Clinical Outcomes of Anterior Cervical Decompression and Fusion Therapy for Patients With Hirayama Disease.

OBJECTIVES: To investigate the clinical outcomes of anterior cervical decompression and fusion (ACDF) surgery for the treatment of Hirayama disease (HD). METHODS: In this study, 15 patients with HD who underwent ACDF operation between March 2022 and March 2023 with complete data were retrospectively analyzed. Following the diagnosis, conservative treatment was ineffective, and thus, disease progression severely affected the quality of life (QOL) of patients. ACDF was performed in the China-Japan Friendship Hospital, and patients were regularly followed up postoperatively. The cervical range of motion (ROM), the anteroposterior and transverse diameter of the spinal cord, and their ratio was measured before and after the operation. The neurologic function of patients before and after the last follow-up was evaluated using the selected brief-Michigan Hand Questionnaire (sb-MHQ), whilst the overall therapeutic effect after the operation was evaluated using Odom's criteria. RESULTS: All patients were followed up for an average of 12 ± 4.5 (6-18) months. Dynamic X-ray displayed that the ROM of cervical vertebrae decreased from 72.73 ± 12.72° (53-97°) to 33.53° ± 10.34° (15-54°) (P < 0.001). Moreover, flexion cervical magnetic resonance imaging (MRI) performed after the operation revealed that spinal cord compression was markedly relieved, and the ratio of the anteroposterior diameter of the spinal cord to the transverse diameter increased from 0.27 ± 0.09 to 0.43 ± 0.03 (P < 0.001). At the last follow-up visit, finger extension tremor symptoms were alleviated, although they did not completely disappear. Contrastingly, muscle atrophy showed no significant improvement. Finally, the sb-MHQ score significantly increased from 17.33±1.76 preoperatively to 24.80±1.78 at the last follow-up (P<0.001). CONCLUSIONS: Our results collectively highlighted the efficacy of ACDF for the treatment of HD. This procedure can limit excessive cervical flexion and repeated compression of the spinal cord during cervical movement and considerably improve upper limb functions.

Anterior cervical discectomy and fusion for the treatment of pediatric Hirayama disease.

PURPOSE: Hirayama disease, a rare cervical myelopathy in children and young adults, leads to progressive upper limb weakness and muscle loss. Non-invasive external cervical orthosis has been shown to prevent further neurologic decline; however, this treatment modality has not been successful at restoring neurologic and motor function, especially in long standing cases with significant weakness. The pathophysiology remains not entirely understood, complicating standardized operative guidelines; however, some studies report favorable outcomes with internal fixation. We report a successful surgically treated case of pediatric Hirayama disease, supplemented by a systematic review and collation of reported cases in the literature. METHODS: A review of the literature was performed by searching PubMed, Embase, and Web of Science. Full-length articles were included if they reported clinical data regarding the treatment of at least one patient with Hirayama disease and the neurologic outcome of that treatment. Articles were excluded if they did not provide information on treatment outcomes, were abstract-only publications, or were published in languages other than English. RESULTS: Of the fifteen articles reviewed, 63 patients were described, with 59 undergoing surgery. This encompassed both anterior and posterior spinal procedures and 1 hand tendon transfer. Fifty-five patients, including one from our institution, showed improvement post-treatment. Eleven of these patients were under 18 years old. CONCLUSION: Hirayama disease is an infrequent yet impactful cervical myelopathy with limited high-quality evidence available for optimal treatment. The current literature supports surgical decompression and stabilization as promising interventions. However, comprehensive research is crucial for evolving diagnosis and treatment paradigms.

Laminoplasty with tented duraplasty for Hirayama disease.

