What 'surgical approach' means and why it matters

If you have been told there are several different ways to perform a hip replacement and wondered whether it actually makes a difference, the short answer is yes — sometimes significantly.

A surgical approach is the route a surgeon takes through the body's tissue layers to reach the hip joint. It is not a variation in the implant itself; the prosthetic components can be largely the same regardless of approach. What changes is which muscles, tendons, and soft tissue structures are cut, retracted, detached, or left untouched along the way. Because the hip is a deep joint surrounded by stabilising tendons and muscle groups, the chosen route influences how much tissue trauma occurs, how quickly early stability returns, and which specific risks — dislocation, nerve irritation, muscle weakness — are most relevant during recovery.

Five approaches are in common clinical use: SuperPATH, SPAIRE, the direct anterior approach (DAA), the lateral (modified Hardinge) approach, and the standard posterior approach. Each represents a different balance between surgical access, tissue preservation, dislocation risk, and the level of specialist training required to perform it safely.

No single approach is the right choice for everyone. Patient anatomy, bone shape, body composition, activity goals, and a surgeon's case-volume all shape that decision. The sections below examine each approach in turn — not as a ranking, but as a structured comparison of trade-offs.

SuperPATH: tissue-sparing technique and what the trials show

SuperPATH — Supercapsular Percutaneously-Assisted Total Hip Arthroplasty — takes its name from where it enters the hip: above (supracapsular to) the joint capsule, through a small percutaneous incision. The goal is to reach the hip socket and femoral neck without detaching any muscle or tendon along the way. Most other approaches require at least some tissue to be divided or lifted from bone; SuperPATH aims to avoid this entirely by working through the natural interval above the capsule.

The strongest direct evidence comes from a 2022 network meta-analysis of 20 randomised controlled trials involving 1,501 patients, which compared SuperPATH, the direct anterior approach (DAA), and the standard posterior approach simultaneously. Against the posterior approach, SuperPATH showed a meaningfully shorter incision (approximately 4.7 cm less), lower intraoperative blood loss (around 82 ml less — roughly a small wineglass), and higher Harris Hip Scores at 3, 6, and 12 months post-operatively. Against DAA, outcomes were broadly comparable on most measures; notably, DAA recorded the highest intraoperative blood loss of the three approaches, exceeding SuperPATH by approximately 174 ml — a margin that may be clinically relevant for patients with anaemia or limited cardiac reserve. A companion 2022 meta-analysis of 14 RCTs (1,021 patients) added that early postoperative pain scores on day 1 and day 3 were measurably lower after SuperPATH, with no significant difference in complication rates or acetabular cup positioning.

A 2023 RCT comparing SuperPATH with the modified Hardinge (lateral) approach in 120 patients produced the sharpest contrast: incision 5.8 cm versus 12.5 cm, blood loss 121.5 ml versus 178.8 ml, hospital stay 8.0 versus 10.8 days, and lower creatine kinase levels — a biochemical marker of muscle trauma — in the SuperPATH group.

One important counterpoint comes from a 2021 RCT against a mini-incision posterolateral technique, in which SuperPATH produced more blood loss, higher creatine kinase, a longer operating time, and less optimal acetabular cup positioning. Most observers attribute this to learning-curve effects, and it is a useful reminder that technique complexity matters when interpreting results. Across all studies, SuperPATH consistently adds approximately 15–17 minutes to operating time — an established structural feature of the approach, not an anomaly.

Overall, early-to-medium-term evidence for SuperPATH is favourable. Long-term comparative data — particularly against SPAIRE — are still accumulating.

SPAIRE: how preserving tendons reduces dislocation risk

Unlike SuperPATH's supracapsular entry, SPAIRE does not take a different route to the hip — it takes the same posterior route as the standard posterior approach, but changes what happens once the surgeon arrives.

SPAIRE stands for Save Piriformis And Internus, Repair Externus. The piriformis and obturator internus are short tendons that run across the back of the hip joint; think of them as a seatbelt-like strap that helps hold the femoral head seated in the socket, especially in the first weeks after surgery. In a traditional posterior approach, all short external rotator tendons — including the piriformis and obturator internus — are detached from bone to provide access, then reattached at the end of the operation. The reattachment heals over time, but during that healing window the hip has less posterior restraint, which is the main mechanical reason the standard posterior approach carries a higher early dislocation risk.

