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Optimal recovery of muscle function after proximal nerve injuries remains a complex and challenging problem. After a nerve injury, alterations in the affected muscles lead to atrophy, and later degeneration and replacement by fat-fibrous tissues. At present, several different strategies for the preservation of skeletal muscle have been reported, including various sets of physical exercises, muscle massage, physical methods (e.g. electrical stimulation, magnetic field and laser stimulation, low-intensity pulsed ultrasound), medicines (e.g. nutrients, natural and chemical agents, anti-inflammatory and antioxidants, hormones, enzymes and enzyme inhibitors), regenerative medicine (e.g. growth factors, stem cells and microbiota) and surgical procedures (e.g. supercharge end-to-side neurotization). The present review will focus on methods that aimed to minimize the damage to muscles after denervation based on our present knowledge. [ABSTRACT FROM AUTHOR]

Peripheral nerve injury often results in poor functional recovery due to a prolonged period of muscle denervation. In particular, absent axonal contact, denervated muscle can undergo irrevocable atrophy and diminished receptiveness for reinnervation over time, ultimately reducing the likelihood for meaningful neuromuscular recovery. While innovative surgical approaches can minimize the harmful effects of denervation by re-routing neighboring--otherwise uninjured--axons, there are no clinically-available approaches to preserve the reinnervation capacity of denervated muscles. Blocking intramuscular connexin hemichannel formation has been reported to improve muscle innervation in vitro and prevent atrophy in vivo. Therefore, the current study investigated the effects of orally administered boldine, a connexin hemichannel inhibitor, on denervated-related muscle changes and nerve regeneration in a rat model of delayed peripheral nerve repair. We found that daily boldine administration significantly enhanced an evoked response in the tibialis anterior muscle at 2 weeks after common peroneal nerve transection, and decreased intramuscular connexin 43 and 45 expression, intraneural Schwann cell expression of connexin 43, and muscle fiber atrophy up to 4 weeks post transection. Additional animals underwent a cross nerve repair procedure (tibial to common peroneal neurorrhaphy) at 4 weeks following the initial transection injury. Here, we found elevated nerve electrophysiological activity and greater muscle fiber maturation at 6 weeks post repair in boldine treated animals. These findings suggest that boldine may be a promising pharmacological approach to minimize the deleterious effects of prolonged denervation and, with further optimization, may improve levels of functional recovery following nerve repair. [ABSTRACT FROM AUTHOR]

Nerve injury requiring surgical repair often results in poor functional recovery due to the inability of host axons to re-grow long distances and reform meaningful connections with the target muscle. While surgeons can re-route local axon fascicles to the target muscle, there are no technologies to provide an exogenous source of axons without sacrificing healthy nerves. Accordingly, we have developed tissue engineered neuromuscular interfaces (TE-NMIs) as the first injectable microtissue containing motor and sensory neurons in an anatomically-inspired architecture. TE-NMIs provide axon tracts that are intended to integrate with denervated distal structures and preserve regenerative capacity during prolonged periods without host innervation. Following implant, we found that TE-NMI axons promoted Schwann cell maintenance, integrated with distal muscle, and preserved an evoked muscle response out to 20-weeks post nerve transection in absence of innervation from host axons. By repopulating the distal sheath with exogenous axons, TE-NMIs also enabled putative delayed fusion with proximal host axons, a phenomenon previously not achievable in delayed repair scenarios due to distal axon degeneration. Here, we found immediate electrophysiological recovery after fusion with proximal host axons and improved axon maturation and muscle reinnervation at 24-weeks post-transection (4-weeks following delayed nerve fusion). These findings show that TE-NMIs provide the potential to improve functional recovery following delayed nerve repair.

