Why the SPAIRE approach changes who qualifies

The question most patients arrive with — "will this approach work for me?" — has a different answer for SPAIRE than for standard hip replacement, and the difference stems directly from how the operation is performed.

In a conventional posterior approach, the short external rotator muscles at the back of the hip are divided to access the joint and not repaired. Patients leave theatre with a mechanically vulnerable hip, which is why strict movement restrictions — no bending past 90°, no crossing the legs — are imposed for several weeks. SPAIRE changes this: the piriformis and obturator internus tendons are preserved entirely, and the obturator externus is repaired at the close of surgery. The reconstructed soft-tissue envelope restores the hip's natural stability before the patient wakes up.

The practical result is no post-operative hip precautions. Because stability is structural rather than enforced by restriction, the patient's activity goals become a genuine clinical selection factor — not just background information. An active person wanting to return to sport faces a different risk-benefit calculation from someone seeking steady pain relief; with SPAIRE, both conversations begin from a more secure baseline.

At Lincolnshire Hip, SPAIRE is offered alongside the bikini-incision approach, and Prof Paul Lee's assessment determines which suits a given patient. The deciding factors are individual anatomy, diagnosis, and activity ambitions — each examined in the sections below.

Patients who benefit most from SPAIRE

Active and sporty patients form the clearest group for whom SPAIRE offers a meaningful clinical advantage. Because the hip's posterior soft-tissue envelope is reconstructed rather than left divided, the technique delivers on-table stability — and that stability is what allows free movement from the first post-operative day, without restricted seating angles or banned positions to manage.

For someone who runs, cycles, plays golf, or does physical work, this translates directly: no movements to memorise and avoid, no temporary furniture adjustments, and no weeks spent managing a rationed range of motion. The same freedom applies to patients in physically demanding occupations or those with long working lives ahead, for whom minimising time away from full function matters practically.

SPAIRE is also applicable across a broader range of body types than some other minimally invasive hip approaches. Patients with a muscular build or larger girth — groups who may not be straightforward candidates for certain anterior-based techniques — are generally appropriate for the SPAIRE approach, widening the pool of patients who can benefit from a muscle-sparing method.

Younger patients, or those with high activity ambitions, should be counselled that younger age places greater cumulative strain on any hip implant, increasing the lifetime probability of revision surgery — a consideration that applies across total hip arthroplasty regardless of surgical technique.

Supporting evidence for early return to function comes from a prospective case series by Kumar et al. (2024, n=35), which recorded a mean time to orthotic-assisted ambulation of 1.5 days and a mean Harris Hip Score of 83.16 at two months, with no major complications at six-month follow-up. This is case-series data rather than an RCT, and larger studies are needed to confirm long-term outcomes specific to the SPAIRE approach.

Hip conditions that make someone a candidate

Reaching the threshold for any hip replacement — SPAIRE included — requires more than a painful hip. The clinical standard is moderate-to-severe arthritis causing meaningful functional impairment, where non-surgical options have been genuinely explored and have not provided adequate, lasting relief.

Osteoarthritis is by far the most common underlying diagnosis, accounting for roughly 90% of total hip arthroplasty cases. Rheumatoid arthritis and post-traumatic arthritis — damage following fracture or significant joint injury — are well-established indications too. In all three, the common thread is structural joint deterioration sufficient to limit daily activity: persistent pain at rest or at night, stiffness that restricts walking distance or normal range of movement, and a quality of life that conservative measures have failed to restore.

That prior conservative pathway matters clinically. Physiotherapy, activity modification, weight management, and analgesic medication are the usual first steps. Where appropriate, hip joint injections — including corticosteroid or hyaluronic acid injections — may be tried before surgical referral is considered. Documenting what has been attempted and for how long gives the consulting surgeon a clearer picture of where a patient sits on the pathway.

Where SPAIRE extends beyond some other minimally invasive approaches is in more complex hip anatomy. Severe hip dysplasia, Perthes disease, and slipped capital femoral epiphysis (SCFE) — conditions that alter the geometry of the joint and sometimes limit surgical access — are clinically appropriate indications for the SPAIRE technique. Certain anterior-based approaches may be less straightforward in these presentations; the posterior window that SPAIRE uses can accommodate the anatomical variation these conditions introduce. A specialist assessment remains essential to confirm whether a given degree of deformity falls within the technique's range.

