The incidence of reoperation for pseudarthrosis after cervical spine surgery.

INTRODUCTION: Pseudarthrosis after cervical spine surgery represents an underreported and challenging complication. Using a large multi-center surgical database, we sought to: (1) report the incidence of cervical pseudarthrosis, (2) evaluate changes in rates of cervical pseudarthrosis, and (3) describe risk factors for suboptimal outcomes after cervical pseudarthrosis surgery. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2019 was used. The primary outcome was occurrence of a cervical fusion procedure with a prior diagnosis of pseudarthrosis. Fusion for pseudarthrosis was divided into anterior and posterior approaches. Post-operative complications were classified as major or minor. Prolonged LOS was defined as exceeding the 75th percentile for total hospital stay. RESULTS: A total of 780 patients underwent cervical fusion for pseudarthrosis, and a significant increase in rates of surgery for pseudarthrosis was seen (0.25-1.2%, p < 0.001). The majority of cervical pseudarthrosis was treated with a posterior approach (66.5%). Postoperatively, 38 (4.9%) patients suffered a complication and 247 (31.7%) had a prolonged LOS. The three strongest risk factors for complications and extended LOS were > 10% weight loss preoperatively, congestive heart failure, and pre-operative bleeding disorder. CONCLUSION: Results from a large multi-center national database revealed that surgery to treat cervical pseudarthrosis has increased from 2012 to 2019. Most pseudarthrosis was treated with a posterior approach. Reoperation to treat cervical pseudarthrosis carried risk, with 5% having complications and 32% having an extended LOS. These results lay the groundwork for a future prospective study to discern the true incidence of cervical pseudarthrosis and how to best avoid its occurrence.

Pseudarthrosis risk factors in lumbar fusion: a systematic review and meta-analysis.

This study presents a systematic literature review and meta-analysis of pseudarthrosis risk factors following lumbar fusion procedures. The odds ratio (OR) and 95% confidence interval (95% CI) were used for outcome measurements. The objective of this study was to identify the independent risk factors for pseudarthrosis after lumbar spinal fusion, which is crucial for mitigating morbidity and reoperation. Systematic searches in PubMed, Embase, and Scopus (1990-July 2021) were conducted using specific terms. The inclusion criteria included prospective and retrospective cohorts and case‒control series reporting ORs with 95% CIs from multivariate analysis. The quality assessment utilized the Newcastle-Ottawa scale. Meta-analysis, employing OR and 95% CI, assessed pseudarthrosis risk factors in lumbar fusion surgery, depicted in a forest plot. Of the 568 abstracts identified, 12 met the inclusion criteria (9 retrospective, 2006-2021). The 17 risk factors were categorized into clinical, radiographic, surgical, and bone turnover marker factors. The meta-analysis highlighted two significant clinical risk factors: age (95% CI 1.02-1.11; p = 0.005) and smoking (95% CI 1.68-5.44; p = 0.0002). The sole significant surgical risk factor was the number of fused levels (pooled OR 1.35; 95% CI 1.17-1.55; p < 0.0001). This study identified 17 risk factors for pseudarthrosis after lumbar fusion surgery, emphasizing age, smoking status, and the number of fusion levels. Prospective studies are warranted to explore additional risk factors and assess the impact of surgery and graft type.

Is Using a Ring External Fixator in the Treatment of Congenital Pseudarthrosis of the Tibia Associated With Better Results or Using a Locking Plate?

BACKGROUND: Congenital pseudarthrosis of the tibia (CPT) is a rare disease. CPT is often unilateral and occurs between the middle and distal third of the tibia. Concurrent involvement of the fibula is present in more than half of cases. histologic studies indicate the presence of fibrous hamartoma tissue and a sick periosteum, which leads to recalcitrant bone fracture and, eventually, pseudoarthrosis. Although there are various surgical techniques, we intend to compare the 2 methods of external fixation versus internal plating. METHODS: Demographic data were collected from 26 patients with frank pseudoarthrosis. After exclusion criteria, patients were compared in groups A (12 patients) and B (11 patients). Resection of hamartoma and sclerotic bone, intramedullary rodding and autologous bone, and periosteal grafting were performed for all patients. In group A, we used a ring external fixator for compression and rotational stability, but in group B, a locking plate was used for these purposes. RESULTS: Plating takes less time to use during surgery. In group A, the primary bony union was obtained in 67% of patients, while in group B, 82% of patients had a primary union. Meanwhile, the average time till the final union in group A was 6 months, while in group B, this time was 3.5 months. Positive union mass was obtained in 58% of the patients in group A and 82% of group B. In addition, plating prevented ankle valgus deformity in group B. CONCLUSIONS: Permanent intramedullary rodding is a surgical requirement for correction of deformity and refracture prevention, but additional stability can be achieved with the use of a ring external fixator or internal plate. Cross union and positive union mass are 2 important factors in the treatment of pseudoarthrosis; these results are achieved to a greater extent and in a shorter period of time using the plate. LEVEL OF EVIDENCE: level IV - case series.