SPAIRE avoids detaching the piriformis and internus entirely. They remain attached to bone throughout. Only the obturator externus is repaired rather than spared. By keeping the primary stabilisers intact, the hip has more of its natural posterior support from the moment the patient wakes from anaesthesia. In suitable patients this may allow some of the strict early movement precautions associated with traditional posterior approaches to be relaxed — though individual suitability still requires clinical assessment.

The technique was described by Hanly et al. and popularised by the Exeter Hip Unit in the UK. A 2017 study confirmed its feasibility and safety across all BMI ranges and skeletal dimensions. A 2023 modified-SPAIRE case report extended the approach further, demonstrating its adaptability for patients with elevated individual dislocation-risk profiles — evidence that the principle can be tailored rather than applied uniformly.

SPAIRE's formal evidence base is smaller than SuperPATH's and is weighted more towards case series and descriptive studies than large randomised trials. No direct head-to-head RCT comparing SPAIRE with SuperPATH has yet been published; any comparison between the two approaches currently relies on indirect inference across separate study populations. That limitation is worth carrying forward when weighing the approaches against each other.

Prof Paul Lee, the consultant behind Lincolnshire Hip, trained in the SPAIRE technique under Prof Timperley at the Exeter Hip Unit — the centre that established SPAIRE's UK clinical footprint.

DAA, lateral, and standard posterior: the established three

Three approaches account for the large majority of hip replacements performed in the UK today: the direct anterior approach (DAA), the lateral (modified Hardinge) approach, and the standard posterior approach. Each has a distinct structural logic — and a distinct set of trade-offs.

Direct anterior approach (DAA)

DAA reaches the hip through a natural interval between muscle groups rather than through them, making it genuinely muscle-sparing in the anatomical sense. Its principal limitation is intraoperative blood loss: the same network meta-analysis discussed in the previous section found DAA's blood loss exceeded SuperPATH's by approximately 174 ml and the standard posterior approach by around 92 ml — a finding grounded in evidence, not opinion. DAA also carries a recognised risk of lateral femoral cutaneous nerve (LFCN) neuropraxia, a temporary or occasionally persistent numbness and tingling over the outer thigh. Femoral component preparation is technically demanding in larger or more heavily muscled patients, and the technique requires specialist positioning equipment not universally available.

Lateral (modified Hardinge) approach

The lateral approach reaches the joint by dividing the gluteus medius muscle. Creatine kinase levels — a biochemical proxy for muscle trauma — were measurably higher in lateral-approach patients than in SuperPATH patients in the 2023 RCT of 120 patients cited earlier. That muscle trauma carries a well-established clinical consequence: Trendelenburg gait, a characteristic hip-drop limp caused by gluteal weakness, which can persist for months and is not a feature of the posterior, anterior, SuperPATH, or SPAIRE routes.

Standard posterior approach

The posterior approach remains the most widely performed hip replacement technique worldwide, valued for its versatility across patient anatomy and the breadth of surgeon experience behind it. Its main limitation is dislocation risk: detaching and reattaching the short external rotators leaves the posterior capsule with reduced restraint during the healing period. Posterior capsular repair reduces this risk but does not eliminate it — which is precisely the gap that SPAIRE was designed to address.

These three approaches are not obsolete. For many patients — depending on anatomy, body habitus, bone geometry, and the operating surgeon's training — one of them remains the most appropriate choice. Surgical approach is a clinical decision, not a hierarchy.

How surgeons decide which approach suits each patient

Choosing between approaches is not a checklist exercise. A specialist weighing up which route to take will consider several overlapping factors simultaneously — patient anatomy, body habitus, bone geometry, the individual's dislocation risk profile, activity goals, and the surgeon's own trained case volume in each technique.

Anatomy and risk profile shape the first layer of the decision. Body composition and hip geometry affect how easily a surgeon can access the femoral canal and position the acetabular cup accurately. Dislocation risk — reflecting a combination of soft-tissue laxity, planned activity level, and cognitive factors — is especially relevant when choosing between SPAIRE and the standard posterior approach, or between posterior and anterior routes.