Peripheral nerve injury often results in poor functional recovery due to a prolonged period of muscle denervation. In particular, absent axonal contact, denervated muscle can undergo irrevocable atrophy and diminished receptiveness for reinnervation over time, ultimately reducing the likelihood for meaningful neuromuscular recovery. While innovative surgical approaches can minimize the harmful effects of denervation by re-routing neighboring—otherwise uninjured—axons, there are no clinically-available approaches to preserve the reinnervation capacity of denervated muscles. Blocking intramuscular connexin hemichannel formation has been reported to improve muscle innervation in vitro and prevent atrophy in vivo. Therefore, the current study investigated the effects of orally administered boldine, a connexin hemichannel inhibitor, on denervated-related muscle changes and nerve regeneration in a rat model of delayed peripheral nerve repair. We found that daily boldine administration significantly enhanced an evoked response in the tibialis anterior muscle at 2 weeks after common peroneal nerve transection, and decreased intramuscular connexin 43 and 45 expression, intraneural Schwann cell expression of connexin 43, and muscle fiber atrophy up to 4 weeks post transection. Additional animals underwent a cross nerve repair procedure (tibial to common peroneal neurorrhaphy) at 4 weeks following the initial transection injury. Here, we found elevated nerve electrophysiological activity and greater muscle fiber maturation at 6 weeks post repair in boldine treated animals. These findings suggest that boldine may be a promising pharmacological approach to minimize the deleterious effects of prolonged denervation and, with further optimization, may improve levels of functional recovery following nerve repair.

Background Limited data are available examining dietary interventions for optimizing protein and leucine intake to stimulate muscle protein synthesis (MPS) in older humans. Objectives We aimed to investigate the aminoacidemia and appetite responses of older adults after consuming breakfast, a meal frequently consumed with high-carbohydrate and below-par amounts of protein and leucine for stimulating MPS. Methods Five men and 3 women (means ± SD; age: 74 ± 7 y, BMI: 25.7 ± 4.9 kg/m2, fat- and bone-free mass: 63 ± 7 kg) took part in this experiment in which they consumed breakfasts with low-protein (LP = 13 ± 2 g), high-protein (HP = 32 ± 5 g), and LP followed by a protein- and leucine-enriched bar formulation 2 h later (LP + Bar = 29 ± 2 g). The LP, HP, and LP + Bar breakfast conditions contained 519 ± 86 kcal, 535 ± 83 kcal, and 739 ± 86 kcal, respectively. Blood samples were drawn for 6 h and analyzed for amino acid, insulin, and glucose concentrations. Visual analog scales were assessed for hunger, fullness, and desire to eat. Results The net AUC for essential amino acid (EAA) exposure was similar between the LP + Bar and HP conditions but greater in the HP condition compared with the LP condition. Peak leucinemia was higher in the LP + Bar condition compared with the HP, and both were greater than the LP condition. Net leucine exposure was similar between HP and LP + Bar, and both were greater than LP. Hunger was similarly reduced in LP + Bar and HP, and LP + Bar resulted in a greater hunger reduction than LP. Both LP + Bar and HP resulted in greater net fullness scores than LP. Conclusions Consuming our bar formulation increased blood leucine availability and net exposure to EAAs to a similar degree as consuming a high-protein meal. High-protein at breakfast results in a greater net exposure to EAAs and leucine, which could support MPS in older persons. This study was registered at clinicaltrials.gov as NCT03712761. [ABSTRACT FROM AUTHOR]

