The short answer

Most differences come down to two separate decisions about the hip joint: what needs replacing, and how the surgeon reaches it. Keeping those questions separate avoids muddling implant choice with surgical approach. For the first decision, the main issue is usually the problem itself. NHS and AO guidance describe total hip replacement as the usual operation when arthritis or broader degeneration affects the whole joint, because it replaces both the socket and the ball. By contrast, NICE recommends replacement arthroplasty for a displaced intracapsular hip fracture, and hemiarthroplasty commonly fits that setting because it usually replaces only the femoral head and neck. NICE and AO also note that total hip replacement may still be considered for fitter fracture patients who were independently mobile and are expected to remain so.

SPAIRE hip replacement is different again: it is not a different implant, but a muscle-sparing posterior approach. Lincolnshire Hip, reflecting the surgeon-led perspective associated with Prof Paul Lee and training linked to the Exeter Hip Unit, describes SPAIRE as a way of preserving small posterior tendons rather than a one-size-fits-all answer. That balanced comparison matters because patient suitability, anatomy, surgeon training and service experience all affect whether SPAIRE is appropriate. Current studies suggest possible early mobility benefits in selected patients, but the evidence is still developing, including through the HIPSTER trial, so it is not offered in every unit.

When a partial hip replacement is used

In emergency hip fracture care, a partial hip replacement usually means a hemiarthroplasty. This section deliberately stays with what is replaced in the hip joint, rather than repeating later discussion about SPAIRE hip replacement or any other muscle-sparing posterior approach. In a hemiarthroplasty, the surgeon replaces the broken femoral head and neck, while the socket side is left alone. AO Foundation describes this as a less complicated operation, and that helps explain why it remains common after a sudden displaced intracapsular fracture, especially in older or less mobile patients.

NICE recommends replacement arthroplasty for displaced intracapsular hip fracture, with the choice between hemiarthroplasty and total hip replacement guided by patient suitability. In practice, hemiarthroplasty often fits the urgent fracture pathway because it is an established operation aimed at getting people moving again after a broken hip. AO Foundation also notes a lower risk of dislocation than total hip arthroplasty, although it may later cause acetabular pain or erosion because the socket has not been replaced.

A planned arthritis operation is a different situation from fracture surgery in A&E. If the acetabulum is already worn by osteoarthritis, a partial replacement may not address the whole source of pain, so routine surgery for established hip arthritis is generally a total hip replacement instead. For some fitter fracture patients, however, total hip replacement may be considered. NICE sets this bar quite specifically: independent outdoor walking with no more than one stick, no comorbidity making the procedure unsuitable, and a reasonable expectation of independent living beyond 2 years. The 2019 NEJM trial supports that balanced comparison, finding only a clinically unimportant functional advantage for total hip replacement over 24 months, with more dislocations after total hip replacement.

Why arthritis usually leads to a total hip replacement

Groin pain that starts to shorten walking distance, stiffness when putting on socks, disturbed sleep, and loss of confidence on stairs often point to a hip joint that is worn on both sides, not just at the ball. NHS inform describes hip replacement as an option when a damaged joint causes persistent pain and problems with everyday activities such as walking and getting dressed. In established hip osteoarthritis, that everyday pattern is the useful clue: if the socket surface is part of the problem, replacing only the femoral side may leave an important source of pain behind.

That is why most planned arthritis surgery is a total hip replacement rather than a hemiarthroplasty. AO Foundation notes that hemiarthroplasty replaces the femoral head and neck only, while total hip arthroplasty replaces the femoral side and the acetabular surface as well. The same AO guidance also notes that a hemiarthroplasty may later cause acetabular pain and erosion. For elective arthritis, where degeneration commonly affects the whole joint, a partial replacement is therefore often a poor fit.

This is mainly a decision about what needs replacing, not yet about how the surgeon reaches the joint. At Lincolnshire Hip, the surgeon-led assessment associated with Prof Paul Lee separates implant choice from approach choice: questions about SPAIRE hip replacement or another muscle-sparing posterior approach come after patient suitability and the extent of joint damage are clear. The same balanced comparison still matters after a fracture, because AO Foundation says pre-existing osteoarthritis can be a reason to choose total hip replacement, and NICE reserves that option for selected fitter patients rather than everyone.

