Question: In patients with sports-related soft-tissue injury, is
cold gel more effective than placebo in reducing pain and disability?
Design: Randomized (allocation concealed), blinded (clinicians and
patients), controlled trial with 28-day follow-up.
Setting: A university hospital in Kuopio, Finland.
Patients: 74 patients (mean age, 32 yr; 64% men) who had sustained a
sports-related soft-tissue injury of the ankle, leg, knee, or hand within the
previous 48 hours. Exclusion criteria were a pain score of <30 mm on the
visual analog scale (VAS); pregnancy; the presence of cutaneous lesions or
injuries at the site of application, thus precluding the use of gel therapy;
or an injury in need of surgery or physiotherapy. Complete follow-up was
achieved for 73 patients
(99%).
Intervention: Patients were allocated to receive the active cold gel
(Ice Power; Fysioline, Tampere, Finland) 4 times per day for 14 days (n = 37)
or a placebo gel (n = 37). The gel was applied with the fingers by way of a
slight massage. The active cold gel consisted of 3.5% menthol and 8% ethanol
and adjuvants. The placebo gel contained no menthol or ethanol.
Main outcome measures: Pain at rest, pain on movement during normal
function, and functional disability. Secondary outcome measures were the
patients' and investigators' global assessment and satisfaction with the
treatment. All outcomes were measured with the 100-mm VAS (0 = no pain or
disability and 100 = extreme pain or disability).
Main results: Analysis was by intention to treat. Pain at rest and
pain on movement decreased more in the cold-gel group than in the placebo
group (Table). The difference favored the cold-gel group at each week of
follow-up. The change in score in terms of functional disability also favored
the cold-gel group more than the placebo group (the change in score from the
baseline to 7 days was 63 to 31 for the cold-gel group compared with 62 to 48
for the placebo group; p < 0.001). Patients in the cold-gel group expressed
more satisfaction with the results of treatment than did patients in the
placebo group (VAS score, 71 for the cold-gel group compared with 44 for the
placebo group; p < 0.001). The global assessment scores of the patients and
the investigators also favored the cold-gel treatment.
Conclusions: For patients with sports-related soft-tissue injury,
cold gel was more effective than placebo gel in reducing pain and
disability.
The strengths of this study are that it was prospective, randomized, and
controlled with intent-to-treat analyses. Although the patients were blinded
regarding the contents of the topical gel, there was a clear possibility for
bias because the experimental gel produced a notable cooling effect that was
not present with the control. Although the bias may not have been avoidable,
the cooling may have affected the subjective pain scores.
The clinical applicability of the study deserves several comments. The
study group was a heterogeneous group of patients who had a soft-tissue injury
that was of a relatively mild nature, that required no surgery or physical
therapy, and that necessitated the use of nonsteroidal anti-inflammatory drugs
by less than 25% of the group. Thus, the cold gel probably can be expected to
provide improvement in pain scores for a heterogeneous group of patients with
painful soft-tissue injuries. The outcomes would also probably be similar to
those attained with any other form of cryotherapy but with the added advantage
of ease of application. Finally, although significant, the increased relative
improvement in VAS scores of 15 mm at week one and of 7 mm at week four was
modest.
The study did show significant pain relief and functional improvement at
each study interval. The authors identified the improved outcome as a global
effect of cold therapy rather than the effect of any specific product. The
advantage of the gel is its convenience and ease of application in comparison
with traditional cryotherapy. Cold gel therefore provides an attractive
treatment modality if it is relatively cost-effective.