Plain English Summary
Background and study aims
Knee replacement, also known as knee arthroplasty, is a surgical procedure to replace the weight-bearing surfaces of the knee joint to relieve pain and disability. It is most commonly performed for osteoarthritis, and also for other knee diseases such as rheumatoid arthritis and psoriatic arthritis.
Unicompartmental knee arthroplasty (UKA) is a surgical procedure used to relieve arthritis in one of the knee compartments in which the damaged parts of the knee are replaced. UKA surgery may reduce post-operative pain and have a shorter recovery period than a total knee arthroplasty (TKA) procedure.
Utilization of tourniquet is considered to compromise the outcome of knee arthroplasty. This study aims to evaluate the hidden blood loss and function restoration of UKA without tourniquet by comparing with total knee arthroplasty (TKA).
Who can participate?
Adults over 18 years, scheduled to undergo UKA or TKA
What does the study involve?
This study is a retrospective analysis of patient records looking at patients who underwent UKA or TKA without tourniquet.
What are the possible benefits and risks of participating?
Where is the study run from?
Department of Orthopedic Surgery, The First People’s Hospital of Huzhou, Huzhou (China)
When is the study starting and how long is it expected to run for?
August 2017 to December 2019
Who is funding the study?
Department of Orthopedic Surgery, the Second Affiliated Hospital, School of Medicine, Zhejiang University (China)
Who is the main contact?
Dr Zhanfeng Zhang
Blood loss and knee function after unicompartmental knee arthroplasty (UKA) without tourniquet
1. UKA or TKA without tourniquet results in lower blood loss compared to with tourniquet.
2. UKA without tourniquet results in less HBL compared with TKA
3. UKA without tourniquet enjoys a better outcome than TKA
Approved 06/06/2019, Medical Ethics Committee of The First People's Hospital of Huzhou (The First People’s Hospital of Huzhou, 158 Guangchang Back Rd, Wuxing District, Huzhou, 313000, China; +86 (0)572 2508930; email@example.com), ref: 2019035
Single-center retrospective controlled study
Primary study design
Secondary study design
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
In this retrospective study, patients were included from August 2017 to October 2018. Both the UKA group and the TKA group underwent procedure without the utilization of tourniquet during the whole process.
The gender, age, body mass index, American Society of Anesthesiologists score, Kellgren-Lawrence grade, perioperative Hb, and volume of hidden blood loss (HBL) were recorded and analysed.
Knee function was assessed at 3 months and 12 months after the procedure by using HSS score.
Primary outcome measure
1. Mean volume of HBL during the procedure (ml)
2. Knee function assessed at 3 months and 12 months after the procedure by HSS score
Secondary outcome measures
Hb level measured using blood test on the 2nd day, 4th day, 6th day, 8th day postoperatively
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Primary UKA or TKA
2. Kellgren-Lawrence (KL) grade of medial knee osteoarthritis grade Ⅳ
Target number of participants
56 cases of UKA, and 56 cases of TKA
Total final enrolment
Participant exclusion criteria
1. Preoperative abnormality in coagulation function, hematonosis history
2. Postoperative poor general situation
3. More than 2000ml per day in fluid infusion
4. Simultaneous bilateral UKA or TKA, and UKA or TKA secondary to a failed arthroplasty procedure
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
Department of Orthopedic Surgery
The First People’s Hospital of Huzhou 158 Guangchang Back Rd Wuxing District
The First People’s Hospital of Huzhou
158 Guangchang Back Rd
+86 0572 2508930
Zhejiang University School of Medicine, Second affiliated hospital
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication in a high-impact peer-reviewed journal.
IPD sharing statement:
The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
Intention to publish date
Participant level data
Available on request
Basic results (scientific)