement mixed with cisplatin or methotrexate: experimental study in pigs.

PURPOSE: To determine the efficacy of cisplatin- or methotrexate-containing acrylic cement for local and systemic antineoplastic drug diffusion. Among the uses of acrylic cement or Polymethylmethacrylate (PMMA), there is the possibility to employ it as vehicle for drug diffusion. This capability is of interest in the treatment of pathological fractures: The curative effects of the cement (cytotoxicity of the monomer and increased temperature) are added to the antineoplastic effect of the drugs. METHODS: In the experimental study, two groups of ten pigs underwent vertebroplasty using cement mixed with 500 mg of powder cisplatin or 1000 mg of powder methotrexate. Vertebroplasty was performed in two non-consecutive lumbar vertebrae with bipedicular cement injection. Transpedicular bone biopsy was performed weekly to measure levels of antineoplastic agent in bone tissue and blood plasma. Cisplatin was studied by atomic absorption spectrometry and methotrexate by fluorescence polarization immunoassay. Renal and hepatic function and blood analysis were performed weekly. RESULTS: Cisplatin and methotrexate levels were found in bone tissue at more than 5 weeks following surgery. The cisplatin peak occurred at week 3 (mean 1269 µg/g bone) and the methotrexate peak at week 1 (mean 862.76 µg/g bone). Plasma drug levels were found 72 h after surgery, with a peak at 24 h for cisplatin (mean 0.23 µmol/L) and at 30 min for methotrexate (mean 0.92 µmol/L). None of the animals died during the study. Animals with intracanal cement leaks showed no neurological involvement. Renal, hepatic and hemogram studies remained within normal limits. CONCLUSIONS: There is local diffusion of antineoplastic agents from the cement to bone and plasma. We found methotrexate and cisplatin levels in bone at up to 5 weeks, comparable to previous in vitro reports. At the doses administered, there were no cases of myelosuppression, hepatotoxicity, or nephrotoxicity.

Efficacy of pedobarographic analysis to evaluate proximal medial gastrocnemius recession in patients with gastrocnemius tightness and metatarsalgia.

PURPOSE: Proximal medial gastrocnemius recession (PMGR) is a surgical procedure performed in patients with gastrocnemius tightness (GT). The purpose of this study is to evaluate the efficacy of pedobarographic analysis on PMGR in patients with GT and metatarsalgia. METHODS: This prospective study included 52 patients diagnosed with GT treated surgically with PMGR and 49 non-operated upon patients (control group). A total of 55 PMGRs (three bilateral) were performed as an isolated or combined procedure in the treatment group. Passive ankle dorsiflexion with knee flexion and extension was evaluated in all patients. In addition, pedobarographic analysis was performed before and after surgery. RESULTS: Median preoperative ankle dorsiflexion was -10.0° (equinus) with extended knee and 10.0° with flexed knee and postoperative differences in median ankle dorsiflexion was 12.5° (extended knee) (p = 0.000) and 5.0° (flexed knee) (p = 0.002). After the PMGR, the median area of the contact surface (-3.0 cm2) (p = 0.009), the maximum (-13,239.0 Pa) (p = 0.019) and mean pressure (-2,942.0 Pa) and the forefoot force (-70.0 N) (p = 0.000) decreased. An increase in hindfoot force (20.0 N), hindfoot bearing time (4.0 ms) (p = 0.005), and forefoot bearing time (1.0 ms) was also observed. CONCLUSIONS: Pedobarographic analysis is an efficient tool to evaluate surgical procedures that assess metatarsal overload. PMGR is an effective surgical procedure to improve passive ankle range of motion and decrease forefoot plantar overload.

Sesamoid Position in Healthy Volunteers Without Deformity: A Computed Tomography Study.

We used coronal computed tomography to determine the normal sesamoid position in 20 healthy volunteers. The sample involved 40 feet (20 left [50%] and 20 right [50%]) in 20 volunteers, including 11 females (55%) and 9 males (45%). The relationship between the first metatarsal head and the sesamoid complex was categorized as Yildirim grade 0 in every case (100%). The mean width of the foot was 77.7 ± 5.8 mm, and the ratio of the foot width to the distance from the second metatarsal head to the tibial sesamoid was 39.6% ± 2.02%. Based on our findings, we consider Yildirim grade 0 to be the normal sesamoid alignment.

The Relationship Between the Sesamoid Complex and the First Metatarsal After Hallux Valgus Surgery Without Lateral Soft-Tissue Release: A Prospective Study.

