In individuals undergoing simultaneous bilateral total knee replacement, does making a lateral skin incision affect skin sensation, ability to kneel and patient satisfaction?

In individuals undergoing simultaneous bilateral total knee replacement, does making a lateral skin incision affect skin sensation, ability to kneel and patient satisfaction.

Status

Completed

Phases

Unknown

Study type

Interventional

Source

ANZCTR

Registry ID

ACTRN12616001706460

Enrollment

Registered

2016-12-13

Start date

2017-06-19

Completion date

2019-03-21

Last updated

2021-07-26

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

Conditions

None listed

Brief summary

The initial skin incision performed to expose the knee during total knee arthroplasty (TKA) is centred over the patella for ease of access to the joint. This places the scar directly over the bony points of the knee that bear load when kneeling, leaving the skin on the lateral side (outside) of the scar with reduced sensation and sometimes the skin on the medial side (inside) of the scar with painfully altered sensation (dysaesthesiae / neuromata). Placing the skin incision lateral to the edge of the patella (kneecap) avoids the necessity of kneeling on a scar and has been shown to reduced dysaesthesiae and neuromata in other knee procedures. Primary Aim: To prove that lateral skin incisions improve the ability to kneel in patients following bilateral total knee arthroplasty Secondary Aim: 1.Investigate whether lateral skin incision has improved retention of skin sensation. 2.Investigate the ability to kneel after TKA. 3.Investigate if there is improved deep flexion. 4.Investigate whether there is decreased pain and better satisfaction as per patient reported outcome measures (PROM) Research Design: Prospective, Randomized Controlled Trial. Patient Demographic: Eligible patients aged between 40-90 years of age with bilateral, tri-compartmental osteoarthritis (OA),undergoing simultaneous bilateral TKA. Patients with previous knee arthrotomy (cut to the joint capsule) will be excluded. Patients' limbs will be randomized for surgery into two groups; (1) Midline Incision Group and (2) Lateral Incision Group. Outcomes:measured at, six months, and 12 months post-operatively. - Knee flexion and extension. - Kneeling Grade Assessment- a novel grading system has been developed that Grades the ability to kneel from 1-5 depending on how far down the patient can knee. - Area of skin dysaesthesia (uncomfortable change in skin sensation) will be mapped and analyzed using imaging software. - Neuroma formation. - PROMs (patient reported outcome measures).

Interventions

Patients will undergo a total knee replacement in both knees to treat osteoarthritis. Two different skin incisions will be used. The study exposure called the lateral incision. It is an incision that starts 5cm midline above the patella (knee cap) and as is curved inferiorly (down the knee) and laterally (the outer side edge) around the patella. It finishes curving back once passed the patella towards the midline of the tibia (shin). (Please see study protocol attached to ANZCTR registration form for images.) We hypothesize that the more lateral or towards the outside of the knee the incision is, the less insensate skin on the outer side of the knee will be and the patient will be able to kneel better. The lateral skin incision will be performed with a scalpel. Deeper dissection will be performed with diathermy cautery. Skin flaps will be mobilised. A midvastus medial parapatellar arthrotomy will be done and the knee joint exposed with the patella flipped laterally Computer navigation will be used. The surgery will take 60-90 minutes.

Study design

Allocation

Randomised controlled trial

Intervention model

Parallel

Primary purpose

Treatment

Masking

Open (masking not used)

Eligibility

Sex/Gender

All

Age

40 Years to 90 Years

Healthy volunteers

Inclusion criteria

Patients scheduled to undergo bilateral knee arthroplasty Male and female Age 40-90 Able to provide informed consent

Exclusion criteria

Conditions causing altered sensation up to knee- Diabetic Neuropathy, regional pain syndrome Previous open surgical procedure to knee Patients with inflammatory arthritis Patients not suitable for patella resurfacing

Outcome results