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Safety and Efficacy of Botulinum Toxin A Injection in Patients With Painful Artificial Knee Arthroplasty (TKA)

Botulinum Toxin A for Painful Total Knee Arthroplasty (TKA): Randomized, Controlled, Triple-blind Study

Status
Completed
Phases
Phase 2
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT00403273
Enrollment
54
Registered
2006-11-23
Start date
2006-07-31
Completion date
2009-01-31
Last updated
2018-05-21

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Knee Pain

Keywords

Painful Knee Arthroplasty, Botulinum Toxin A, Randomized Controlled Trial, Pain and Function

Brief summary

Primary Total Knee joint replacement surgery is highly successful surgery for relieving pain and improving function in patients with disabling arthritis. Unfortunately, like all biomedical devices, prosthesis failure is a complication of knee replacement surgery that leads to disabling pain, stiffness and loss of function. Approximately 1% of the knee replacements fail every year leading to a 20% failure rate over 20 years. The common causes of failure of prosthetic joint are infection, loosening, trauma or wear of the prosthesis. Currently, a revision surgery is the best option for long term pain relief (analgesics or other pain medications are options but are of limited benefit). Surgery may not be feasible in patients due to advancing age, other medical conditions and surgical/technical difficulties or patient's choice. In addition, the results from revision surgery are not as good as the initial knee joint surgery. Therefore, there is a great need for a novel, targeted therapy that provides an option to patients who are unfit, unable, or unwilling to undergo surgery. In the investigators' recent pilot study, a single injection of Botulinum toxin A (Botox) in painful natural knee, ankle and shoulder joints of patients with various types of arthritis led to significant and durable improvement in pain and function and was safe to use. The investigators propose this 6-month study to compare pain relief, improvement of function and safety of an injection of Botulinum toxin compared to placebo in patients with a painful prosthetic knee joint. Both patients and investigators will be blinded to the treatment assignment to a patient until the study is completed. The investigators will assess the amount and duration of pain relief, improvement in function and short term safety of Botulinum toxin using standard validated measures. Patients will be evaluated at baseline, 2 weeks, 1-, 2-, 3-, 4- and 6-months after a single injection of either placebo or BoNT/A in the hip or knee prosthesis. The six-month follow-up is to assess the duration of meaningful pain relief. If successful, this will offer a new treatment option for patients with a chronically painful knee prosthetic joint, provide more insight into the origin and cause of pain in prosthetic joints and direct future investigations in new directions.