Some investigators have emphasized restoring the relationship between the sesamoid complex and the first metatarsal head to reduce the risk of hallux valgus recurring after surgical reconstruction. In a prospective study, we analyzed whether the first metatarsophalangeal joint could be realigned after scarf-Akin bunionectomy without lateral soft tissue release. A total of 25 feet, in 22 patients, were prospectively enrolled and analyzed using anteroposterior radiographs and coronal computed tomography scans obtained before and 3 months after surgery. The Yildirim sesamoid position decreased from a preoperative of 2 (range 1 to 3) to a postoperative position of 0 (range 0 to 1; p < .001), the mean first intermetatarsal angle decreased from 12.6° ± 2.4° to 5.8° ± 2.1° (p < .001), and the mean distance between the second metatarsal and the tibial sesamoid changed from 25.7 ± 4.6 to 25.9 ± 4.6 (p = .59). Our findings suggest that dislocation of the sesamoid complex is actually caused by displacement of the first metatarsal. In conclusion, the scarf-Akin bunionectomy adequately restores the alignment of the first metatarsophalangeal joint, including restoration of the sesamoid apparatus, without direct plantar-lateral soft tissue release.

Sensitivity to change and responsiveness of provocative load tests among athletes with patellar tendinopathy.

BACKGROUND: Pain provocation tests are recommended for assessing pain severity and as an outcome measure for individuals with patellar tendinopathy. OBJECTIVE: To evaluate floor and ceiling effects, sensitivity to change, and responsiveness cut-offs of two provocative load tests among athletes with patellar tendinopathy. METHODS: Athletes (N = 41) performed six repetitions for the single leg decline squat (SLDS) and resisted knee extension (KE) at baseline and 12 weeks. Participants rated their pain during each test on a visual analog scale (VAS). Sensitivity to change was assessed by calculating effect size (ES) and the standardized response mean (SRM). The responsiveness cut-offs were assessed using a combination of anchor and distribution- based methods to determine the minimal clinically important difference (MCID) for each test. RESULTS: A floor or ceiling effect was observed in only a small number of participants for both tests except for KE, for which approximately one third of participants had a floor effect at week 12. There was higher sensitivity to change for SLDS (ES: 1.93/SRM: 1.43) compared with KE (ES:0.96/SRM: 1.09). The MCID corresponded to a decrease of 1.6 points for SLDS and 1.0 for KE, while the distribution-based method estimated 1.2 points for SLDS and 1.1 for KE. CONCLUSION: This study found moderate to high sensitivity to change and established MCID values for the SLDS and KE test in athletes with patellar tendinopathy before and after rehabilitation. Both tests may be useful as pain on loading outcomes as athletes progress with their rehabilitation, but the KE test results in higher floor effects and has lower sensitivity to change.

Vertebral Body Height Changes in Acute Symptomatic Osteoporotic Vertebral Compression Fractures Treated with Vertebral Cement Augmentation-Which Factors Affect Vertebral Body Height during Follow-up? A Multiple Linear Regression Study.

Changes in vertebral body height depend on various factors which were analyzed in isolation and not as a whole. The aim of this study is to analyze what factors might influence the restoration of the vertebral body height after vertebral augmentation. We analyzed 48 patients (108 vertebrae) with osteoporotic vertebral fractures who underwent vertebral augmentation when a conservative treatment proved to be unsatisfactory. The analyses were carried out at the time of the fracture, during surgery (pre-cementation and post-cementation), at the first medical check-up (6 weeks post-surgery) and at the last medical check-up. The average vertebral height was measured, and the differences from the preoperative values were calculated at each timepoint. A Pearson correlation coefficient and a linear multivariable regression were carried out at different timepoints. The time since the vertebral fracture was 60.4 ± 41.7 days. The patients' average age was 73.8 ± 7 years. The total follow-up period was 1.43 ± 1 year. After vertebral cementation, there was an increase in the vertebral body height of +0.3 cm (13.6%). During the post-operative follow-up, there was a progressive collapse of the vertebral body, and the pre-surgical height was reached. The factors that most influenced the vertebral height restoration were: a grade III collapse, an intervertebral-vacuum-cleft (IVVC) and the use of a flexible trocar before cement augmentation. The factor that negatively influenced the vertebral body height restoration was the location of the thoracolumbar spine.

Symptomatic medial exostosis of the great toe distal phalanx: a complication due to over-correction following akin osteotomy for hallux valgus repair.