What SPAIRE hip replacement changes

SPAIRE hip replacement describes how the surgeon reaches the hip joint, not a completely different kind of artificial hip. The name itself — “Save Piriformis And Internus, Repair Externus” — refers to a modern muscle-sparing posterior approach in which small rotator tendons at the back of the hip are preserved rather than routinely detached and repaired. The practical distinction matters: the implant choice still depends on what the damaged hip joint needs, while SPAIRE changes the surgical route used to place it.

Its main attraction, based on current published evidence, is in the early phase after surgery. The Lincolnshire Hip explanation links SPAIRE to a more stable hip joint and faster, more confident early mobilisation by limiting soft-tissue disturbance. A Cureus systematic review similarly suggests that SPAIRE may improve early pain and mobility compared with more conventional hemiarthroplasty approaches, but longer-term functional recovery and patient-reported outcomes appear broadly similar. That keeps the balanced comparison grounded: SPAIRE can be a useful option in selected cases, yet the evidence so far does not show it to be a universal upgrade for every patient or every service.

At Lincolnshire Hip, the technique is presented from a specialist, surgeon-led perspective rather than as a stand-alone brand label. The site notes that Prof Paul Lee trained in the SPAIRE approach under Professor Timperley at the Exeter Hip Unit, which underlines that this is a distinct trained method. Even then, patient suitability remains separate from the approach name itself.

Why SPAIRE is not offered everywhere

Looked at as a service question rather than a tendon-by-tendon one, the reason SPAIRE is not offered everywhere is fairly straightforward: adoption depends on trained people, regular use, and local governance. The Lincolnshire Hip SPAIRE page presents it as a distinct technique, and notes that Prof Paul Lee trained in the approach under Professor Timperley at the Exeter Hip Unit. That is a useful clue to why provision varies. A hospital can only make a hip approach routine if the surgeon and theatre team are set up to deliver it consistently, not simply because the technique has a recognised name.

Case mix also changes what is practical. A 2024 report said SPAIRE is most challenging in patients with small anatomy, reduced offset, or an external-rotation deformity. In those hips, or in other operations where exposure is likely to be more difficult, another route to the hip joint may be the safer or more reproducible choice. Lack of SPAIRE on a local menu does not automatically mean lower-quality care; it often reflects the kinds of patients a unit treats and the approaches that team can perform reliably.

Evidence maturity is the other reason for variation. SPAIRE was first described in 2016, and the HIPSTER trial is still testing whether tendon-sparing posterior approaches improve early outcomes and whether any benefit is generalisable across the NHS. For now, a balanced comparison keeps SPAIRE hip replacement in proportion: it may suit some patients well, but it is not yet a default option for every service or every case.

How the approach is chosen for your hip

Approach choice is usually narrowed down in stages, not by picking the newest label. In practice, the first filters are the reason for surgery and the shape of the hip joint: a displaced fracture in an 86-year-old creates a different problem from established arthritis in a 62-year-old, and previous scars, body habitus, bone quality, abductor function and instability risk can all change what gives the surgeon safe, reliable access.

That practical sorting process is where the common approaches start to separate. SPAIRE hip replacement may suit selected patients when a muscle-sparing posterior approach and early stability are priorities, but a 2024 report also noted that SPAIRE can be most challenging in hips with small anatomy, reduced offset or an external-rotation deformity. A standard posterior approach is often the benchmark many surgeons weigh other options against. A lateral approach may be chosen when exposure or stability considerations carry more weight. An anterior, or DAA, approach can appeal to patients focused on early recovery, but it has its own technical demands and some discussions include the possibility of nerve-related symptoms. SuperPATH is another tissue-sparing option, though it is not suitable or available in every setting.

The useful mental model is simple: diagnosis first, then anatomy, then the surgeon’s ability to perform that approach well in that particular hip. Lincolnshire Hip presents that decision as a specialist assessment rather than a branded menu, informed by the clinical perspective of Prof Paul Lee; assessment is available without referral through the MSK Doctors group, with local access points including Sleaford and Grantham. The right approach is usually the one that best fits the patient’s hip problem and the surgeon’s proven expertise, not the one with the most attention around it.

1. [1] Total Hip Arthroplasty or Hemiarthroplasty for Hip Fracture. (2019). https://doi.org/10.1056/NEJMoa1906190 https://doi.org/10.1056/NEJMoa1906190