Detailed description

This 6-month randomized, placebo-controlled, double blind trial will compare a single intra-articular (IA) injection of 100 units of Botulinum Toxin A (BoNT/A) to placebo for improvement in pain, function and quality of life (QOL), and safety in patients with painful total knee arthroplasty (TKA). Patients will be recruited at the Minneapolis VA Medical Center. Patients will be eligible if they are over age 18, have TKA, have pain ≥6/10 on 0-10 numeric rating scale (NRS) and are not candidates for revision surgery. The primary outcome is: (1) proportion with clinically meaningful change in pain severity (on 0-10 scale) 2 months after IA injection. The choice of 2-month for primary end-point is based on previous observations from open-label case series in painful TKA. Secondary outcomes will be assessed at each efficacy follow-up (FU) visit. The duration of the trial is 6-months to capture the duration of pain relief. Based on other trials of Botulinum toxin, we expect the peak effect between 2-8 weeks and expect the effect to wear off between 2-4 months. Therefore, for all analyses except duration of pain relief, the efficacy time-points (2 wk, 4 wk, 2 month) and possibly 3- or 4-month (depending on duration of pain relief) will be used. Secondary outcomes include: (1) clinically meaningful pain relief (≥2-point or ≥30% decrease) in pain severity (0-10 scale); (2) change in pain severity at 2 months and at all efficacy time-points; (3) percent with Minimal Clinically Important Improvement on Western Ontario MacMaster Arthritis Index (WOMAC) pain and function sub-scales at 2 months and at all efficacy time-points; (4) amount and duration of pain relief; (5) patient and physician global assessment of response at 2 months and at all efficacy time-points; (6) QOL assessed by WOMAC and Short-form 36 (SF-36) scores at 2 months and at all efficacy time-points; (7) change in function by Timed Stands Test (TST) and Timed-up-and-go (TUG) tests at 2 months and at all efficacy time-points; (8) change in dose of analgesics during the study. We will determine time to onset of and duration of pain relief and time to improvement in function. Safety will be assessed by structured interview form for adverse effects, sensory and manual muscle strength testing, and index joint examination for swelling, erythema and tenderness. At visit #1, after informed consent and screening for inclusion/exclusion criteria, patients will undergo: index joint X-ray, laboratory tests; history, physical examination, index joint pain history, comorbidity and medication history; patient pain assessments, WOMAC and SF-36; and blinded index joint, neurological examination, TST and TUG tests. 50 patients will be randomized to receive either IA BoNT/A 100 units or sterile saline in the index joint. FU phone interviews at 2 and 4-weeks will include pain assessments, WOMAC, patients' global assessment and adverse effects. Interim visits at 2, 3 and 4-months will be identical to visit #1, but will also include patients' and physicians' global assessment and there will be no joint injection. End of study visit at 6 months will be identical to interim visits with the addition of index joint X-ray and laboratory tests. Main analyses will include patients with unilateral TKAs. Sensitivity analyses will be done by including patients with bilateral knees, accounting for correlatedness of observations. Multiple analysis of variance, mixed model regression analyses and/or generalized estimating equations will be used for analysis of continuous and categorical outcomes respectively. Chi-square tests will be used to compare frequency of adverse events. Analysis will be intention-to-treat.

Interventions

DRUGBotulinum toxin A

100 units of Botulinum toxin A in 5 cc of normal saline in the Painful TKA at screening visit

DRUGNormal Saline

Single Intra-articular Injection of 5 cc of normal saline in the Painful TKA at screening visit

Sponsors

University of Minnesota
CollaboratorOTHER
Arthritis Foundation
CollaboratorOTHER
Minneapolis Veterans Affairs Medical Center
Lead SponsorFED

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Healthy volunteers
No

Inclusion criteria

* Male or female subjects, 18 years of age or older. * Written informed consent and written authorization for use or release of health and research study information have been obtained. * Subject has chronic Prosthetic knee joint pain for more than 3 months. * Subject has pain 6 or greater on a 10 point Numerical Pain Rating scale * Ability to follow study instructions and likely to complete all required visits. * Negative urine pregnancy test on the day of treatment prior to the administration of study medication (for females of childbearing potential). (if applicable) * Negative infectious etiology workup (joint aspiration, serological parameters such as Erythrocyte Sedimentation Rate (ESR) or C-reactive protein (CRP) and clinical examination). * Patients who were considered not to be candidates for Prosthetic knee joint revision surgery and have failed traditional treatments including oral pain medications, as determined by referring orthopedic surgeon

Exclusion criteria

* Use of aminoglycoside antibiotics, curare-like agents, or other agents that might interfere with neuromuscular function. * Any medical condition that may put the subject at increased risk with exposure to BOTOX ®including diagnosed myasthenia gravis, Eaton-Lambert syndrome, amyotrophic lateral sclerosis, or known disorders of neuromuscular function * Females who are pregnant, breast-feeding, or planning a pregnancy during the study or who think that they may be pregnant at the start of the study, or females of childbearing potential who are unable or unwilling to use a reliable form of contraception during the study. * Know allergy or sensitivity to any of the components in the study medication. * History of recent or ongoing alcohol or drug abuse. * Known, uncontrolled systemic disease. * Concurrent participation in another research study * Any condition or situation that, in the investigator's opinion, may put the subject at significant risk, confound the study results, or interfere significantly with the subject's participation in the study. * Patients whose pain is rated as less than 6 on a 10 point Numerical Pain Rating scale at the screening visit