Optimal recovery of muscle function after proximal nerve injuries remains a complex and challenging problem. After a nerve injury, alterations in the affected muscles lead to atrophy, and later degeneration and replacement by fat-fibrous tissues. At present, several different strategies for the preservation of skeletal muscle have been reported, including various sets of physical exercises, muscle massage, physical methods (e.g. electrical stimulation, magnetic field and laser stimulation, low-intensity pulsed ultrasound), medicines (e.g. nutrients, natural and chemical agents, anti-inflammatory and antioxidants, hormones, enzymes and enzyme inhibitors), regenerative medicine (e.g. growth factors, stem cells and microbiota) and surgical procedures (e.g. supercharge end-to-side neurotization). The present review will focus on methods that aimed to minimize the damage to muscles after denervation based on our present knowledge., Competing Interests: Declaration of conflicting interestsThe authors declare no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Study Design: A retrospective single-center study.Objective: The aim of this study was to investigate the influence of the K-line in the neck-flexed position (flexion K-line) on the surgical outcome after muscle-preserving selective laminectomy (SL) for cervical spondylotic myelopathy (CSM).Summary Of Background Data: Development of CSM is associated with dynamic factors and cervical alignment. The flexion K-line, which reflects both dynamic and alignment factors, provides an indicator of surgical outcome after posterior decompression surgery for patients with ossification of the posterior longitudinal ligament. However, the value of the flexion K-line for patients with CSM has not been evaluated.Methods: Our study group included 159 patients treated with SL for CSM. Patients were divided into a flexion K-line (+) group and a flexion K-line (-) group. The influence of the flexion K-line on radiological and surgical outcomes was analyzed, with multivariate analysis conducted to identify factors affecting the surgical outcome.Results: Patients in the flexion K-line (-) group were younger (P = 0.003), had a less lordotic cervical alignment (pre-and postoperatively, P < 0.001), a smaller C7 slope (pre-and postoperatively, P < 0.001), and a greater mismatch between the C7 slope and the C2-C7 angle (preoperatively, P = 0.047; postoperatively, P = 0.001). The postoperative increase in Japanese Orthopedic Association (JOA) score and the JOA score recovery rate (RR) were lower for the flexion K-line (-) than for the K-line (+) group (P < 0.001 and P < 0.001, respectively). On multivariate regression analysis, the flexion K-line (-) (β = -0.282, P < 0.001), high signal intensity (SI) changes on T2-weighted image (WI) combined with low SI changes on T1-WI in the spinal cord (β = -0.266, P < 0.001), and older age (β= -0.248, P = 0.001) were predictive of a lower JOA score RR.Conclusion: The flexion K-line may be a useful predictor of surgical outcomes after SL in patients with CSM.Level Of Evidence: 4. [ABSTRACT FROM AUTHOR]

Surgical laminoplasty techniques have been developed to reduce cervical kyphosis and postoperative axial neck pain and preserve the posterior cervical extensor muscles. We compared a unilateral conventional open approach (OA) and a contralateral muscle preserving approach (MPA) for laminoplasty in the same patients to determine differences in the preservation of the posterior cervical muscles after the 2 approaches. This study was a prospective observational study involving 44 patients who underwent laminoplasty with unilateral OA and contralateral MPA for cervical myelopathy from January 2005 to December 2013. The cross-sectional area (CSA) changes in the posterior cervical extensor muscles (multifidus, semispinalis cervicis, and semispinalis capitis muscles) were measured on computed tomography scan, both pre- and postoperatively. Using an OA, the multifidus and semispinalis cervicis muscle preservation was 58.2% and 67.0%, but using an MPA, muscle preservation was 97% and 90.8% (P < 0.001 and P = 0.042), respectively. However, the CSA of the semispinalis capitis muscle did not differ significantly between the 2 groups. In terms of the level, conservation of the multifidus muscle was significantly different according to the approach at all levels, and the conservation of the deep extensor muscles was significantly different at the C3-4 level. MPA was effective in preserving the volume of deep cervical extensor muscles and helping minimize postoperative musculoskeletal complications. In addition, muscle preservation was more effective at the C3-4 level. [ABSTRACT FROM AUTHOR]

