Initial experience, feasibility, and technical development with an electromagnetic navigation assistance in percutaneous pelvic bone cementoplasty: retrospective analysis.

OBJECTIVES: To assess the feasibility and technical outcomes of pelvic bone cementoplasty using an electromagnetic navigation system (EMNS) in standard practice. MATERIALS AND METHODS: Monocentric retrospective study of all consecutive patients treated with cementoplasty or reinforced cementoplasty of the pelvic bone with EMNS-assisted procedures. The endpoints were periprocedural adverse events, needle repositioning rates, procedure duration, and radiation exposure. RESULTS: A detailed description of the technical steps is provided. Thirty-three patients (68 years ± 10) were treated between February 2016 and February 2020. Needle repositioning was required for 1/33 patients (3%). The main minor technical adverse event was soft tissue PMMA cement leaks. No major adverse event was noted. The median number of CT acquisitions throughout the procedures was 4 (range: 2 to 8). Radiation exposure and mean procedure duration are provided. CONCLUSION: Electromagnetic navigation system-assisted percutaneous interventions for the pelvic bone are feasible and lead to low rates of minor technical adverse events and needle repositioning. Procedure duration and radiation exposure were low. KEY POINTS: • Initial experience for 33 patients treated with an electromagnetic navigation assistance for pelvic cementoplasty shows feasibility and safety. • The use of an electromagnetic navigation system does not expose to high procedure duration or radiation exposure. • The system is efficient in assisting the radiologist for extra-axial planes in challenging approaches.

Reinforced cementoplasty for pelvic tumour lesions and pelvic traumatic fractures: preliminary experience.

OBJECTIVES: Pelvic bone pathological lesions and traumatic fractures are a considerable source of pain and disability. In this study, we sought to evaluate the effectiveness of reinforced cementoplasty (RC) in painful and unstable lesions involving the pelvic bone in terms of pain relief and functional recovery. METHODS: All patients with neoplastic lesion or pelvic fracture for whom a pelvic bone RC was carried out between November 2013 and October 2017 were included in our study. All patients who failed the medical management, patients unsuitable for surgery, and patients with unstable osteolytic lesions were eligible to RC. Clinical outcome was evaluated with a 1-month and 6-month post-procedure follow-up. The primary endpoint was local pain relief measured by the visual analogue scale (VAS). RESULTS: Twenty-two patients (18 females, 4 males; mean age of 65.4 ± 13.3 years [range 38-80]) presenting with painful and unstable pelvic lesions were treated by RC during the study period. Among the 22 patients, 8 patients presented with unstable pelvic fractures (3 patients with iliac crest fracture, 3 with sacral fractures, and the remaining 2 with peri-acetabular fractures). No procedure-related complications were recorded. All patients had significant pain relief and functional improvement at 1 month. One patient (4.5%) had suffered a secondary fracture due to local tumour progression. CONCLUSIONS: Reinforced cementoplasty is an original minimally invasive technique that may help in providing pain relief and effective bone stability for neoplastic and traumatic lesions involving the pelvic bone. KEY POINTS: • Reinforced cementoplasty is feasible in both traumatic fractures and tumoural bone lesions of the pelvis. • Reinforced cementoplasty for pelvic bone lesions provides pain relief and functional recovery. • Recurrence of pelvic bone fracture was observed in 4.5% of the cases in our series.

Safety of vertebral augmentation with cranio-caudal expansion implants in vertebral compression fractures with posterior wall protrusion.

