Recovering from knee surgery takes time, patience, and the right kind of support. One option often used to improve movement and confidence after procedures like total knee replacement, robotic-assisted knee surgery, or ligament reconstruction is hydrotherapy. Also known as aquatic physiotherapy, hydrotherapy after knee surgery uses water-based movement to gently reintroduce mobility in a safe, supported environment.
It isn’t about soaking in a spa or swimming laps. It’s structured, therapeutic exercise guided by qualified professionals. The goal? To restore function without overloading the healing joint too early.
Whether you’ve had a traditional knee procedure or robotic-assisted surgery using platforms like Mako SmartRobotics™ or the VELYS™ Robotic-Assisted Solution, hydrotherapy may offer meaningful benefits in the right stage of your rehabilitation. This article explores how and when hydrotherapy can help, and what to expect if it’s recommended as part of your post-op plan.
Why Water Helps After Knee Surgery
Water creates a naturally supportive environment for movement, especially after joint surgery. Its buoyancy reduces the impact of gravity, allowing for gentler motion without placing full weight on your recovering knee.
Warm water, typically maintained at 32–34°C in clinical hydrotherapy pools, can also ease joint stiffness and promote circulation. This can help reduce swelling, improve comfort, and allow you to focus on retraining muscle patterns and regaining range of motion.
The added resistance of water, even when just walking, also supports low-impact muscle strengthening. Unlike land-based exercise, water lets you move earlier with more confidence, which is especially helpful when land exercises feel painful or unstable.
It also allows the brain and body to reconnect through rhythmic, repeated movements, helping rebuild proprioception, the sense of joint position and coordination, which can be temporarily disrupted after surgery.
When Can You Start?
The right time to begin hydrotherapy depends on the type of surgery, your wound healing, and your surgeon’s protocol.
For total knee replacements, including those performed using robotic-assisted systems like Mako or VELYS, hydrotherapy is generally introduced once the surgical wound has fully closed, usually around 2 to 4 weeks post-operation. For less invasive procedures, such as arthroscopy or minor ligament repairs, entry to hydrotherapy may occur slightly sooner.
Timing must always be guided by your orthopaedic knee surgeon in Sydney or physiotherapist. Starting too early, particularly before the incision is sealed, can increase infection risk. Clearance is essential before entering a pool, even for gentle walking or water-based stretches.
It’s also important to monitor wound healing closely during this time, as even small openings in the skin can pose a barrier to safe hydrotherapy entry, especially in shared or public-use pools.
What Does a Session Look Like?
A hydrotherapy session is typically led by a physiotherapist and tailored to your stage of recovery. Sessions usually last 20 to 40 minutes and are held in a heated pool specifically designed for therapeutic use.
You might begin with simple activities like:
- Walking forward, backward, or sideways in waist-high water
- Gentle knee bends or straight leg raises
- Light squats or balance drills using floatation tools
These exercises are designed to target range of motion, strength, balance, and coordination, without aggravating the healing joint. Some patients attend one-on-one sessions, while others may join small rehab groups. Either way, the pace is adjusted to your needs and energy levels on the day.
Your physiotherapist may also gradually introduce directional changes or controlled step patterns to retrain walking symmetry, especially useful for those who’ve developed compensations due to pre-surgery pain.
This stage may also be when you begin noticing gradual improvements in how you walk. Tracking walking milestones after knee surgery, such as smoother step transitions, more balanced weight distribution, or improved endurance over short distances, can help you and your care team gauge your progress over time.
Who Can Benefit From Hydrotherapy (And Who Should Wait)
Hydrotherapy can be particularly helpful if you’re:
- Struggling with pain or swelling during land-based rehab
- Hesitant to put full weight through the operated leg
- Experiencing early stiffness, joint tightness, or altered walking patterns
However, it’s not appropriate for everyone. You may need to delay or avoid hydrotherapy if:
- Your wound has not fully healed
- You have an active infection, fever, or an untreated heart condition
- You experience dizziness, uncontrolled epilepsy, or incontinence
Your physiotherapy team will assess your readiness and determine whether water-based therapy is safe and suitable for your recovery stage.
Even if cleared medically, some individuals may initially feel anxious about water-based movement, especially after falls or long-standing knee instability, so psychological readiness is also considered during screening.
Robotic Surgery and Hydrotherapy: Is There a Difference?
Robotic-assisted knee surgery, such as procedures performed using Mako SmartRobotics™ or the VELYS™ Robotic-Assisted Solution, is designed to enhance surgical precision, optimise alignment, and support smoother early recovery.
This improved joint balance may help some patients regain movement and confidence sooner. However, hydrotherapy timelines do not automatically shorten based on the type of surgery performed. Clearance still depends on wound healing and the surgeon’s clinical judgment.