BACKGROUND: Hirayama disease (HD) is a characterized by progressive amyotrophy of the upper limbs due to a forward displacement of the cervical dura during neck flexion. METHODS: Unlike other treatment options aiming at preventing cervical flexion (e.g., collar or arthrodesis), laminoplasty with tented duraplasty addresses dural dysplasia. Technically, the procedure consists in enlarging the dural sac by performing an expansile duraplasty that is secured to the yellow ligaments, in association with an open-book laminoplasty. CONCLUSION: Laminoplasty with tented duraplasty is a surgical option addressing the cause of HD to prevent further neurological deterioration while preserving cervical motion.

Single-institution Series of Hirayama Disease in North America.

STUDY DESIGN: A retrospective chart review. OBJECTIVE: The aims of this study were to review pathophysiology, workup, and treatment for Hirayama disease (HD); and to assess outcomes from a single institution. SUMMARY OF BACKGROUND DATA: HD is a rare, painless, cervical myelopathy with distal upper extremity weakness, muscle wasting, and spinal cord atrophy. Disease progression-a consequence of repeat flexion injury-occurs up to 5 years from the initial diagnosis. METHODS: Single-institution review of pediatric HD patients from 2010 to 2020. RESULTS: Patients (n=10 male, n=2 female) presented in the second decade (14-20 y) with painless progressive distal upper extremity weakness and atrophy without sensory loss. Electromyography (n=12) demonstrated denervation in C7-T1 myotomes and flexion/extension magnetic resonance imaging showed focal cord atrophy and anterior displacement of the posterior dura with epidural enhancement in flexion. Treatment included observation and external orthoses (n=9) and anterior cervical discectomy with fusion (n=3). One of the 9 patients managed conservatively experienced further deterioration; no patient who underwent anterior cervical discectomy with fusion progressed. CONCLUSIONS: Patients with HD require a multidisciplinary approach to diagnosis and treatment to preserve function. Treatment is preventive and aims to minimize flexion injury by inhibiting motion across involved joints. First-line management is avoidance of neck flexion and use of rigid orthosis; in cases of failed conservative management and/or rapid clinical deterioration, surgical fixation can be offered.

Monomelic Amyotrophy/Hirayama Disease: Surgical Outcome in a Large Cohort of Indian Patients.

BACKGROUND: Hirayama disease (HD) is a cervical compressive myelopathy. Anterior cervical discectomy and fusion (ACDF) is identified as the best surgical approach. We evaluated surgical outcomes and factors influencing ACDF in HD. METHODS: Between 2015 and 2019, 126 patients with HD underwent ACDF. Contrast magnetic resonance imaging of the cervical spine in full flexion was performed. Clinical examination and preoperative/postoperative assessment of hand function using Fugl-Meyer assessment, Jebsen-Taylor hand function test, and handheld dynamometry were performed at 3-monthly intervals for 1 year. Surgical outcomes were assessed as per the Odom criteria and Hirayama outcome questionnaire. RESULTS: Age at onset and duration of illness were 12-31 years (mean, 18 ± 2.7) and 1-96 months (32.7 ± 24.4), respectively. All patients had progressive weakness and wasting of the affected limb. Cord atrophy was seen in 97.1%, with epidural detachment and engorgement of the posterior epidural venous plexus in all. All patients underwent ACDF. Of these patients, 54% had an excellent/good outcome and 39% had a satisfactory outcome as per the Odom scale at last follow-up (mean, 44.9 ± 16.5 months) after surgery. Handheld dynamometry showed improvement from preoperative values to 1 year follow-up. Duration of illness and age at onset had a negative correlation and the preoperative Fugl-Meyer score had a positive correlation with improvement. CONCLUSIONS: ACDF resulted in remarkable improvement or stabilization in neurologic deficits in many patients with HD. Because motor disability ensues over time, early surgical intervention during the progressive phase is advocated.

Spinal Muscular Atrophy Type III Recognized After Delayed Recovery From Neuromuscular Blockade After an Orthognathic Surgery.

