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.

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.

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.

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.

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.

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.

Lumbar scoliosis and stenosis: What outcomes for which treatment? Analysis of three surgical techniques in 154 patients with minimum two-year follow-up.

STUDY DESIGN: Prospective multicentric study. OBJECTIVE: This study goal was to analyze the clinical and radiographic outcomes of lumbar stenosis and scoliosis (LSS) patients, treated with lumbar decompression (LD), short fusion and decompression (SF) or long fusion with deformity correction (LF). HYPOTHESIS: Procedures without correction lead to poorer long-term outcomes. METHODS: Consecutive patients with two-year minimum follow-up, older than 50, with lumbar scoliosis (Cobb angle>15°), and symptomatic lumbar stenosis were included. Age, gender, Lumbar and Radicular Visual Analog Scale, ODI, SF12 and SRS30 were collected. Main and adjacent curves Cobb angles, C7 coronal tilt (C7CT), spinopelvic parameters, and spino-sacral angle (SSA) were measured preoperatively, at one and two years. Patients were sorted into surgery type groups. RESULTS: In total, 154 patients were included, with respectively 18, 58 and 78 patients in LD, SF and LF groups. Mean age was 69, 85% were women. Clinical scores improved in each group at one year, but only LF group exhibited persistent improvement at 2years. A significant fractional Cobb angle increase was noted in the SF group at 2years (from 12±11° to 18±14°). C7CT significantly increased in the LD group at 2years (from 2.5±1.3° to 5.1±3.5°). LF group presented the highest complication rate (45%, 19% for SF and 0% for LD). The overall revision rate was 14% in SF group and 30% in LF group. CONCLUSION: LSS is a complex pathology requiring custom-made surgical treatment. LD, SF and LF allow satisfactory clinical outcome, with a better and more sustained clinical improvement for LF despite higher complication and revision rates. LEVEL OF EVIDENCE: IV.

Thoracolumbar Sagittal Shape Varies With Pelvic Morphology and Aging.

STUDY DESIGN: Retrospective study of a multicenter prospective database. OBJECTIVE: The objective of this study was to determine the organization and correlations between different spinal segments according to pelvic incidence (PI) and age. SUMMARY OF BACKGROUND DATA: When planning surgery for the correction of adult spinal deformities, considering lumbar lordosis (LL) as a uniform segment is an approximation that can lead to planning errors. MATERIALS AND METHODS: Radiographs of 1540 subjects were analyzed and divided into three PI groups: low <45, intermediate 45 to 60, high >60, and stratified by age (<45, 45-70, and >70 yr). The different segments of L1-L4 proximal lumbar lordosis (PLL), L4-S1 distal lumbar lordosis (DLL), and T10-L1 thoracolumbar junction (TLJ) were analyzed. RESULTS: The mean age was 53.5 years (SD=17, minimum=20, maximum=93). There was a significant correlation between thoracic kyphosis T5-T12 and TLJ segment T10-L1 ( r =0.581, P <0.001). Only the L1-L4 PLL segment correlated with PI ( r =0.47, P <0.001). The T10-L1 TLJ segment was constant regardless of age or PI groups considered (mean=-8, SD=9). PLL did not vary with aging but differed according to PI. The DLL showed significant differences between age and PI groups but without a significant correlation between PI and DLL. CONCLUSIONS: Pelvic morphology is known to determine the curvatures of the spine, however, the distribution of LL is not homogeneous. Our study provided a normative value reference and showed that T10-L1 is constant regardless of age or PI. LEVEL OF EVIDENCE: III.

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.

Pre- and postoperative MRI analysis of central decompression in MIS fusion with lumbar stenosis.

OBJECTIVES: Mini-invasive approaches have grown substantially these last decades in spinal surgery, notably for lumbar decompressions and fusion, with advantages over open approaches in terms of morbidity reduction. However, to our knowledge, no study has measured on MRI the amount of central decompression obtained by MIS approach. The goal of this study was to precisely measure the decompression of central stenosis by unilateral MIS approaches. METHODS: The files of 42 patients that had a MIS lumbar fusion with central decompression for central stenosis were reviewed. All patients had a pre- and postoperative MRI that allowed on T2 axial images to classify the central stenosis, according to Schizas' classification, and measure the dural sac cross-sectional area (DSCA) and the anteroposterior diameter (DAP). The statistical analysis was made with paired t-test. RESULTS: Fifty-six levels were analyzed, mostly L4L5 (58%). The mean preoperative DSCA was 70.53mm2 and the mean postoperative DSCA was 172.2mm2. The mean preoperative DAP was 6.15mm and postoperative was 10.68mm. Preoperatively, the levels analyzed were rated B, C or D according to Schizas for 53 out of 56 levels and A1-4 for 51 out of 56 levels in postoperative. All the results were statistically significant (p<0.001). CONCLUSION: Decompression, assessed by MRI, seems to be equivalent by MIS approach to open laminarthrectomy. MIS approaches have been studied clinically in these indications with very satisfying results. As a conclusion, MIS approaches seems to be a relevant and efficient option in the treatment of lumbar degenerative stenosis. LEVEL OF EVIDENCE: IV, retrospective study.

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.

Variation of Global Sagittal Alignment Parameters According to Gender, Pelvic Incidence, and Age.