The cervical extensor musculature is important in cases of neck pain and loss of cervical lordosis after laminoplasty. Therefore, various surgical methods have been developed to preserve the muscle during laminoplasty. We have developed a posterior cervical muscle-preserving interspinous process (MIS) approach and decompression method. We have described the operation details and clinical outcomes of selected patients who have undergone this procedure. The MIS approach and decompression method were performed in 20 consecutive patients who had only required central decompression for cervical stenosis. This procedure includes an approach to the interspinous space that is similar to Shiraishi's method but includes decompression without fracturing the spina bifida. The patients had no complications and did not require conversion to conventional laminoplasty. The mean operative time and mean blood loss was 53.0 minutes and 63.0 mL per level, respectively, and the mean hospital stay was 4.0 days. The mean preoperative and 3-month postoperative modified Japanese Orthopedic Association scores were 12.6 and 16.2, and the mean preoperative and 3-month postoperative neck disability index scores were 15.4 and 2.5, respectively. The postoperative neck visual analog scale score was 0.8. The mean preoperative and postoperative sagittal vertical axis was 1.6 and 1.8 cm, respectively. The mean loss of lordosis was 1.0°, and the mean cervical range of motion did not change from preoperatively to postoperatively. The MIS approach and decompression method was less invasive than both conventional laminoplasty and Shiraishi's selective laminectomy. It is a safe and effective minimally invasive technique for central stenosis caused by cervical spondylotic myelopathy. [ABSTRACT FROM AUTHOR]

Purpose: To present a novel posterior approach in multilevel cervical posterior decompression and fusion (PDF) using C2 pedicle screws that preserves the rectus capitis posterior major, oblique capitis inferior, and semispinalis cervicis.Methods: We analyzed 30 consecutive patients who underwent C2-T1 PDF using an approach that preserved these three muscles without resecting. We assessed O-C2 range of motion (ROM), cross-sectional area of the cervical posterior muscles, rotational ROM, visual analog scale (VAS) for axial pain, neck disability index (NDI), and limitations of activities of daily living (ADL) involving neck movements.Results: Mean preoperative O-C2 ROM (23.6°) was significantly increased postoperatively (33.0°). Mean atrophy rate of the cross-sectional area was 3.9%. Postoperatively, 69.8% of the preoperative rotational ROM (113.3°) was retained. The preoperative VAS for axial pain and the NDI did not increase postoperatively. The postoperative O-C2 ROM (33.9°) in 26 patients for whom extension ADL were possible was significantly larger than that in four patients for whom extension ADL were impossible (26.9°). The postoperative retained rate of rotational ROM (75.8%) in 18 patients for whom rotation ADL were possible was significantly larger than that in 12 patients for whom rotation ADL were impossible (62.3%).Conclusions: This is potentially an effective approach for maintaining O-C2 ROM and rotational ROM, which enabled good levels of ADL after C2-T1 PDF. Axial pain and NDI were not worse after PDF. [ABSTRACT FROM AUTHOR]

Study Design. A retrospective single-center study. Objective. The aim of this study was to evaluate the compensatory mechanism of cervical lordosis (CL), the changes in cervical sagittal alignment, and range of motion (ROM) after muscle-preserving selective laminectomy (SL). Summary of Background Data. CL increases as a compensatory mechanism for the adjustment of cervical sagittal balance or horizontal gaze. However, laminoplasty invades this mechanism and causes kyphosis in higher T1 (C7) slope patients. Methods. SL is a posterior surgery selecting the decompression laminae without disturbing the extensor musculature and facet joints. The clinical features and radiological findings of 125 cervical compressive myelopathy patients who underwent C6 single-level SL, C5-C6 two consecutive levels SL, C4-C6 three consecutive levels SL, and C3-C6 four consecutive levels SL were enrolled. Cervical spine lateral radiography was performed before surgery and at the final follow-up. The patients were divided into two groups according to the preoperative C7 slope. Postoperative cervical alignment change was compared between the higher and lower C7 slope groups. Subsequently, pre- and postoperative cervical alignment and cervical ROM were analyzed according to the number of consecutive laminae surgically treated. Results. Patients with higher C7 slope had greater lordotic cervical alignment and larger C2-C7 sagittal vertical axis (SVA) pre- and postoperatively. No kyphotic alignment change was observed, even in the higher C7 slope group. C6 SL and C5-C6 SL did not affect C2-C7 angle, and did not increase C2-C7 SVA after surgery. Although C4-C6 SL and C3-C6 SL demonstrated postoperative slight increase in C2-C7 SVA, C2-C7 angle never decreased after surgery. Cervical ROM slightly reduced in the C4-C6 SL and C3-C6 SL groups; however, no reduction of ROM was observed in the C6 SL and C5-C6 SL groups. Conclusion. SL preserved the inherent compensatory CL that had been observed preoperatively and maintained cervical sagittal balance after surgery. [ABSTRACT FROM AUTHOR]