OBJECTIVES: Vertebral augmentation (VA) has become routinely used in vertebral compression fractures (VCFs). VCFs are often associated with posterior wall protrusions (PWPs), which theoretically contraindicates vertebroplasty due to a higher risk of neurological complications. The latest generation of VA devices uses intravertebral cranio-caudal expandable implants to improve the correction of structural deformities but could also be used to prevent further PWP during cement injection. The aim of this study was to evaluate the safety of VA with expandable implant for VCFs with PWP. METHODS: All consecutive patients treated with expandable implants were considered eligible for inclusion if they met the following criteria: (1) non-neurological VCF, (2) considered unstable (A3-A4 in AOSpine classification), (3) significant PWP (> 2 mm), (4) back pain with a visual analogue scale (VAS) ≥ 4. PWPs were independently measured by two investigators; Pearson's statistics were used for interobserver reproducibility. RESULTS: Fifty-one consecutive patients, with a mean age of 75 ± 8.3 years (range, 50-92), were included. There was a slight decrease between mean preoperative (6.7 mm ± 2.2 mm) and postoperative (6.5 mm ± 2.2 mm) PWP (p = 0.02), with an excellent interobserver reproducibility (Pearson correlation coefficient = 0.92). A mean kyphosis reduction of 34.9% (± 28.4) was observed (p < 0.001). Forty-two patients (82.4%) had significant pain improvements (mean preoperative VAS = 6.9 [± 1.7] versus 3.1 [± 2.0] postoperatively [p < 0.001]). Secondary adjacent level fractures were noted in 16 patients (31.4%), with a reduction of that risk down to 18.8% if a preventive adjacent vertebroplasty was performed, without reaching the significance threshold (p = 0.14). CONCLUSIONS: VA with expandable implants appeared safe for non-neurological VCFs with PWP, while allowing satisfactory pain relief. KEY POINTS: • Vertebral augmentation with cranio-caudal expandable implants is safe for non-neurological vertebral compression fractures with posterior wall protrusions. • Vertebral augmentation with cranio-caudal expandable implants might increase the occurrence of secondary adjacent level fractures. • Adjacent level vertebroplasty might be helpful to prevent secondary adjacent level fractures.

Intervertebral foramen variation following dynamic L4-L5 interspinal device implantation: foramen size after interspinal device implantation.

STUDY DESIGN: This is a biomechanical study. OBJECTIVE: Measuring changes in foraminal size after L4-L5 interspinous devices implantation. SUMMARY OF BACKGROUND DATA: Low-back pain aetiologies include foraminal stenoses. A niche is developing for interspinal implants that are minimally invasive with few harmful side effects. At present, we do not have sufficient understanding about their impact on the foraminal opening. METHODS: Six fresh L2-S1 columns were prepared with preservation of the capsuloligamentary and discal structures. The L4-L5 foramen was particularly carefully prepared. A 2-dimensional photographic analysis measured the length and width of the foramen and the extraforaminal surface, both before and after the implantation of a supple interspinal device that preserves the supraspinal ligaments. Photographic calibration and the use of precise and identical photographic landmarks (pixels) permitted the calculation of the foraminal deformity. A Wilcoxon test was performed for statistical analysis with P<0.05 for significance. RESULTS: The average foraminal length was 15.7±2.8 mm and the average width was 9.4±1.2 mm. After the implantation of an interspinal device, it was 16.8±2.5 and 10.1±1.3 mm, respectively. The increase in the average foraminal opening was 7.45% and 7.63%, respectively (P=0.02). The average foraminal surface area was 150.4±35.8 mm and following intervention, this was 165.1±28.3 mm, that is an average gain of 14.65 mm (5.3-26.9) (P=0.03). CONCLUSIONS: Few interspinal devices have been the subject of studies on the foraminal opening after implantation. Among the initial strict indications on root compressions for which conventional surgery is too invasive, these implants could present a true therapeutic alternative. This supple implant significantly opened the L4-L5 foramen on the cadavers. Nevertheless, biomechanical data are lacking on its effects on the 3 planes following stress. Even if the impact on the foraminal opening is of interest, kinematic studies are needed to determine the exact effects before clinical implantation.

Femoral intercondylar notch: Accuracy of a novel MRI measurement protocol.