Guided Growth to Treat Anterolateral Tibial Bowing Associated with Congenital Pseudarthrosis of the Tibia.

BACKGROUND: Anterolateral tibial bowing associated with congenital tibial pseudarthrosis occurs often in patients with neurofibromatosis type 1 and results from the inability of the fractured bone to unite, leading to persistent nonunion, abnormal bone growth, and further bowing of the tibia. Current surgical and nonsurgical approaches demonstrate persistent nonunion or refracture, often resulting in amputation. METHODS: This report describes the management of 3 patients with anterolateral tibial bowing and NF1 who underwent distal tibia-guided growth. RESULTS: The patients had an average age of 1.6 years at initial operation, with a total of 3 to 4 surgeries over an average of 2.1 years. The latest follow-up on all patients is included, at a mean of 5.1 years after the initial operation. All 3 patients experienced substantial functional improvement and improved alignment of the mechanical axis of the tibia. One patient has experienced refracture. CONCLUSIONS: Our study indicates that guided growth can serve as an additional surgical option to improve ALTB and potentially reduce the risk of fracture and pseudarthrosis by restoring normal mechanical alignment. LEVEL OF EVIDENCE: Level-IV, Case Series.

Surgery for Spinal Stenosis in Achondroplasia: Causes of Reoperation and Reduction of Risks.

BACKGROUND: Individuals with achondroplasia are prone to symptomatic spinal stenosis requiring surgery. Revision rates are thought to be high; however, the precise causes and rates of reoperation are unknown. The primary aim of this study is to investigate the causes of reoperation after initial surgical intervention in individuals with achondroplasia and spinal stenosis. In addition, we report on surgical techniques aimed at reducing the risks of these reoperations. METHODS: A retrospective review was conducted over an 8-year period of all patients with achondroplasia at a single institution that serves as a large referral center for patients with skeletal dysplasias. Patients with achondroplasia who underwent spinal surgery for stenosis were identified and the need for revision surgery was studied. Data collected included demographic, surgical, and revision details. Fisher exact test was used to determine if an association existed between construct type and the need for revisions. RESULTS: Thirty-three of the 130 (22%) patients with achondroplasia required spinal stenosis surgery. Twenty-four individuals who met the criteria were selected for analysis. The initial spine surgery was at an average age of 18.7 years (SD: 10.1 y). Nine patients (38%) required revision surgeries, and 3 required multiple revisions. Five of 9 (56%) of the revisions had primary surgery at an outside institution. Revision surgeries were due to caudal pseudarthrosis (the distal instrumented segment) (8), proximal junctional kyphosis (PJK) (7), and new neurological symptoms (7). There was a significant association found between construct type and the need for revision ( P =0.0111). The pairwise comparison found that short fusions were significantly associated with the need for revision compared with the interbody group ( P =0.0180). PJK was associated with short fusions when compared with the long fusion group ( P =0.0294) and the interbody group ( P =0.0300). Caudal pseudarthrosis was associated with short fusions when compared with the interbody group ( P =0.0015). Multivariate logistic regression found long fusion with an interbody was predictive of and protective against the need for revision surgery ( P =0.0246). To date, none of the initial cases that had long fusions with caudal interbody required a revision for distal pseudarthrosis. CONCLUSIONS: In patients with achondroplasia, the rate of surgery for spinal stenosis is 22% and the risk of revision is 38% and is primarily due to pseudarthrosis, PJK, and recurrent neurological symptoms. Surgeons should consider discussing spinal surgery as part of the patient's life plan and should consider wide decompression of the stenotic levels and long fusion with the use of an interbody cage at the caudal level in all patients to reduce risks of revision. LEVEL OF EVIDENCE: Level IV-Retrospective case series.

Vascularized Femoral Myo-Periosteal Graft for Congenital Pseudarthrosis of the Tibia: A Case Report.