Design outcomes

Primary

MeasureTime frameDescription
Participants With Clinically Meaningful Improvement in Pain Severity (0-10 cm; Higher Score on Pain Scale is Worse)2-month post-injection2-point reduction in pain Visual Analog Scale (VAS) from baseline to the 2-month follow-up visit, which is considered clinically meaningful Change in Pain Severity; Pain Severity on VAS ranges from 0 (no pain) to 10 (maximum pain)

Secondary

MeasureTime frameDescription
Physician Global Assessment of Response to Treatment2-month (primary end-point)Physician global assessed on an ordinal scale with very much improved category as the outcome of interest (compared to all other categories of global assessment as reference category)
Physical Function Subscale of the WOMAC at 2-months2-monthPhysical Function subscale score of the WOMAC at 2-months on a 0 (best physical function) to 100 (worst physical function), with higher score indicating worse physical function
WOMAC Stiffness (0-100)2-monthsWOMAC stiffness subscale score on 0-100 scale at 2-month follow-up visit with scores ranging 0 (no joint stiffness) to 100 (worst joint stiffness), with higher score indicating worse joint stiffness
Timed Up-and-go (TUG) Test2-monthTime to get up from a chair, walk 3 meters turn back and sit in the chair in seconds at the 2-month visit (higher number is worse, i.e., taking a longer time to complete the task is worse)
QOL: SF-36 Score Physical Functioning Scale, a Generic Health Status Measure2-monthShort Form (SF)-36 physical functioning subscale on 0-100, at 2-month FU visit, as a generic health status measure, with a score ranging from 0 (worst physical functioning) to 100 (best physical functioning), with higher score indicating better physical functioning (higher number is better)
Number of Participants With Occurrence of Joint Erythema, Warmth, Swelling or TendernessUpto 6 monthsOccurence of any of the above clinical features (erythema, warmth, swelling or tenderness) as a new finding compared to the absence of the same feature at baseline
Manual Muscle Strength Testing of Knee Flexion and ExtensionUpto 6-monthsOccurence of decrease in strength of knee flexion or extension at any of the follow-up visits, as measured by the Manual muscle strength testing (MMT) with scores ranging 0-5; 0 indicates None: No visible or palpable contraction; 1 indicates Trace: Visible or palpable contraction with no motion; 2 indicates Poor: Full range of motion (ROM) gravity eliminated; 3 indicates Fair: Full ROM against gravity; 4 indicates Good: Full ROM against gravity, moderate resistance; and 5 indicates Normal: Full ROM against gravity, maximal resistance
Mean Pain VAS (0-10)2-months post-injectionVAS pain score at 2-month post-injection; Pain Severity on VAS ranges from 0 (no pain) to 10 (maximum pain) with higher score indicating worse pain
Change in Serum Cytokine (Interleukin 7) Levels at 2-month Post-injectionBaseline to 2-monthsThe change in serum interleukin 7 was defined as the difference between the follow-up (2-month) and the baseline value of serum interleukin 7. We compared the mean change in serum interleukin 7 levels between the WOMAC pain responders vs. the WOMAC pain non-responders.
McGill Sensory Pain Score2-monthMcGill Sensory pain score on 0-33 at 2-month FU visit (higher score is worse)
Change in Serum Cytokine (Interleukin 10) Levels at 2-month Post-injectionBaseline to 2-monthsThe change in serum interleukin 10 was defined as the difference between the follow-up (2-month) and the baseline value of serum interleukin 10. We compared the mean change in serum interleukin 10 levels between the WOMAC pain responders vs. the WOMAC pain non-responders.
Change in Serum Cytokine (Interleukin 12 p70) Levels at 2-month Post-injectionBaseline to 2-monthsThe change in serum interleukin 12 p70 was defined as the difference between the follow-up (2-month) and the baseline value of serum interleukin 12 p70. We compared the mean change in serum interleukin 12 p70 levels between the WOMAC pain responders vs. the WOMAC pain non-responders.
Change in Serum Cytokine (Eotaxin) Levels at 2-month Post-injectionBaseline to 2-monthsThe change in serum Eotaxin was defined as the difference between the follow-up (2-month) and the baseline value of serum Eotaxin. We compared the mean change in serum Eotaxin levels between the WOMAC pain responders vs. the WOMAC pain non-responders.
Change in Serum Cytokine (Interferon Gamma) Levels at 2-month Post-injectionBaseline to 2-monthsThe change in serum Interferon Gamma was defined as the difference between the follow-up (2-month) and the baseline value of serum Interferon Gamma. We compared the mean change in serum Interferon Gamma levels between the WOMAC pain responders vs. the WOMAC pain non-responders.
Change in Serum Cytokine (Tumor Necrosis Factor Alpha) Levels at 2-month Post-injectionBaseline to 2-monthsThe change in serum tumor necrosis factor alpha was defined as the difference between the follow-up (2-month) and the baseline value of serum tumor necrosis factor alpha. We compared the mean change in serum tumor necrosis factor alpha levels between the WOMAC pain responders vs. the WOMAC pain non-responders.
McGill Affective Dimension2-monthMcGill Affective Dimension Score on 0-12 scale at 2-months (higher number is worse)