Spinal muscular atrophy (SMA) is an autosomal recessive neuromuscular disease characterized by the degeneration of alpha motor neurons in the spinal cord, resulting in progressive proximal muscle weakness and paralysis. SMA is classified into types I-IV based on the age at symptom onset or maximum motor function achieved, and its clinical manifestations vary. SMA affects maxillofacial growth because of muscle dysfunction and results in abnormal maxillofacial morphology. In addition, definitive diagnosis is not often made because of the older onset age and symptoms are rarely severe. Therefore, the possibility of undiagnosed SMA in craniofacial surgeries must be considered. This report described a case of an SMA type III recognized after delayed recovery from the neuromuscular blockade in an orthognathic surgery under general anesthesia.

Procedural sedation for paediatric patients with spinal muscular atrophy undergoing intrathecal treatment.

AIMS: Nusinersen is administered intrathecally for treating spinal muscular atrophy (SMA). Procedural sedation is common with intrathecal treatment in children. The purpose of this study is to emphasize that intrathecal treatment of paediatric patients with SMA I, II and III can be tolerated with procedural sedation instead of general anaesthesia. METHODS: Data were collected the from the anaesthesia charts and electronic medical records of 14 paediatric patients with SMA types I, II and III who underwent procedural sedation for repeated intrathecal treatments for SMA. Intravenous induction was performed, and patients were oxygenated with a face mask or nasal cannula while spontaneous breathing continued. RESULTS: Fourteen patients were included in the study: one SMA I, eight SMA II and five SMA III. They underwent 88 intrathecal nusinersen injections in total. In the one SMA I patient, of 8 months, the procedure was performed under local anaesthesia. In all other patients, the treatments were performed under procedural sedation. Different combinations of midazolam, ketamine, propofol, fentanyl and remifentanil were used. The mean doses of the agents used were 0.03 mg kg-1 , 0.97 mg kg-1 , 2.71 mg kg-1 , 0.84 µg kg-1 and 0.5 µg kg-1 , respectively. There were no intraoperative or postoperative complications. CONCLUSION: We found the procedural sedation to be sufficient, safe and effective in SMA II and III paediatric patients who underwent nusinersen treatment intrathecally, provided anaesthetic agents are titrated and administered carefully.

Surgical correction of a ventricular septal defect in a child with spinal muscular atrophy type 2 treated with nusinersen sodium: a case report.

INTRODUCTION: Spinal muscular atrophy (SMA) is a severe, inherited neuromuscular disorder characterized by progressive muscle weakness and atrophy. Cardiac pathology co-existence is reported more frequently in the severely affected patient groups. Structural heart anomalies, mainly septal, and outflow tract defects are commonly observed pathologies. CASE PRESENTATION: We herein report the case of a 23 days-old female patient with the diagnosis of spinal muscular atrophy type 2 complicated with structural heart defects. Successful pulmonary banding, and at the age of 17 months, subsequent surgical atrial and ventricular septal defect closure were performed on our patient who was under treatment of Nusinersen Sodium. Post-operative recovery was uncomplicated. Cardiac assessments were normal, and the patient was neurologically improving in her recent follow-up. CONCLUSION: In the literature, there are no reported cases of successful surgical repair of heart defects in spinal muscular atrophy patients. These patients can be perceived as risky surgical candidates with suboptimal postoperative recovery given the unfavorable disease prognosis of SMA in untreated patients. We report our promising experience with a SMA type 2 patient undergoing a disease-modifying medical treatment. The SMA patients under treatment may be potential candidates for successful surgical cardiac correction given their overall improved prognosis.

Surgical Management of Hirayama Disease (Monomelic Amyotrophy): Systematic Review and Meta-Analysis of Patient-Level Data.

