Minimally invasive femoral head fracture fixation using three-dimensional navigation: a technical note.

Femoral head fractures are rare traumatic injuries that are usually associated with hip dislocations. Open reduction and internal fixation are performed when indicated, but can be associated with a higher risk of avascular necrosis. We report the case of a 24-year-old patient with a Pipkin type II fracture dislocation of the femoral head fixed via a minimally invasive three-dimensional navigated internal fixation technique. This technique minimizes deep soft tissue dissection to the hip capsule and associated vascularity and allows for accurate implant positioning.Level of evidence: Therapeutic case report Level IV.

Pedagogy in spine surgery: developing a free and open-access virtual simulator for lumbar pedicle screws placement.

PURPOSE: Simulators for pedicle screws placement range from basic sawbones to virtual reality. Yet, they remain expensive and often require specific devices. No free online virtual simulator has yet been developed. The goal was to design a freely accessible Web-based simulator. METHODS: The computer simulator consisted of a lumbar spine, a red box hiding the pedicles and five pairs of screws. After inserting the screws, the red box was removed to assess their position. A validation study was conducted with 24 medical students randomized into a simulation and a control group. All had a basic course on pedicle screws. The 12 simulation group students performed two sessions on computer. All 24 students then conducted a final common step on sawbones. The number of misplaced screws, types of breaches, and simulation times were analyzed. RESULTS: In the final sawbones simulation, 96 real screws were studied. Control group misplaced 50% of their screws compared with only 20.8% in the simulation group (p < 0.05). More careful, simulation group students were slower to insert their real screws. Over the two computer simulations, the rate of misplaced screws decreased (12.5% vs. 38.3%), showing a good handling of the simulator. Students were able to analyze and correct their pedicle breaches. CONCLUSION: This tool is the first free online lumbar pedicle screws simulator. Simulation helped students to better position the final real screws on sawbones. This project showed it was possible to create a free educational tool with no special equipment. LEVEL OF EVIDENCE: Level 3.

The Saint-Joseph Acetabular score: a reproducible and accurate prediction of the outcome of open reduction and internal fixation of acetabular fractures.

PURPOSE: Acetabular fractures are associated to an increased risk of subsequent hip osteoarthritis. The only available score for post-operative reduction assessment in acetabular fractures (Matta's score) is x-ray based. CT-scan was shown superior to X-rays in post-operative reduction assessment. We aim to describe a CT-scan-based post-operative reduction score in acetabular fractures and evaluate its accuracy and reproducibility. METHODS: This is a retrospective study that includes 138 patients who underwent surgery for an acetabular fracture in our tertiary referral centre with a mean follow-up of 104.39±42.2 months. The post-operative CT-scan was reviewed and residual displacement (maximum gap and step) measured by three independent observers. The association between the occurrence of THA and the CT-scan measurements was evaluated. This led to a new prognostic score. The interobserver reliability and accuracy of this score were calculated. RESULTS: Interobserver reproducibility for the residual maximal gap was 0.82 (95% CI [0.70-0.89]) and 0.61 (95% CI [0.52-0.70]) for the residual maximal step displacement measurements. We created a score from a logistic regression model, attributing 1 point for every 1 mm of residual maximal step displacement and 1 point for every 2 mm of residual maximal gap displacement. The interobserver reproducibility of this score was 0.78 (95% CI [0.71-0.84]), and its AUC was 0.79 (95% CI [0.69-0.88]). CONCLUSION: This is the first CT-scan-based score for the assessment of residual displacement of a surgically treated acetabular fracture. It shows good interobserver reproducibility and accuracy in predicting the risk for secondary THA. It should be regularly used per-operatively (if per-operative 3D imaging is available) and post-operatively to predict the prognosis.

Variation of cervical sagittal alignment parameters according to gender, pelvic incidence and age.

