The Rotoglide™ total replacement of the first metatarso-phalangeal joint. A prospective series with 7-15 years clinico-radiological follow-up with survival analysis.

BACKGROUND: The Rotoglide total replacement of the MTP-1 joint. 15 years survival analysis. The purpose of this prospective study was to evaluate the long-term performance clinico-radiographically of an uncemented three-component total replacement for the first metatarso-phalangeal joint (MTP-1) used for hallux rigidus (primary osteoarthritis grades 3 and 4). The follow-up was median 11.5 years (7-15). METHODS: The AOFAS forefoot score was used preoperatively and at follow-up. Radiographs were taken weight-bearing in the AP-projection and in tip-toe standing in the lateral view. Arthrosis in the sesamoid junction, prosthetic loosening, subsidence (of prosthesis as well as sesamoids), and dorsiflexion were measured, recorded and subjected to multiple variance analysis. Survival analysis was performed for 15 years. MATERIAL: Ninety implants in 80 patients (53 women and 27 men); median age 58 (41-76) were evaluated. RESULTS: Six patients representing seven prostheses in situ had died from unrelated reason. The median preoperative AOFAS increased significantly from 40 to 95. The median gain was 45. Four replacements (4.4%) were extracted for other reasons than loosening. No aseptic loosenings were recorded. The survival rate at 15 years was 91.5% (83-100). Multiple variance analysis showed that arthrosis in the metatarso-sesamoid junction correlated with reduced AOFAS score. CONCLUSION: The prosthesis has stood the test of time; the results justify its further use.

Conventional Supine MRI With a Lumbar Pillow-An Alternative to Weight-bearing MRI for Diagnosing Spinal Stenosis?: A Cross-sectional Study.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To investigate if adding a lumbar pillow in supine position during magnetic resonance imaging (MRI) is superior to standing positional MRI for diagnosing lumbar spinal stenosis (LSS). SUMMARY OF BACKGROUND DATA: The upright standing position and especially extension of the lumbar spine seem to worsening symptoms of LSS. However, it is unclear whether a forced lumbar extension by a pillow in the lower back during conventional supine MRI may improve the diagnostics of LSS compared with standing MRI. METHODS: Patients suspected for LSS and referred to conventional MRI were included to an additional positional MRI scan (0.25T G-Scan) performed in: (1) conventional supine, (2) standing, (3) supine with a lumbar pillow in the lower back. LSS was evaluated for each position in consensus on a 0 to 3 semi-quantitative grading scale. Independently, L2-S1 lordosis angle, spinal cross-sectional diameter (SCSD), dural cross-sectional diameter (DCSD), and dural cross-sectional diameter (DCSA) were measured. The smallest dural diameter was defined as stenosis level and the largest control level for comparison. RESULTS: Twenty-seven patients (60.6 years; ±9.4) were included. The lordosis angle increased significantly from supine to standing (3.2° CI: 1.2-5.2) and with the lumbar pillow (12.8° CI: 10.3-15.3). One-way analysis of variance (ANOVA) showed significant differences between positions (P < 0.001). When compared with the supine position, pairwise comparisons showed decreased SCSD, DCSD, DCSA, and increasing semi-quantitative grading, during both standing and supine with the lumbar pillow. A difference in the semi-quantitative grades was only found between standing and supine with a lumbar pillow, and the scan with a lumbar pillow was significantly more painful. CONCLUSION: Standing MRI and supine MRI with a lumbar pillow resulted in equal changes in the lumbar spine, although standing MRI may be more sensitive in the assessment of patients suspected for LSS. LEVEL OF EVIDENCE: 2.

Effect of Lumbar Disc Degeneration and Low-Back Pain on the Lumbar Lordosis in Supine and Standing: A Cross-Sectional MRI Study.

STUDY DESIGN: Cross-sectional study. OBJECTIVE: To examine the influence of low-back pain (LBP) and lumbar disc degeneration (LDD) on the lumbar lordosis in weight-bearing positional magnetic resonance imaging (pMRI). SUMMARY OF BACKGROUND DATA: The lumbar lordosis increases with a change of position from supine to standing and is known as an essential contributor to dynamic changes. However, the lordosis may be affected by disc degeneration and pain. METHODS: Patients with LBP >40 on a 0 to 100 mm Visual Analog Scale (VAS) both during activity and rest and a sex and age-decade matching control group without LBP were scanned in the supine and standing position in a 0.25-T open MRI unit. LDD was graded using Pfirrmann's grading-scale. Subsequently, the L2-to-S1 lumbar lordosis angle (LA) was measured. RESULTS: Thirty-eight patients with an average VAS of 58 (±13.8) mm during rest and 75 (±5.0) mm during activities, and 38 healthy controls were included. MRI findings were common in both groups, whereas, the summation of the Pfirrmann's grades (LDD-score) was significantly higher in the patients [(MD 1.44; 95% confidence intervals (CI) 0.80 to 2.10; P < 0.001]. The patients were less lordotic than the controls in both the supine (MD -6.4°; 95% CI -11.4 to -1.3), and standing position (MD -5.6°; 95% CI -10.7 to -0.7); however, the changes between the positions (ΔLA) were the same (MD 0.8°; 95% CI -1.8 to 3.3). Using generalized linear model the LDD-score was associated with age (P < 0.001) for both groups. The LDD-score and ΔLA were negatively associated in the control group (P < 0.001), also after adjustments for gender and age (ß-coefficient: -2.66; 95% CI -4.3 to -1.0; P = 0.002). CONCLUSION: Patients may be less lordotic in both the supine and standing position, whereas, change in the lordosis between the positions may be independent of pain. Decreasing lordosis change seems to be associated with age-related increasing disc degeneration in healthy individuals. LEVEL OF EVIDENCE: 2.