Pure vascularized periosteal transplants have been shown to be extremely effective at achieving rapid bone healing in children with biologically complex non-union. Free tibial and fibular periosteal transplants are generally indicated when large periosteal flaps are necessary. We report using a vascularized femoral myo-periosteal graft (VFMPG) to treat distal tibial osteotomy non-union in a six-year-old boy with congenital pseudarthrosis of the tibia. The graft consisted of a 9 cm myo-periosteal flap (after 50% of elastic retraction) that incorporated the vastus intermedius muscle and diaphyseal femoral periosteum nourished by the descending branch of the lateral circumflex femoral vessels. Plantaris medialis was used as a recipient vessel. Healing occurred 10 weeks after surgery. The patient resumed gait and sports activity without orthosis. No donor or recipient site complications occurred 17 months after surgery. Employing a VFMPG might be an alternative to other free or large vascularized periosteal flaps currently in use for complex pediatric non-unions.

Reconstruction of congenital pseudarthrosis of the radius with a vascularized tibial periosteal transplant: A case report.

Congenital pseudarthrosis of the forearm poses a considerable challenge because of its rarity. The objective of this report is to introduce a novel surgical technique for its treatment. Here, we document a case of congenital pseudarthrosis of the radius in a 3-year-old boy diagnosed with type-1 neurofibromatosis. The surgical treatment involved the excision of approximately 9 cm of native radial periosteum and a bifocal radius osteotomy, which was supplemented with a vascularized tibial periosteal transplant to facilitate bone healing. Anastomosis between the anterior tibial vessels and radial vessels was performed. No immediate or late postoperative complications were observed. After 3 weeks, a robust callus formation was observed, and during a follow-up examination 3 years and 4 months later, a wide range of active forearm rotation was noted. This report suggests that vascularized periosteal flaps show promise as a viable treatment option for congenital pseudarthrosis of the forearm. They offer an alternative to vascularized fibular grafts or single-bone forearm constructs.

Trans-sacral interbody fixation in long fusions to the sacrum for adult spinal deformity: complications and fusion rates at minimum two years follow-up.

PURPOSE: This study aims to investigate the fusion rate and complications associated with trans-sacral interbody fusion (TSIF) in long fusions to the sacrum for adult spinal deformity (ASD) over a two year follow-up period. Potential predictor variables associated with pseudarthrosis were also examined. METHODS: A retrospective clinical review was conducted on a consecutive series of ASD patients who underwent long fusions to the sacrum, with TSIF performed as a same-day or staged procedure. Patient demographics, bone mineral density, operative details, perioperative and late complications, and fusion rates were reviewed. Univariate analysis was used to identify the risk factors associated with pseudarthrosis. RESULTS: The study included 43 patients with an average age of 55.3 ± 8.9 years. The perioperative complication rate was 28%, with 12% of the complications directly related to TSIF. The late complication rate was 33%, with 16% related to TSIF. The most common complications were pseudarthrosis (14%) and postoperative ileus (7%). The overall radiographic fusion rate at two years was 86%. Univariate analysis revealed that revision surgery was significantly associated with pseudarthrosis (p = 0.027). Over the follow-up period, patients who underwent TSIF during long posterior fusions to the sacrum showed improvement in overall SRS scores, ODI scores, and SF-36 physical health and mental health (p < 0.05). CONCLUSION: TSIF is a relatively safe and minimally invasive method for achieving interbody fusion at the lumbosacral junction in the treatment of ASD, with acceptable fusion rates and a low complication rate. However, TSIF is not recommended for revision reconstruction in ASD.

[The clinical characteristics of 497 children with congenital pseudarthrosis of the tibia].