OBJECTIVE: The most common mechanical complication following an anterior cruciate ligament (ACL) reconstruction is joint stiffness, due in part to cyclops syndrome. A narrow intercondylar notch is an anatomical risk factor. A reliable preoperative notch measurement would help anticipate proper graft size, or plan a notchplasty during the ligament reconstruction, if necessary. No study has yet assessed the accuracy of the methods used to measure notch size. HYPOTHESIS: The novel measurement protocol proposed in this study would be more reproducible than the reference technique. METHODS: A total of 20 preoperative knee MRIs performed during the assessment of an ACL rupture were randomly selected. The notch size was measured using 2 methods: traditional (ratio of the notch and metaphyseal widths measured on a line drawn through the popliteal groove) and novel. The latter was measured using the same ratio but took into account the notch width in its proximal third, according to a coronal slice that passes through the ACL tibial attachment. Three orthopedic surgeons with different levels of experience (senior surgeon, junior surgeon and surgical resident) performed these measurement protocols twice on anonymized MRI scans, 10days apart. Spearman's rank correlation coefficient was used to assess the intraobserver correlations and a concordance index was used to assess the interobserver correlations. The influence of the second MRI reading was analyzed with a bootstrap test. RESULTS: The mean intraobserver reliability was 0.73 for the reference method and 0.83 for the proposed method. The values of the bootstrap tests were higher for the proposed method (0.45 vs. 0.45 and 0.70; p<05 for interobserver; 0.49 vs. 0.69 and 0.62; p<05 for intraobserver). CONCLUSION: The proposed measurement protocol showed a higher reproducibility in assessing notch size than the traditional method. This technique therefore provides a reliable assessment of the intercondylar notch width. LEVEL OF EVIDENCE: IV; retrospective study.

Return to sport after early surgical repair of acute patellar tendon ruptures.

INTRODUCTION: Patellar tendon ruptures make up about 5% of all extensor mechanism injuries. They mainly occur in young, athletic men who have contributing risk factors such as chronic tendinopathy. The aim of this study was to evaluate the return to sport after repair of an acute patellar tendon rupture. We hypothesized that surgical repair yields good functional outcomes with a high rate of return to competitive sports in patients treated with the same surgical technique. METHODS: This retrospective study involved 23 cases of patellar tendon rupture in 20 patients (2 women, 18 men). The average age was 42.0±13.8 years (24-68). Eighteen ruptures occurred at the patellar attachment and five were mid-substance. Either transosseous reattachment or direct suture repair was carried out within 21 days; all tendons were augmented with a non-metallic tibiopatellar suture. At the final assessment, a clinical examination was carried out (extensor mechanism testing and range of motion) with collection of functional scores (pain, VISA-P, Lysholm and satisfaction), date of return to sport and final radiographs. RESULTS: At a mean follow-up of 47.7 months (15-120), there were no cases of significant knee stiffness. Seventeen patients (94.4%) had returned to sport, 15 at their pre-injury level (83%). The mean time before running could be restarted was 9 months (6-15 months) and 17 months for sports at the same pre-injury level (8-18 months). The mean VISA score and the mean Lysholm score were 85.5 (62-99) and 67.3 (35-97) respectively; 85% of patients were satisfied or very satisfied. The prognosis was worse when the patient was older than 40 and had a BMI above 25. Early surgical repair of patellar tendon rupture yields good functional outcomes with return to sport possible at high levels. LEVEL OF EVIDENCE: IV, Retrospective cohort study.

Transoral vertebroplasty for the C1 lateral mass.