UNLABELLED: The authors present the case of a 54-year-old female who developed a painful compression lesion localized to the medial aspect of the base of the distal phalanx of the great toe as a complication of hallux valgus surgery. Preoperative radiographic evaluation of the patient's foot revealed the first ray to be longer than the second, a 12 degrees first intermetatarsal angle, a 33 degrees hallux abductus angle, and an exostosis at the medial aspect of the base of the hallux that was not considered by the surgeon to be important. Correction of the hallux valgus deformity was performed with a combination of scarf and Akin osteotomies, and the intermetatarsal and hallux abductus angles reduced to 2 degrees and 8 degrees , respectively. By 2 months postoperative, the patient was complaining of pain at the medial aspect of the distal phalanx of the hallux associated with shoe pressure. The pain correlated both clinically and radiologically with the exostosis at the base of the distal phalanx, and had become symptomatic only after the hallux had been operatively realigned. At 6 months postoperative, percutaneous exostectomy was undertaken to remove the exostosis. Pain relief was complete, thereafter, and after 2 years of postoperative follow-up the patient remained pain free. The clinical importance of a medial exostosis localized to the base of the distal phalanx of the hallux must be taken into consideration whenever hallux valgus correction is undertaken, and this is particularly important whenever an Akin osteotomy is being considered. LEVEL OF CLINICAL EVIDENCE: 4.

Feasibility of open and percutaneous corrective osteotomies of the second phalanx of the great toe: An approach on a cadaveric model.

BACKGROUND: Having had a previous experience of 4 open F2 osteotomies to correct interphalangeal hallux valgus, the aim of this study was to test the efficacy of a percutaneous approach for this correction. METHODS: 3 open and 12 percutaneous F2 osteotomies in 15 cadaver feet were performed. Interphalangeal (IPH), F2 asymmetry (AF2) and joint deviation (JD) angles were measured on radiographs. The operated great toes were anatomically analyzed looking for possible lesions to surrounding tissues. RESULTS: Mean IPH decreased from 10.7° to 2.9°, AF2 from 7.8° to 1°, and JD from 1.4° to 0.5°. Damage to the hallux extensor tendon was detected in 1 foot and a nail bed lesion was detected in 1 case, both operated percutaneously. CONCLUSIONS: F2 Valgus deformity can be corrected using open or percutaneous osteotomy. The authors consider the open correction worthwhile because percutaneous techniques may damage surrounding tissues and the incision length difference is minor. LEVEL OF CLINICAL EVIDENCE: 3.

Neurectomy versus neurolysis for Morton's neuroma.

BACKGROUND: We evaluated a series of patients who underwent neurectomy or neurolysis for the surgical treatment of Morton's neuroma. MATERIALS AND METHODS: A group of 50 patients (69 feet) who underwent surgery for a symptomatic Morton's neuroma were retrospectively reviewed. Surgery was performed through a dorsal approach in all cases. When the nerve showed macroscopic thickening or the typical pseudoneuroma, it was resected; when the nerve had no macroscopic changes, the intermetatarsal ligament and any other potentially compressive structure were released. In 17 cases, adjacent claw toes were treated. RESULTS: Nerve thickening (pseudoneuroma) were resected in 46 cases; in the other 23 cases, the nerve was preserved. Total relief from digital nerve related symptoms was obtained in all cases but one in each group. These patients were reoperated on 6 months later by performing a neurectomy in the case where the nerve had been preserved, and a more proximal resection in the case in which the nerve had been resected. Both patients finally achieved complete pain relief. CONCLUSION: When treating Morton's neuromas surgically, neurolysis can be a valid option when a pseudoneuroma has not developed.

Pure cervical radiculopathy due to spontaneous spinal epidural haematoma (SSEH): report of a case solved conservatively.

INTRODUCTION: Spontaneous spinal epidural haematoma (SSEH) is widely recognised throughout the literature as a cause of myelopathy, radicular compression being very rarely reported. Surgical management is almost always recommended, especially in the cases of spinal cord compression. Conservative treatment is reported as a curiosity and only in the case of spontaneous improvement. This report presents the particular case of a 64-year-old patient undergoing anticoagulant therapy that had a cervical radiculopathy due to a SSEH confirmed by MRI. The patient improved spontaneously and symptoms were solved with unconventional conservative treatment and without stopping the anticoagulant therapy. CONCLUSIONS: Spontaneous epidural haematoma must be kept in mind when patients undergoing anticoagulant therapy have a sudden onset of cervicobrachialgia. Even though most spinal surgeons advocate surgical treatment, a conservative approach may lead to a complete recovery and may be considered as a good option in the case of radicular involvement. Discontinuation of the anticoagulant therapy may not always be needed, especially when the clinical syndrome improves spontaneously.