PURPOSE: The aim was to describe radiographic cervical sagittal alignment variations according to age, gender and pelvic incidence (PI) and to investigate relationships with thoracic alignment. METHODS: A total of 2599 individuals (5-93 years) without spinal deformity were studied. Cranial cervical parameters were: McGregor slope, occipita-C2 angle, McGregor-C2 lordosis and C1-C2 lordosis. Caudal cervical parameters were: C2-C7, cranial arch and caudal arch lordosis and C7- and T1-slope. A Bayesian inference compared parameter distributions. Correlations with spinopelvic and global alignment parameters were investigated. RESULTS: Among cranial cervical parameters, variations of McGregor slope were non-significant. McGregor-C2 lordosis and C1-C2 lordosis were smaller in males and increased significantly during growth, whereas the occipito-C2 angle decreased (Pr > 0.95). The occipito-C2 angle was larger and McGregor-C2 lordosis was smaller in low PI (Pr > 0.95). Among caudal cervical parameters, C2-C7 lordosis and C7- and T1-slope were larger in males and increased after 50 years (Pr > 0.95). Lordosis changes were non-significant in the cranial arch, whereas values increased in the caudal arch after 35 years (Pr > 0.95). Caudal parameter differences were non-significant between PI groups. Strong correlations existed between C2-C7, caudal arch lordosis, C7-slope, T1-slope and thoracic kyphosis. The sagittal vertical axis C2 correlated with caudal arch lordosis and T1-slope (ρ > 0.5; Pr > 0.95). CONCLUSION: Cervical alignment parameters vary according to age, gender and PI. In the cranial cervical spine, changes occur mainly during growth. In the caudal cervical spine, lordosis increases in the caudal arch, which is related to thoracic kyphosis increase with age. The caudal cervical arch acts as a compensatory segment by progressive extension, allowing horizontal gaze.

Pseudarthrosis in adult spine deformity surgery: risk factors and treatment options.

PURPOSE: Highlight risk factors for pseudarthrosis in long-segment spinal fusions, collect the approaches carried to address this complication. METHODS: Patients with ASD and fusion of ≥ 4 levels with minimum follow-up (FU) of ≥ 2 years were included. Full-body X-rays were done preoperatively, < 3 months and ≥ 2 years. Oswestry disability index (ODI), Scoliosis Research Society-22 and SF36 assessed pre- and postoperatively. The relationship between demographic, surgical and radiological variables with the development of pseudarthrosis was evaluated. RESULTS: Out of 524 patients included, 65 patients (12.4%) developed pseudarthrosis and 53 underwent revision surgery. Notably, 88% of pseudarthrosis cases are associated with fusion length (OR = 1.17, 95% CI = 1.05-1.292, p = 0.004), osteotomy requirement (OR = 0.28, 95% CI = 0.09-0.85, p = 0.025), pelvic fixation (OR = 0.34, 95% CI = 0.13-0.88, p = 0.026) and combined approaches (OR = 3.29, 95% CI = 1.09-9.91, p = 0.034). Sagittal alignment is not related to the rate of pseudarthrosis. Health related and quality of life scores were comparable at last FU between patients revised for pseudarthrosis and those that didn't require revision surgery (ODI = 28% no revision and 30% revision group). CONCLUSIONS: Pseudarthrosis is not related to malalignment, but with the surgical techniques employed for its treatment. Anterior approaches with anterior support decrease the rate by 30%, while long fusions, osteotomies and pelvic fixation increase its rate.

Knee injuries concomitant to posterior acetabular fractures: an association to look for.