Objective: To investigate the clinical and radiologic characteristics of children with congenital pseudarthrosis of the tibia (CPT) in a single center. Methods: This is a retrospective case series study. According to inclusion and exclusion criteria, clinical data of 497 children(507 limbs) with CPT who were treated at Department of Orthopedics, the Children's Hospital Affiliated to Xiangya School of Medicine, Central South University from January 2011 to December 2020 were collected. Baseline data included gender, age at initial visit, age at onset of symptoms, accompanying symptoms, domicile, whether first treated at our hospital, and treatment-related information such as surgical or conservative treatment, surgical complications, etc., were extracted and analyzed using the health information system. Imaging data of the children, including Crawford classification, bilateral leg lengths, presence of fibular pseudarthrosis, and location of pseudarthrosis along the tibia segment, were analyzed using the Picture Archiving and Communication System. Data were compared using independent sample t test or χ2 tests. Results: Among 497 children with CPT, there were 305 males (61.4%) and 192 females (38.6%). The age at initial visit was (3.6±3.2) years (range: 0.1 to 16.2 years). Neurofibromatosis type 1 (NF1) symptoms were positive in 340 children (68.4%), and negative in 157 children (31.6%). Among NF1-positive children, those with symptoms onset before 1 year of age were significantly more than NF1-negative children (74.1%(252/340) vs. 66.2%(104/157);χ2=9.24, P=0.001), and the proportion of fractures (92.9%,316/340) was significantly higher than that in the NF1-negative group (84.7%,133/157) (χ2=8.33, P=0.004). According to imaging data, Crawford type Ⅳ was the most common type, with 321 limbs (63.3%), followed by type Ⅱ in 100 limbs (19.7%), type Ⅲ in 54 limbs (10.7%) and type Ⅰ in 32 limbs (6.3%). Pseudarthrosis occurred in the proximal third of the tibia in 14 limbs (2.8%), in the middle third in 185 limbs (36.5%), and in the distal third in 308 limbs (60.8%). Seventy-four children (14.9 %) had associated fibular pseudarthrosis. The lateral proximal tibial angle was 86.91°±5.21°(range: 72.17° to 102.08°), and the lateral distal tibial angle was 87.27°±10.73°(range: 51.07° to 128.17°). A total of 421 children (84.7%) underwent surgical treatment with (3.1±2.4) surgeries performed per child (range:0 to 12 surgeries); 76 children (15.3%) received conservative treatment. Postoperative complications mainly included ankle valgus (77 cases), leg length discrepancy (71 cases),refracture (48 cases), osteomyelitis (11 cases), and hardware failure (10 cases). NF1-positive children underwent more surgeries than NF1-negative children ((5.1±2.2)times vs.(2.1±1.8)times;t=14.93,P<0.01). Conclusions: Crawford type Ⅳ is the most common type of CPT in children in this study. CPT predominantly occurs in the middle or distal third of the tibia. The majority of children with CPT experienced symptoms and were seen at outpatient clinics before the age of 3 years. The main surgical complications currently associated with CPT treatment are ankle valgus and leg length discrepancy. Compared with CPT without NF1, children with NF1-positive CPT tend to have earlier symptom onset and may require more frequent treatments.

Do postoperative outcomes vary between midshaft clavicle fractures of 2, 3, or more than 3 fragments?

OBJECTIVE: This study aims to assess differences in clinical and surgical outcomes associated with the surgical treatment of midshaft clavicle fractures of different complexities based on fragment number. Additionally, the investigation seeks to present the outcomes of a series of patients who underwent surgery at our institution. MATERIALS AND METHODS: A retrospective analysis was conducted on the medical records of patients aged over 18 who underwent midshaft clavicle fracture surgery at our center from November 2009 to May 2021. Patients were categorized based on the number of fracture fragments into groups of two, three, or more than three fragments. Consolidation, implant removal, complications, surgical duration, and functional outcomes (assessed through VAS, ASES, and Constant-Murley scale) were evaluated for each specific group and for the overall cohort. RESULTS: In total, 260 patients were analyzed. There were no significant differences in any of the parameters between the three groups except for surgical time, which was shorter in simple fractures than in those with more than three fragments (68.2 min vs. 75.3 min; p = 0.01). Pseudoarthrosis rate was 2.69%, implant removal rate was 9.61%, and 4.23% of patients presented with complications other than the previous ones. Functional results were excellent, with averages of 97.3 (72.7-100) for the ASES score, 97.5 (75-100) for the Constant score, and 0.6 (0-8) on the VAS. CONCLUSION: According to our results, there were no differences in postoperative results between simple and multifragmentary midshaft clavicle fractures. Patients across all groups reported satisfactory results.

Reconstruction of bone defects around the ankle with retrograde gentamicin-coated tibial intramedullary nail (ETN PROtect™) for tibiotalocalcaneal arthrodesis: a case series.