Countries

United States

Participant flow

Recruitment details

Of the 194 TKAs (188 patients) screened, 60 TKAs (54 patients) were recruited in the 6-month study. Main analyses were performed only on 49 TKAs, after excluding bilateral TKAs, to meet the assumption of independence of observations.

Pre-assignment details

No enrolled participants were excluded from analyses. Main analyses were done for Single TKA per patient, since 6 were bilateral TKAs; sensitivity analyses were done on all, regardless of unilateral or bilateral

Participants by arm

ArmCount
Intra-articular Botulinum Toxin
Single Intra-articular Injection of 100 units of Botulinum toxin A in 5 cc of normal saline in the Painful TKA at screening visit
25
Intra-articular Placebo
Single Intra-articular Injection of 5 cc of normal saline in the Painful TKA at screening visit
29
Total54

Withdrawals & dropouts

PeriodReasonFG000FG001
Overall StudyLost to Follow-up32
Overall StudyPhysician Decision01
Overall Studypt. wanted to have a surgical procedure01

Baseline characteristics

CharacteristicIntra-articular Botulinum ToxinIntra-articular PlaceboTotal
Age, Continuous67 years
STANDARD_DEVIATION 10
67 years
STANDARD_DEVIATION 12
67 years
STANDARD_DEVIATION 11
Race/Ethnicity, Customized
caucasian
24 participants28 participants52 participants
Race/Ethnicity, Customized
Non-Caucasian
1 participants1 participants2 participants
Sex: Female, Male
Female
5 Participants3 Participants8 Participants
Sex: Female, Male
Male
20 Participants26 Participants46 Participants

Adverse events

Event typeEG000
affected / at risk
EG001
affected / at risk
deaths
Total, all-cause mortality
— / —— / —
other
Total, other adverse events
19 / 2323 / 26
serious
Total, serious adverse events
3 / 239 / 26

Outcome results

Primary

Participants With Clinically Meaningful Improvement in Pain Severity (0-10 cm; Higher Score on Pain Scale is Worse)

2-point reduction in pain Visual Analog Scale (VAS) from baseline to the 2-month follow-up visit, which is considered clinically meaningful Change in Pain Severity; Pain Severity on VAS ranges from 0 (no pain) to 10 (maximum pain)

Time frame: 2-month post-injection

Population: all with follow-up data, allowing only single TKA per participant

ArmMeasureValue (NUMBER)
Intra-articular Botulinum ToxinParticipants With Clinically Meaningful Improvement in Pain Severity (0-10 cm; Higher Score on Pain Scale is Worse)15 participants
Intra-articular PlaceboParticipants With Clinically Meaningful Improvement in Pain Severity (0-10 cm; Higher Score on Pain Scale is Worse)9 participants
Secondary

Change in Serum Cytokine (Eotaxin) Levels at 2-month Post-injection

The change in serum Eotaxin was defined as the difference between the follow-up (2-month) and the baseline value of serum Eotaxin. We compared the mean change in serum Eotaxin levels between the WOMAC pain responders vs. the WOMAC pain non-responders.