PURPOSE: Acetabular fractures are frequently associated with other skeletal injuries, particularly knee injuries. This study aims to evaluate the relationship between posterior acetabular fractures and knee injury, analyzing its patterns and association with other injuries. METHODS: This is a retrospective monocentric study in a tertiary referral centre. We reviewed the data (age, sex, type of fracture, and concomitant injury) of patients hospitalized for a posterior acetabular fracture. We recorded concomitant knee injury diagnosed up to one year following acetabular fracture. RESULTS: Two-hundred-seventeen patients (177 males/40 females) were included. The mean age was 40.5 years. Eighty-five patients (39%) had a concomitant hip dislocation, nine (4.1%) had sciatic nerve palsy, 17 (7.8%) had upper extremity injury, and 18 (8.3%) had lower extremity injury (other than the knee). Eight (3.7%) patients had spine injury, 11 (5.1%) had severe thoracic injury, nine (4.1%) had an abdominal injury, and four (1.8%) had a head injury. There were 33 (15.21%, 95% CI 10.80-20.8%) patients (30 M/3 F) (group 1) with a concomitant knee injury and 184 patients without a concomitant knee injury(group 2). The mean age in group 1 was 34.3 compared to 45.4 in group 2(p = 0.021). The pattern analysis revealed five fractures, 14 ligamentous injuries (PCL injuries = 68%), and 14 soft tissue injuries. Sixteen (48.48%) injuries were identified during hospitalization and 17 (51.51%) during follow-up. There were an association between knee injury and upper extremity injury (OR = 3.49 95% CI 1.12-10.00,p = 0.022) and other lower extremity injury (OR = 3.18 95% CI 1.03-8.95,p = 0.032). DISCUSSION: Knee injury is the second most frequent lesion associated with posterior acetabular fractures. Being missed in half of cases, we recommend a systematic examination of ipsilateral knees under general anaesthesia, keeping a high index of suspicion and a low threshold for complementary knee imaging. Knee injury should be mainly looked for in patients younger than 60 years and in those with upper and/or lower extremities injuries.

Clinical impact of intraoperative cone beam tomography and navigation for displaced acetabular fractures: a comparative study at medium-term follow-up.

INTRODUCTION: The use of per-operative cone beam tomography imaging for displaced acetabular fractures yields increased post-operative articular reduction accuracy. This study evaluates the need for total hip replacement (THR) and hip-related functional outcomes in patients with displaced acetabular fractures treated with O-ARM guidance compared to those treated under C-ARM guidance. MATERIALS AND METHODS: This is a prospective matched cohort study. Adult patients (35) with acetabular fractures operated under O-ARM guidance were included. These were matched (age, fracture type) to classically treated patients (35) from our data base. The primary outcome was the need for THR during three year follow-up period. Secondary outcomes were functional scores [Harris Hip score (HHS), Postel-Merle d'Aubigné (PMA)] and hip osteoarthritis grade at three year follow-up. Correlation between reduction gap and THR was evaluated. RESULTS: At three years, five patients were lost to follow-up in O-ARM group and four in control group. Two patients (6.66%) in the O-ARM group needed THR compared to eight patients in controls (25.80%) (p = 0.046). Hip X-ray osteoarthritis grade averaged 0.00 in patients without THR in O-ARM group compared to 0.22 in patients without THR in controls (p = 0.008). HHS averaged 95.79 in patients without THR in O-ARM group, compared to 93.82 in patients without THR in the control group (p = 0.41%). PMA averaged 17.25 in patients without THR in the O-ARM group compared to 17.04 in patients without THR in group 2 (p = 0.37). Evaluation of correlation between reduction gap and THR rate yielded OR = 1.22 (1.06-1.45). DISCUSSION: Increased accuracy in articular reduction, with per-operative three-dimensional control of impaction, in acetabular fractures led to significantly less need for THR in patients treated under O-ARM. Patients in both groups are comparable for functional outcomes because those with the lowest scores were offered THR. Per-operative cone beam guidance and navigation use are recommended in tertiary referral centres for acetabular trauma.

Proximal junctional kyphosis in adult scoliosis: comparison of four radiological predictor models.

