ACTRN: 12606000179538.

Objective To assess the relationship between knee osteoarthritis (KOA)-specific quality-of-life (QoL) and intra-articular cartilage volume (CV) in participants treated with prolotherapy. KOA is characterized by CV loss and multifactorial pain. Prolotherapy is an injection therapy reported to improve KOA-related QoL compared to blinded saline injections and at-home exercise but the mechanism of action is unknown. Design Two-arm (Prolotherapy, Control), partially blinded, controlled trial. Setting Outpatient. Participants 37 adults with ≥3 months of symptomatic KOA. Intervention Prolotherapy: 5 monthly injection sessions; Control: blinded saline injections or at-home exercise. Outcome Measures Primary: KOA-specific QoL scores (baseline, 5, 9, 12, 26, 52 weeks; Western Ontario McMaster University Osteoarthritis Index, WOMAC). Secondary: KOA-specific pain, stiffness, function (WOMAC subscales), magnetic resonance imaging (MRI)-assessed CV (baseline, 52 weeks). Results Knee-specific QoL improvement among Prolotherapy participants exceeded that of Controls (17.6±3.2 versus 8.6±5.0 points, p=0.05) at 52 weeks. Both groups lost CV over time (p<0.05); no between-group differences were noted (p=0.98). While Prolotherapy participants lost CV at varying rates, those who lost the least CV (“Stable CV”) had the greatest improvement in pain scores. Among Prolotherapy, but not Control participants, the change in CV and the change in pain (but not stiffness or function) scores were correlated; each 1% CV loss was associated with 2.7% less improvement in pain score (p<0.05). Conclusions Prolotherapy resulted in safe, substantial improvement in KOA-specific QoL compared to Control over 52-weeks. Among prolotherapy participants, but not Controls, MRI-assessed CV change (CV stability) predicted pain severity score change, suggesting prolotherapy may have pain-specific disease-modifying effect. Further research is warranted.

BackgroundHypertonic dextrose injection (prolotherapy) is reported to reduce pain including non-surgical chronic low back pain (CLBP), and subcutaneous injection of 5% dextrose is reported to reduce neurogenic pain, hyperalgesia and allodynia. The mechanism in both cases is unclear, though a direct effect of dextrose on neurogenic pain has been proposed. This study assessed the short-term analgesic effects of epidural 5% dextrose injection compared with saline for non-surgical CLBP.MethodsRandomized double-blind (injector, participant) controlled trial. Adults with moderate-to-severe non-surgical low back pain with radiation to gluteal or leg areas for at least 6 months received a single epidurogram-confirmed epidural injection of 10 mL of 5% dextrose or 0.9% saline using a published vertical caudal injection technique. The primary outcome was change in a numerical rating scale (NRS, 0 - 10 points) pain score between baseline and 15 minutes; and 2, 4, and 48 hours and 2 weeks post-injection. The secondary outcome was percentage of participants achieving 50% or more pain improvement at 4 hours.Results and ConclusionsNo baseline differences existed between groups; 35 participants (54 ± 10.7 years old; 11 female) with moderate-to-severe CLBP (6.7 ± 1.3 points) for 10.6 ± 10.5 years. Dextrose participants reported greater NRS pain score change at 15 minutes (4.4 ± 1.7 vs 2.4 ± 2.8 points; P = 0.015), 2 hours (4.6 ± 1.9 vs 1.8 ± 2.8 points; P = 0.001), 4 hours (4.6 ± 2.0 vs 1.4 ± 2.3 points; P < 0.001), and 48 hours (3.0 ± 2.3 vs 1.0 ± 2.1 points; P = 0.012), but not at 2 weeks (2.1 ± 2.9 vs 1.2 ± 2.4 points; P = 0.217). Eighty four percent (16/19) of dextrose recipients and 19% (3/16) of saline recipients reported ≥ 50% pain reduction at 4 hours (P < 0.001). These findings suggest a neurogenic effect of 5% dextrose on pain at the dorsal root level; waning pain control at 2 weeks suggests the need to assess the effect of serial dextrose epidural injections in a long-term study with robust outcome assessment.

Mannitol cream reduced self-reported pain scores in a capsaicin pain model more rapidly than a control cream, potentially via a TRPV1 receptor effect.

Epidural D5W injection, in the absence of anesthetic, resulted in consistent postinjection analgesia and clinically significant improvement in pain and disability through 12 months for most participants. The consistent pattern postinjection analgesia suggests a potential sensorineural effect of dextrose on neurogenic pain.