Time frame: Baseline to 2-months

Population: This protocol modification was made in the middle of the trial conduct, based on a suggestion on the K-12 application. Therefore, the total number of patients with these data is smaller than the total number of participants.

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinChange in Serum Cytokine (Eotaxin) Levels at 2-month Post-injection7.85 pg/mlStandard Deviation 12.28
Intra-articular PlaceboChange in Serum Cytokine (Eotaxin) Levels at 2-month Post-injection-2.03 pg/mlStandard Deviation 13.92
p-value: 0.046t-test, 2 sided
Secondary

Change in Serum Cytokine (Interferon Gamma) Levels at 2-month Post-injection

The change in serum Interferon Gamma was defined as the difference between the follow-up (2-month) and the baseline value of serum Interferon Gamma. We compared the mean change in serum Interferon Gamma levels between the WOMAC pain responders vs. the WOMAC pain non-responders.

Time frame: Baseline to 2-months

Population: This protocol modification was made in the middle of the trial conduct, based on a suggestion on the K-12 application. Therefore, the total number of patients with these data is smaller than the total number of participants.

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinChange in Serum Cytokine (Interferon Gamma) Levels at 2-month Post-injection15.61 pg/mlStandard Deviation 13.35
Intra-articular PlaceboChange in Serum Cytokine (Interferon Gamma) Levels at 2-month Post-injection-1.24 pg/mlStandard Deviation 23.18
p-value: 0.03t-test, 2 sided
Secondary

Change in Serum Cytokine (Interleukin 10) Levels at 2-month Post-injection

The change in serum interleukin 10 was defined as the difference between the follow-up (2-month) and the baseline value of serum interleukin 10. We compared the mean change in serum interleukin 10 levels between the WOMAC pain responders vs. the WOMAC pain non-responders.

Time frame: Baseline to 2-months

Population: This protocol modification was made in the middle of the trial conduct, based on a suggestion on the K-12 application. Therefore, the total number of patients with these data is smaller than the total number of participants.

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinChange in Serum Cytokine (Interleukin 10) Levels at 2-month Post-injection27.72 pg/mlStandard Deviation 21.56
Intra-articular PlaceboChange in Serum Cytokine (Interleukin 10) Levels at 2-month Post-injection8.51 pg/mlStandard Deviation 20.9
p-value: 0.01t-test, 2 sided
Secondary

Change in Serum Cytokine (Interleukin 12 p70) Levels at 2-month Post-injection

The change in serum interleukin 12 p70 was defined as the difference between the follow-up (2-month) and the baseline value of serum interleukin 12 p70. We compared the mean change in serum interleukin 12 p70 levels between the WOMAC pain responders vs. the WOMAC pain non-responders.

Time frame: Baseline to 2-months

Population: This protocol modification was made in the middle of the trial conduct, based on a suggestion on the K-12 application. Therefore, the total number of patients with these data is smaller than the total number of participants.

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinChange in Serum Cytokine (Interleukin 12 p70) Levels at 2-month Post-injection12.91 pg/mlStandard Deviation 9.6
Intra-articular PlaceboChange in Serum Cytokine (Interleukin 12 p70) Levels at 2-month Post-injection3.36 pg/mlStandard Deviation 8.17
p-value: 0.004t-test, 2 sided
Secondary

Change in Serum Cytokine (Interleukin 7) Levels at 2-month Post-injection

The change in serum interleukin 7 was defined as the difference between the follow-up (2-month) and the baseline value of serum interleukin 7. We compared the mean change in serum interleukin 7 levels between the WOMAC pain responders vs. the WOMAC pain non-responders.