Purpose: Between 2006 and 2010, we performed wide laminectomy (wide LAM) alone, with decompression performed between the bilateral medial margin of the zygapophyseal joints, or double-door laminoplasty (DL) combined with wide LAM for cervical compressive myelopathy (CCM). From 2010, instead of wide LAM and DL, we began to perform narrow LAM, where the laminectomy width was no more than 2-3 mm wider than the spinal cord width (SW). This study aimed to elucidate the risk factors for C5 palsy by reviewing surgical outcomes.Methods: The clinical features and radiological findings of 263 CCM patients with or without C5 palsy were compared. Risk factors for C5 palsy were assessed using logistic regression analysis. The decompression width (DW) was defined as the laminectomy width or the width between the bilateral medial margins of the bony gutters in DL.Results: Narrow LAM reduced the incidence of C5 palsy from 9.2 to 1.2%. DL was performed more frequently in the C5 palsy group. The difference between the DW and the SW (DW - SW) was significantly greater in the C5 palsy group. Posterior spinal cord shift, aging, and the number of consecutive laminae surgically treated were significantly higher in the C5 palsy group. The diameter of the foramen (DF) at C4/5 was significantly smaller in the C5 palsy patients. The logistic regression analysis revealed that DL, DW - SW, DF, and aging were risk factors for C5 palsy.Conclusions: Cervical laminectomy of limited width prevented postoperative C5 palsy without compromising the functional recovery. [ABSTRACT FROM AUTHOR]

Background Postoperative epidural fibrosis (PEF) localized around the exposed dura and nerve roots is a known radiologic entity seen after lumbar surgery. Although excessive PEF is associated with residual and new lumbar pain and radiculopathy, its role as the generator of the pain is still discussed. Various materials acting as an adhesion barrier have been tested. There is no undebated class I evidence that any one of them is suitable to reduce or avoid PEF and provide a better clinical outcome. In revision surgery, the dissection of epidural scar tissue is time consuming and related to an elevated risk of dural tear and nerve damage. To avoid the formation of posterior PEF, we propose a surgical approach whose working corridor is situated lateral to the dural sac and the nerve roots: the extraforaminal lumbar interbody fusion (ELIF) technique. Methods Description of ELIF surgical technique. Conclusions The ELIF technique is a muscle-sparing approach to the intervertebral disk space and the spinal canal that avoids the formation of posterior PEF. It represents an option to treat various degenerative lumbar spinal diseases as well as offering another approach for revision surgery in patients who have developed PEF. [ABSTRACT FROM AUTHOR]

Since laminoplasty was first introduced, several techniques have been developed to reduce postoperative neck pain and progressive kyphosis following this procedure. We describe the importance of deep muscle preservation to prevent postoperative neck pain following cervical posterior surgery, using the inter-muscular plane. We performed cervical laminoplasty on 10 patients from March to July 2012. The mean follow-up duration was 14.6 (range 12–18) months, and the mean age was 58.8 (48–68) years. There were eight men and two women in the study cohort, which consisted of eight cases of cervical spondylotic myelopathy and two cases of ossification of the posterior longitudinal ligament. The Japanese Orthopaedic Association (JOA) score and neck disability index (NDI) score were assessed before and at 6 and 12 months after surgery. The numeric rating scale (NRS) for neck pain was evaluated at 1, 3, 6, and 12 months after surgery. CT scan was performed immediately after the operation, and a radiograph was performed preoperatively and during the follow-up evaluation at 1, 3, 6, and 12 months after surgery. The preoperative JOA and NDI scores improved in all patients. Although there were two patients who complained of moderate postoperative neck pain (NRS 4 and 5), their condition gradually improved. Seven patients had mild or no neck pain (below NRS 3) at the 12 month follow-up. In addition, the cervical alignment was well maintained in all but one patient. Although larger prospective cohorts, longer follow-up periods, and comparative analyses are still needed, the clinical and radiological outcomes observed in the short 12 month period in this small cohort are promising. [ABSTRACT FROM AUTHOR]