BACKGROUND: Osteolytic lesions of the atlas (C1) are challenging to treat by vertebroplasty due to the vicinity of the vertebral artery and the spinal cord. OBJECTIVE: To present our experience with transoral vertebroplasty (TOV) for osteolytic lesions of the lateral mass of the atlas. METHODS: Retrospective case series involving 15 consecutive patients (nine male, six female, mean age 63 years) who underwent TOV for the treatment of an osteolytic lesion of the lateral mass of the atlas. Among the osteolytic lesions, 10/15 (67%) were bone metastases from various cancers; 4/15 (27%) were lesions related to multiple myeloma; and one lesion (7%) was an aggressive hemangioma. All the TOVs were performed under general anesthesia and in most cases (10/15; 67%) in a hybrid angiosuite combining a C-arm flat panel and a CT scan. The remaining five patients were treated under biplane fluoroscopic guidance. RESULTS: Vertebroplasty of the lateral mass of C1 through a transoral route was feasible in all cases. Significant pain relief was obtained in most cases (1 month average decrease in Numeric Rating Scale: 4.9±4.1). No major complication was recorded. In 7/15 cases (47%), cement leakage surrounding the C1 lateral mass was seen; none of these leakages had a significant clinical consequence. No additional spine surgery was required in any of the patients. CONCLUSION: TOV of osteolytic lesions of the lateral mass of the atlas is feasible and seems safe and effective, providing pain relief and bone stabilization.

The level of the joint line after cruciate-retaining total knee replacement: a new coordinate system.

This study assessed joint line changes after knee replacement surgery. Sixty consecutive cruciate-retaining total knee replacements were followed up. The height of the femorotibial joint line in extension and in 90 degrees flexion were analysed. A new coordinate system was used. It is based on two perpendicular axes applied to a lateral X-ray: one axis is drawn along the anterior cortex of the distal femur and the other axis overlies the intersection of the inter-condylar roof and the posterior femoral condyles. In patients with non-posterior stabilised implants, the landmarks chosen appear to be reliable and useful. In this study, the femorotibial joint line was displaced distally, and the surgical instrumentation was changed accordingly.

Risk factors for cut-out after internal fixation of trochanteric fractures in elderly subjects.

INTRODUCTION: Proximal femoral fracture is associated with severe morbidity and mortality and high socioeconomic costs. The main mechanical complication of internal fixation in trochanteric fracture is lag-screw cut-out through the femoral head. Several factors are involved, but remain controversial. The aim of the present study was to determine risk factors for cut-out in internal fixation of extracapsular proximal femoral fracture. METHODS: A single-center retrospective study was conducted on a continuous series of 228 patients aged over 75 years, operated on for trochanteric fracture by gamma3 nail or DHS screw plate between July 2009 and December 2014. RESULTS: Thirteen patients experienced mechanical failure of the internal fixation (5.7%). Tip-apex distance (TAD) differed significantly between the group with cut-out (32.69mm) and the group with consolidation (23.70mm; p-value=0.003052). Cut-out rate was 0.89% in good reduction, versus 9.64% in moderate and 12.12% in poor reduction (p-value=0.002693). In contrast, there were no significant differences according to age, type of fracture, or severity of osteoporosis. CONCLUSION: To minimize mechanical complications exacerbating morbidity and mortality, great attention should be paid to fracture reduction and lag-screw positioning. LEVEL OF EVIDENCE: IV, retrospective study.

Just a drop of cement: a case of cervical spine bone aneurysmal cyst successfully treated by percutaneous injection of a small amount of polymethyl-methacrylate cement.

Aneurysmal bone cyst (ABC) is a benign hemorrhagic tumor, commonly revealed by local pain. The best treatment for this lesion is still controversial. We report the case of a patient with chronic neck pain revealing an ABC of the third cervical vertebra. After percutaneous injection of a small amount of polymethyl-methacrylate bone cement, the patient experienced significant clinical and radiological improvement.

Just a drop of cement: a case of cervical spine bone aneurysmal cyst successfully treated by percutaneous injection of a small amount of polymethyl-methacrylate cement.

Aneurysmal bone cyst (ABC) is a benign hemorrhagic tumor, commonly revealed by local pain. The best treatment for this lesion is still controversial. We report the case of a patient with chronic neck pain revealing an ABC of the third cervical vertebra. After percutaneous injection of a small amount of polymethyl-methacrylate bone cement, the patient experienced significant clinical and radiological improvement.

Therapeutic strategies for treating osteolytic bone metastases.