Surgeon experience is a genuine clinical variable, not a secondary consideration. SuperPATH's technical complexity means outcomes are closely tied to the operating surgeon's case volume; the divergent results seen across published trials (discussed in the SuperPATH section) are most plausibly explained by this learning-curve effect rather than any inherent limitation of the technique. The same principle applies to DAA, where specialist positioning equipment and demanding femoral preparation make surgeon familiarity a prerequisite.

SPAIRE tends to suit patients where the posterior approach is otherwise appropriate and reducing dislocation risk is a clinical priority — a judgement that incorporates anatomy, lifestyle, and postoperative movement capacity. Its adaptability across varying body types and BMI ranges is supported by the feasibility data outlined in the previous section.

The lateral approach may remain the appropriate choice where the surgeon's primary familiarity lies there, or where specific anatomical factors make posterior access more hazardous — a reminder that training and local case volume are legitimate safety considerations in their own right.

None of these five approaches is automatically superior across all patients. The multi-factor framework described here — anatomy, risk profile, activity goals, and technique-specific training — is the basis on which SPAIRE patient selection at Lincolnshire Hip is conducted, informed by Prof Paul Lee's surgical training at the Exeter Hip Unit.

What patients comparing these approaches should know

Across five approaches and multiple evidence streams, the honest position is this: no randomised trial has compared SuperPATH and SPAIRE directly, and meaningful data beyond twelve months for these two techniques remain limited — which makes the questions a patient asks in consultation more important than arriving with a fixed preference.

Lincolnshire Hip is part of the MSK Doctors group and accepts patients without referral for hip assessment at Sleaford and Grantham.

Three questions tend to be most productive when that conversation begins:

• What approach do you recommend for my anatomy, and why? A specific answer signals that the recommendation is tailored to the individual rather than a default position.
• What is your case volume in this technique? Learning-curve effects are real — the divergent results seen across published SuperPATH trials are a reminder that surgeon familiarity with the chosen method is a legitimate safety consideration.
• What early movement precautions will I need, and for how long? The practical difference between approaches often shows up here; SPAIRE's tendon-preservation logic is designed precisely to reduce the period of strict restriction after surgery.

No single route suits every patient. Those where the posterior approach is otherwise appropriate and early hip stability is a clinical priority tend to be better placed with SPAIRE; those where minimising muscle trauma via a supracapsular entry is the primary aim may be better suited to SuperPATH — provided surgeon case volume supports it. Both choices involve trade-offs that specialist assessment, not reading alone, can properly weigh.

1. [1] Comparison of the early clinical efficacy of the SuperPath approach versus the modified Hardinge approach in total hip arthroplasty: a randomized controlled trial. (2023). https://doi.org/10.1186/s13018-023-03713-9 https://doi.org/10.1186/s13018-023-03713-9
2. [2] Details of a Tendon–Sparing Posterior Approach in Hemiarthroplasty: SPAIRE technique. (2017). https://doi.org/10.4172/2167-7921.1000243 https://doi.org/10.4172/2167-7921.1000243
3. [3] Direct and indirect comparisons in network meta-analysis of SuperPATH, direct anterior and posterior approaches in total hip arthroplasty. (2022). https://doi.org/10.1038/s41598-022-20242-3 https://doi.org/10.1038/s41598-022-20242-3
4. [4] Minimally invasive surgery supercapsular percutaneously-assisted total hip (SuperPath) arthroplasty: Applicability to mildly dysplastic osteoarthritis and early recovery of lower limb function. (2023). https://doi.org/10.23750/abm.v94i3.13922 https://doi.org/10.23750/abm.v94i3.13922
5. [5] An Updated Meta-Analysis of Randomized Controlled Trials on Total Hip Arthroplasty through SuperPATH versus Conventional Approaches. (2022). https://doi.org/10.1111/os.13239 https://doi.org/10.1111/os.13239
6. [6] Supercapsular percutaneously-assisted total hip (SuperPath) versus mini-incision posterolateral total hip arthroplasty for hip osteoarthritis: a prospective randomized controlled trial. (2021). https://doi.org/10.21037/atm-20-1793a https://doi.org/10.21037/atm-20-1793a