STUDY DESIGN: Retrospective cross-sectional study. OBJECTIVE: The aim was to describe existing global sagittal alignment parameters across ages and to analyze differences according to gender and pelvic incidence (PI). SUMMARY OF BACKGROUND DATA: Variability with age has been reported. It remains unclear how gender and spinopelvic morphology could additionally influence global alignment parameters. MATERIALS AND METHODS: Radiographs of 2599 individuals (5-93 y) were analyzed. Translation parameters were: Sagittal Vertical Axis (SVA)-C7, SVA-C2, SVA-Center Acoustic Meatus (CAM), C7/Sacrofemoral Distance (SFD) ratio. Inclination parameters were: C7-Vertical Tilt (VT), T1-VT and T9-VT, Odontoid-Hip Axis (OD-HA), OD-CAM. Pelvic compensation parameters were: T1-Pelvic Angle (TPA), Global Tilt (GT), Spino-Sacral Angle (SSA). Global sagittal alignment (GSA) was considered among formulae. The distribution of parameters was analyzed using a Bayesian inference. Correlations with spinopelvic parameters were investigated. RESULTS: SVA-C7, SVA-C2, SVA-CAM were larger in males and high PI, and increased significantly after 50 years (Pr>0.9999). C7/SFD decreased during growth and was larger in low PI (Pr=0.951). There was no correlation with spinopelvic parameters. Age-related variations of inclination parameters were nonsignificant. T1-VT and T9-VT increased with PI and were significantly larger in high PI (Pr>0.95). C7-VT was significantly larger in low PI (Pr>0.9999). OD-HA and OD-CAM were constant and increased after 80 years. TPA and GT increased with PI (Pr>0.9999) and age after 35 years (Pr>0.9999). SSA decreased nonsignificantly after 50 years. TPA correlated with PI (ρ=0.6130) and pelvic tilt (PT) (ρ=0.8375). GT correlated with PI (ρ=0.5961) and PT (ρ=0.8996). SSA correlated with sacral slope (ρ=0.9026). GSA was larger in high PI (Pr>0.9999) and increased after 35 years (Pr>0.9999). GSA correlated with PT (ρ=0.7732). CONCLUSION: Translation parameters increase with age, more prominently in males and high PI. Variations of inclination parameters are smaller. Pelvic compensation parameters and GSA increase with age and are closely related to PT and spinopelvic morphology. LEVEL OF EVIDENCE: Level III.

Minimally invasive removal of intra-articular hip fragments under navigation guidance.

The interposition of foreign bodies between the femoral head and the acetabulum represents a danger to the articular cartilage with a definite progression to osteoarthritis. Their removal is necessary and usually involves two surgical techniques: by open arthrotomy or under arthroscopy. The present article proposes a new surgical technique allowing the removal of intra-articular foreign bodies from the hip by a minimally invasive approach and aCT-guided navigation system. This technique is a good alternative that overcomes some shortcomings of other minimally invasive techniques, which struggle to access the fragment. It can also avoid specific complications of these procedures, such as the risk of abdominal compartment syndrome with arthroscopy, in the case of an associated acetabulum fracture.

Identification and treatment of atypical acetabular fractures having an independent acetabular roof fragment: Three-column fractures.

INTRODUCTION: A unique type of both-column fracture of the acetabulum that also has an independent roof fragment seems to occur relatively often. It is challenging to diagnose, thus our ability to detect it and its frequency are not known. This led us to analyze a database of acetabular fractures to 1) determine the incidence of this type of fracture, 2) describe its radiological characteristics, 3) attempt to set out a specific treatment strategy. HYPOTHESIS: The need for a dual surgical approach depends on the type and displacement of the independent roof fragment. METHODS: Four surgeons and radiologists independently analyzed a set of acetabular fractures that occurred between 2007 and 2017. The diagnosis was made using two-dimensional (2D) and three-dimensional (3D) CT reconstructions. Once the fractures had been identified, a detailed description was made of all 2D and 3D slices. A retrospective analysis was done of the reduction and fixation of the independent roof fragment relative to the chosen surgical approach. RESULTS: The study comprised 534 acetabular fractures, of which 96 where both-column fractures. In that subset, 41% (39 fractures) had an independent roof fragment. A detailed analysis resulted in the identification of two subtypes of three-column fracture with independent fragment: type 1 has a posterosuperior fragment (22 cases); type 2 has an independent fragment separated by a juxtatectal fracture line (17 cases). The best radiological outcomes were achieved when the independent fragment was minimally displaced and did not require additional reduction. CONCLUSION: The isolated roof fragment is common, as it occurs is more than one-third of both-column fractures. We were able to identify two subtypes that require different surgical strategies. Surgical treatment of these fractures is difficult; thus a combined surgical approach (anterior followed by posterior) may provide the best reduction, especially for subtype 1. LEVEL OF EVIDENCE: IV.

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.

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.

Modified Stoppa Approach: Beyond Acetabular Fractures: A Report of 2 Cases.

CASES: We used the modified Stoppa approach in a 17-year-old man with a retained bullet in his acetabular fossa. The acetabular hole was used to irrigate the hip joint. We also used this approach in a 29-year-old woman with right hip pain and limping to remove an isolated tenosynovial giant cell tumor ("localized pigmented villonodular synovitis") in the acetabular fossa expanding through the acetabulum. DISCUSSION: We believe that this approach should become more familiar because it offers a simple alternative for treating acetabular pathologies mainly involving the acetabular fossa, sparing patients the hazards of capsulotomy, trochanteric osteotomy, dislocation, and traction and fluid pressure in hip arthroscopy.