The recent progress in oncologic management of patients with localized cancer or metastatic disease has permitted a significant improvement in life expectancy. Nevertheless, bone metastases and their consequent skeletal-related events (SREs) are still associated with unfavorable prognosis and greatly affect quality of life. Global management of these bone metastases includes traditional local approaches (surgery, radiotherapy, etc.) and systemic administration of chemotherapeutic agents. This review focuses on treatments specific for bone metastases and, in particular, on inhibitors of bone resorption that are effective for preventing and delaying the development of SREs.

In vivo study of the kinematics in axial rotation of the lumbar spine after total intervertebral disc replacement: long-term results: a 10-14 years follow up evaluation.

INTRODUCTION: We did not find any in vivo study of spinal segment kinematics after disc replacement, especially over the long term. In vitro studies did show that it restores almost normal kinematics except for axial rotation. The goal of this study is to develop a new technique in order to analyse axial rotation of a spinal segment, in vivo, after total disc replacement. MATERIALS AND METHODS: A comparative retrospective study of motion in axial rotation at L4L5 level was carried out on 17 patients with artificial discs versus six healthy volunteers. Five patients carried one prostheses at L4L5 level and 12 carried two prosthesis at L4L5 and L5S1 levels. The follow up ranged from 10.8 to 14.3 years (average 12.4+/-1, median 12.6). Dynamic radiographs in axial rotation were made using a special protocol. A new technique associating a stereographic method and image processing software was developed in order to evaluate the range of motion in axial rotation as well as the mechanical coupling. RESULTS: The standard deviation of angular measurements was 1.8 degrees . Eleven (65%) patients had a normal mobility in torsion, identical to those of the volunteers and of the literature, whereas six (35%) had an abnormal increased mobility. If only one disc was replaced, mobility in torsion was identical to that of the volunteers, in the case of two replaced discs, 50% (6/12) of the patients had an abnormal increased mobility. In the sub-group of normal mobility, the coupling was identical to that of the volunteers. In the sub-group of increased mobility, the coupling was different with a strong flexion (10 degrees ), increased by about 7 degrees (P<0.001). CONCLUSION: The implementation of only one discal prosthesis SB Charité seems to restore kinematics close to that of the healthy volunteers and comparable to the literature. The implementation of two adjacent prostheses does not restore normal kinematics in 50% of the cases. It is probable that the existence of active stabilizing elements explains the difference with the in vitro studies carried out beforehand.

Wedge osteotomy for treating post-traumatic kyphosis at thoracolumbar and lumbar levels.

Local post-traumatic kyphosis may impair spinal sagittal balance and result in severe disability. The goal of this study is to evaluate posterior closing wedge osteotomy at the level of injury, by comparing thoracolumbar (T12-L1) and lumbar (L2-4) spinal levels. Thirteen consecutive patients had surgery in an average 13 months after the initial injury. There were 8 thoracolumbar and 5 lumbar deformities. Nine patients already had posterior fixation. Eight patients had preoperative neurological deficits. Sagittal correction was assessed in terms of regional angulation (RA) and effective regional deformity (ERD), which was defined as the difference between the actual RA and the physiological RA for the level. The average follow up was 2.1 years. The average RA passed from 43.8 degrees (31 to 55) to 2.2 degrees (-5 to 7) after surgery. It was 5.3 degrees (-4 to 12), at follow-up. RA and surgical correction were not significantly different between thoracolumbar and lumbar groups. The average ERD was 47.2 degrees (24 to 66) preoperatively and 8.6 degrees (-5 to 37) at follow-up. The ERD passed from 41.8 degrees (24 to 54) to 0.5 degrees (-5 to 6) in the thoracolumbar group, and from 55.8 degrees (50 to 66) to 21.6 degrees (17 to 37) in the lumbar group. The ERD was significantly different initially (P=0.014) and after surgery (P=0.06). The anatomical result was complete in the thoracolumbar group, because the correction of the deformity at this level does not require more than correction of the vertebral body kyphosis. On the contrary, due to adjacent disc damage, the technique did not fully restore the physiological regional lordosis at lower levels.