OBJECTIVE: The objective of this retrospective study is to identify the best immediate postoperative radiological predictors for the occurrence of proximal junctional kyphosis (PJK). Four proposed methods will be explored. METHODS: A homogeneous database of adult scoliosis from multiple centers was used. Patients with whole spine X-rays at the required follow-up (FU) periods were included. Spinal and pelvic parameters were measured and calculated to compare four predictive methods: Method 1: assessment of the global sagittal alignment (GSA); Method 2: restoration of the theoretical values of lumbar lordosis (LL) and thoracic kyphosis (TK) according to pelvic incidence (PI); Method 3: evaluation of TK + LL, and Method 4: restoration of the apex of sagittal LL to its theoretical values according to various spine shapes in Roussouly Classification. PJK occurrence was assessed at the last FU radiograph. RESULTS: 250 patients were included; mean age was 56.67 years and mean FU was 2.5 years. PJK occurred in 25.6% of cases. PJK occurred in 19.9% in patients with a GSA <45° and in 29.9% where GSA >45° (p = 0.04, OR = 1.71). Restoring the sagittal apex of the LL to its theoretical values according to PI deceased PJK to 13.5% compared to 38.9% in the other cases (p = 0.01, OR = 4.6). The two other described methods (2 and 3) were not significant predictors. DISCUSSION: The comparison between the four predictive methods showed that a GSA >45° and restoration of sagittal apex of lordosis according to PI, were the most predictive methods for PJK in ASD. The latter had a higher predictive value. Our findings could prove useful in effective preoperative planning in ASD surgery to reduce PJK rates. LEVEL OF EVIDENCE: Level IV.

Posterior-only versus combined anterior/posterior fusion in Scheuermann disease: a large retrospective study.

PURPOSE: The literature shows controversies concerning surgical treatment of Scheuermann's kyphosis between posterior-only fixation and combined anterior/posterior fusion. The aim of this study is to compare the clinical and radiological results and the rate of complications between these two techniques. METHODS: We performed a multicentric retrospective review of 131 patients who underwent primary fusion for Scheuermann's kyphosis divided into two groups: 67 patients operated via posterior approach only and 64 operated via combined anterior/posterior approach. Classical clinical, surgical and radiological data were collected. A descriptive and statistical analysis was performed between the two groups to evaluate the influence of the surgical procedure on the rate of complications, the functional results and radiological correction. RESULTS: The average age was 23 and the average kyphosis was 77 degrees. The mean follow-up was 4.2 years (range 0.1-27.3). There was no difference regarding demographic data, preoperative radiographic data and length of fusion between the two groups. Functional results were good in 81% of cases. Kyphosis correction was on average 15° and the correction of the compensatory lumbar lordosis was 20°. The correction was stable at final follow-up. There was no difference between the two groups in terms of functional results, the complications rate and radiological correction. CONCLUSION: Surgery for Scheuermann's kyphosis gives good and stable functional and radiological results. Given the fact that the two surgical strategies give the same results, it appears that the anterior/posterior fusion technique to treat Scheuermann's kyphosis should be reserved for major deformations. These slides can be retrieved under Electronic Supplementary Material.

Standardized three dimensional computerised tomography scanner reconstructions increase the accuracy of acetabular fracture classification.

PURPOSE: Evaluate the role of four standardized 3D reconstruction views in the accurate diagnosis of acetabular fractures. MATERIALS AND METHODS: Thirty-five acetabular fracture cases were selected from a tertiary centre database. Fourteen reviewers with different experience level evaluated this set of images which were provided in axial 2D views and multiplanar reconstruction (MPR) without 3D views in the first two readings then the standardized 3D views were added for the subsequent two readings. The primary outcome was the accuracy of diagnosis while inter-observer reliability and reading time as well as time needed for accurate diagnosis were evaluated. RESULTS: Accuracy of classification was 56.7% using the 2D and 73% using the described 3D (p < 0.001). Improvement was noted in all groups even though the expert group showed the least improvement (6.7% (p = 0.04)) and the least experience group showed the most improvement (35.7% (p < 0.001)). Average time of interpretation was 96 minutes for the 2D sets and 47 minutes for the 3D sets. Finally, the adding of the four standardized views increased the inter-observer reliability in all groups compared to the standard 2D sets with MPR. CONCLUSION: Acetabular fracture diagnosis according to Letournel classification is difficult and depends greatly on the experience of the reader. The described set of 3D images yields better accuracy and renders the diagnosis more repeatable and faster. We recommend the use of these images in classifying acetabular fractures.

