Motion-preserving surgery for degenerative cervical myelopathy: balancing innovation with evidence based practice

Motion preservation in the context of DCM

DCM arises from both static and dynamic mechanisms of spinal cord injury. Chronic compression from disc degeneration, osteophytes, and ligamentous hypertrophy is compounded by repetitive microtrauma during cervical motion. Fusion has traditionally been favored to eliminate this dynamic component, providing stability alongside decompression.

At the same time, fusion alters normal cervical biomechanics. Reduced segmental motion may increase stress at adjacent levels, potentially contributing to adjacent segment pathology over time. As the GSJ focus issue highlights, motion preserving surgery seeks to address decompression while maintaining more physiological kinematics, an idea that resonates strongly with surgeons managing younger, active patients. 

Posterior motion preserving techniques 

Cervical laminectomy 

Cervical laminectomy involves removal of the lamina to decompress the spinal cord without additional hardware or stabilization. This offers several advantages including shorter operative time, reduced blood loss, reduced cost and preservation of cervical motion segments. This approach is particularly appealing for patients with poor bone quality and high surgical risk. 

In the pooled analysis published in the GSJ Focus Issue, laminectomy alone had comparable neurological outcomes, pain improvement and complication rate as laminectomy and fusion. Acknowledging the heterogeneity in the studies, multi-level laminectomy (>4 levels) may confer a higher risk of post-surgical kyphosis. A prospective randomized trial comparing laminectomy and laminectomy with fusion (POLYFIX-DCM) is underway and the results are awaited.

Skip laminectomy 

Skip laminectomy is another posterior decompression option intended to preserve spinous processes and muscular attachments while decompressing the spinal canal. In the scoping review by Lomax and colleagues, only three studies compared skip laminectomy with laminoplasty, but skip laminectomy achieved at least equivalent functional outcomes and preserved range of motion.  

Cervical laminoplasty

Cervical laminoplasty is another motion-preserving posterior approach for DCM that involves decompression of the spinal cord without fusion of the facet joints. The laminae are elevated off the spinal cord to enlarge the spinal canal and kept open using plates, sutures or graft. The different techniques are described in the GSJ Focus Issue. 

In the meta-analysis published in the GSJ Focus Issue, compared to laminectomy and fusion, laminoplasty had lower costs though this data was largely from the United States. Although laminoplasty is more commonly performed in Asia, published healthcare cost data from this region is limited. Laminoplasty is increasingly being performed in the United States and the CSM-S study published by Ghogawala et al. [1] found that laminoplasty outperformed anterior and posterior fusion surgeries for quality of life, complications and outpatient medical service utilization after surgery. Post-surgical kyphosis is a potential complication of laminoplasty, though appropriate patient selection can mitigate this risk.  

Both laminectomy and laminoplasty are durable surgical options for DCM patients and with appropriate patient selection these may be offered as motion-preserving options in DCM. The results of ongoing and future randomized trials will further reveal the comparative effectiveness of these approaches over laminectomy and fusion. 

Anterior motion preserving techniques

Cervical disc arthroplasty (CDA)

Cervical disc arthroplasty (CDA) was developed to preserve motion at the operated segment after anterior decompression. In the systematic review by Bautista and colleagues, 17 studies were identified that addressed CDA in cervical myelopathy. Across clinical outcomes, radiographic analysis, and implant-related complications, the available literature found CDA outcomes to be at least equal to anterior cervical discectomy and fusion (ACDF) in selected myelopathy patients. The authors also concluded that concern for persistent symptoms after CDA due to the dynamic component of myelopathy remains theoretical and is not supported by the available evidence.

However, the review also highlights familiar limitations of CDA: heterogeneous devices, heterogeneous outcome reporting, few randomized trials focused specifically on myelopathy, and at least moderate bias in many included studies. Many studies excluded patients with ossification of the posterior longitudinal ligament (OPLL) or cervical instability. The same caution applies to patients with poor bone quality, inflammatory spondyloarthropathy, severe systemic disease, advanced facet arthropathy, or anatomy that would make motion preservation unsafe.

