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.

[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.

Spatial transcriptomics implicates impaired BMP signaling in NF1 fracture pseudarthrosis in murine and patient tissues.

The neurofibromatosis type 1 (NF1) RASopathy is associated with persistent fibrotic nonunions (pseudarthrosis) in human and mouse skeletal tissue. Here, we performed spatial transcriptomics to define the molecular signatures occurring during normal endochondral healing following fracture in mice. Within the control fracture callus, we observed spatially restricted activation of morphogenetic pathways, such as TGF-ß, WNT, and BMP. To investigate the molecular mechanisms contributing to Nf1-deficient delayed fracture healing, we performed spatial transcriptomic analysis on a Postn-cre;Nf1fl/- (Nf1Postn) fracture callus. Transcriptional analyses, subsequently confirmed through phospho-SMAD1/5/8 immunohistochemistry, demonstrated a lack of BMP pathway induction in Nf1Postn mice. To gain further insight into the human condition, we performed spatial transcriptomic analysis of fracture pseudarthrosis tissue from a patient with NF1. Analyses detected increased MAPK signaling at the fibrocartilaginous-osseus junction. Similar to that in the Nf1Postn fracture, BMP pathway activation was absent within the pseudarthrosis tissue. Our results demonstrate the feasibility of delineating the molecular and tissue-specific heterogeneity inherent in complex regenerative processes, such as fracture healing, and reconstructing phase transitions representing endochondral bone formation in vivo. Furthermore, our results provide in situ molecular evidence of impaired BMP signaling underlying NF1 pseudarthrosis, potentially informing the clinical relevance of off-label BMP2 as a therapeutic intervention.

Three-dimensional modelling and printing in anterior chest wall reconstruction and stabilisation.

Anterior chest wall instability as a result of sternocostal non-union is a rare complication but can give rise to invalidating pain and cardiac arrhythmias. A woman in her 40s was referred to us with anterior chest wall pain and instability after a modified Ravitch procedure. Sternocostal pseudoarthrosis was seen for which multiple operations were performed which were complicated by low-grade infections. A patient-specific three-dimensional modelled and printed prostheses was used in an operation to both lift the sternum for pectus correction and to reconnect the sternum and the sternal costal junction to regain anterior chest wall stability.

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.

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.

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.

[Non-unions of the upper extremities]. / Pseudarthrosen der oberen Extremität.

The diagnosis and treatment of non-unions still represents an interdisciplinary challenge. Therefore, prevention, early detection and specific treatment are of great importance. Non-unions of the upper extremities, although less common than that of the lower extremities, requires special attention for successful treatment due to the central role of the shoulder girdle and arm in day to day activities. Successful treatment of non-unions requires a comprehensive evaluation of the patient's medical history, a thorough clinical examination and in particular radiological imaging. In order to effectively treat the pseudarthrosis it is crucial to distinguish between pseudarthroses that are suspected to be due to infections and those that are not. This article presents a treatment algorithm for managing both pseudarthrosis due to infection and pseudarthrosis without infection in the upper extremities.

MEK-SHP2 inhibition prevents tibial pseudarthrosis caused by NF1 loss in Schwann cells and skeletal stem/progenitor cells.

Congenital pseudarthrosis of the tibia (CPT) is a severe pathology marked by spontaneous bone fractures that fail to heal, leading to fibrous nonunion. Half of patients with CPT are affected by the multisystemic genetic disorder neurofibromatosis type 1 (NF1) caused by mutations in the NF1 tumor suppressor gene, a negative regulator of RAS-mitogen-activated protein kinase (MAPK) signaling pathway. Here, we analyzed patients with CPT and Prss56-Nf1 knockout mice to elucidate the pathogenic mechanisms of CPT-related fibrous nonunion and explored a pharmacological approach to treat CPT. We identified NF1-deficient Schwann cells and skeletal stem/progenitor cells (SSPCs) in pathological periosteum as affected cell types driving fibrosis. Whereas NF1-deficient SSPCs adopted a fibrotic fate, NF1-deficient Schwann cells produced critical paracrine factors including transforming growth factor-ß and induced fibrotic differentiation of wild-type SSPCs. To counteract the elevated RAS-MAPK signaling in both NF1-deficient Schwann cells and SSPCs, we used MAPK kinase (MEK) and Src homology 2 containing protein tyrosine phosphatase 2 (SHP2) inhibitors. Combined MEK-SHP2 inhibition in vivo prevented fibrous nonunion in the Prss56-Nf1 knockout mouse model, providing a promising therapeutic strategy for the treatment of fibrous nonunion in CPT.