PURPOSE: The objective of this study was to describe the use of retrograde gentamicin-coated tibial intramedullary nail (ETN PROtect™) in patients with tibial defects who required a tibiotalocalcaneal arthrodesis (TTC). METHODS: Consecutive series case review of seven men treated with TTC using retrograde PROtect™ between January 2018 and December 2023. The main outcomes evaluated were fracture union, complications, and the health-related quality of life using the EuroQol five-dimension three-level questionnaire (EQ-5D-3L). RESULTS: The mean age was 45.3 ± 8.0 years. Six patients had a clinical history of chronic osteomyelitis, and one case underwent TTC for congenital pseudoarthrosis. Fracture union was achieved in 5 of 7 patients between 4 and 11 months after surgery. Three patients developed complications; two patients had fistulas, and one had persistent pain. At the end of the follow-up, a median of 70 points (interquartile range: 60 to 90) on the EQ-5D-3L was reported. No complications directly attributed to the use of the PROtect™ were reported. CONCLUSION: TTC with retrograde PROtect™ is a prophylactic treatment option in patients with tibial defects treated with external fixation requiring a tibiotalar and subtalar arthrodesis. This novel use of PROtect™ allows simultaneous fixation of the tibiotalocalcaneal joint and protection of the regenerated bone, facilitating earlier rehabilitation in patients at high risk for postoperative infections.

Osteoporosis related to WNT1 variants: a not infrequent cause of osteoporosis.

Nearly 10% of subjects with severe idiopathic osteoporosis present pathogenic WNT1 mutations. Clinical characteristics include a family history of osteoporosis, early adulthood onset, and fragility fractures which may evolve to pseudoarthrosis. WNT1 should be genetically screened in these patients as the phenotype is often variable and therapeutic approaches may differ. INTRODUCTION: Recent studies have shown that homozygous WNT1 gene mutations may be related to severe osteoporosis resembling osteogenesis imperfecta (OI). Conversely, heterozygous WNT1 mutations are linked to a milder phenotype of early-onset osteoporosis. Treatment with bisphosphonates is reported to be unsatisfactory. Our aim was to analyze the presence and prevalence of WNT1 mutations and the main associated clinical characteristics in subjects with primary early-onset osteoporosis. METHODS: A cohort comprising 56 subjects (aged 19-60 years) with severe, early-onset osteoporosis was screened by massive parallel sequencing with a 23-gene panel. The gene panel included 19 genes known to cause OI (including the WNT1 gene), three genes related to osteoporosis, and the gene related to hypophosphatasia (ALPL). RESULTS: We identified five patients (3 men) with heterozygous WNT1 variants. All presented severe osteoporosis with early fracture onset and a family history of fragility fractures. None presented a characteristic phenotype of OI or skeletal deformities. One patient was previously treated with bisphosphonates, presenting inadequate response to treatment and two developed pseudoarthrosis after upper arm fractures. All subjects were diagnosed in adulthood. CONCLUSIONS: Nearly 1/10 adult subjects with severe idiopathic osteoporosis may present pathogenic WNT1 mutations. Clinical characteristics commonly include a family history of osteoporosis, onset in early adulthood, marked decrease in bone mass, and prevalent fractures, particularly vertebral. WNT1 should be genetically screened in these subjects as the phenotype is often variable and the therapeutic approach may differ. The role of WNT1 mutations in the development of pseudoarthrosis should also be elucidated.

Clinical Results of Decortication with Bone Grafting Method versus Extracorporeal Shock Wave Treatment in Long-Bone Pseudoarthrosis.

BACKGROUND Despite advanced treatment methods, the treatment of pseudoarthrosis still poses a significant challenge for orthopedists. In this study, we aimed to assess the clinical results of decortication and bone grafting and extracorporeal shock wave treatment (ESWT) in long-bone pseudoarthrosis. MATERIAL AND METHODS Between 2007 and 2015, 68 fractures of 66 patients treated for long-bone pseudoarthrosis were evaluated retrospectively. ESWT was used in 36 extremities and decortication and iliac bone grafting was used in 32. The treatment results of these patients were evaluated and compared with rates in the literature. RESULTS The mean patient age was 43.9 years (range, 21-69). The mean interval between the occurrence of the fracture and treatment with bone grafting or ESWT was 8.6 months and the mean interval between the procedure and achievement of union was 6.9 months. The patients were followed up for a mean period of 25.2 months. After the mean follow-up period, bone union had occurred in all 32 patients (100%) in the decortication and bone grafting group and in 28 (78%) of the 36 patients in the ESWT group (P=0.023). CONCLUSIONS This study shows that extracorporeal shock wave treatment should be considered the first option in treatment of pseudoarthrosis as it is a non-invasive method and also provides good rates of union. In patients that do not heal with ESWT, decortication and bone grafting remains the criterion standard therapy.

Adult spinal deformity patients revised for pseudarthrosis have comparable two-year outcomes to those not undergoing any revision surgery.

