Scaling the Steep Learning Curve of Total Hip Replacement Surgery

Kenneth A. Johnson, MVSc, PhD, FACVSc, DACVS, DECVS

The prospect of having a major complication develop following a total hip replacement surgery is a very dispiriting experience for young surgeons in their quest to gain proficiency with this procedure. One study found that the learning curve to achieve a 90% success rate with cemented total hip replacement was 44 cases,[1] with a higher incidence of major complications in the earlier cases. While some major complications can be resolved by revision surgery, this can result in additional patient morbidity and financial costs.

Short courses taught by experts in total hip replacement surgery are an important starting point in learning the required skills for this surgery. However, the fastest route to ascension of the steep learning curve is to work both directly and indirectly with an expert surgeon who can guide and mentor the trainee.

Orthopaedic surgeons training to perform total hip replacement in human patients typically undertake a 6-to-12-month fellowship with an experienced senior surgeon, following their residency. Surgeons in training operate as part of a team. In this environment, the operative time is shorter when the hip replacement procedure is done under the direct supervision of an experienced surgeon.[2] It was suggested that the trainee surgeon could improve their surgical technique faster and progress with more confidence when a senior surgeon assisted and could anticipate or resolve problems during the surgical procedure.

The volume of people having a total hip replacement in the United Kingdom is now in excess of 100,000 annually, with a similar number of people having a total knee replacement. These numbers are growing annually in the United Kingdom, as they are in other developed countries, due to the aging population suffering from osteoarthritis; this makes the available patient load more than adequate for the conduct of fellowship training programs.

Similarly, formal fellowship training programs in canine total hip replacement would seem to be valuable in assisting aspiring surgeons develop the requisite skills and experience to successfully conquer their learning curve. One obstacle to this is case numbers. The United Kingdom canine hip registry data suggest that the number of canine hip replacement surgery cases performed annually in the United Kingdom would be in the hundreds, not hundreds of thousands. Many veterinary surgeons perform approximately 50 procedures a year (one a week on average). So having enough cases available for training purposes over a short period of time is a challenge.

Currently there are several different manufacturers of canine total hip implants. A study by one surgeon published in this issue of the journal[3] suggests that skills and experience gained from performing BioMedtrix hips are transferrable to the Kyon hip because his major complication rate was approximately 10% in his first 21 procedures. However, this surgeon found that intrinsic differences in technique and implants did require some accommodations and adjustments to successfully make the transition.

Most of the studies on canine total hip replacement have focused on outcome of this procedure for the patient. What is needed is more data on how to ease the learning curve for new surgeons-in-training, which in turn should improve patient outcome data.

Publication History

Article published online:
20 September 2021

• References

• 1 Hayes GM, Ramirez J, Langley Hobbs SJ. Use of the cumulative summation technique to quantitatively assess a surgical learning curve: canine total hip replacement. Vet Surg 2011; 40 (01) 1-5
• 2 McCulloch RA, Howgate D, Gibbs VN, Palmer A, Taylor AH, Kendrick B. Assessing the performance and learning curve of orthopaedic surgical trainees in primary total hip arthroplasty. Ann R Coll Surg Engl 2021; 103 (07) 514-519
• 3 Franklin SP, Miller NA, Riecks T. Complications with the Zurich Canine Total Hip Replacement System in an initial series of cases performed by a single surgeon. Vet Comp Orthop Traumatol 2021; 34: 346-351