Comparison of the Anterior and Posterior Approaches

Ossification of the posterior longitudinal ligament (OPLL) is a disease characterized by the gradual calcification of the ligament, leading to the compression of the spinal cord or nerve root, and its progression over time.

OPLL has a high prevalence in Asia, reaching up to 3.0%, whereas its estimated incidence rates in North America and Europe range from 0.1% to 1.7%. The goal of surgical intervention is twofold: to relieve pressure on the spinal cord and to maintain stability of the spinal column. Patients exhibiting moderate to severe cervical spondylotic myelopathy require surgical intervention.

For certain patients who display hyperintensity on MRI T2-weighted images of the cervical cord, surgical decompression is the primary treatment option. Typically, the anterior approach involves anterior corpectomy with fusion (ACF) and discectomy with fusion (ADF), while the posterior approach usually consists of laminectomy (LA) and laminoplasty (LP).

In general, patients with localized pathology are more likely to undergo treatment via the anterior approach, while the decision to use the posterior approach is primarily influenced by our doctors at Complete Orthopedic preference and the patient’s individual characteristics.

According to literature, patients with cervical OPLL that affects fewer than 3-4 vertebrae below the C3 level, has thicknesses less than 5-6 mm, and spinal stenosis of less than 50% are recommended to undergo anterior surgery. 

Patients with OPLL affecting more than four segments, the C1/C2 vertebrae, or cervical vertebrae below C6/C7 are usually treated with posterior surgery due to the difficulty in achieving a clear surgical field of vision in these areas. Anterior corpectomy with fusion (ACF) or discectomy with fusion (ADF) procedures can restore cervical stability and alleviate compression on the level of the affected cervical spinal cord.

Nevertheless, it is important to take into account possible complications, such as dural tearing, cerebrospinal fluid (CSF) leakage, hematoma, and C5 palsy. The posterior approach is considered a less complex surgical technique in comparison to the anterior approach. At present, there are no established standards or guidelines for the management of OPLL.

Patients with cervical OPLL tend to have better neurological outcomes following treatment via the anterior approach. The anterior approach is a surgical technique that can effectively alleviate direct compression of the cervical spinal cord. When the mean spinal canal occupation ratio is less than 60%, the posterior approach is recommended for treating multilevel cervical OPLL.

Patients that undergo the anterior approach tend to exhibit superior postoperative JOA scores and recovery rates. However, there is a high degree of heterogeneity in postoperative JOA scores and recovery rates among the individual studies reported by the literature.

The observed heterogeneity in the indexes, such as the number of patients, sex ratios, and follow-up times, may account for the differences observed in postoperative JOA scores and recovery rates among the studies. The anterior approach, which involves direct decompression, is linked with superior functional recovery compared to other treatment methods for cervical OPLL.

Numerous novel techniques and approaches have been utilized to eliminate OPLL. The anterior approach group may experience a greater frequency of postoperative complications compared to the posterior approach group.

The anterior approach group tends to have a higher incidence of dural tearing and CSF leakage, while the posterior approach group more commonly experiences axial neck pain. The rate of reoperation is almost six times higher in the anterior group compared to the posterior group.

The anterior and posterior approaches are prevalent surgical techniques used to manage OPLL. Despite the higher rates of complications and reoperations associated with the anterior approach, this technique is associated with better postoperative final JOA scores, functional recovery rates, and overall clinical outcomes compared to the posterior approach. When the occupying ratio is greater than or equal to 60%, the recommended treatment for OPLL is the anterior approach.

If you are interested in knowing more about the comparison of the anterior and posterior approaches for managing OPLL in the cervical spine you have come to the right place!