Background: Intentional weight loss in obese older adults is a risk factor for muscle loss and sarcopenia. Objective: The objective was to examine the effect of a high whey protein-, leucine-, and vitamin D-enriched supplement on muscle mass preservation during intentional weight loss in obese older adults. Design: We included 80 obese older adults in a double-blind randomized controlled trial. During a 13-wk weight loss program, all subjects followed a hypocaloric diet (-600 kcal/d) and performed resistance training 3x/wk. Subjects were randomly allocated to a high whey protein-, leucine-, and vitamin D-enriched supplement including a mix of other macro- and micronutrients (150 kcal, 21 g protein; 10x/wk, intervention group) or an isocaloric control. Primary outcome was change in appendicular muscle mass. Secondary outcomes were body composition, handgrip strength, and physical performance. Data were analyzed by using ANCOVA and mixed linear models with sex and baseline value as covariates. Results: At baseline, mean ± SD age was 63 ± 5.6 y, and body mass index (in kg/m²) was 33 ± 4.4. During the trial, protein intake was 1.11 ± 0.28 g ⋅ kg body weight-1 ⋅ d-1 in the intervention group compared with 0.85 ± 0.24 g ⋅ kg body weight-1 ⋅ d-1in the control group (P < 0.001). Both intervention and control groups decreased in body weight (-3.4 ± 3.6 kg and -2.8 ± 2.8 kg; both P < 0.001) and fat mass (-3.2 ± 3.1 kg and -2.5 ± 2.4 kg; both P < 0.001), with no differences between groups. The 13-wk change in appendicular muscle mass, however, was different in the intervention and control groups [+0.4 ± 1.2 kg and -0.5 ± 2.1 kg, respectively; β = 0.95 kg (95% CI: 0.09, 1.81); P = 0.03]. Muscle strength and function improved over time without significant differences between groups. Conclusion: A high whey protein-, leucine-, and vitamin D-enriched supplement compared with isocaloric control preserves appendicular muscle mass in obese older adults during a hypocaloric diet and resistance exercise program and might therefore reduce the risk for sarcopenia. This trial was registered at the Dutch Trial Register (http://www.trialregister.nl) as NTR2751. [ABSTRACT FROM AUTHOR]

In this retrospective cohort study, two surgical methods of conventional open-door laminoplasty and deep extensor muscle-preserving laminoplasty were allocated for the treatment of cervical myelopathy, and were specifically compared in terms of axial pain, cervical spine function, and quality of life (QOL) with a minimum follow-up period of 2 years. Eighty-four patients were divided into two groups and received either a conventional open-door laminoplasty (CL group) or laminoplasty using a deep extensor muscle-preserving approach (MP group). The latter approach was performed by preserving multifidus and semispinalis cervicis attachments followed by open-door laminoplasty and re-suture of the bisected spinous processes at each decompression level. The average follow-up period was 38 months (25–53 months). The preoperative and follow-up evaluations included the original Japanese Orthopaedic Association (JOA) score, the new tentative JOA score including cervical spine function and QOL, and the visual analogue scale (VAS) of axial pain. Radiological analyses included cervical lordosis and flexion–extension range of motion (flex–ext ROM) (C2–7), and deep extensor muscle areas on MR axial images. The JOA recovery rates were statistically equivalent between two groups. The MP group demonstrated a statistically superior cervical spine function (84% vs 63%) and QOL (61% vs 45%) when compared to the CL group at final follow-up ( P < 0.05). The average VAS scores at final follow-up were 2.3 and 4.9 in MP and CL groups ( P < 0.05). The cervical lordosis and flex–ext ROM were statistically equivalent. The percent deep muscle area on MRI demonstrated a significant atrophy in CL group compared to that in MP group (56% vs 88%; P < 0.01). Laminoplasty employing the deep extensor muscle-preserving approach appeared to be effective in reducing the axial pain and deep muscle atrophy as well as improving cervical spine function and QOL when compared to conventional open-door laminoplasty. [ABSTRACT FROM AUTHOR]

