Connection of discontinuous segments in early functional recovery from thoracic ossification of the posterior longitudinal ligament treated with posterior instrumented surgery

Perioperative complications and cost of posterior decompression with fusion in thoracic spine for ossification of the posterior longitudinal ligament and ossification of the ligamentum flavum -a comparative study using a national inpatient database

BACKGROUND

Although posterior decompression with fusion (PDF) are effective for treating thoracic myelopathy, surgical treatment has a high risk of various complications. There is currently no information available on the perioperative complications in thoracic ossification of the longitudinal ligament (T-OPLL) and thoracic ossification of the ligamentum flavum (T-OLF). We evaluate the perioperative complication rate and cost between T-OPLL and T-OLF for patients underwent PDF.

METHODS

Patients undergoing PDF for T-OPLL and T-OLF from 2012 to 2018 were detected in Japanese nationwide inpatient database. One-to-one propensity score matching between T-OPLL and T-OLF was performed based on patient characteristics and preoperative comorbidities. We examined systemic and local complication rate, reoperation rate, length of hospital stays, costs, discharge destination, and mortality after matching.

RESULTS

In a total of 2,660 patients, 828 pairs of T-OPLL and T-OLF patients were included after matching. The incidence of systemic complications did not differ significantly between the T-OPLL and OLF groups. However, local complications were more frequently occurred in T-OPLL than in T-OLF groups (11.4% vs. 7.7% P = 0.012). Transfusion rates was also significantly higher in the T-OPLL group (14.1% vs. 9.4%, P = 0.003). T-OPLL group had longer hospital stay (42.2 days vs. 36.2 days, P = 0.004) and higher medical costs (USD 32,805 vs. USD 25,134, P < 0.001). In both T-OPLL and T-OLF, the occurrence of perioperative complications led to longer hospital stay and higher medical costs. While fewer patients in T-OPLL were discharged home (51.6% vs. 65.1%, P < 0.001), patients were transferred to other hospitals more frequently (47.5% vs. 33.5%, P = 0.001).

CONCLUSION

This research identified the perioperative complications of T-OPLL and T-OLF in PDF using a large national database, which revealed that the incidence of local complications was higher in the T-OPLL patients. Perioperative complications resulted in longer hospital stays and higher medical costs.

Comparison of perioperative complications in anterior decompression with fusion and posterior decompression with fusion for thoracic ossification of the posterior longitudinal ligament -a retrospective cohort study using a nationwide inpatient database

BACKGROUND

Thoracic ossification of the posterior longitudinal ligament (T-OPLL) is a rare disease, which can cause spinal cord compression leading to various neurological symptoms. There are limited treatment options for T-OPLL, surgery is generally considered the only effective treatment. However, few studies have investigated surgical complications in patients with T-OPLL, and there are no data regarding surgical risks in anterior decompression with fusion (ADF) when compared with posterior decompression with fusion (PDF) for T-OPLL.

METHODS

Patients who were diagnosed as T-OPLL and underwent ADF via the anterior approach and PDF via the posterior approach from April 1, 2012 to March 31, 2018, were extracted from the Diagnosis Procedure Combination (DPC) database. We analyzed perioperative systemic and local complication rates after ADF and PDF and compared them using propensity score matching (PSM) method. In each of the two groups, we investigated the details of length of stay, costs, mortality, and discharge destination.

RESULTS

In total 1344 patients (ADF: 88 patients, PDF: 1256 patients), 176 patients were investigated after PSM (88 pairs). While the incidence of overall systemic complication was significantly higher in the ADF group (ADF/PDF: 25.0%/8.0%, P = 0.002), there was no significant difference in the overall local complication rate (15.9%/19.3%, P = 0.55). Specifically, respiratory complications were more frequently observed in the ADF group (9.1%/0%, P = 0.004), however, other systemic and local complications did not differ significantly between the two groups. The length of stay was 1.7 times longer (P < 0.001) and the medical costs were 1.4 times higher (P < 0.001) in patients with perioperative complications, compared to those without perioperative complications.

CONCLUSION

We demonstrated the perioperative complications of ADF and PDF in patients with T-OPLL using a large national database. ADF showed a higher incidence of respiratory complications. Development of perioperative complications was associated with longer hospital stay and higher medical costs.