Who is not suitable for SPAIRE

Not every patient who needs a hip replacement is a straightforward SPAIRE candidate, and being outside that group does not mean being without options — it means a different approach is more appropriate for the specific situation.

Three technique-specific exclusions stand out. Complex revision hip surgery, particularly where there is significant bone loss, requires a more extensile surgical exposure than the SPAIRE window provides; a standard posterolateral or other approach gives the surgeon the access and structural support these cases demand. Similarly, severe pre-existing anatomical deformity that prevents adequate visualisation through the posterior route may make a different technique the more practical choice. A third exclusion relates to the tissue the technique depends on: if the posterior rotator muscles — the piriformis and obturator internus — are severely wasted or functionally absent before surgery, the repair step that underpins SPAIRE's stability cannot be performed meaningfully.

Beyond these technique-specific considerations, the contraindications common to any total hip arthroplasty apply: active joint or systemic infection, uncontrolled cardiac or metabolic disease, severe osteoporosis with inadequate bone stock for secure implant fixation, and significant peripheral vascular compromise.

One practical safety note worth mentioning: if an intraoperative complication such as a femoral fracture arises during a SPAIRE procedure, the approach can be converted directly to a standard posterolateral approach without a second incision. The surgical access expands rather than requires a separate intervention — a feature that limits the downside of the technique choice.

For patients who fall outside the SPAIRE indication, specialist assessment will identify the approach best suited to their anatomy and diagnosis.

The grey zone: patients who can have SPAIRE but need extra consideration

Between clear candidacy and firm exclusion sits a smaller group of patients where the picture is more nuanced — not ruled out, but where the usual advantages of SPAIRE may be partial or where specific risk factors warrant a closer look before proceeding.

Cognitive impairment or dementia is the clearest example. The SPAIRE technique is technically feasible in these patients, but the principal benefit — freedom from post-operative hip precautions — rests on a patient being able to understand and reliably follow guidance in the days after surgery. Where that capacity is significantly reduced, the surgical team may apply conventional precautions regardless of technique, which changes the risk-benefit calculation without making SPAIRE impossible.

A history of prior hip dislocation follows similar reasoning. The restored soft-tissue stability that SPAIRE provides reduces dislocation risk substantially, yet some surgeons will still advise precautionary movement restrictions in patients with this background, at least during the early recovery period.

For patients with a BMI above 40, the consideration is slightly different. SPAIRE accommodates higher BMI and heavier musculature better than several other minimally invasive approaches, which is a genuine advantage. Even so, AAOS guidance identifies BMI above 40 as a threshold at which complication risk rises across any total hip arthroplasty; pre-operative weight management is typically recommended for this group before any surgical pathway is confirmed.

None of these factors is a categorical exclusion. Each one is a reason for an honest, individual conversation with the surgical team — weighing the specific clinical picture against the expected benefits of the approach.

Getting an accurate suitability assessment

SPAIRE candidacy is partly defined by what the patient will not need after surgery — no post-operative movement restrictions — and that absence follows directly from restoring the posterior soft-tissue anatomy, not from a preference for novelty. That distinction matters when comparing techniques: active patients who would otherwise face weeks of restricted movement form a specific clinical group, not simply anyone who wants a faster recovery.

Establishing whether a patient fits that profile requires clinical examination, weight-bearing imaging, full medical and surgical history, and a frank conversation about activity goals and comorbidities. Imaging alone does not settle the question.

The clinical approach Prof Paul Y. F. Lee takes at Lincolnshire Hip places SPAIRE alongside the bikini-incision technique and other standard approaches, selecting on anatomy and individual diagnosis rather than by default. Lincolnshire Hip is part of the MSK Doctors group and accepts patients without GP referral, with clinics in Sleaford and Grantham. What that assessment determines is not whether SPAIRE is the better technique in the abstract, but whether the specific conditions that make it advantageous — intact posterior musculature, an active lifestyle, and no history requiring a more extensile surgical exposure — are present in that particular patient.