Free fibula flap to achieve bone union after congenital pseudoarthrosis of the forearm in neurofibromatosis: Technical report based on 3 cases, and literature review.

Congenital pseudarthrosis of the forearm bones (CPFBs) is rare, with only 106 reported cases, and is frequently associated with neurofibromatosis (NF). Approximately 5% of patients with NF develop pseudarthrosis, and 50% of patients with pseudarthrosis have NF. Achieving bone union is difficult in congenital pseudarthrosis. Many methods have been attempted, including casting, internal fixation with or without grafting, and electrical stimulation, but failure is frequent. Free vascularized fibular flaps (FVFs) have been used to bridge long bone defects since 1975 and in tibial pseudarthrosis since 1979. In CPFB, FVF is more successful than other methods in achieving union and is the current treatment of choice. Here, we presented three cases of forearm pseudarthrosis treated with FVF, reviewed the literature on CPFB, and discussed some technical aspects of FVF treatment. Three cases of congenital pseudoarthrosis were treated with free fibula flaps, diagnosed at ages of 7 years (ulna), 15 months (radius), and 9 years (radius and ulna). Two flaps were stabilized with intramedullary wires and latterly, one with compression plates. One persistent nonunion received revision nonvascularized bone grafting and plating. All patients achieved union by 11 months after index surgery. Reconstruction with vascularized fibula is the treatment of choice because it offers the highest published union rates and good functional results. Complete resection of the affected bone and stable fixation, latterly with compression plates are critical to success. Surgery is technically demanding, and complications are common. Secondary surgery may be required, but outcomes are favorable. LEVEL OF EVIDENCE: IV.

Comparative study of different extendable intramedullary rods combined with surgery in the treatment of congenital pseudarthrosis of the tibia.

BACKGROUND: When using traditional extensible intramedullary rods to treat congenital pseudarthrosis of the tibia (CPT), there were cases of re-fracture and internal fixation fracture. Therefore, the authors propose a research hypothesis that a thicker distal extensible intramedullary rod can better protect the tibia and reduce the incidence of refracture PURPOSE: To investigate the clinical efficacy of new and traditional extensible intramedullary rods in the treatment of CPT in children METHODS: From January 2017 to December 2021, the clinical data of 49 children with CPT who were treated with traditional extensible intramedullary rod combined surgery (group A) and new extensible intramedullary rod combined surgery (group B) in our hospital were collected. Inclusive criteria: ① Crawford type IV CPT children; ② The operation was performed by the same team. EXCLUSION CRITERIA: patients with multiple tibial angulation. During follow-up, the initial healing, proximal tibial valgus, tibial length, ankle valgus, refracture and intramedullary rod displacement of CPT children in the two groups were evaluated RESULTS: It was a retrospective investigation. In group A, 26 cases met the inclusion criteria, 24 cases achieved primary healing, with an primary healing rate of 92%, including 1 case of nonunion due to osteomyelitis complications after surgery, and 1 case of delayed healing, with an average healing time of 4.7 ± 0.8 months. 17 cases (68%) had unequal tibia length, with an average difference of 1.6 ± 0.8 cm. Ankle valgus occurred in 10 cases (40%) with an average of 14.4°±4.8°; Proximal tibial valgus occurred in 6 cases (24%) with an average of 7 °± 1.8 °. 20 cases (80%) had tip of the rod migration.10 cases (40%) had re-fracture; The average follow-up time was 2.4 ± 0.4 years. In group B, 22 patients achieved primary healing, and the primary healing rate was 95%, including 1 case with delayed healing. The average healing time was 4.7 ± 1.7months. 14 cases (61%) had unequal tibia length, with an average difference of 1 ± 0.5 cm. Ankle valgus occurred in 4 cases (17%) with an average of 12.3 °±4.9°; The proximal tibia valgus occurred in 9 cases (39%), with an average of 7.7 °±2.5 °. 14 cases (61%) had new type of intramedullary rod displacement. 3 cases (13%) had re-fracture; The average follow-up time was 2.3 ± 0.6years CONCLUSION: Compared with the traditional extended intramedullary rod combined operation, the new type of extended intramedullary rod combined operation has a lower incidence of re-fracture after CPT, but it still needs to be verified by large sample and multi-center research.