Time frame: Baseline to 2-months

Population: This protocol modification was made in the middle of the trial conduct, based on a suggestion on the K-12 application. Therefore, the total number of patients with these data is smaller than the total number of participants.

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinChange in Serum Cytokine (Interleukin 7) Levels at 2-month Post-injection1.07 pg/mlStandard Deviation 1.17
Intra-articular PlaceboChange in Serum Cytokine (Interleukin 7) Levels at 2-month Post-injection0.08 pg/mlStandard Deviation 0.91
p-value: 0.01t-test, 2 sided
Secondary

Change in Serum Cytokine (Tumor Necrosis Factor Alpha) Levels at 2-month Post-injection

The change in serum tumor necrosis factor alpha was defined as the difference between the follow-up (2-month) and the baseline value of serum tumor necrosis factor alpha. We compared the mean change in serum tumor necrosis factor alpha levels between the WOMAC pain responders vs. the WOMAC pain non-responders.

Time frame: Baseline to 2-months

Population: This protocol modification was made in the middle of the trial conduct, based on a suggestion on the K-12 application. Therefore, the total number of patients with these data is smaller than the total number of participants.

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinChange in Serum Cytokine (Tumor Necrosis Factor Alpha) Levels at 2-month Post-injection22.22 pg/mlStandard Deviation 24.65
Intra-articular PlaceboChange in Serum Cytokine (Tumor Necrosis Factor Alpha) Levels at 2-month Post-injection4.46 pg/mlStandard Deviation 21.32
p-value: 0.03t-test, 2 sided
Secondary

Manual Muscle Strength Testing of Knee Flexion and Extension

Occurence of decrease in strength of knee flexion or extension at any of the follow-up visits, as measured by the Manual muscle strength testing (MMT) with scores ranging 0-5; 0 indicates None: No visible or palpable contraction; 1 indicates Trace: Visible or palpable contraction with no motion; 2 indicates Poor: Full range of motion (ROM) gravity eliminated; 3 indicates Fair: Full ROM against gravity; 4 indicates Good: Full ROM against gravity, moderate resistance; and 5 indicates Normal: Full ROM against gravity, maximal resistance

Time frame: Upto 6-months

Population: patients providing the data

ArmMeasureValue (NUMBER)
Intra-articular Botulinum ToxinManual Muscle Strength Testing of Knee Flexion and Extension0 participants
Intra-articular PlaceboManual Muscle Strength Testing of Knee Flexion and Extension0 participants
Secondary

McGill Affective Dimension

McGill Affective Dimension Score on 0-12 scale at 2-months (higher number is worse)

Time frame: 2-month

Population: patients providing data

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinMcGill Affective Dimension3.8 units on a scaleStandard Deviation 3.1
Intra-articular PlaceboMcGill Affective Dimension4.8 units on a scaleStandard Deviation 3.4
Secondary

McGill Sensory Pain Score

McGill Sensory pain score on 0-33 at 2-month FU visit (higher score is worse)

Time frame: 2-month

Population: patients providing data

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinMcGill Sensory Pain Score14.5 units on a scaleStandard Deviation 8
Intra-articular PlaceboMcGill Sensory Pain Score14.6 units on a scaleStandard Deviation 7.5
Comparison: For primary outcome analysis, we compared the proportion of responders with clinically meaningful change \[improvement\] in 0-10 VAS Pain, i.e. those with 2-point reduction in 0-10 VAS pain score at 2-mths, in the 2 groups using comparison of proportions. Proportion of responders were also analyzed at all efficacy timepoints using generalized estimating equation (GEE) modeling. We used GEE for between-group comparisons in secondary outcomes at all efficacy endpoints, adjusted for baseline scores.p-value: <0.05comparison of proportions
Secondary

Mean Pain VAS (0-10)

