Why same-day discharge is possible with SPAIRE

Going home the same day as a hip replacement sounds implausible — until the biology is explained. The answer lies not in administrative shortcuts but in a single structural decision made during surgery.

In a traditional posterior hip replacement, the short external rotator tendons — principally the piriformis and obturator internus — are divided to reach the joint. Severing them removes the tissues that hold the femoral head in the socket. The joint is stable again only once those tendons have healed, a process that typically takes 90 days. During that window, patients are kept in hospital for three to five days, then sent home under strict 'hip precautions' prohibiting flexion beyond 90°. If dislocation does occur, the consequences are serious: research suggests 57% of patients who dislocate go on to dislocate again, and 45.6% require complex revision surgery within two years.

SPAIRE — Saves Piriformis And (Obturator) Internus with Repair of (Obturator) Externus — takes a different route. Developed by Professor Timperley at the Exeter Hip Unit in 2016, the technique preserves both the piriformis and obturator internus throughout surgery. Only the obturator externus is divided, and it is repaired along with the posterior capsule before the patient leaves the operating theatre. The intact obturator internus functions as a mechanical strap, holding the femoral prosthesis seated in the acetabulum from the moment surgery ends — not 90 days later. That immediate, day-zero stability is the clinical basis for safe same-day discharge.

The preserved tendons also maintain their Golgi tendon organ and muscle spindle signalling, providing continuous proprioceptive feedback that may contribute further to the low dislocation rates associated with the approach.

Professor Paul Lee, who refined the SPAIRE technique under Professor Timperley at Exeter and now uses it as his routine practice, frames it within a broader biological rapid recovery programme — one that integrates surgical technique, implant selection, anaesthesia choice, and mobilisation design as a single coherent pathway. The operation is one component; the system is what makes same-day discharge achievable for suitable patients.

Who is suitable for the same-day pathway

Most patients who ask about same-day discharge ask a version of the same question: is that actually for someone like me? The honest answer is that suitability is assessed individually at consultation — it is never assumed in advance.

On the clinical side, the assessment reviews the hip joint itself (degree of arthritis, bone quality, anatomy), alongside general health markers such as BMI, cardiovascular status, and any bleeding or renal risk. These are the same filters applied to any hip arthroplasty candidate; same-day discharge does not lower the surgical threshold.

The pathway then adds a second layer of criteria tied specifically to discharge:

• Anaesthesia response — spinal or regional block is preferred because it minimises nausea and allows mobilisation within two to four hours of surgery. Patients for whom a general anaesthetic is clinically necessary may need an overnight stay.
• Home circumstances — live-in support for the first 24–48 hours is required; a ground-floor toilet is helpful, though the ability to manage stairs safely is sufficient if the home layout demands it.
• Logistical readiness — most patients arrange these practicalities well in advance once the pathway has been explained at consultation.

Imaging review and physical assessment during the initial consultation with Professor Paul Lee are what determine which pathway is appropriate for a given patient. For those who meet all criteria on the day, discharge follows; for those who do not, an overnight stay is built into the programme as a planned option — not a fallback that reflects poorly on the surgery or the patient.

Steps 1–4: From first contact to pre-operative preparation

Step 1 — Discovery call Before any appointment is booked, a short discovery call establishes whether the SPAIRE pathway assessment is likely appropriate. The conversation covers the patient's hip condition, symptom history, and what they are hoping to achieve. If the pathway is a plausible fit, a full consultation is arranged.

Step 2 — Consultation with Professor Paul Lee The 60-minute consultation combines imaging review — X-ray at minimum, MRI where hip joint anatomy or bone quality warrants closer examination — with a physical assessment of mobility and strength. Implant options are discussed at this stage, alongside the expected anaesthetic approach and what same-day or next-day discharge would involve in practice. Patients leave with a clear picture of whether they are a candidate and what the operative plan would be.

Step 3 — Pre-habilitation Guided physiotherapy before surgery targets the hip and gluteal muscles specifically. Patients with stronger pre-operative musculature tend to mobilise faster after the procedure — not as a guarantee, but as a consistent pattern in hip arthroplasty recovery. A few focused weeks of exercise is usually sufficient.

Step 4 — Health optimisation and scheduling Blood tests and an anaesthesia pre-assessment are completed. Modifiable factors — weight, smoking status, any medication that affects bleeding — are reviewed and adjusted where possible in the weeks before the date. Operating day scheduling places the patient as the first or second case of the morning, leaving adequate time for post-operative monitoring and safe discharge before the day ends.

Steps 5–8: The day of surgery

Step 5 — Anaesthesia

Patients arrive on the morning of surgery, scheduled as the first or second operating case to allow sufficient post-operative monitoring time. A spinal or regional nerve block is administered rather than a general anaesthetic — the preferred approach here because it avoids the nausea commonly associated with general anaesthesia and allows the leg's muscle control to return within a predictable window. Most patients remain awake or lightly sedated throughout the procedure.