[Is the 95°blade plate still important in the treatment of proximal femoral pseudarthrosis?] / Hat die 95°-Winkelplatte bei der Behandlung von proximalen Femurpseudarthrosen noch einen Stellenwert?

Due to demographic changes, fractures and subsequently delayed fracture healing as well as pseudarthrosis of the proximal femur are on the increase. In the acute fracture situation, a load-stable treatment with an intramedullary implant (cephalomedullary nail) is generally sought. To date, there is no uniform consensus on the optimal treatment for complicated cases. The aim of this study was to evaluate the clinical and radiological outcome after revision of pseudarthrosis using a 95° blade plate in aseptic proximal femoral pseudarthrosis and to identify the specifications of blade plate treatment.The retrospective study design was used to evaluate data, some of which were prospectively collected. The study period covered January 2010 to December 2020 and 22 patients (10 women, 12 men) with an average age of 59 years were included in this single-center study. All patients showed pseudarthrosis after a femoral fracture type AO 31 A1-A3 or proximal femoral fracture type AO 32 A-C. Clinical and radiological follow-up were performed after 3, 6 and 12 months. Functional outcomes were assessed using the modified Harris hip score (mHHS), the numerical rating scale (NRS) and the short form health survey (SF-12).The postoperative radiological results after reosteosynthesis using a blade plate showed good results and 86.4% of the patient population were healed during the observation period. Pseudarthrosis persisted in four patients and was surgically revised.The functional results showed good results on average, albeit with a high dispersion of 17-91 points in the mHHS. The SF-12 averaged 42.6 (±10.4) points and the psychological score 49.4 (±9.6) points. The postoperative pain level was low both at rest and under stress.It was shown that reosteosynthesis with a blade plate is a surgically demanding but effective treatment option with a low potential for infection and safe bone consolidation, especially for the correction of high-grade axial deviation or varus malalignment.

Treatment of non-hypertrophic pseudoarthrosis of long bones with a Tissue Engineered Product loaded with autologous bone marrow-derived Mesenchymal Stromal Cells: Results from a phase IIa, prospective, randomized, parallel, pilot clinical trial comparing to iliac crest autograft.

BACKGROUND: Atrophic pseudoarthrosis is a serious complication with an incidence of 5-10 % of bone fractures located in the diaphysis of long bones. Standard treatments involve aggressive surgical procedures and re-interventions requiring the use of autografts from the iliac crest as a source of bone-forming biological activity (Standard of Care, SoC). In this context, regenerative ex vivo expanded osteogenic cell-based medicines could be of interest. Particularly, Mesenchymal Stromal Cells (MSC) offer new prospects to promote bone tissue repair in pseudoarthrosis by providing biological activity in an osteoconductive and osteoinductive environment. METHODS: We conducted a phase IIa, prospective, randomised, parallel, two-arms, open-label with blinded assessor pilot clinical trial to compare SoC vs. a tissue-engineered product (TEP), composed of autologous bone marrow (BM)-derived MSCs loaded onto allogeneic decellularised, lyophilised spongy bone cubes, in a cohort of 20 patients with non-hypertrophic pseudoarthrosis of long bones. Patients were followed up for 12 months. Radiological bone healing was evaluated by standard X-ray and computed tomography (CT) scanning. Quality of life was measured using the EUROQOL-5D questionnaire. RESULTS: Ten patients were randomized to TEP and 10 to SoC with iliac crest autograft. Manufacturing of TEP was feasible and reproducibly achieved. TEP implantation in the bone defect was successful in all cases and none of the 36 adverse events (AE) reported were related to the treatment. Efficacy analyses were performed in the Full Analysis Set (FAS) population, which included 17 patients after 3 patients withdrew from the study. The degree of consolidation, estimated by measuring Hounsfield units (HU) on CT, showed no significant differences between the two treatment groups at 12 months post treatment (main efficacy variable) (p = 0.4835) or at 6 months. CONCLUSIONS: Although only a small number of patients were included in our study, it is notable that no significant differences were observed between the experimental treatment and SoC, thus suggesting TEP as an alternative where autograft is not available or contraindicated.