BACKGROUND: Hirayama disease or juvenile-onset monomelic amyotrophy is a clinical syndrome that disproportionately affects young males. Standard of care revolves around conservative management, but some patients experience disease progression that may benefit from surgical intervention. METHODS: Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, a systematic review of previous reports of surgical treatment for Hirayama disease was performed. Studies were included if they provided individual patient-level data, described the clinical presentation and surgical intervention, and reported neurological improvement at last follow-up. Comparison between those who improved and those with stable symptoms at last follow-up was performed. Decision-tree analysis was used to identify the best predictors of neurological improvement by last follow-up. RESULTS: Of 624 unique articles, 30 were included in the qualitative review and 23 in the meta-analysis. Among the 70 patients in the meta-analysis, mean age was 21.2 ± 6.3 years, 91% were male, and mean symptom duration at presentation was 43.3 ± 61.8 months. Fifty-nine patients (84.3%) had improvement in their neurological symptoms by last follow-up. Univariable analysis showed the only significant predictor of improvement in neurological symptoms by last follow-up was the use of stabilization-alone versus decompression with or without stabilization. Baseline clinical symptoms nor radiographic features predicted outcome. Decision-tree analysis showed surgical strategy (stabilization-alone vs. decompression ± stabilization), age (<20 vs. ≥20), and surgical approach (anterior-only vs. posterior-only or anterior-posterior) predicted a higher likelihood of neurological improvement by last follow-up. CONCLUSIONS: Nearly 85% of patients experienced improvement in neurological symptoms. Improvement was best for those who underwent stabilization-alone, and decision-tree analysis suggested that the likelihood of improvement was also superior for patients under 20 years of age and those treated with an anterior versus posterior or staged approach.

Outcome of Tendon Transfer for Monomelic Amyotrophy (Hirayama Disease).

Hirayama disease is a motor neuron disease predominantly affecting adolescent males. The identifying feature of Hirayama disease is unilateral forearm and intrinsic muscle weakness that spares the brachioradialis, termed "oblique atrophy." Hirayama disease progresses slowly over several years, followed by an abrupt arrest. The pathognomonic finding is the anterior displacement of the cervical spinal cord with the detachment of the posterior dura. Systematic clinical evaluation and appropriate diagnostic studies are crucial to rule out a variety of compressive, immune-mediated, and genetic disorders. We present a patient with Hirayama disease whose hand function was improved dramatically by a tendon transfer after nearly 3 years without a definitive diagnosis and call attention to the hand surgeon's role in identifying this rare disease to enable timely functional restoration.

Finger trembling improvement after surgery in Hirayama disease: a case report.

INTRODUCTION: Finger trembling is a characteristic physical finding in Hirayama disease. Although conservative treatment is recommended to stop disease progression, surgery is optional in some cases. However, the postoperative recovery of finger trembling is scarcely reported. CASE PRESENTATION: A 26-year-old Japanese female patient whose chief complaint was left finger trembling with active finger extension presented at our hospital. Hand weakness without muscle atrophy of the left arm was observed. MRI showed left-side oriented intramedullary signal change with concomitant cord atrophy at C4-5 and C5-6. The CT myelogram (CTM) on flexion showed anterior cord compression and anterior shift of posterior dura matter from C4 to C6. And CTM on extension showed the resolution of both findings. Electrophysiological studies showed active and chronic neuronal damage and preserved motor neuron pool of hand muscle. Since she had exhibited a gradual aggravation of symptoms over a period of 5 years, she underwent anterior cervical discectomy and fusion after careful assessment of both conservative and surgical treatment. Finger trembling recovered soon after surgery. DISCUSSION: Finger trembling is an unfamiliar physical finding in terms of postoperative recovery prediction. Anterior horn cell impairment is postulated as a cause of finger trembling. Postural restoration of spinal cord shape and cerebrospinal fluid around the cord with preserved neural function could facilitate functional recovery.

Supercharged End-to-Side Anterior Interosseous to Ulnar Motor Nerve Transfer for Hirayama Disease: A Case Report.

Hirayama disease is a rare condition of cervical myelopathy. Its early identification and correction can optimize functional outcomes. However, late presentation and some more severe cases may be associated with loss of hand function. Among the cases described, there are no reports of nerve transfers for this condition. We presented the first case report of a Hirayama disease of isolated ulnar nerve impairment managed with nerve transfer. Electroneuromyography showed isolated preganglionic involvement of C7, C8, and T1, with no sensory changes. The patient underwent nerve transfer with anterior interosseous nerve to ulnar nerve supercharge end-to-side, recovering hand function in 7 months.