PURPOSE: This study aimed to evaluate whether adult spinal deformity patients undergoing revision for symptomatic pseudarthrosis have comparable two-year outcomes as patients who do not experience pseudarthrosis. METHODS: Patients whose indexed procedure was revision for pseudarthrosis (pseudo) were compared with patients who underwent a primary procedure and did not have pseudarthrosis by 2Y post-op (non-pseudo). Patients were propensity-matched (PSM) based on baseline (BL) sagittal alignment, specifically C7SVA and CrSVA-Hip. Key outcomes were 2Y PROs (SRS and ODI) and reoperation. All patients had a minimum follow-up period of two years. RESULTS: A total of 224 patients with min 2-year FU were included (pseudo = 42, non-pseudo = 182). Compared to non-pseudo, pseudo-patients were more often female (P = 0.0018) and had worse BL sagittal alignment, including T1PA (P = 0.02], C2-C7 SVA [P = 0.0002], and CrSVA-Hip [P = 0.004]. After 37 PSM pairs were generated, there was no significant difference in demographics, BL and 2Y alignment, or operative/procedural variables. PSM pairs did not report any significantly different PROs at BL. Consistently, at 2Y, there were no significant differences in PROs, including SRS function [3.9(0.2) vs 3.7(0.2), P = 0.44], pain [4.0 (0.2) vs. 3.57 (0.2), P = 0.12], and ODI [25.7 (5.2) vs 27.7 (3.7), P = 0.76]. There were no differences in 1Y (10.8% vs 10.8%, P > 0.99) and 2Y (13.2% vs 15.8%, P = 0.64) reoperation, PJK rate (2.6% vs 10.5%, P = 0.62), or implant failure (2.6% vs 10.5%, P = 0.37). Notably, only 2 patients (5.4%) had recurrent pseudarthrosis following revision. Kaplan-Meier curves indicated that patients undergoing intervention for pseudarthrosis had comparable overall reoperation-free survival (log-rank test, χ2 = 0.1975 and P = 0.66). CONCLUSIONS: Patients undergoing revision for pseudarthrosis have comparable PROs and clinical outcomes as patients who never experienced pseudarthrosis. Recurrence of symptomatic pseudarthrosis was infrequent.

Surgical management of high-grade paediatric spondylolisthesis: meta-analysis and systematic review.

PURPOSE: There is currently no consensus on the management of high-grade spondylolisthesis (HGS) in paediatric populations. The objective of this analysis is to compare the outcomes of reduction followed by fusion (RFF) or in situ fusion (ISF) in paediatric patients. METHODS: Using major databases, a systematic literature search was performed. Primary studies comparing ISF with RFF in paediatric and adolescent patients were identified. Study data including patient-reported outcomes, complications, and spinopelvic parameters were collected and analysed. RESULTS: Seven studies were included, comprising 97 ISF and 131 RFF. Average patient age was 14.4 ± 2.1 years and follow up was 8.2 ± 5.1 years. Patients undergoing RFF compared to patients undergoing ISF alone were less likely to develop pseudarthrosis (RR 0.51, 95% CI, [0.26, 0.99], p = 0.05). On average, RFF led to 11.97º more reduction in slip angle and 34.8% more reduction in sagittal translation (p < 0.00001) compared to ISF. There was no significant difference between patient satisfaction and pain at follow up. Neurologic complications and reoperation rates were not significantly different. CONCLUSIONS: Both RFF and ISF are effective techniques for managing HGS. Performing a reduction followed by fusion reduces the likelihood of pseudarthrosis in paediatric patients. The difference between risk of neurologic complications, need for reoperation, patient satisfaction, and pain outcomes did not reach statistical significance. Correlation with patient-reported outcomes still needs to be further explored. LEVEL 3 EVIDENCE: Meta-analysis of Level 3 studies.

Adjacent segment mobility after ACDF considering fusion status at the implant insertion site.

PURPOSE: This paper sets out to analyse mobility changes in segments adjacent to the operated segment. Additionally, it investigates the relationship between the degree of fusion in the operated disc space and mobility changes in the adjacent segments. METHODS: In total, 170 disc spaces were operated on in 104 consecutive patients qualified for one- or two-level surgery. The degree of mobility of segments directly above and below the implant insertion site was calculated. Measurements were performed the day before the surgery and 12 months post-surgery. Functional (flexion and extension) radiographs of the cervical spine and CT scans obtained 12 months post-surgery were used to evaluate the fusion status. The results were subjected to statistical analysis. RESULTS: Statistically significant increase in mobility was recorded for the segments situated immediately below the operative site, with a mean change in mobility of 1.7 mm. Complete fusion was demonstrated in 101 cases (71.1%), and partial fusion in 43 cases (29.9%). In the complete fusion subgroup, the ranges of both flexion and extension in the segments directly below the operative site were significantly greater than those in the partial fusion (pseudoarthrosis) subgroup. CONCLUSION: The mobility of the adjacent segment below the implant insertion site was significantly increased at 12 months post-ACDF surgery. The range of this compensatory hypermobility was significantly greater in patients with complete fusion at the ACDF site than in cases of pseudoarthrosis. Implant subsidence was not associated with mobility changes in the segments directly above or directly below the site of ACDF surgery.

