How preserved tendons change rehabilitation from day one

The difference begins with what is not cut.

In a standard posterior hip replacement, the surgeon divides the piriformis tendon, the obturator internus tendon, and the obturator externus — short rotator muscles that cross the back of the hip joint. Severing them creates a 90-day healing window during which the joint lacks its natural posterior restraint. Dislocation risk is at its highest, and strict movement restrictions follow: no hip flexion beyond 90 degrees, no crossing the legs, no internal rotation. These precautions are not simply cautious advice — they reflect a genuine anatomical gap in the joint's defences while damaged tissue scars and reattaches.

The SPAIRE technique (Saves Piriformis And Internus, Repairs Externus) leaves the piriformis and obturator internus intact, and repairs rather than sacrifices the obturator externus. The obturator internus tendon travels directly over the posterior femoral head; when preserved, its anatomical path generates a continuous passive tension — a 'strap effect' — that holds the joint stable from the moment the wound is closed, without depending on any healing process.

Woven through those same preserved tendons are muscle spindles and Golgi tendon organs — mechanoreceptors that relay continuous position signals to the brain. Keeping them intact means the hip remains neurologically aware of its own position from day one, a capacity that is lost when these structures are divided and can only return as tissue regenerates.

It is these two properties together — immediate mechanical stability and uninterrupted proprioceptive feedback — that remove the anatomical rationale for the most restrictive elements of traditional post-operative physiotherapy, and on which the SPAIRE rehabilitation approach is built. How that translates into practical exercise progression, and what it means day to day for a patient, is what the sections that follow address.

The first 48 hours: what happens before you go home

On the ward, physiotherapy begins within hours of leaving the operating theatre — not the following morning, and not once the pain settles. This early start is deliberate.

Ankle pumps — rhythmically moving the feet up and down — activate the calf muscle pump to reduce the risk of blood pooling in the lower legs during those first hours of stillness. Quadriceps sets involve pressing the back of the knee gently into the bed, firing the thigh muscles that will carry load the moment you stand. Gluteal squeezes begin waking the muscles that stabilise the pelvis during walking. None of these exercises strains the hip; each one prepares the body to trust it.

Standing and taking first steps usually follow on the same day, guided by the inpatient physiotherapy team. Because SPAIRE preserves the posterior tendons, the physiotherapist is not managing a flexion limit here — they are watching for confidence, weight distribution, and steadiness on the operated side.

For selected patients on the Biological Rapid Recovery pathway developed by Professor Paul Lee — the Consultant Orthopaedic Surgeon leading this approach — discharge within 24 hours is a realistic aim. Physiotherapy readiness is one of the gatekeeping factors. So too are the home environment, pre-operative strength, and the level of support available at home. Not every patient reaches that point on the same schedule, and the decision rests with the clinical team on the day.

Weeks 2–6: building strength and gait confidence

Between roughly the second and sixth week, the programme shifts its weight from activation to loading — from waking muscles up to making them work.

The core exercises in this phase are heel slides (gliding the heel toward the buttock while lying down, restoring flexion range without ballistic force), standing hip abduction (lifting the leg to the side to target the gluteus medius and resist the Trendelenburg lean that makes early walking look effortful), and straight leg raises (rebuilding quadriceps strength in a controlled, single-leg pattern). These feed into progressive gait training with whatever walking aid the patient currently needs — initially a frame, typically transitioning to a stick as strength accumulates.

What changes in SPAIRE rehabilitation is the physiotherapist's decision-making framework. Without a fixed flexion ceiling, exercise selection and range are calibrated against load tolerance and the patient's own confidence and pain response. The therapist is coaching gait quality — reducing a Trendelenburg lean, lengthening stride, smoothing the transition through the stance phase — rather than monitoring an angular limit.

The intact short external rotators contribute here in a practical way: because the mechanoreceptors within those tendons are still active, patients often report that confidence on the operated side builds more naturally than they expected. The hip is already sending positional information to the brain; the exercises channel it.

The pace within this phase varies — patients who arrived at surgery with reasonable hip strength typically move through it faster. But whether progress is quicker or more measured, the governing principle is the same: what can the hip load and control, not what position must it avoid.