Hirayama Disease in a Patient with a History of Late-Onset Symptomatic Vein of Galen Aneurysmal Malformation.

INTRODUCTION: The purpose of this report is to present a rare case of Hirayama disease (HD) in a patient with a history of late-onset symptomatic vein of Galen aneurysmal malformation (VGAM). This report may provide new insights into the pathophysiology of HD, a rare disorder consisting of insidious onset of unilateral weakness and atrophy of the forearm and intrinsic hand muscles. These symptoms are believed to result from cervical myelopathy affecting the anterior horn cells due to abnormal compressive forces on the spinal cord from adjacent anatomical structures (i.e., dura and/or epidural veins), but this has not been proven. VGAM is a rare congenital cerebral vascular malformation, consisting of high-flow arteriovenous shunting between a persistent median prosencephalic vein and arterial feeders, which most frequently presents in the early neonatal period with congestive heart failure. CASE PRESENTATION: We report the case of an otherwise healthy boy who presented with heart failure due to VGAM at 7 years and subsequently presented at 14 years with left-sided HD. His cervical MRI with neck flexion revealed enlarged epidural veins at the C5-C6 spinal level with anterior, leftward displacement of the posterior dura and spinal cord as well as left hemicord flattening and/or atrophy at this level. He underwent successful surgical treatment by C5-C6-C7 osteoplastic laminotomies and tenting and expansile autologous duraplasty, during which enlarged, engorged epidural veins were confirmed and coagulated. This halted the progression of his left hand weakness and atrophy and allowed significant functional improvement. Postoperative catheter angiogram showed no anatomical connection between the persistent VGAM and the engorged epidural veins, and genetic testing revealed no genetic predisposition of vascular malformations. DISCUSSION/CONCLUSION: In this patient, a combined surgical technique was performed that included epidural venous plexus coagulation with posterior autologous duraplasty and dural fixation using tenting sutures. This combined approach led to a favorable clinical and radiographic outcome with no complications or limitations and has not been previously proposed in the literature, to our knowledge. Although not completely ruled out, we found no angiographic connection or genetic predisposition to suggest there is a pathophysiological link between HD and VGAM.

The Short-Term to Midterm Follow-Up of Patients with Hirayama Disease After Anterior Cervical Discectomy and Fusion.

OBJECTIVE: Surgical treatment is widely used to treat patients with Hirayama disease (HD). However, postoperative follow-up with abundant samples is still scarce. This study investigated short-term to midterm clinical outcomes after anterior cervical discectomy and fusion (ACDF) among patients with HD. METHODS: We enrolled 115 patients with HD who had undergone ACDF. Radiographic parameters included cervical lordosis (CL), sagittal vertical axis, segment lordosis (SL), T1 slope (T1S), T1S minus CL, range of motion (ROM), upper/lower adjacent segment ROM, and upper adjacent SL. Electrophysiologic parameters included the maximal compound muscle action potentials (CMAPs) of abductor digit minimi and abductor pollicis brevis, the latency of the ulnar nerve F reaction, and abnormal spontaneous action potentials. Clinical assessment included the selected brief-Michigan Hand Questionnaire and Odom scale. RESULTS: The average age was 19.5 ± 4.5 years. The mean follow-up time was 16.35 ± 9.21 months. CL, SL, and T1S increased, whereas sagittal vertical axis and ROM decreased at the final follow-up (P < 0.001). Upper adjacent SL, upper adjacent ROM, and lower adjacent ROM were stable after ACDF (P > 0.05). The maximal CMAPs of abductor digit minimi and the latency of the ulnar nerve F reaction improved bilaterally (P < 0.05), whereas there was no significance in the maximal CMAPs of abductor pollicis brevis (P > 0.05). Abnormal spontaneous action potentials reduced remarkably. The selected brief-Michigan Hand Questionnaire score increased after surgery (P < 0.001). The Odom scale showed a ratio of 79.1% (excellent and good ratio). CONCLUSIONS: This study showed favorable radiologic, electrophysiologic, and clinical outcomes after ACDF among patients with HD.