L1-pelvic angle: a convenient measurement to attain optimal deformity correction.

PURPOSE: (1) Evaluate the associations between L1-pelvic angle (L1PA) and both sagittal vertical axis (SVA) and T1-pelvic angle (T1PA), and (2) assess the clinical impact of L1PA. METHODS: A single-institution retrospective cohort study was undertaken for patients undergoing adult spinal deformity (ASD) surgery from 2013 to 2017. Ideal L1PA was defined as (0.5xPelvic Incidence)-21. Pearson correlation was performed to compare L1PA, SVA, and T1PA. Univariate/multivariate regression was performed to assess the effect of L1PA on mechanical complications, controlling for age, BMI, and postoperative pelvic incidence-lumbar lordosis mismatch (PI/LL). Due to the overlapping nature of patients with pseudarthrosis and rod fracture, these patients were analyzed together. RESULTS: A total of 145 patients were included. Mean preoperative L1PA, SVA, and T1PA were 15.5 ± 8.9°, 90.7 ± 66.8 mm, and 27.1 ± 13.0°, respectively. Mean postoperative L1PA, SVA, and T1PA were 15.0 ± 8.9°, 66.7 ± 52.8 mm, and 22.3 ± 11.1°, respectively. Thirty-six (24.8%) patients achieved ideal L1PA. Though the correlation was modest, preoperative L1PA was linearly correlated with preoperative SVA (r2 = 0.16, r = 0.40, 95%CI = 0.22-0.60, p < 0.001) and T1PA (r2 = 0.41, r = 0.62, 95%CI = 0.46-0.76, p < 0.001). Postoperative L1PA was linearly correlated with postoperative SVA (r2 = 0.12, r = 0.37, 95%CI = 0.18-0.56, p < 0.001) and T1PA (r2 = 0.40, r = 0.62, 95%CI = 0.45-0.74, p < 0.001). Achieving ideal L1PA ± 5° was associated with a decreased risk of rod fracture/pseudarthrosis on univariate and multivariate regression (OR = 0.33, 95%CI = 0.12-0.86, p = 0.024). No association between achieving ideal L1PA and patient-reported outcomes was observed. CONCLUSION: L1PA was modestly correlated with SVA and T1PA, and achieving ideal L1PA was associated with lower rates of rod fracture/pseudarthrosis. Future studies are warranted to better define the clinical implications of achieving a normal L1PA. LEVEL OF EVIDENCE: III.

Pseudoarthrosis after anterior cervical discectomy and fusion: rate of occult infections and outcome of anterior revision surgery.

BACKGROUND: Pseudoarthrosis after anterior cervical discectomy and fusion (ACDF) is relatively common and can result in revision surgery. The aim of the study was to analyze the outcome of patients who underwent anterior revision surgery for pseudoarthrosis after ACDF. METHODS: From 99 patients with cervical revision surgery, ten patients (median age: 48, range 37-74; female: 5, male: 5) who underwent anterior revision surgery for pseudoarthrosis after ACDF with a minimal follow up of one year were included in the study. Microbiological investigations were performed in all patients. Computed tomography (CT) scans were used to evaluate the radiological success of revision surgery one year postoperatively. Clinical outcome was quantified with the Neck Disability Index (NDI), the Visual Analog Scale (VAS) for neck and arm pain, and the North American Spine Society Patient Satisfaction Scale (NASS) 12 months (12-60) after index ACDF surgery. The achievement of the minimum clinically important difference (MCID) one year postoperatively was documented. RESULTS: Occult infection was present in 40% of patients. Fusion was achieved in 80%. The median NDI was the same one year postoperatively as preoperatively (median 23.5 (range 5-41) versus 23.5 (7-40)), respectively. The MCID for the NDI was achieved 30%. VAS-neck pain was reduced by a median of 1.5 points one year postoperatively from 8 (3-8) to 6.5 (1-8); the MCID for VAS-neck pain was achieved in only 10%. Median VAS-arm pain increased slightly to 3.5 (0-8) one year postoperatively compared with the preoperative value of 1 (0-6); the MCID for VAS-arm pain was achieved in 14%. The NASS patient satisfaction scale could identify 20% of responders, all other patients failed to reach the expected benefit from anterior ACDF revision surgery. 60% of patients would undergo the revision surgery again in retrospect. CONCLUSION: Occult infections occur in 40% of patients who undergo anterior revision surgery for ACDF pseudoarthrosis. Albeit in a small cohort of patients, this study shows that anterior revision surgery may not result in relevant clinical improvements for patients, despite achieving fusion in 80% of cases. LEVEL OF EVIDENCE: Retrospective study, level III.

