Double-blind, placebo-controlled trial of the pain-relieving effect of the implantation of gold beads in dogs with hip dysplasia“Hip dysplasia is a common, incurable and painful disease of medium- and large-breed dogs, and the present methods of treatment are palliative at best. This paper describes a double-blind and placebo-controlled clinical trial of the effectiveness of implantation of gold beads in the treatment of painful arthrosis due to hip dysplasia in 78 dogs” in order to “evaluate gold bead implantation as a pain-relieving treatment.” “The dogs were all family dogs, recruited from all over Norway through veterinary and breeders’ clubs’ magazines. Dogs of any breed and either sex, between one and eight years of age, with a history of pain and/or lameness or dysfunction of the hindlimbs due to hip dysplasia, and which had not been treated by acupuncture, were invited to participate. Treatments with non-steroidal anti-inflammatory drugs (NSAIDs) and corticosteroids were withdrawn at least 14 days and three months, respectively, before the animals joined the trial, but NSAIDs could be used during the trial if the dogs’ owners considered them necessary, and their use was recorded.” 80 dogs of 28 different breeds were recruited: 19 German shepherd dogs, 7 Golden and 7 Labrador Retrievers, 6 mixed-breed dogs, and 41 more dogs of 24 different breeds; 33 male, 47 female, mean weight 34.8 kg, signs of pain for 2.3 years on average. The status of the dogs’ hips was evaluated by a veterinarian or surgeon before allocation to the placebo or active treatment groups. “The Norwegian Animal Research Authority approved the study, and the owners gave their written consent and were not charged for their participation.” The study had stratified parallel groups, the stratification factors assumed to influence the outcome being bodyweight (
“Both groups were treated equally regarding anaesthesia, hair clipping and penetration of the skin with the same type of needle. The gold implantation group had [two] small pieces of 24 carat gold” – 1 mm in diameter and 2 mm long, 35–40 mg, cut from a gold wire – “inserted through needles at five different acupuncture points and the placebo group had the skin penetrated at five non-acupuncture points so as to avoid any possible effect of stimulating the acupuncture points. A certified veterinary acupuncturist marked the points, and two surgeons performed the implantations according to a randomisation code made in advance. After 14 days, three months and six months, the owners assessed the overall effect of the treatments by answering a questionnaire, and the same veterinarian examined each dog and evaluated its degree of lameness by examining videotaped footage of it walking and trotting. The treatment was blinded for both the owners and the veterinarian.” The owner scored:
The veterinarian assessed “the signs of pain provoked by the rotation, flexion and extension of the affected hip, and graded on a four-point scale” (1=no pain response, 2=mild p.r., tries to move away, 3=moderate p.r., turns head toward hip, slight vocalisation, 4=large p.r., turns head with intention to bite, howls). Both hip scores were added to a total pain score [yielding totals 2…8]. “At each visit, the dog was videotaped when walking and when trotting, before and after stretch/extension of each hip, and in left and right turns. Lameness was graded on a five-point scale at each gait” (0=no lameness, 1=barely disturbed locomotion, 2=locomotion disturbed but limb(s) still bearing weight, 3=lameness with limb(s) not always bearing weight, 4=no weight-bearing on limb(s)). “The scores for the five gaits for each dog at each examination were added to give a total lameness score.” Assessment results were also statistically analysed. Factors and variables “assumed continuously distributed” “are expressed as mean values with 95 per cent confidence intervals (CIs), calculated by the Student procedure”. “Discontinuously distributed factors and variables are expressed in contingency tables”. Comparisons between and “changes within groups were assessed by two-tailed tests with a significance level of 5%. Comparisons between groups were made with respect to: (a) discontinuously distributed factors and variables using contingency table analysis; (b) “the assumed continuously distributed variables” “by using analyses of variance [ANOVA] with repeated measurements and the initial score as a covariate”. “A matched-pairs analysis of variance [ANOVA] was used for the analyses within groups. To compare the groups with respect to the variable ‘number of days until an observed reduction in signs of pain’, survival analysis” and Kaplan-Meier plots were used. The overall response after 14 days/3 months/6 months [as assessed by the owners] improved for 54.8/59.5/52.4% of the dogs in the placebo group, and for 38.9/69.4/83.3% of the dogs in the gold implementation group, i.e. was significantly better after 6 months (P=0.02). The mean pain score initially/after 14 days/3 months/6 months was 4.8/3.8/3.1/3.1 in the placebo group, and 5.6/4.8/2.6/1.9 in the gold implementation group, which means somewhat higher in the beginning but significantly lower after 6 months (P<0.01). The “median period until a reduction in the signs of pain was observed was 21 days” in the gold and 10 days in the placebo group (P=0.04) [seen in Kaplan-Meier plot]. The veterinarian’s assessment of pain when manipulating the hips was also significantly lower after 6 months in the gold implantation group than in the placebo group. The mean dysfunction score [owner assessment] at the same point in time was 4.1/3.4/2.7/2.4 in the placebo and 4.6/4.4/2.3/1.6 in the gold implementation group, i.e. significantly lower after 6 months (P=0.03), the mean reduction being 39.3 and 64.6%, respectively (P<0.03). While the mood did not change significantly in the placebo group, the improvements were significant after 6 months in the gold implementation group. The quality of life increased significantly over 6 months in both groups, but not significantly between them. Lameness was found by the veterinarian in 20 of 36 dogs in the gold implementation group in the beginning and in 7 dogs after 6 months, with a total mean lameness score of 85 and 28 respectively; while in the placebo group the numbers of lame dogs were 22 and 11 of 42 dogs, with a mean score of 73 and 39 respectively. In summary there “were significantly greater improvements in mobility and greater reductions in the signs of pain in the dogs treated with gold implantation than in the placebo group. The veterinarian’s and the owners’ assessments corresponded well.” The “present results are in agreement with practical experience and anecdotal reports.” One possible explanation for the “placebo effect is the owners’ positive attitude towards a new and potentially controversial treatment such as gold bead implantation, which was a potential source of bias that could have resulted in a placebo effect in both groups.” Treatment with analgesics was allowed and recorded. Towards the end of the trial, more of the dogs in the placebo group were being treated, and none in the gold implantation group. Based on the positive outcome of their study the authors conclude and advise: “Gold bead implantation should therefore be considered when conservative or medical treatments fail to give the desired effect, or when surgical intervention is not an option.”
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20, 20.1–34.9,
35 kg) and grade of hip dysplasia (mild/moderate, severe). By block randomisation with a block size of four “the dogs were randomly assigned to two groups, 38 in the gold implantation group” of which 36 completed the trial “and 42 in the placebo group”. The dogs were equally distributed with respect to sex, age, weight, grade of hip dysplasia, duration of signs of pain, and in terms of mood, degree of dysfunction, mobility and stiffness in the morning and after exercise, vocalisation in response to pain and avoiding jumping into a car. “However, the general level of pain and the need for taking rests during exercise were significantly higher in the gold implantation group than the placebo group.” The owners were advised to give their dogs the same type of exercise and food as before the study and to record any pain-relieving medications.