Complications and their management

This chapter reviews the complications that can occur after minimally invasive surgical fusion of the sacroiliac joint, focusing on infection and neurovascular injuries and their prevention and treatment. The sacroiliac joint has been identified as a potential pain generator in 15% to 30% of chronic low back pain and post-laminectomy syndrome patients. Minimally invasive sacroiliac joint fusion via the lateral approach is effective and better tolerated than the open surgical approach. Most of the current studies have focused on efficacy and patient satisfaction as opposed to the safety profile of the procedure. There is a dearth of literature regarding the safety of minimally invasive sacroiliac joint fusion. Over the past few years, a novel posterior approach to sacroiliac joint fusion has become more common that theoretically is safer and potentially as efficacious as the lateral approach.

APKASS Consensus Statement on Chronic Syndesmosis Injury, Part 3: Fusion Techniques, Comorbidity Treatments, Postoperative Rehabilitation, and Return-to-Sport Indications

Background: Questions regarding surgical fusion techniques, postoperative treatment, and indications for return to sport after chronic syndesmosis injury or its comorbidities remain unanswered. Purpose: An international group of experts representing the field of injuries in the foot and ankle area was invited to collaboratively advance toward consensus opinions based on the best available evidence regarding chronic syndesmosis injury. All were members of the Asia-Pacific Knee, Arthroscopy and Sports Medicine Society (APKASS). Study Design: Consensus statement. Methods: From November to December 2020, a total of 111 international experts on sports medicine or ankle surgery participated in a 2-stage Delphi process that included an anonymous online survey and an online meeting. A total of 13 items with 38 statements were drafted by 13 core authors. Of these, 4 items with 6 clinical questions and statements were related to surgical fusion techniques, comorbidity treatments, postoperative rehabilitation, and return-to-sports indications and are presented here. Each statement was individually presented and discussed, followed by a general vote. The strength of consensus was characterized as follows: consensus, 51% to 74%; strong consensus, 75% to 99%; and unanimous, 100%. Results: Of the 6 questions and statements, 5 achieved unanimous support and 1 reached strong consensus. Conclusion: This APKASS consensus statement, developed by international experts in the field, will assist surgeons and physical therapists with surgical and postoperative treatment strategies for chronic syndesmosis injury.

Spine surgery in children: past, present and future

In accordance with almost 55 years of experience in pediatric spine surgery, it is easy for me to describe the evolution of surgical technique, as well as indications for surgical interventions that were initially performed without the use of any instrumentation (which now are still occasionally considered as useful) through the anterior and posterior approaches, and with postoperative immobilization with plaster braces. The first types of really effective instrumentations were created sequentially by Harrington and Luque, and in parallel with their development, the pedicle screws (Roy-Camille) were introduced into practice. We had to wait another 20 years before the segmental 3D strategy and CD instrumentation appeared, which remain the basis of modern spinal technologies to this day, regardless of the type of anchoring elements (hooks, screws, universal clamps or hybrid structures). For the present and the future, early interventions remain indicated for local pathological foci, which are usually the result of congenital anomalies with or without spinal cord compression. But for extended deformities, especially of thoracic localization, plaster and removable braces remain a good choice, regardless of the etiology and the presence or absence of pelvic tilt. When such methods did not give the desired result, a lot of efforts were made using various technologies to preserve the growth potentials of the spinal column without impairing respiratory function. At the same time, it was obvious that the incidence of complications was high, and the need for a final fusion was often stated. Hence the emergence of bipolar minimally invasive technologies with very promising results and significant number of patients who developed a spontaneous bone block, made the fusion surgery meaningless. As for older children and adolescents, the race to achieve maximum Cobb angle correction is becoming more controversial. It has been convincingly shown that it is much more important for the future, from the point of view of spinal function, to achieve 3D dynamic balance, which is determined by intervertebral discs located cranial and caudal to the area of surgical fusion.

SUN-353 Physical and Cognitive Functioning Before and Six Months After Initiating Enzyme Replacement Therapy for an Adult with Hypophosphatasia: A Case Study