Step 6 — The SPAIRE procedure

The surgery uses a posterolateral incision. Of the short external rotator tendons at the back of the hip, only the obturator externus is divided; piriformis and obturator internus remain attached to the bone throughout. The worn femoral head is removed, the acetabular socket is prepared, and prosthetic components — a cup for the socket and a stem carrying the replacement femoral head — are implanted using the same well-tested implants used in standard total hip arthroplasty.

What SPAIRE adds at the surgical level is practical intraoperative feedback: because the obturator internus remains under its natural tension during component placement, the surgeon can gauge how the hip sits against a consistent soft-tissue reference — which supports more accurate judgement of leg-length equality and femoral offset than is possible once the posterior soft tissues have been released. This is a discrete intraoperative benefit, separate from the post-operative stability described in the opening section.

Step 7 — Recovery room

The motor block fades over roughly one to two hours. Sensation and muscle control return, nausea and pain levels are monitored, and the patient is moved to the ward once observations are stable.

Step 8 — First mobilisation

Physiotherapy-assisted weight-bearing walking typically begins two to four hours after surgery. In a prospective series of 35 patients by Kumar et al. (PMC, 2024), the mean time to orthotically assisted ambulation was 1.5 days — a small, short-term dataset that should be read as indicative, but one that reflects how early walking can begin when intact posterior anatomy supports the joint from the outset. The physiotherapist guides the first steps; the aim is confident movement rather than speed.

Steps 9–11: The discharge checklist and first weeks at home

Step 9 — Discharge readiness checklist

Before leaving, each patient must demonstrate four things:

• Eat and take oral analgesia without assistance
• Use the toilet independently
• Manage any stairs the home environment requires
• Follow the written analgesia plan unaided

If those criteria are not met by early evening — because the motor block cleared late or nausea slowed the day's progress — a one-night stay is arranged. That is a clinical decision applied to individual circumstances, not a complication of the procedure.

Step 10 — Leaving hospital

Patients who clear the checklist leave with a written analgesia plan, emergency contact details, and movement guidelines. There are no mandatory 90-day hip precautions: because the posterior tendons were never divided, stability is present from the moment of closure. The mechanism behind that is covered in the opening section; the practical consequence for recovery at home is that normal daily movement can begin without the positional restrictions that accompany traditional posterior hip arthroplasty.

Step 11 — Follow-up at 10–14 days

The appointment at around a fortnight covers wound inspection, a mobility review, and confirmation of the physiotherapy plan. A Harris Hip Score is recorded here as a baseline — a 100-point scale covering pain, function, and range of movement, where scores above 80 indicate a good functional result.

In the Kumar et al. 2024 prospective series of 35 patients, the mean Harris Hip Score at two months was 83.16, with no recorded complications for infection, wound healing, periprosthetic fracture, or nerve injury. In practical terms, a score in the low-to-mid eighties at eight weeks typically corresponds to walking without significant pain and managing most daily activities unaided — a useful directional indicator, though the 35-patient series and six-month follow-up limit how broadly those figures can be generalised.

How SPAIRE compares to other hip replacement approaches

No two hip replacement approaches carry the same trade-offs, and understanding where each sits helps patients ask sharper questions at consultation.

Standard posterior THA severs the short external rotator tendons, creating the 90-day dislocation window that makes strict movement precautions necessary. Historically this meant three to five days in hospital; it remains the most widely practised approach and carries the longest published outcome record.

Anterior/direct anterior approach (DAA) accesses the hip without cutting through the gluteal muscles, which can support faster initial recovery. The trade-off is a requirement for specialist positioning equipment and a fluoroscopy-capable table, and the nerve that runs along the front of the thigh carries a higher risk of irritation or injury — a concern that increases in larger patients, where acetabular visualisation can also be limited.

Direct lateral (Hardinge) approach avoids posterior dislocation risk but divides the gluteus medius, the primary hip abductor. Recovery of this muscle is slower, and some patients experience a prolonged limp.

SuperPATH is a minimally invasive posterolateral technique that preserves the joint capsule. It differs from SPAIRE in the specific tendons preserved, and published data for same-day discharge comparable to the SPAIRE prospective series are not currently available.

SPAIRE's limitations are worth stating plainly: the technique carries a surgeon learning curve, and patients with a very high BMI or unusual hip geometry may not be ideal candidates. Large-scale randomised trial data comparing SPAIRE directly to standard posterior THA do not yet exist.

The pattern that emerges from this comparison is anatomy-driven as much as surgeon-driven. Patients with a healthy BMI, straightforward posterior anatomy, and no contraindications to spinal anaesthesia tend to be strong candidates for the SPAIRE same-day pathway — the muscle-sparing posterior approach that Professor Lee uses as his routine practice for total hip arthroplasty. A patient who requires fluoroscopy-guided cup positioning for complex acetabular anatomy, by contrast, may be better served by DAA. Which description fits a given hip joint is determined by imaging reviewed alongside clinical findings — not by the approach itself.