Modified "SUPERhip2" to Reconstruct Postinfectious Femoral Neck Pseudoarthrosis (Hunka Type 3): A Case Report.

CASE: We report a case of a 3-year-old girl who developed a post-infectious femoral neck pseudoarthrosis after a proximal hematogenous femoral osteomyelitis (type 3 according to Hunka classification of the sequelae of the septic hip in children). The patient was treated by a modified "SUPERhip 2" procedure (a reconstructive procedure described to reconstruct congenital femoral neck pseudoarthrosis). This report describes the surgical technique in details and discusses the advantages, pitfalls, and complications and possible complications. CONCLUSION: Our modification simplifies the "SUPERhip 2" procedure. Postinfectious neck pseudoarthrosis was successfully treated, and we believe this modification is applicable for the treatment of congenital femoral neck pseudoarthrosis as well.

Association of Poor Bone Quality with Pseudarthrosis and Poor Clinical Outcomes in Single-Level Instrumented Lumbar Arthrodesis Using Local Autologous Bone Graft.

INTRODUCTION: Although osteoporosis and low bone mineral density is thought to lead to poor fusion outcomes, few studies have adequately addressed the correlation, and they were limited by small sample size at a single institution. METHODS: We completed a secondary analysis of 182 patients enrolled at 26 spine centers across the United States in the EXO-SPINE FDA-approved clinical trial with 12-month CT-based fusion status determined by two independent, blinded radiologists. Using previously described CT-based techniques, we measured local and global Hounsfield units (HU) and examined the relationship with radiographic and clinical outcomes. RESULTS: CT scans were available for review from 95 patients, with a mean age of 56.2 years and mean global density of 153.0 HU. No relationship was observed between HU and radiographic fusion status or clinical outcomes. Although 12% of patients had lumbar vertebral body HU measurements consistent with osteoporosis, this classification had no relation with fusion or clinical outcomes. Patients with pseudarthrosis had higher Oswestry Disability Index (22.2 vs. 16.6, P = 0.037) and back pain visual analog scale (7.0 vs. 4.9, P = 0.014) scores than patients with at least unilateral fusion at the 12-month follow-up. DISCUSSION: In this large, multicenter study, lower vertebral body HU was not associated with worse fusion status after single-level instrumented posterolateral lumbar fusion using only local autologous bone graft. However, there was an association between radiographic fusion status and clinical outcomes, validating the importance of determining predictors of successful fusion. Assessment of fusion status with CT scans yielded a much lower fusion success rate with local bone graft than previously reported and may warrant additional investigation.

Instrumented L5-S1 interbody graft with IFUSE implant using the reverse Bohlman technique.

BACKGROUND: In case of high sacral slope, anterior lumbosacral fusions can be performed by retroperitoneal or transperitoneal approach using a reversed Bohlman technique with an autologous corticocancellous fibular graft. The use of a trans-lumbosacral implant can avoid the iatrogenic effects but currently, there is no implant specifically designed for this fusion technique. Could the IFUSE implant from SI BONE replace a fibular graft to avoiding the iatrogenic effect induced by sampling during a Reverse Bohlman technique? PATIENTS AND METHODS: We present the case of a 38-year-old woman with L5S1 interbody pseudarthrosis after posterior fixation for grade 2 L5-S1 spondylolisthesis with isthmic lysis of L5, and that of a 69-year-old woman who underwent a posterior T4 fusion to the pelvis for degenerative scoliosis. Both required a trans-lumbosacral instrumented fusion via an anterior approach using the reverse Bohlman technique. Surgical technique was described. RESULTS: There were no perioperative or postoperative complications. At 6 months, the patients reported a decrease in lumbar and radicular symptomatology. There were no infectious, neurological or vascular complications. CT-scans confirmed the good position and stability of the IFUSE implant. DISCUSSION: We present an innovative interbody grafting technique adapted to spines with high pelvic incidence. The surgical technique is safe, minimally invasive, and reduces surgical iatrogeny. The short and medium-term results are positive but require longer-term follow-up and a larger cohort.

