Coflex

• "Comparing sub-bandage pressure and stiffness dynamics in two two-component compression systems for the lower limb: Influence of skill level and partial compression layer addition"
• A Biomechanical Evaluation of a Novel Interspinous Process Device: In Vitro Flexibility Assessment and Finite Element Analysis
• Coflex Interspinous Stabilization with Decompression for Lumbar Spinal Stenosis: An Average 14-Year Follow-Up
• Are early child teachers' coping flexibility and narcissism associated with the teacher-child relationship?: The mediation of teacher efficacy
• Surgical interventions for degenerative lumbar spinal stenosis: a systematic review with network meta-analysis
• Analysis of 1027 Adverse Events Reports for Interspinous Process Devices From the US Food and Drug Administration Manufacturer and User Facility Device Experience Database
• Biomechanical assessment of lumbar stability: finite element analysis of TLIF with a novel combination of coflex and pedicle screws
• Biomechanical investigation of a customized interspinous spacer system in the treatment of degenerative disc diseases: A finite element analysis

Coflex is a U-shaped titanium interspinous process device used in lumbar spine surgery following decompression, primarily for the treatment of spinal stenosis.

Coflex: A non-fusion, motion-preserving titanium implant placed between the spinous processes of two adjacent lumbar vertebrae. It provides segmental stability and maintains indirect decompression while preserving motion at the treated level.

• Material: Titanium alloy (biocompatible)
• Placement: Between adjacent spinous processes
• Function:
  • Stabilizes the spinal segment after decompression
  • Maintains some degree of motion (unlike fusion)
  • Reduces the risk of restenosis and mechanical low back pain

• Moderate to severe lumbar spinal stenosis
• Following surgical decompression (e.g., laminectomy)
• Patients without segmental instability

• Segmental instability or high-grade spondylolisthesis
• Osteoporosis or poor bone quality
• Severe facet joint degeneration

• Clinical trials (e.g., IDE study) show Coflex is non-inferior or superior to decompression with fusion in selected patients
• Benefits include shorter operative time and preservation of mobility
• Potential complications: spinous process fracture, implant migration, or restenosis

• Fusion (PLIF/TLIF)
• Other interspinous devices (e.g., X-Stop, Superion)

The results of this first prospective controlled study indicate that the additional placement of a Coflex™ interspinous device does not improve the already good clinical outcome after decompressive surgery for LSS in the 24-month follow up interval ¹⁾.

After microsurgical decompression, Coflex™ device was applied. Patients were evaluated at a month after surgery and last follow-up using the visual analogue scale (VAS) and Oswestry Disability Index (ODI). Foraminal height and lumbar lordosis angle were recorded.

The mean preoperative VAS was 7.85 and fell to 1.7 a month after surgery (p < 0.0001). At the last follow-up the mean VAS score was 1.65 (p < 0.0001). The mean foraminal heights were measured 19.95 mm preoperatively and 25.05 mm a month after surgery (p < 0.0001). The mean foraminal height was 21.60 mm at the last follow-up (p=0.002). The mean lumbar lordosis were measured 32.05 and 34.3 degrees at preoperative and a month after surgery respectively (p=0.155). The mean lumbar lordosis was 32 (±5.99) degrees at the last follow-up (p=0.974).

Restoration of the foraminal height may not be a responsible factor for clinical improvement. Microsurgical decompression looks responsible of the good clinical outcome and using interspinous device is unnecessary. Comparative clinical studies can be informative ²⁾.

So far, inconsistent results in currently available retrospective studies. Comparable short-term results in prospective studies of sole decompression without implantation of an interspinous spacer. Prospective randomized comparative studies are not yet available ³⁾.

A high incidence of heterotopic ossification (HO) has been detected after implantation of Coflex devices. Clinicians should be aware of this possible outcome, and more studies should be conducted to clarify the clinical effects of HO. ⁴⁾.

Coflex implants should be avoided in patients with osteoporosis, a narrow interspinous space and intervertebral coronal spondylolysis, or sagittal instability. Furthermore the device choice, depth of implantation, and clamping intensity should be appropriate. Conservative treatment can be provided to patients with symptoms if the device remains in the correct position; however, revisions and salvages should be undertaken with internal fixation of pedicle screws for patients with device malposition, intraoperative implantation failure, or device intolerance ⁵⁾.

In a retrospective cohort study, single‑center, average 14‑year follow‑up Juneyoung Heo *et al.* from

1. Joint & Arthritis Research, Department of Neurosurgery, Himchan Hospital – Seoul
2. Department of Orthopaedic Surgery, Himchan Hospital – Seoul
3. Department of Neurosurgery, Soonchunhyang University Seoul Hospital – Seoul

published in the *Journal of Clinical Medicine* to assess long‑term clinical outcomes and radiologic changes after Coflex interspinous device insertion with decompression in single‑level degenerative lumbar spinal stenosis. Coflex preserves disc and foramen height, yields lasting pain relief (mean VAS from 8.22 to 2.08), but has high overall reoperation rate (25% at index level, 10.8% at adjacent levels), especially in patients with preoperative instability ⁶⁾.

• Strengths:
  1. Longest follow‑up reported for Coflex (mean 174 ± 24 months) :contentReference[oaicite:1]{index=1}
  2. Robust sample size (n=147) with comprehensive radiographic and clinical data
• Limitations:
  1. Single‑center, retrospective design—susceptible to selection and information bias
  2. No control arm (fusion or decompression‑only), limiting comparative assessment
  3. Reliance on VAS without functional scores (e.g., ODI, JOA)
  4. Instability subgroup may be underpowered to examine causality
• Interpretation:
  1. Coflex offers sustained pain relief and height preservation, but quarter of patients require index‑level reoperation—unacceptably high for many practitioners
  2. Preoperative translational and angular instability strongly predicted failures (OR 7.77 and OR 1.59, respectively), highlighting need for strict selection :contentReference[oaicite:2]{index=2}
  3. Adjacent‑level reoperations (10.8%) remain lower than fusion literature, perhaps indicating a modest protective effect

6/10

1. High scientific value in long‑term data but moderated by design weaknesses and lack of comparator
2. Clinically relevant: reinforces known instability risk and need for targeted indications

1. Coflex may offer a motion‑preserving alternative to fusion in carefully selected patients without preoperative instability
2. Requires thorough preoperative radiographic analysis to exclude translational/ angular instability
3. Counsel patients on ~25% risk of further surgery at index level over long term

In patients with single‑level DLSS and no radiographic instability, Coflex + decompression can yield lasting pain relief and height preservation—but surgeons must prepare patients for a substantial long‑term reoperation risk. Rigorous patient selection is essential.