A computed tomographic anatomical study of the upper sacrum. Application for a user guide of pelvic fixation with iliosacral screws in adult spinal deformity.

PURPOSE: Widely used in traumatic pelvic ring fractures, the iliosacral (IS) screw technique for spino-pelvic fixation remains anecdotal in adult spinal deformity. The objective of this study was to assess anatomical variability of the adult upper sacrum and to provide a user guide of spino-pelvic fixation with IS screws in adult spinal deformity. METHODS: Anatomical variability of the upper sacrum according to age, gender, height and weight was sought on 30 consecutive pelvic CT-scans. Thus, a user guide of spino-pelvic fixation with IS screws was modeled and assessed on ten CT-scans as described below. Two invariable landmarks usable during the surgical procedure were defined: point A (corresponding to the connector binding the IS screw to the spinal rod), equidistant from the first posterior sacral hole and the base of the S1 articular facet and 10 mm-embedded into the sacrum; point B (corresponding to the tip of the IS screw) located at the junction of the anterior third and middle third of the sacral endplate in the sagittal plane and at the middle of the endplate in the coronal plane. Point C corresponded to the intersection between the A-B direction and the external facet of the iliac wing. Three-dimensional reconstructions modeling the IS screw optimal direction according to the A-B-C straight line were assessed. RESULTS: Age had no effect on the anatomy of the upper sacrum. The distance between the base of the S1 superior articular facet and the top of the first posterior sacral hole was correlated with weight (r = 0.6; 95% CI [0.6-0.9]); p < 0.001). Sacral end-plate thickness increased for male patients (p < 0.001) and was strongly correlated with height (r = 0.6; 95% CI [0.29-0.75]); p < 0.001) and weight (r = 0.8; 95% CI [0.6-0.9]); p < 0.001). The thickness of the inferior part of the S1 vertebral body increased in male patients (p < 0.001). Other measured parameters slightly varied according to gender, height and weight. Simulating the described technique of pelvic fixation, no misplaced IS screw was found whatever the age, gender and morphologic parameters. CONCLUSION: This user guide of spinopelvic fixation with IS screws seems to be reliable and reproducible independently of age, gender and morphologic characteristics but needs clinical assessment. LEVEL OF EVIDENCE: Level IV.

Risk of revision surgery for adult idiopathic scoliosis: a survival analysis of 517 cases over 25 years.

PURPOSE: Little is known about the long-term status of patients operated for spine deformities. The aim of this study was to determine the survival of primary fusion in adult idiopathic scoliosis and identify the risk factors of revision surgery. METHODS: Adult patients who underwent primary fusion for idiopathic scoliosis between 1983 and 2011 were included in a continuous monocentric retrospective series. Any additional surgery was registered for survival analysis. Survival and follow-up were estimated by the Kaplan-Meier method and an analysis was performed to identify the risk factors of revision surgery. RESULTS: This series included 447 women (86.5 %) and 70 men (13.5 %) reviewed after a mean follow-up of 7 years (range 0-26.4). Mean age was 44.4 years. Fusion was performed on a median 11 levels (range 3-15); revision rate was 13 % (CI 10-17), 18 % (CI 14-23) and 20 % (CI 16-26) at 5, 10 and 15 years, respectively. Revision surgery was associated with age, anterior release, length of fusion, the inferior limit of fusion, post-operative sagittal balance and junctional kyphosis. The length of fusion (HR 1.13 per vertebrae fused, p = 0.007) and the lower limit of fusion (HR 5.9, p < 0.001) remained independent predictors of revision surgery on multivariate analysis. CONCLUSION: This series evaluated the risk of revision surgery following spinal fusion for idiopathic scoliosis. Our results show that the risk seemed to increase linearly with a rate of nearly 20 % after 10 years. The length and lower limit of fusion are the main risk factors for revision surgery. Level IV (e.g. case series).