Impact of various cervical surgical interventions in patients with Hirayama's disease-a narrative review and meta-analysis.

Hirayama disease (HD) is a relatively uncommon cause of lower cervical myelopathy. A number of surgical approaches have been described in patients with HD in literature. We reviewed the literature and did a systematic review and meta-analysis of the studies which presented the clinical outcome following surgical intervention in HD. A systematic search of literature was performed with the keywords "Surgical treatment in Hirayama Disease", "Surgical approach in Hirayama Disease" and "Hirayama disease surgery". Data related to clinical outcome following surgery was pooled to calculate the pooled proportion of clinical improvement following anterior and posterior surgical approach. Thirty-four articles met the inclusion criteria and were included in the final review. Altogether, there were 10 types of surgical procedures performed for Hirayama disease. The most commonly described surgical technique was anterior cervical discectomy and fusion with cervical plating. The pooled proportion of patients experiencing clinical improvement following all cervical approaches was 80% (95% confidence interval 76 to 84%). Pooled proportion was maximum for anterior cervical plating (96% (95% confidence interval 62 to 100%)) and minimum for ACDF without plating (57% (95% confidence interval 20 to 88%)). Subgroup analysis based on different surgical approaches was not significant (p value = 0.61). The pooled proportion of patients experiencing clinical improvement following anterior and posterior cervical approach was 80% (95% confidence interval 76 to 84%) and 81% (95% confidence interval 66 to 91%). The indications of surgical treatment in patients with HD include poor patient compliance for neck collar or rapidly progressing severe disease. Good results with more than 80% chances of clinical improvement have been reported following various anterior and posterior surgical approaches. However, there was no significant difference in the pooled outcome of different surgical approaches. Most common technique used in literature is anterior cervical discectomy and fusion with plating.

Evolving Surgical Management for Early-Onset Scoliosis in Spinal Muscular Atrophy Type 1 Given Improvements in Survival.

CASE: We present a case of an 18-month-old child with early-onset scoliosis in the setting of spinal muscular atrophy (SMA) type 1 whose rapidly progressive scoliosis is successfully managed with magnetic growing rods, the youngest age of implantation in a patient with SMA we are currently aware of. Technical challenges, complications, and outcome are described in this case presentation. CONCLUSION: Patients with SMA type 1 and early-onset scoliosis can be managed with growing-rod constructs given dramatic improvements in medical care that have expanded life expectancy.

Successful weaning from mechanical ventilation in a patient with SMA type 1 treated with nusinersen.

SMA type 1 is the most severe type, characterized by early onset at <6 months of age, and rapid progression resulting in permanent assisted ventilation before 2 years of life. Supportive care was the only treatment until the approval of nusinersen, an antisense oligonucleotide drug that increases functional SMN protein levels. We present a case of successful weaning from permanent ventilation via tracheostomy with nusinersen in an infant who had been diagnosed with SMA type 1 at the age of one month and had become ventilator-dependent from the age of 3 months.

The Influence of "Loss of Attachment" on the Outcome of Anterior Cervical Fusion Procedures in Patients With Hirayama Disease.

