What’s the difference between a Minimally Invasive Direct Anterior Approach and a traditional Posterior Approach?
Why I love this operation
Total Hip Replacement is my favourite operation. Why? I know that well over 95% of those patients will be happy with their outcome. Seeing patients pain-free and getting back to enjoying life is what I find rewarding about this job (it’s definitely not the late nights and weekends). After my fellowship in London, I was asked to write a book chapter¹ on surgical approaches to the hip, so I compiled all the research on the topic. I can lend you a copy if you’re struggling with insomnia.
Faster early recovery with the anterior approach
Numerous research papers²⁻⁵ show that following a primary (‘first time’) Total Hip Replacement performed by a well-trained and appropriately experienced surgeon, the average patient will have a faster recovery. They’ll also experience less pain over the first six weeks or so with an anterior approach than with a posterior approach. The skin incision is shorter, but more importantly, the muscles are simply spread apart rather than cut to gain access to the hip joint. This has also been proven to lower the dislocation risk.
What the long-term data shows
But we want hip replacements to last for life in most cases. So it’s not just about the initial early recovery — it’s about the long-term results. The Australian Joint Registry⁶ data published in October 2024 shows that the anterior approach has only a marginally better re-operation rate (better survivorship) than posterior or lateral approaches. That data should be treated with some caution. Why? Anterior approach hip replacements performed in this country are generally more likely to be performed by experienced, specialised hip surgeons doing higher volumes of cases. The majority of generalist surgeons, trainees and public (teaching) hospitals use posterior approaches instead. As a result, the data is likely to be skewed by these “confounding factors.”
The cause of revision surgery on the Australian registry is also different. Revision for dislocation is more likely with a posterior approach; fracture is more likely with an anterior approach. Research also shows that those risks are, of course, significantly reduced with training and experience⁷. So the main difference between approaches really comes down to the speed of recovery and the amount of postoperative pain over the first few months.
Why doesn’t every surgeon use the anterior approach?
I’m often asked: if the anterior approach offers faster recovery, less pain, and survivorship that’s as good if not better, why doesn’t everyone do it? The risk of fracture is greatest during a surgeon’s “learning curve” — their first 100 patients. Australian research⁷ from our registry has shown that after the first 100 cases, a surgeon’s complication rates “normalise.” According to the Australian registry, most Australian orthopaedic surgeons who perform hip replacements only perform less than 50 per year⁸.
Understandably, many of my colleagues have made the ethically sound decision not to inflict the risk of re-training on their current patients. Some only perform limited numbers of hip replacements each year, so their learning curve would be hard to justify. I was fortunate enough to train under some highly experienced anterior approach surgeons in Sydney and London when I was still a trainee surgeon. There was always somebody experienced watching over me, so patients were kept safe throughout the training process. I now “pay it forward” by teaching both visiting surgeons and trainee orthopaedic surgeons the direct anterior approach for total hip replacement at the Sunshine Coast University Hospital. This lets them learn this technically demanding operation in an environment that’s safe for patients.
The bottom line
Regardless of how you have your hip replacement performed, most patients will experience significant relief of pain and restoration of their quality of life. That’s the reason I love performing this potentially life-changing procedure.
References:
(1) Connon F, Logishetty K Approaches for Total Hip Arthroplasty. Chapter 4 in Controversies in Orthopaedic Surgery of the Lower Limb (ed. Rodriguez- Merchan and Liddle) Springer 2021 ISBN 978-3-030-80694-1
(2) Miller L, Gondusky J, Bhattacharyya S, Kamath A, Boettner F, Wright J. Does surgical approach affect outcomes in total hip arthroplasty through 90 days of follow-up? A systematic review with meta-analysis. J Arthroplast. 2018;33(4):1296–302
(3) Nam D, Nunley RM, Clohisy JC, Lombardi AV, Berend KR, Barrack RL. Does patient-reported per- ception of pain differ based on surgical approach in total hip arthroplasty? Bone Joint J. 2019;101-B(6 Suppl B):31–6.
(4) Barrett WP, Turner SE, Leopold JP. Prospective randomized study of direct anterior vs postero-lateral approach for total hip arthroplasty. J Arthroplast. 2013;28(9):1634–8.
(5) Parvizi J, Restrepo C, Maltenfort MG. Total hip arthroplasty performed through direct anterior approach provides superior early outcome: results of a randomized, prospective study. Orthop Clin North Am. 2016;47(3):497–504.
(6) Australian Orthopaedic Association National Joint Replacement Registry. Australian Orthopaedic Association National Joint Replacement Registry Annual Report 2024. https://aoanjrr.sahmri.com/.
(7) De Steiger R, Lorimer M, Solomon M What is the learning curve for the Anterior Approach for Total Hip Arthroplasty CORR (2015) 473: 3860-3866.
(8) Koltsov JCB et al Risk-Based Hospital and Surgeon-Volume Categories for Total Hip Arthroplasty J Bone Joint Surg Am. 2018;100:1203-8