Transformation of transverse fractures of the acetabulum in T-shaped fractures and sequential approaches.

Transverse acetabular fractures are difficult to reduce and generally associated with poorer clinical outcomes than other types of acetabular fractures. For these fractures affecting both columns, the surgical strategy is subject to controversy and there is currently no optimal method of management. The transformation of these transverse fractures in to a T-shaped fracture makes it possible to make the anterior and posterior components of the fracture independent and to reduce them sequentially. This technique has made it possible to obtain a satisfactory reduction of the fracture in certain cases and gives hope for good long-term functional results. LEVEL OF EVIDENCE: IV.

Approaches in Anterior Column Support in Adult Spinal Deformity Surgery: A Meta-Analysis of Clinical and Radiologic Outcomes.

OBJECTIVE: This meta-analysis was conducted to compare anterior lumbar interbody fusion (ALIF) with transforaminal lumbar interbody fusion (TLIF) in terms of postoperative complications, improvement in radiographic parameters, and patient-reported outcomes. METHODS: PubMed, Cochrane, and Google Scholar (pages 1-20) databases were searched up to June 2023. The studied outcomes were the rate of rod failures, rod failures requiring revision surgery, all complications, all revision surgeries, the change in pelvic tilt, sacral slope, Cobb angle, lumbar lordosis (LL), sagittal vertical axis, the postoperative pelvic incidence-LL, and LL, and the improvement in back pain and Oswestry Disability Index (ODI). RESULTS: Six studies were included in this meta-analysis. ALIF showed higher postoperative lordosis (P = 0.003) and better improvement in ODI (P = 0.0001). No difference was seen in the remaining outcomes between ALIF and TLIF. CONCLUSIONS: Although ALIF had better improvement in ODI, the mean difference was 6.5 points, which is below the minimal clinically important difference, stripping this result of any clinical value. Furthermore, even though ALIF had better postoperative lordosis, the change in LL postoperatively was not different between ALIF and TLIF. With no difference in complications, sagittal and coronal alignment, and patient-reported outcomes, TLIF was shown in this study to be favored instead of ALIF in adult spinal deformity surgery to avoid all the double approach-related comorbidity.

Division of the iliac vessels in the anterior intrapelvic approach to acetabular fracture.

INTRODUCTION: The modified Stoppa approach is gradually becoming the gold standard in pelvic ring and acetabulum surgery. One of the potential intraoperative complications is vascular injury. The aim of this study was to identify the level of division of common iliac vessels with respect to a bone landmark, their inter-individual variability and their correlation with morphological criteria. MATERIAL AND METHODS: This was a single-center continuous retrospective study of patients who had preoperative CT angiography for pelvic fracture between February 2017 and May 2018. The level of arterial and venous division and the angle of vein division were measured bilaterally for each patient from the most antero-inferior part of the sacroiliac joint on multiplanar reconstruction and standardized analysis. Relationships with morphological data (age, gender, BMI, height), anterior column fracture and deep venous thrombosis were analyzed. RESULTS: The right arterial division level was 50±16mm (-2.35; 96) from the landmark and the left arterial division level 44±14mm (0; 80). The right venous division level was 30±12mm (-9; 75) and the left venous division level 30±13mm (-5; 66). The right venous bifurcation angle was 65±18° (22; 119) and the left venous bifurcation angle 68±17° (18; 117). The arterial division level was significantly higher on the right side (p=0.007). There were no significant correlations with morphological data. CONCLUSION: The great inter-individual variability of iliac vessels should prompt analysis of their morphology on routine imaging when planning pelvic surgery using the modified Stoppa approach, in order to anticipate the risk of bleeding. LEVEL OF EVIDENCE: IV; cases series.

