Protection of Knee Joints in Bleeding Disorder Patients
Condition: Bleeding Disorder; Knee Injuries; Hemophilia
MeSH terms: Hemostatic Disorders; Blood Coagulation Disorders; Hemorrhagic Disorders; Hemorrhage; Knee Injuries
Study type: Interventional

Summary: 
      INTRODUCTION Knee supports, usually made with sponge cushion, are used to protect knee joint
      and prevent its injury. Sponge has less elasticity and durability compared with natural
      rubber. To our knowledge, there has been no study regarding effectiveness of natural rubber
      and sponge for knee joint protection and injury prevention in children with bleeding
      disorders.

      AIMS The study aimed to compare the effectiveness and satisfaction between natural rubber and
      sponge knee supports for knee joint protection among children with bleeding disorders METHODS
      The study had three phases: 1) measurement of compression force, 2) fabrication of knee
      supports, and 3) a randomized crossover trial. The supports were fabricated in 4 sizes, S, M,
      L, and XL. They comprised two parts: body, made from stretchable cotton; and cushion
      (protection part), made from either natural rubber or sponge. The trial included 8 weeks of
      alternatively wearing natural rubber knee support and sponge knee support with a 4-week
      wash-out period. Numbers of knee bleeds and satisfied users were recorded.
    

Detailed description: 
      The study employed a prospective design, conducted at the Faculty of Medicine Ramathibodi
      Hospital, a tertiary care hospital in Thailand, from April 2021 to September 2022; and
      approved by the Hospital's Committee on Human Rights Related to Research Involving Human
      Subjects (COA. MURA2021/292). Written informed consents were obtained from individual
      patients and their legal guardians. The study was divided into three phases: measurement of
      transmitted impact force, fabrication of knee supports, and randomized cross-over trial of
      natural rubber and sponge knee supports.

      Phase I: Transmitted impact forces were measured using an impact tester (Model DC Power
      Supply GW Instek GPS-30300 and Multi-Meter Fluke DT-9208a). Three types of knee support
      samples, size 30 x 30 x 1 cm (W x L x H), were prepared: with no barrier, with natural rubber
      cushion, and with sponge cushion and tested. The test was performed using the same force in
      the ballistic pendulum test (1 kg momentum ball with a radius of 50 cm). The test was
      repeated three times, and the average results were recorded as force (Newton) and time (sec)
      after the sphere hit the receptive sensor. Natural rubber used in this study was made from
      natural rubber and polymer (Patent ID 74814).

      Phase II: Knee supports were designed and fabricated in various sizes. Three measurements,
      knee circumferences, patella sizes, and knee heights, were taken from 20 Thai children aged
      between 9 months and 10 years and having body weights within the 50th to 75th percentile. The
      knee support comprised two parts, the support body and the protective cushion. The width of
      the support body was derived from half of the knee circumference, and the length was taken
      from 80% of the knee height, measured from knee to medial malleolus. From those measurements,
      final knee supports were categorized into four sizes, S, M, L and XL according to widths and
      lengths, as follows: size S, 8x17 cm; size M, 10x19 cm; size L, 12x24 cm; and size XL, 14x28
      cm. The support body was made of stretchable natural cotton fabrics, which were comfortable,
      breathable, washable, less irritant and flexible.22 Similarly, the protective cushion was
      classified into four sizes: S, M, L and XL with diameters (based on the patellar diameters)
      of 5, 6, 7 and 8 cm, respectively. Cushions were made from either natural rubber or sponge
      and inserted at the front of the support body (to cover the patellar). As a result, natural
      rubber and sponge knee supports were fabricated, and they both had similar external
      appearance.

      Phase III: A randomized cross-over trial using natural rubber and sponge knee supports was
      conducted among patients with bleeding disorders. The patients were divided into two groups,
      A and B, by computer-generated randomization sequence using a box of ten. A total of 44
      patients were enrolled with 21 in Group A and the other 23 in Group B. Later, two patients in
      Group A were excluded due to loss of follow-ups. Therefore, the final number of patients in
      the study was 42 with 19 in Group A and 23 in Group B. Group A was first assigned to
      Treatment I of natural rubber knee support followed by Treatment II of sponge knee support,
      while Group B was first assigned to Treatment II followed by Treatment I. Patients were
      advised to use the supports during physical activities; for example, walking and crawling
      among toddlers and playing sports among school-aged children. Each treatment covered a period
      of eight weeks, with four weeks of wash-out period of cross-over from the first treatment to
      the second. Survey data on demographics, number of bleeds, types of bleeding (extraarticular
      or intraarticular), and user's satisfaction were collected. User's compliance and bleeding
      data, including severity and activity when injury occurred, were collected weekly using
      freeware application, online electronic form, or direct telephone contact. Satisfaction
      survey was conducted following the Client Satisfaction with Device module of Orthotics and
      Prosthetic User' Survey (CSD-OPUS)24 with Thai translation. The survey consisted of nine
      aspects: fitting well, weight, comfort, ease to use, attractiveness, durability, irritation,
      pain, and overall satisfaction. Patients aged >7 years and all parents were included in the
      survey, sent to them in electronic format, twice; i.e., at the end of the two treatments.
      Scores were graded in absolutely agree, agree, disagree, and absolutely disagree. At the end
      of the second treatment, parents of both groups were asked to choose either the knee support
      of Treatment I or Treatment II as a preference.

      Patients The inclusion criteria were bleeding disorder patients, aged 9 months to 12 years
      old, with written consents The enrolled patients had no coexisting diseases affecting their
      activities, or bleeding episodes two weeks before the study. Children or parents who were not
      able to continue the study until the end were excluded.
    

Intervention name(s): Natural rubber knee support; Sponge knee support
Intervention type(s): Device; Device
Intervention description(s): The knee support comprised two parts, the support body and the protective cushion. Which were categorized into four sizes, S, M, L and XL according to widths and lengths, as follows: size S, 8x17 cm; size M, 10x19 cm; size L, 12x24 cm; and size XL, 14x28 cm. The support body was made of stretchable natural cotton fabrics, which were comfortable, breathable, washable, less irritant and flexible. Similarly, the protective cushion was classified into four sizes: S, M, L and XL with diameters (based on the patellar diameters) of 5, 6, 7 and 8 cm, respectively. Cushions were made from either natural rubber and inserted at the front of the support body (to cover the patellar).; The knee support comprised two parts, the support body and the protective cushion. Which were categorized into four sizes, S, M, L and XL according to widths and lengths, as follows: size S, 8x17 cm; size M, 10x19 cm; size L, 12x24 cm; and size XL, 14x28 cm. The support body was made of stretchable natural cotton fabrics, which were comfortable, breathable, washable, less irritant and flexible. Similarly, the protective cushion was classified into four sizes: S, M, L and XL with diameters (based on the patellar diameters) of 5, 6, 7 and 8 cm, respectively. Cushions were made from either sponge and inserted at the front of the support body (to cover the patellar).
Other intervention name(s): Sponge knee support
Allocation: Randomized
Intervention model: Crossover Assignment
Intervention model description: Randomized crossover trial
Masking: None (Open Label)
Primary purpose: Prevention