Thoracic myelopathy due to ossification of the posterior longitudinal ligament shown on dynamic MR

Background:

Magnetic resonance (MR) and computed tomography (CT) studies combined are the optimal studies for diagnosing thoracic ossification of the posterior longitudinal ligament (OPLL) contributing to myelopathy. Here, we report a 71-year-old female, whose additional dynamic thoracic MR demonstrated transient T6–T9 anterior OPLL with cord compression.

Case Description:

A 71-year-old female presented with a progressive myelopathy originally attributed to cervical cord compression resulting in a cervical laminoplasty. However, when she failed to improve postoperatively, a dynamic thoracic MR was performed. On the flexion study, it demonstrated significant although transient T6–T9 anterior thoracic cord compression due to both OPLL and kyphosis. The patient’s symptoms resolved following a posterior thoracic fusion alone (i.e., no decompression was warranted).

Conclusion:

Dynamic MR studies (i.e., flexion studies) in addition to the routine MR and CT evaluations should be performed for patients with myelopathy attributed to thoracic OPLL/kyphosis.

Recurrent ossification of the posterior longitudinal ligament in the upper thoracic region 10 years after initial decompression

Background:

Posterior decompression surgery consisting of laminoplasty is generally considered be the treatment of choice for upper thoracic OPLL. Here, we describe a patient who, 10 years following a C3–T4 level laminectomy, developed recurrent OPLL at the T2–3 level with kyphosis requiring a posterior fusion.

Case Description:

A 64-year-old male with CT documented OPLL at the C3–4, C6–7, and T1–4 levels, originally underwent a cervicothoracic laminectomy with good results. However, 10 years later, when T2–3 OPLL recurred along with kyphosis, he warranted an additional posterior fusion.

Conclusion:

Due to the long-term risks of developing kyphotic deformity/instability, more patients undergoing initial decompressive surgery alone for upper thoracic OPLL should be considered for primary fusions.

Postoperative progression of ligamentum flavum ossification after posterior instrumented surgery for thoracic posterior longitudinal ligament ossification: long-term outcomes during a minimum 10-year follow-up

OBJECTIVE

The authors sought to investigate clinical and radiological outcomes after thoracic posterior fusion surgery during a minimum of 10 years of follow-up, including postoperative progression of ossification, in patients with thoracic ossification of the posterior longitudinal ligament (T-OPLL).

METHODS

The study participants were 34 consecutive patients (15 men, 19 women) with an average age at surgery of 53.6 years (range 36-80 years) who underwent posterior decompression and fusion surgery with instrumentation at the authors' hospital. The minimum follow-up period was 10 years. Estimated blood loss, operative time, pre- and postoperative Japanese Orthopaedic Association (JOA) scores, and JOA score recovery rates were investigated. Dekyphotic changes were evaluated on plain radiographs of thoracic kyphotic angles and fusion levels pre- and postoperatively and 10 years after surgery. The distal junctional angle (DJA) was measured preoperatively and at 10 years after surgery to evaluate distal junctional kyphosis (DJK). Ossification progression at distal intervertebrae was investigated on CT.

RESULTS

The Cobb angles at T1-12 were 46.8°, 38.7°, and 42.6°, and those at the fusion level were 39.6°, 31.1°, and 34.1° pre- and postoperatively and at 10 years after surgery, respectively. The changes in the kyphotic angles from pre- to postoperatively and to 10 years after surgery were 8.0° and 7.2° at T1-12 and 8.4° and 7.9° at the fusion level, respectively. The DJA changed from 4.5° postoperatively to 10.9° at 10 years after surgery. There were 11 patients (32.3%) with DJK during follow-up, including 4 (11.8%) with vertebral compression fractures at lower instrumented vertebrae or adjacent vertebrae. Progression of ossification of the ligamentum flavum (OLF) on the caudal side occurred in 8 cases (23.6%), but none had ossification of the posterior longitudinal ligament (OPLL) progression. Cases with OLF progression had a significantly lower rate of DJK (0% vs 38.5%, p < 0.01), a lower DJA (3.4° vs 13.2°, p < 0.01), and a smaller change in DJA at 10 years after surgery (0.8° vs 8.1°, p < 0.01).

CONCLUSIONS

Posterior decompression and fusion surgery with instrumentation for T-OPLL was found to be a relatively safe and stable surgical procedure based on the long-term outcomes. Progression of OLF on the caudal side occurred in 23.6% of cases, but cases with OLF progression did not have DJK. Progression of DJK shifts the load in the spinal canal forward and the load on the ligamentum flavum is decreased. This may explain the lack of ossification in cases with DJK.