Update on post-traumatic periprosthetic acetabular fractures.

Aims: Post-traumatic periprosthetic acetabular fractures are rare but serious. Few studies carried out on small cohorts have reported them in the literature. The aim of this work is to describe the specific characteristics of post-traumatic periprosthetic acetabular fractures, and the outcome of their surgical treatment in terms of function and complications. Methods: Patients with this type of fracture were identified retrospectively over a period of six years (January 2016 to December 2021). The following data were collected: demographic characteristics, date of insertion of the prosthesis, details of the intervention, date of the trauma, characteristics of the fracture, and type of treatment. Functional results were assessed with the Harris Hip Score (HHS). Data concerning complications of treatment were collected. Results: Our series included 20 patients, with a mean age of 77 years (46 to 90). All the patients had at least one comorbid condition. Radiographs showed that 75% of the fractures were pure transverse fractures, and a transverse component was present in 90% of patients. All our patients underwent surgical treatment: open reduction and internal fixation, revision of the acetabular component, or both. Mean follow-up was 24 months, and HHS at last follow-up was 75.5 (42 to 95). The principal complications observed were dislocations of the prosthesis (30%) and infections (20%). A need for revision surgery was noted in 30% of patients. No dislocation occurred in patients undergoing osteosynthesis with acetabular reconstruction. We did not note either mechanical loosening of the acetabular component nor thromboembolic complications. In all, 30% of patients presented acute anemia requiring transfusion, and one death was reported. Conclusion: Post-traumatic periprosthetic acetabular fractures frequently have a transverse component that can destabilize the acetabular implant. The frequency of complications, principally dislocations, led to a high rate of revision surgery. Improvements in preoperative planning should make it possible to codify management to reduce this high rate of complications. The best results were obtained when the surgical strategy combined osteosynthesis with acetabular reconstruction.

Functional outcomes and center of rotation restoration in total hip arthroplasty after acetabular fracture: A review of 367 hips.