Osteotomía percutánea de la falange distal del hallux. Indicaciones y técnica / Percutaneous osteotomy of the distal phalanx of the hallux. Indications and technique

Introducción: Las técnicas para corregir las deformidades del hallux incluyen osteotomías metatarsianas y falángicas. Las osteo-tomías sobre la falange proximal corrigen el DASA y el ángulo interfalángico. Sin embargo, no se han publicado las indicaciones para la osteotomía de la falange distal. El objetivo de este artículo es comunicar la técnica y las indicaciones de la osteotomía percutánea de la falange distal del hallux, y evaluar los resultados de una serie de casos. materiales y métodos: Se analizaron 14 pies en los que se realizó una osteotomía de la falange distal del hallux para corregir una deformidad. Se midieron el DASA, la oblicuidad interfalángica y el ángulo falange distal-interfalángico en las radiografías. La técnica quirúrgica fue percutánea con control fluoroscópico. Los resultados se evaluaron mediante las escalas analógica visual de dolor y AOFAS. Seguimiento medio: 52 meses. Resultados: 13 pies de mujeres y un pie de hombre. Edad promedio: 58 años. Los resultados clínico y estético fueron excelentes, con alivio del dolor. Mejoría de la escala AOFAS: promedio 37 puntos. Análisis comparativo de ángulos preoperatorios y posoperatorios: DASA (p = 0,01), excepto cuando se aisló de la muestra a los pacientes con osteotomía tipo Akin (p = 0,33); ángulos F2-IF y F2-MTF (p <0,00001). Se registraron las complicaciones. Conclusiones: En la deformidad en valgo de la falange distal del hallux sintomática, se debe considerar una osteotomía correctora sola o asociada a osteotomía de la falange proximal. La osteotomía percutánea de la falange distal es un método eficaz, seguro y rápido. Nivel de Evidencia: IV

Introduction. There are many techniques to correct the hallux deformity. Most of them include metatarsal and/or phalanx osteotomies. The Akin osteotomy of the proximal phalanx is used to correct the distal articular set angle (DASA), or the interphalangeal angle. However, indications for the distal phalanx osteotomy remain unpublished. The aim of this study is to communicate the technique of performing and the indications for percutaneous osteotomy of the distal phalanx of the hallux, and evaluate the results of a cases series. Materials and methods. We report 14 cases in which distal phalangeal osteotomy was performed. Radiographic measurements were performed on dorsal-plantar view foot, to analyze distal articular set angle (DASA), interphalangeal obliquity, and F2-IP angle. Surgical technique was performed by minimally incision surgery. The clinical and functional results were evaluate by the visual analogue scale pain, and the AOFAS score. Mean follow-up was 52 months. Results. The clinical result for all the patients was excellent, pain was relieved and deformities corrected. Pre- and post-operative comparative angles: DASA (p: 0.01), except when isolated from the sample for Akin-type osteotomy (p: 0.33). Angle F2-IF and angle F2-MTF (p: <0.00001). The patients where highly satisfied with both the aesthetic and functional results. Complications were registered. Conclusion. In the symptomatic hallux´s distal phalanx deformity a corrective distal phalanx osteotomy should be considered alone, or associated with the osteotomy of the proximal phalanx. Percutaneous distal phalanx osteotomy is an effective, safe, and fast procedure. Level of Evidence: IV

Does the shape of the L5 vertebral body depend on the height of CT slices in the pedicle? Evaluation of the shape of the L5 vertebral body with a multicut CT scan.

STUDY DESIGN: The shape of the L5 vertebral body was analyzed using a computerized tomography (CT) scan. OBJECTIVE: The aim of this study is to determine if the vertebral L5 body shape varies depending on the height of the CT slices through the L5 pedicle. SUMMARY OF BACKGROUND DATA: The morphometry of L5 has been studied to help the introduction of pedicular screws. The shape of the vertebral body has been seldom looked into, and the findings obtained show a triangular shape and hemispherical shape, supposedly owing to interpersonal variability. The hemisphere shape enables pedicular screws to be introduced nonconvergently, whereas the triangular shape enables pedicular screws to be introduced at a convergent angle but posing the risk of cortical perforation unless these guidelines are followed. METHODS: Abdominal CT multicut with 64 crowns was performed in 101 consecutive patients with diverse indications. Width of CT slices was with a 1-mm reconstruction increase. We selected one axial slice that passed through the upper part of the pedicle and another one that passed through the lower part of the pedicle and compared next parameters in both cuts: pedicular cortical width, pedicular endostal width, pedicular angle, vertebral body length, vertebral body width, vertebral perimeter angles, and visual appearance of vertebral body shape. RESULTS: We found statistical differences between all values except the anterior vertebral perimeter angle on comparing values of upper part with values of lower part and visual vertebral body shape was different in 93% of vertebrae. In the upper part the vertebral body is hemispherical whereas in the lower part it is triangular. CONCLUSION: In most cases, the vertebral body shape is hemispherical in the upper part of the pedicle and triangular in the lower part of the pedicle. It means that in the lower part pedicular screws must be introduced at a more convergent angle than in the upper part if we do not want to break any cortical of the vertebral body.