Week 6 onward: returning to everyday function

Reaching six weeks marks a shift in the programme's orientation — away from restoring basic movement and toward rebuilding the functional strength that daily life actually demands.

Step-ups develop the eccentric quad control needed to manage stairs and kerbs; mini-squats and resistance band work load the gluteals and hip abductors under progressively greater challenge, addressing the muscle groups most responsible for a smooth, balanced gait. Stationary cycling builds cardiovascular endurance with minimal joint loading, making it well-suited to this stage. Each exercise maps to something the patient will need at home: carrying a light bag of shopping, lowering into a car seat, walking an uneven pavement.

Functional activities — getting in and out of vehicles, navigating slopes, managing low-impact walking routes — are introduced as tolerance allows, rather than held back for a fixed healing period. Because the posterior tendons remain intact, the physiotherapist is adjusting load and distance in response to the patient's strength and confidence, not to a countdown on tissue repair.

Return to recreational activity such as swimming, cycling, and longer walks is broadly realistic from around three months, though the exact point depends on individual progress and baseline fitness. Standing or physically demanding work typically takes eight to twelve weeks; sedentary or desk-based roles are often manageable earlier, subject to comfort and travel arrangements.

The core and gluteal strength built across this phase has value beyond the recovery period itself. Robust hip stabilisers reduce the long-term risk of a persistent limp, protect the lumbar spine, and improve balance — outcomes that remain relevant well past the point where most patients stop thinking of themselves as recovering.

Realistic milestones: what most patients can expect and when

Milestones after hip replacement are best understood as ranges rather than fixed dates — the SPAIRE pathway is designed to support earlier progress than a traditional posterior approach, but the precise pace still depends on the individual's baseline strength, home environment, and how recovery unfolds in the weeks after surgery.

The following milestones reflect what most patients on this pathway experience:

• Walking without a stick — typically around week six for patients who entered surgery with reasonable hip strength, though some patients manage earlier and others need a little longer.
• Driving — usually six to eight weeks for an automatic vehicle, subject to the ability to perform an emergency stop comfortably and confirmed by surgeon sign-off; manual transmission may take longer.
• Desk-based or sedentary work — often manageable within two to four weeks, depending on comfort, commute demands, and whether the role requires sustained sitting.
• Standing or physically demanding work — typically eight to twelve weeks; a phased return is appropriate for many patients.
• Recreational activity (walking longer routes, swimming, cycling) — broadly from around three months, progressing in line with individual strength and fitness.

These are realistic guides, not guarantees. Professor Lee's team reviews progress at follow-up appointments and adjusts expectations accordingly — the milestone that matters most is the one that fits each patient's recovery, not the one printed on a generic chart.

How Professor Lee's programme is structured around each patient

The exercises and milestones described so far reflect shared principles — what applies those principles is an individually constructed programme that begins before surgery.

In the weeks beforehand, prehabilitation — muscle conditioning, cardiovascular preparation, and nutritional support — builds the functional baseline that early post-operative mobilisation depends upon. Starting physiotherapy three to four weeks before the operation means arriving at the ward with stronger quadriceps and gluteals, and a familiarity with the movement patterns that will matter again from day one. That preparation matters because the SPAIRE approach removes the ceiling on early exercise choice; it does not automatically supply the strength to take advantage of it.

Post-operatively, the programme is shaped around each patient's procedure, baseline strength, and confidence rather than a standard protocol applied uniformly. The pace of loading, the exercise selection within each phase, and the transition to functional activity are calibrated to what the individual can safely and confidently do — not to what a generic chart suggests at a given week.

Professor Paul Lee, who trained at the Exeter Hip Unit under Professor Timperley before making SPAIRE his routine practice, designed this pathway to connect surgical planning, implant selection, early mobilisation, and physiotherapy into a coherent whole rather than a sequence of separate handoffs. Suitability for the pathway is assessed individually; not every patient is a candidate for early discharge, and that assessment determines which elements apply to whom.

For a patient who has spent months limited by hip pain, the practical difference is a physiotherapy plan that adjusts to their actual progress — one that responds to what they can do, not to how many days have elapsed since surgery.