BACKGROUND: Total hip arthroplasty (THA) after acetabular fracture is typically performed months or years later for posttraumatic arthritis after initial conservative treatment. But THA can be performed earlier after open reduction and internal fixation (ORIF) of the fracture. The aim of this study was to determine which strategy is best. The primary outcome measure was the radiological restoration of the hip's center of rotation (COR). The secondary outcome measures were the incidence of complications and the hip's functional scores. MATERIALS AND METHODS: A multicenter cohort was analyzed by splitting patients into three groups: group A (THA within 3weeks of fracture); group B (THA deferred after early ORIF); group C (THA more than 3weeks after fracture, without ORIF). Group B was separated into two subgroups: B- (THA less than 1year after ORIF) and B+ (THA more than 1year after ORIF). The demographics, surgical techniques, COR superior and lateral migration coefficient and functional scores (HHS, HOOS-PS and FJS) were recorded. The functional scores were gathered using PROMs. RESULTS: In all, 367 patients were included: 108 in group A, 69 in group B-, 113 in group B+ and 77 in group C. The mean follow-up was 5.8years [3.4 months-35years]. The mean age of the patients was 69.2years [SD 15; 26-101], 52years [SD 16; 19-83], 49years [SD 16; 16-85] and 58.1years [SD 17; 13-94], respectively (p<0.01). The mean ASA score was 2.13 [SD 0.70], 1.84 [SD 0.65], 1.67 [SD 0.63] and 1.79 [SD 0.60], respectively (p<0.01). A complex Letournel fracture was present in 63 patients (61%), 46 patients (71%), 48 patients (49%) and 38 patients (62%), respectively (p<0.01). A reinforcement cage was implanted in 38 patients (69%), 16 patients (62%), 5 patients (12%) and 19 patients (66%), respectively (p<0.01). Cement was used in 45 patients (45%), 23 patients (35%), 19 patients (18%) and 21 patients (32%), respectively (p<0.01). A graft was needed in 46 patients (46%), 35 patients (53%), 17 patients (16%) and 21 patients (48%), respectively (p<0.01). Posterior ORIF was done in 40 patients (46%), 32 patients (55%), 64 patients (61%) and 9 patients (82%), respectively (p<0.01). The COR lateral migration coefficient was significantly higher in group C with a mean of +0.17 (SD 0.85) [-0.27 to +6] compared to the other groups (p=0.02). The COR superior migration coefficient was comparable between groups, with a mean of +0.77 (SD 2.26) [-0.99 to 27], p>0.05. There were complications in 10 patients (9.2%), 6 patients (8.7%), 6 patients (5.3%) and 3 patients (3.9%), respectively, with no significant difference between groups. The PROMs were completed by 51% of patients. At the final review, the mean HHS was 79.2 (SD 21.8) and the mean HOOS-PS was 77.7 (SD 20.1) in the entire cohort, p>0.05. The mean FJS by group was 55.9 (30.2), 47.7 (SD 36.4), 66.1 (SD 30.4) and 65.8 (SD 30.3), respectively (p=0.02). DISCUSSION AND CONCLUSION: The B strategy (B+) yielded good outcomes in terms of function and COR restoration. When using this strategy, anterior ORIF preserves the native hip for a subsequent THA through a posterior approach. Strategy C also produces good functional outcomes but shifts the COR laterally. This study confirms the poor results of strategy A in previous publications. When the prognosis is poor, immediate mobilization after anterior ORIF followed by THA within 1year appears to be a good strategy (group B-). LEVEL OF EVIDENCE: IV, observational study.

Is Minimally Invasive Bipolar Technique a Better Alternative to Long Fusion for Adult Neuromuscular Scoliosis?

STUDY DESIGN: Prospective cohort study. OBJECTIVES: To report the results for an alternative technique based on minimally invasive fusion-less surgery. This approach is original in that it corrects deformities by proximal and distal fixation, with reliable pelvic fixation through the use of iliosacral screws on osteoporotic bones. METHODS: Adult cerebral palsy patients requiring spinal correction surgery were included prospectively between 2015 and 2019. The technique involved the use of a double-rod construct anchored proximally by four clawed hooks and distally by iliosacral screws, in a minimally invasive approach. Cobb angle and pelvic obliquity were measured before and after initial surgery and at final follow-up. Complications and functional results were reviewed. This group (P) was compared with a second group (R) of patients who underwent surgery between 2005 and 2015, for whom data were collected retrospectively. RESULTS: Thirty-one patients were included in group P, and 15 in group R. The two groups were comparable for demographic data and deformity. At most recent follow-up (3 years for group P [2-6] and 5 years for group R [2-16]), neither correction nor surgical complications differed between the two groups. However, group P had 50% less blood loss and a lower medical complication rate than group R. CONCLUSIONS: Our results confirm the effectiveness of this minimally invasive technique for neuromuscular scoliosis in adults. The results were similar to those obtained with the usual techniques, but with fewer medical complications. Confirmation of these results is now required for a longer follow-up period.

Computer Navigation-Assisted Resection of Heterotopic Ossification Around the Hip: A Technical Note.

Heterotopic ossification is a rare but debilitating situation. It occurs in patients who have undergone paralysis and/or immobilization. Hip osteoma is one of the most frequent locations and is associated with a significant functional handicap. Its treatment is based on surgical resection, which is a risky surgery that is not devoid of complications such as infections, hematoma, and recurrence. We describe in this paper a new surgical technique that adds to the classic hip osteoma resection: guidance with a navigation system coupled to a 3D imaging tool. We performed this technique on two patients (three hips, one bilateral case). We think that this technique makes the surgery safer with fewer complications.