The objective of this study was to identify the influence of the measurements of "loss of attachment" on the surgical outcome in Hirayama disease (HD). Forty-two patients with HD underwent neutral and cervical-flexion magnetic resonance imaging (MRI) before surgery, and the cervical-flexion MRI was repeated at the 3-month postoperative visit. The longitudinal separation range (LSR) of loss of attachment, the maximum forward-shifting (MFS) degree in the cervical cord, and the relative morphological changes of the cervical cord were measured on MRI. Additionally, all patients underwent handgrip strength (HGS) testing, the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, and Medical Research Council scales at the 1-year postoperative visit. Postoperatively, the cervical-flexion X/Y and the LSR decreased significantly at a mean of 94.17±8.65 days (range, 75-110 days) (P<.01), while the cervical-flexion A/B increased (P<.01). Loss of attachment was resolved in fused segments in all 42 patients, but there were 7 instances of residual loss of attachment at adjacent segments. Twenty (47.6%) of the 42 patients' DASH scores decreased at the 1-year postoperative visit. According to the logistic regression analysis, both LSR and MFS were related to the surgical outcomes. Receiver operating characteristic curve analysis found that area under the curve and cutoff values were 0.959 and 4.5, respectively (P<.05) for LSR and 0.782 and 0.215, respectively (P<.05) for MFS. Anterior cervical fusion procedures can effectively improve the abnormal loss of attachment and prevent further progression of HD. The LSR is an important risk factor for the prognosis, and longer fused segments may be required when the LSR is 5 segments or more. [Orthopedics. 2021;44(1):30-37.].

A 5-year-old boy with acute neurological disorder from anteflexion-induced cervical cord compression after tracheal surgery: Radiological findings similar to Hirayama disease.

Constant neck flexion has been considered crucial to reducing anastomotic tension after tracheal resection. However, in rare cases, anteflexion can cause cervical cord damage, leading to acute neurological disorders such as tetraplegia. Here, we report a case of 5-year-old boy presenting with acute neurological disorder triggered by a chin-to-chest position over 4 days of deep sedation after cricotracheal resection. The radiological findings would suggest a mechanism similar to Hirayama disease, in which a shift of the dura leads to chronic muscular weakness and atrophy in young populations.

Improvement of Pulmonary Function Measured by Patient-reported Outcomes in Patients With Spinal Muscular Atrophy After Growth-friendly Instrumentation.

BACKGROUND: Children with spinal muscular atrophy (SMA) sustain a progressive reduction in pulmonary function (PF) related to both muscular weakness and the concomitant effects of spinal deformity on the thorax. Growth-friendly instrumentation is commonly utilized for younger patients with scoliosis and SMA to halt the progression of spinal curvature, but its effect on PF in these patients has not previously been investigated. Using the change in Early Onset Scoliosis 24-Item Questionnaire (EOSQ-24) PF subdomain scores, the authors will investigate whether PF improves in patients with SMA after a growth-friendly intervention. METHODS: This was a multicenter retrospective cohort study from 2 international registries of patients with SMA undergoing spinal deformity surgery from 2005 to 2015. Data collected were age, sex, degree of major coronal curve, type of growth-friendly construct, forced vital capacity (FVC), and EOSQ-24 scores at the patient's preoperative, 1-year postoperative, and 2-year postoperative visits. Differences in EOSQ-24 PF scores and FVC between baseline and postoperative assessment were examined by paired tests. RESULTS: A total of 74 patients were identified (mean age, 7.6±2.3 y, major curve 68.1±22.4 degrees, 51.4% female individuals). The mean EOSQ-24 PF scores improved significantly from 70.6 preoperatively to 83.6 at 1 year (P=0.092) and 86.5 at 2 years postoperatively (P=0.020). The scores in patients with rib-based constructs showed steeper increases at 1-year assessments than those in patients with spine-based constructs. The mean paired FVC value decreased from 63.9% predicted preoperatively, to 57.6% predicted at 1 year postoperatively (P=0.035), and 61.9% predicted preoperatively, to 56.3% predicted at 2 years postoperatively (P=0.178). CONCLUSIONS: Patients with SMA who received growth-friendly instrumentation did experience improvements in PF as measured by EOSQ-24 assessing the caregivers' perception. Given the uncertain reliability of PFTs in this young population, EOSQ-24 is an important tool for measuring improvements in health-related quality of life. LEVEL OF EVIDENCE: Level III-retrospective study.