CDA may be a reasonable motion-preserving option for selected patients with disc-level anterior pathology, preserved stability, and appropriate anatomy. It should not be presented as a replacement for fusion, particularly when the primary surgical goals include stabilization, correction of kyphosis, or management of significant OPLL. In DCM, the primary goal is complete and durable decompression. Motion preservation is valuable only when it doesn’t compromise that goal.

Oblique corpectomy

Oblique corpectomy is a less commonly used anterior-lateral motion-preserving strategy for selected retrovertebral pathology without dynamic instability. In the scoping review by Lomax and colleagues, oblique corpectomy improved or stabilized functional outcomes in appropriately selected patients, but it carries a distinctive complication profile. Horner syndrome was the most notable concern, with reported transient and permanent rates higher than those typically seen in standard anterior cervical approaches. For this reason, oblique corpectomy is a niche option.

Endoscopic cervical spine surgery and its expanding role

Endoscopic cervical spine surgery (ECSS) represents another motion preserving approach gaining attention. It includes anterior endoscopic cervical discectomy, posterior endoscopic cervical foraminotomy and discectomy, cervical endoscopic unilateral laminotomy for bilateral decompression, and unilateral biportal endoscopy. These techniques aim to reduce soft tissue disruption, preserve stabilizing structures, and accelerate recovery while maintaining adequate decompression. 

Within the GSJ focus issue, endoscopy is presented as part of a broader minimally invasive movement in spine surgery.  Every included study reported postoperative improvement compared with preoperative measurements. However, the evidence remains heterogeneous, largely nonrandomized, and limited by variation in technique, follow-up, and outcome reporting.

Two persistent challenges need to be highlighted: the learning curve and the complication profile. In the systematic review, common complications included dural tears, transient hypesthesia, and CSF leakage. Complications also differed by approach, which means surgeons need technique-specific training and careful patient selection before applying ECSS broadly in DCM.

Endoscopic cervical surgery demands precise orientation and familiarity with specialized instrumentation, and outcomes may be highly dependent on surgeon experience. From an evidence standpoint, data in myelopathy are heterogeneous, often limited to small series from high volume centers. Questions remain about the adequacy of decompression in severe stenosis and the reproducibility of results across different practice settings. These factors temper enthusiasm and reinforce the need for structured training and outcome tracking. 

Innovation versus established outcomes

A central theme of the focus issue is the tension between innovation and proven results. Fusion based strategies for DCM are supported by decades of data demonstrating reliable neurological improvement. Motion preserving techniques, while attractive, must meet the same standard. Inadequate decompression or ineffective surgery reduces the likelihood of neurological decompression and persistent disability in these patients. Patient selection and appropriate surgical approach are paramount.

We do not wish to argue against innovation. Instead, we advocate for measured adoption, where new techniques should be introduced with clear indications, transparent patient counseling, and a commitment to data collection. Motion preservation should be viewed as a potential advantage, not an endpoint in itself. 

Practical considerations for clinical practice

For surgeons considering these techniques, several practical lessons emerge from the focus issue. Patient selection is critical. CDA may be appropriate for a narrow subset of patients with limited disease, preserved facet joints, absence of OPLL, and no instability. Laminoplasty is most relevant for multilevel posterior decompression in patients with suitable alignment and no major instability. Laminectomy alone may have a role when decompression can be achieved without creating clinically meaningful kyphosis or instability. Endoscopic techniques may offer benefits in select decompression scenarios but require formal training and experience. Skip laminectomy and oblique corpectomy remain niche options that depend heavily on anatomy and surgeon expertise.

Equally important is expectation management. Surgeons must clearly communicate where evidence is strong, where it is limited, and where a motion-preserving technique may carry a trade-off. Patients should understand that preserving motion does not automatically mean less pain, faster recovery, or lower reoperation risk. Participation in registries and multicenter studies can help advance the field while safeguarding patient outcomes. 

Looking ahead

As DCM becomes increasingly recognized in an aging population, the demand for durable, patient centered solutions will continue to grow. Motion preserving strategies represent meaningful areas of exploration, but their role must be defined by outcomes rather than enthusiasm alone.

Ideally, these innovations are situated within an evidence based framework, reminding us, that progress in spine care is incremental. The future of DCM surgery will likely involve a thoughtful blend of established techniques and carefully validated innovations, guided by long term neurological results and shared clinical experience.