VAS pain score at 2-month post-injection; Pain Severity on VAS ranges from 0 (no pain) to 10 (maximum pain) with higher score indicating worse pain

Time frame: 2-months post-injection

Population: patients providing pain VAS data at 2-month FU visit

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinMean Pain VAS (0-10)4.4 units on pain VAS scaleStandard Deviation 2.5
Intra-articular PlaceboMean Pain VAS (0-10)5.7 units on pain VAS scaleStandard Deviation 2.9
Secondary

Number of Participants With Occurrence of Joint Erythema, Warmth, Swelling or Tenderness

Occurence of any of the above clinical features (erythema, warmth, swelling or tenderness) as a new finding compared to the absence of the same feature at baseline

Time frame: Upto 6 months

Population: patients providing data

ArmMeasureValue (NUMBER)
Intra-articular Botulinum ToxinNumber of Participants With Occurrence of Joint Erythema, Warmth, Swelling or Tenderness0 participants
Intra-articular PlaceboNumber of Participants With Occurrence of Joint Erythema, Warmth, Swelling or Tenderness0 participants
Secondary

Physical Function Subscale of the WOMAC at 2-months

Physical Function subscale score of the WOMAC at 2-months on a 0 (best physical function) to 100 (worst physical function), with higher score indicating worse physical function

Time frame: 2-month

Population: people providing data at 2-months

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinPhysical Function Subscale of the WOMAC at 2-months48.5 units on a scaleStandard Deviation 14.1
Intra-articular PlaceboPhysical Function Subscale of the WOMAC at 2-months59.7 units on a scaleStandard Deviation 17.4
Secondary

Physician Global Assessment of Response to Treatment

Physician global assessed on an ordinal scale with very much improved category as the outcome of interest (compared to all other categories of global assessment as reference category)

Time frame: 2-month (primary end-point)

Population: 2 patients did not have the outcome assessment; 1 lost to FU

ArmMeasureValue (NUMBER)
Intra-articular Botulinum ToxinPhysician Global Assessment of Response to Treatment6 participants
Intra-articular PlaceboPhysician Global Assessment of Response to Treatment0 participants
Secondary

QOL: SF-36 Score Physical Functioning Scale, a Generic Health Status Measure

Short Form (SF)-36 physical functioning subscale on 0-100, at 2-month FU visit, as a generic health status measure, with a score ranging from 0 (worst physical functioning) to 100 (best physical functioning), with higher score indicating better physical functioning (higher number is better)

Time frame: 2-month

Population: patients providing data

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinQOL: SF-36 Score Physical Functioning Scale, a Generic Health Status Measure30.7 units on a scaleStandard Deviation 21.8
Intra-articular PlaceboQOL: SF-36 Score Physical Functioning Scale, a Generic Health Status Measure23.6 units on a scaleStandard Deviation 17.5
Secondary

Timed Up-and-go (TUG) Test

Time to get up from a chair, walk 3 meters turn back and sit in the chair in seconds at the 2-month visit (higher number is worse, i.e., taking a longer time to complete the task is worse)

Time frame: 2-month

Population: patients providing data

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinTimed Up-and-go (TUG) Test17.2 secondsStandard Deviation 18.2
Intra-articular PlaceboTimed Up-and-go (TUG) Test9.6 secondsStandard Deviation 13.8
Secondary

WOMAC Stiffness (0-100)

WOMAC stiffness subscale score on 0-100 scale at 2-month follow-up visit with scores ranging 0 (no joint stiffness) to 100 (worst joint stiffness), with higher score indicating worse joint stiffness

Time frame: 2-months

Population: patients providing the data

ArmMeasureValue (MEAN)Dispersion
Intra-articular Botulinum ToxinWOMAC Stiffness (0-100)51.8 units on a scaleStandard Deviation 19.1
Intra-articular PlaceboWOMAC Stiffness (0-100)60.4 units on a scaleStandard Deviation 16.3

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026