That said, the stability and alignment achieved with robotic-assisted surgery may assist with early gait retraining in water, particularly when re-learning basic movement patterns like walking or standing balance.
This can be especially helpful in patients who have had significant pre-operative deformity or joint instability, as robotic systems aim to restore more consistent mechanics during recovery.
How Hydrotherapy Fits Into Your Recovery Program
Hydrotherapy is often one phase of a broader rehabilitation program, not a standalone solution. It’s typically used in the middle stages of recovery, once initial healing has occurred but before full land-based strength and function return.
Some patients may alternate between land-based physiotherapy and hydrotherapy to reduce strain, improve variety, and build confidence. Others may use water-based sessions to reintroduce movement before progressing to more intensive exercise.
Your post-surgical rehab plan may include hydrotherapy for a few weeks, then gradually taper as you build tolerance for dry-land activity. Your physiotherapist will help you decide when to phase in and out of hydrotherapy based on your functional goals and recovery progress.
It also provides a valuable recovery buffer for those managing complex rehab timelines, such as bilateral knee surgery, chronic comorbidities, or delayed strength return, where pacing and joint protection are critical.
For those who have undergone robotic-assisted procedures, reviewing the recovery timeline after robotic knee surgery can help place hydrotherapy within the wider context of your rehabilitation stages.
Finding Hydrotherapy in Sydney
If hydrotherapy is part of your post-op care plan, you’ll find several options in Sydney depending on your hospital, location, and level of coverage.
Access points include:
- Hospital-based hydrotherapy pools may be part of your inpatient or outpatient rehab
- Private physiotherapy clinics often offer tailored hydrotherapy sessions by referral
- Community pools or local rehab centres sometimes run supervised hydro classes suitable for joint recovery.
Costs can vary. Some patients use private health extras cover, while others may access hydro under GP-referred EPC (Enhanced Primary Care) plans. It’s worth checking with your physio or practice to understand fees, session length, and whether prior approval is required.
If you’re recovering under the care of Dr Jonathan Negus, hydrotherapy may be discussed as part of your wider rehabilitation pathway, particularly after procedures such as robotic knee replacement, arthroscopy, or ligament reconstruction.
Availability and pool access may also depend on proximity to specialised orthopaedic physio providers, so confirming local options early in your planning can help streamline your post-op experience.
Is It Worth It?
Hydrotherapy after knee surgery can be a gentle, progressive way to regain movement, especially when land-based rehabilitation feels limited or painful. While not essential for everyone, it offers a clinically sound, low-impact option for building confidence and function in a protected setting.
If you’re unsure whether it’s right for you, speak with your physiotherapist or surgical team. With the right timing and guidance, hydrotherapy may provide valuable support as you move through your recovery, one step at a time, even if it’s underwater.
Its greatest strength lies in offering movement without fear, a space to rebuild trust in your body, regain momentum, and take pressure off the process, both literally and figuratively.
If you’re planning knee surgery or exploring your recovery options, you can book a consultation with Dr Jonathan Negus to discuss a tailored surgical and rehabilitation pathway that may include hydrotherapy, physiotherapy, and robotic-assisted techniques where appropriate.
Frequently Asked Questions (FAQs)
1. Is hydrotherapy safe after a knee replacement?
Yes, hydrotherapy can be safe once your surgical wound has healed and your knee surgeon or physiotherapist confirms it’s appropriate. Timing varies but often starts from 2 to 4 weeks post-op.
2. Can I do hydrotherapy if I had robotic knee surgery?
Yes. Whether your procedure involved robotic-assisted technology such as Mako or VELYS, hydrotherapy may still be part of your recovery plan, guided by your healing and mobility needs.
3. Will hydrotherapy speed up my recovery?
Hydrotherapy supports safe, low-impact movement and may help improve early mobility and confidence. However, overall recovery speed depends on many factors, including the type of surgery and your individual response to rehabilitation.
4. Do I need a referral for hydrotherapy in Sydney?
Some hydrotherapy services, particularly those in private physiotherapy clinics, may require a referral. Your surgical team or GP can advise on access options and whether you’re eligible for Medicare-funded sessions.
5. Can I swim instead of doing hydrotherapy?
No. Swimming is not the same as hydrotherapy. Hydrotherapy is structured, guided rehabilitation in water, while swimming may not be safe or suitable during early recovery.
6. How long will I need hydrotherapy after surgery?
Most people attend hydrotherapy for a few weeks as part of a broader rehabilitation plan. Duration is adjusted based on progress and clinical goals.
7. Can I discuss hydrotherapy during my surgical consult?
Yes. If you’re planning knee surgery with Dr Jonathan Negus, hydrotherapy can be discussed as part of your personalised recovery plan, including when to begin, how it fits into your rehab, and what other supports may be recommended.