We present changes on physical therapy (PT), occupational therapy (OT), and speech-language pathology (SLP) assessments for a patient pre- and 6 months post-initiation of recombinant alkaline phosphatase therapy for hypophosphatasia (HPP). Our patient is a 30-year-old male diagnosed with pediatric onset HPP at the age of 28. Features of his HPP include skull deformities and scoliosis noted as a toddler, early loss of primary dentition with the root intact prior to the age of 4, severe bone and muscle pain described as “severe growing pain”, and fatigue as a teenager. He was noted to have arthritis in his feet requiring surgical fusion, which was complicated by nonunion. By the age of 30, he required the use of assistive devices for ambulation due to fatigue and pain. Biochemistry was notable for ALP 17U/L (40-150), serum PLP 241 mcg/L (5-50), urine phosphethanolamine 47 nmolmgCr (0-27), and genetic testing demonstrated a variant of undetermined significance of ALPL genet (Het. C.1364G>A p.Gly455Asp). PT and OT assessments included a thorough musculoskeletal and neurologic examination, as well as functional testing of mobility, balance, motor control, and activity of daily living tasks. After 6 months of enzyme replacement therapy (ERT), the patient’s scores on measures of body structure and function were grossly unchanged or diminished (muscle strength). However, activity-based measures of functional performance generally improved on ERT. Performance on the Five Times Sit to Stand Test (FTSTS), gait speed, Functional Gait Assessment, Sensory Organization Test, and Six-Minute Walk Test (6MWT) improved. His most significant improvements were on the FTSTS and 6MWT; his FTSTS improved from 15.4 seconds to 9.1 seconds, surpassing the cut-off for falls risk (12s), while his 6MWT improved from 1,228 feet to 1,541 feet, surpassing the minimal detectable change for individuals with osteoarthritis (201 ft). Cognitive testing revealed improvement in delayed memory (e.g., word-list recognition, story-retell) on the Repeatable Battery of the Assessment of Neuropsychological Status from baseline (7%tile) to 6 months post therapy (47%tile). He also demonstrated improvement in Trail Making Part A [TM A, cognitive processing speed] & TM B (executive functioning) from baseline (45s, 49s) to 6 months post therapy (21s, 38s). Mean performance on TM A&B for adults 25-34 yrs is 24.4s±8.71 and 50.7s±12.4, respectively. Overall, the patient demonstrated improvement in delayed memory, cognitive processing speed and executive functioning on ERT. Additionally, while his performance on bedside impairment-based testing generally declined or remained unchanged, his performance on standardized functional assessments improved on ERT. These functional improvements in physical and cognitive domains likely enable the patient to more fully participate in life roles to improve quality of life.

Methods of Cryoprotectant Preservation: Allogeneic Cellular Bone Grafts and Potential Effects

Debridement of the bone surface during a surgical fusion procedure initiates an injury response promoting a healing cascade of molecular mediators released over time. Autologous grafts offer natural scaffolding to fill the bone void and to provide local bone cells. Commercial bone grafting products such as allografts, synthetic bone mineral products, etc., are used to supplement or to replace autologous grafts by supporting osteoinductivity, osteoconductivity, and osteogenesis at the surgical site. To assure osteogenic potential, preservation of allogeneic cells with cryoprotectants has been developed to allow for long-term storage and thus delivery of viable bone cells to the surgical site. Dimethyl sulfoxide (DMSO) is an intracellular cryoprotectant commonly used because it provides good viability of the cells post-thaw. However, there is known cytotoxicity reported for DMSO when cells are stored above cryogenic temperatures. For most cellular bone graft products, the cryoprotectant is incorporated with the cells into the other mineralized bone and demineralized bone components. During thawing, the DMSO may not be sufficiently removed from allograft products compared to its use in a cell suspension where removal by washing and centrifugation is available. Therefore, both the allogeneic cell types in the bone grafting product and the local cell types at the bone grafting site could be affected as cytotoxicity varies by cell type and by DMSO content according to reported studies. Overcoming cytotoxicity may be an additional challenge in the formation of bone at a wound or surgical site. Other extracellular cryoprotectants have been explored as alternatives to DMSO which preserve without entering the cell membrane, thereby providing good cellular viability post-thaw and might abrogate the cytotoxicity concerns.

Computed Tomographic Evaluation of Adjacent Segment Motion after Ex Vivo Fusion of Equine Third and Fourth Cervical Vertebrae

Objective Surgical fusion of vertebral segments is a treatment option for horses with cervical stenotic myelopathy or cervical fracture.Degenerative disease affecting adjacent vertebral segments is a reported complication following surgical vertebral fusion in other species, termed adjacent segment disease. The aim of this study was to evaluate the impact of cervical vertebral fusion on the biomechanics of adjacent vertebral segments in the horse. Study Design Neck specimens of 12 horses were assessed using computed tomographic imaging. Range of motion (ROM) was determined by measuring the maximum sagittal flexion, extension and lateral bending between C2 and C5. C3/4 was subsequently fused using a standard locking compression plate and locking head screws and computed tomographic scans and ROM measurements were repeated. Results Prior to intervertebral fusion, a significant increase in ROM along the vertebral segments from cranial to caudal was observed. Range of motion measurements of C3/4 decreased significantly after fusion (p = 0.01).Range of motion of the adjacent segments (C2/3 and C4/5) did not change significantly after fusion. Conclusion Fusion of one cervical intervertebral joint did not affect the ROM of the adjacent vertebral segments. Further research investigating the implications of vertebral fusion on the intervertebral pressure in the equine patient is indicated.