Nerve injury requiring surgical repair often results in poor functional recovery due to the inability of host axons to re-grow long distances and reform meaningful connections with the target muscle. While surgeons can re-route local axon fascicles to the target muscle, there are no technologies to provide an exogenous source of axons without sacrificing healthy nerves. Accordingly, we have developed tissue engineered neuromuscular interfaces (TE-NMIs) as the first injectable microtissue containing motor and sensory neurons in an anatomically-inspired architecture. TE-NMIs provide axon tracts that are intended to integrate with denervated distal structures and preserve regenerative capacity during prolonged periods without host innervation. Following implant, we found that TE-NMI axons promoted Schwann cell maintenance, integrated with distal muscle, and preserved an evoked muscle response out to 20-weeks post nerve transection in absence of innervation from host axons. By repopulating the distal sheath with exogenous axons, TE-NMIs also enabled putative delayed fusion with proximal host axons, a phenomenon previously not achievable in delayed repair scenarios due to distal axon degeneration. Here, we found immediate electrophysiological recovery after fusion with proximal host axons and improved axon maturation and muscle reinnervation at 24-weeks post-transection (4-weeks following delayed nerve fusion). These findings show that TE-NMIs provide the potential to improve functional recovery following delayed nerve repair., Competing Interests: D.K.C is a co-founder of Axonova Medical, LLC, and Innervace, Inc. which are University of Pennsylvania spin-out companies focused on translation of advanced regenerative therapies to treat nervous system disorders. Multiple patents relate to the composition, methods, and use of tissue engineered nervous tissue [U.S. Patent 9,895,399 (D.K.C.), U.S. Patent 10,525,085 (D.K.C.), U.S. Patent Application 16/753,634 (D.K.C), and U.S. Provisional Patent Application 62/937,489 (D.K.C. and J.C.B.)], microtissue-engineered neural networks [U.S. Patent Application 15/032,677 (D.K.C.), U.S. Patent Application 16/093,036 (D.K.C.), and U.S. Provisional Patent Application 63/209,639 (D.K.C., J.C.B., J.M.R.)], and innervated engineered tissue for organ modulation [U.S. Provisional Patent Application 62/758,203 (D.K.C. and S.D.)]. No other author has declared a potential conflict of interest., (© 2022 The Authors.)

In the conventional posterior approach to the lumbar spine, the lamina is exposed by stripping the paravertebral muscles from the spinous process, and the resulting paravertebral muscle damage can produce muscle atrophy and decreased muscle strength. The author developed a novel surgical approach to the lumbar spine in which the attachment of the paravertebral muscles to the spinous process is preserved. In the novel approach, the spinous process is split on the midline without stripping the attached muscles, and a hemilateral half of the spinous process is then resected at the base, exposing only the ipsilateral lamina. Before closing, the resected half is sutured and reattached to the remaining half of the spinous process. Thirty-eight patients with lumbar spinal canal stenosis (LSCS) undergoing unilateral partial laminectomy and bilateral decompression using this novel approach were analyzed. Postoperative changes in the multifidus muscle were evaluated by T2 signal intensity on MR images. MRI performed 1 year after the operation revealed no significant difference in the T2 signal intensity of the multifidus muscle between the approach and nonapproach sides. This result indicated that postoperative changes of the multifidus muscle on the approach side were slight. The clinical outcomes of unilateral partial laminectomy and bilateral decompression using this approach for LSCS were satisfactory. The novel approach can be a useful alternative to the conventional posterior lumbar approach.