Pseudarthrosis after four-level anterior cervical discectomy and fusion without posterior fixation.

OBJECTIVE: Fusion rates and long-term outcomes are well established for anterior cervical discectomy and fusion (ACDF) of 3 levels or fewer, but there is a paucity of similar data on 4-level fusions. The authors evaluated long-term fusion rates and clinical outcomes after 4-level ACDF without supplemental posterior instrumentation. METHODS: The authors retrospectively reviewed patients who underwent 4-level ACDF at a single institution with at least 1-year of radiological follow-up. Fusion was determined by measuring change in interspinous distance at each segment on dynamic radiographs or by the presence of bridging bone on CT scans at minimum 1-year follow-up. Clinical outcomes were assessed using Neck Disability Index and Short Form-36. RESULTS: A total of 63 patients (252 levels) met the inclusion criteria for the study, with a mean follow-up of 2.6 years. Complete radiographic fusion at all 4 levels was observed in 26 patients (41.3%). Of the 37 patients (58.7%) with radiographic pseudarthrosis, there was a mean of 1.35 nonfused levels. The fusion rate per level, however, was 80.2% (202/252 levels). The most common level demonstrating nonunion was the distal segment (C6-7), showing pseudarthrosis in 29 patients (46.8%), followed by the most proximal segment (C3-4) demonstrating nonunion in 9 patients (14.5%). The mean improvement in Neck Disability Index and Short Form-36 was 15.7 (p < 0.01) and 5.8 (p = 0.14), respectively, with improvement in both scores surpassing the minimum clinically important difference. One patient (1.6%) required revision surgery for symptomatic pseudarthrosis, and 5 patients (7.9%) underwent revision for symptomatic adjacent-segment disease. Patient-reported outcomes results are limited by the low rate of 1-year follow-up (50.8%), whereas reoperation data were available for all 63 patients. CONCLUSIONS: More than half of patients undergoing 4-level ACDF without posterior fixation demonstrated pseudarthrosis of at least 1 level-most commonly the distal C6-7 level. One patient required revision for symptomatic pseudarthrosis. Patient-reported outcomes showed significant improvements at 1-year follow-up, but clinical follow-up was limited. This is the largest series to date to evaluate fusion outcomes in 4-level ACDF.

Treatment of Concomitant Congenital Pseudarthrosis of the Fibula With Propeller Periosteal Flap.

INTRODUCTION: Congenital pseudarthrosis of the fibula is not an uncommon condition to accompany congenital pseudarthrosis of the tibia. Persistence of the fibular pseudarthrosis has been linked to inferior outcomes including tibial union and alignment, refractures, and ankle alignment. In this report, we present the results of a pedicled periosteal propeller flap technique for the treatment of fibular pseudarthrosis. METHODS: Ten children with an average age at surgery of 5.3 years who had congenital pseudarthrosis of both tibia and fibula were studied. The tibia was treated with free vascularized fibular grafting, and the ipsilateral fibula was treated with a technique after resection of the pseudarthrosis. A periosteal flap from the proximal healthy part of the fibula is harvested off the bone, rotated 180° based on a branch from the peroneal vessels to cover the fibular defect and fashioned in the form of a tube filled with bone fragments. RESULTS: The periosteal flap size ranged from 5 to 7 cm. Follow-up averaged 37.2 months. The tibia was united in all cases; in 2 of them, refractures occurred and healed with conservative management. The fibula was united in 8 cases. At final follow-up, 5 cases showed residual tibial deformity, and 5 showed residual ankle deformity. Average leg-length discrepancy was 1.4 cm (0-3 cm). CONCLUSION: The pedicled periosteal propeller flap presents a useful new technique for managing concomitant congenital fibular pseudarthrosis.