Unilateral Versus Bilateral Cages in Lumbar Interbody Fusions: A Meta-Analysis of Clinical and Radiographic Outcomes.

BACKGROUND: Bilateral cages are often used for interbody fusion. However, this procedure may not be possible in some cases making unilateral cages a reasonable alternative. The literature remains divided on the clinical and radiological distinctions when comparing unilateral to bilateral cages in lumbar interbody fusion. Thus, this meta-analysis will analyze the clinical and radiographic outcomes between these 2 groups. METHODS: PubMed, Cochrane, and Google Scholar (page 1-20) were searched till January 2024. The clinical outcomes evaluated were the incidence of adverse events, surgery-related parameters, and patient reported outcomes. RESULTS: Lower rates of pseudoarthrosis, subsidence, were reported in the bilateral cages group (P = 0.01, P = 0.001, respectively) whereas shorter operative time (OR time), and lower estimated blood loss were seen in unilateral cage group (P < 0.001, and P = 0.003). There was no statistically significant difference in the remaining analyzed outcomes. CONCLUSIONS: Unilateral cages were shown to be superior due to their reduced OR time and estimated blood loss. As for the higher rate of pseudoarthrosis, this outcome may not be related to the cage numbers and it did not affect clinical outcomes. Nevertheless, one must consider other factors such as radiographic sagittal parameters before making a surgical decision.

Adjunctive Use of Bone Growth Stimulation Increases Cervical Spine Fusion Rates in Patients at Risk for Pseudarthrosis.

STUDY DESIGN: A prospective multicenter clinical trial (NCT03177473) was conducted with a retrospective cohort used as a control arm. OBJECTIVE: The purpose of this study was to evaluate cervical spine fusion rates in subjects with risk factors for pseudarthrosis who received pulsed electromagnetic field (PEMF) treatment. SUMMARY OF BACKGROUND DATA: Certain risk factors predispose patients to pseudarthrosis, which is associated with prolonged pain, reduced function, and decreased quality of life. METHODS: Subjects in the PEMF group were treated with PEMF for 6 months postoperatively. The primary outcome measure was fusion status at the 12-month follow-up period. Fusion status was determined using anterior/posterior, lateral, and flexion/extension radiographs and computed tomography (without contrast). RESULTS: A total of 213 patients were evaluated (PEMF, n=160; Control, n=53). At baseline, the PEMF group had a higher percentage of subjects who used nicotine ( P =0.01), had osteoporosis ( P <0.05), multi-level disease ( P <0.0001), and were >65 years of age ( P =0.01). The PEMF group showed over two-fold higher percentage of subjects that had ≥3 risk factors (n=92/160, 57.5%) compared with the control group (n=14/53, 26.4%). At the 12-month follow-up, the PEMF group demonstrated significantly higher fusion rates compared with the control (90.0% vs. 60.4%, P <0.05). A statistically significant improvement in fusion rate was observed in PEMF subjects with multi-level surgery ( P <0.0001) and high BMI (>30 kg/m 2 ; P =0.0021) when compared with the control group. No significant safety concerns were observed. CONCLUSIONS: Adjunctive use of PEMF stimulation provides significant improvements in cervical spine fusion rates in subjects having risk factors for pseudarthrosis. When compared with control subjects that did not use PEMF stimulation, treated subjects showed improved fusion outcomes despite being older, having more risk factors for pseudarthrosis, and undergoing more complex surgeries.

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.