Positioning of the acetabular component: Preoperative planning

By design, total hip arthroplasty (THA) requires the careful consideration of each patient’s unique anatomy. Surgeons must carefully plan their approach, customizing the procedure based on preoperative images, physical examinations, a patient’s history, and their own experience. Accurately templating the placement of the acetabular cup is critical to a successful THA. Anticipating potential complications and having the right instrumentation and device options on hand is also integral to good planning. We look at preoperative planning considerations that prioritize a patient’s anatomy and share expert opinion on the relationship between stiff/fused spines and cup placement.



For any surgical discipline, preoperative planning is critical to the success of a procedure. The AO Principles of Fracture Management remind us that planning is a focused endeavor that allows surgeons to contemplate their approach and “mentally rehearse the operation: Problems can be anticipated and avoided and alternative plans can be developed in case of arising difficulties” [1].

Aside from facilitating the delivery of a considered, patient-specific total hip arthroplasty (THA), the records generated by comprehensive planning can communicate the professionalism, thought, and motivation behind a surgeon’s approach, which could help in the defense against litigation [1].

Inaccurate cup placement is a persistent problem that has been linked to dislocations and bearing surface wear. [2] Jolles et al. reported dislocation risk to be 6.9 times higher if total anteversion did not fall between 40°–60° and stated that “ [s]urgeons should pay attention to total anteversion (cup and stem) of THA [3]. Part I of this article series looked at the elements that influence accurate acetabular cup placement.

Callanan et al. found that out of 1823 hips, only 50 percent of the acetabular cups were placed within the safe zone (abduction (30°–45°) and version (5°–25°)) for both anteversion and inclination. In their study, low volume surgeons (two times higher risk), a minimally invasive approach (six times higher risk), and obesity (1.3 times higher risk) were contributing factors to malpositioned cups [4]. 

THA is a surgically demanding procedure and preoperative planning for acetabular cup placement involves consideration of several related factors. Bassam Masri, MD, and Head of Orthopaedics at the University of British Columbia, Canada, points out that,

“The most important technical aspect in planning hip replacement is restoring the biomechanics of the hip by restoring an anatomic center of rotation, restoring femoral offset, and equalizing leg lengths.”

That being said, let’s see how a surgeon’s preoperative plan can improve the likelihood that cup placement will be as precise as possible for each patient.


Patient assessment

Preoperative, comprehensive patient assessment is vitally important, but this is tempered with the knowledge that too many tests risk fatiguing and burdening the patient, stressing clinical resources, and demand time to document and interpret. When assessing function, surgeons usually combine elements from a patient-reported questionnaire and functional tests [5].

New technologies, such as accelerometers, are making it possible to gather real-time information about a patient’s movement as they go about their lives [5]. However, these types of technology are in early stages of adoption by the orthopedic field and despite being identified as feasible, they currently have little proof of efficacy, particularly in the post-THA rehabilitation phase [6].


Read the full article with your AO login

  • Thorough medical history
  • Physical assessment
  • Special consideration of the spine
  • The role of imaging
  • Templating: defining the puzzle pieces
  • Digital templating
  • Digital templating with acetate overlay
  • Landmarking and making measurements when templating
  • Conclusion
  • References

Part 1 | Key elements

Part 3 | Intraoperative considerations

Additional AO resources

Access videos, tools, and other assets to learn more about this topic.

Contributing experts

This series of articles was created with the support of the following specialists (in alphabetical order):

Mohamad Allami

Burjeel Hospital
Abu Dhabi, United Arab Emirates

Chad Johnson

University of British Columbia
Vancouver, Canada

Bas A  Masri

University of British Columbia
Vancouver, Canada

This issue was created by Word+Vision Media Productions, Switzerland



  1. Porteous M, Südkamp NP, Schatzker J. Preoperative Planning. In: Ruedi TP, Buckley RE, Morgan CG (eds). AO Principles of Fracture Management. 2nd ed. New York, Stuttgart: Thieme; 2007. 
  2. Bhaskar D, Rajpura A, Board T. Current Concepts in Acetabular Positioning in Total Hip Arthroplasty. Indian J Orthop. 2017 Jul;51(4):386-396.
  3. Jolles BM, Zangger P, Leyvraz PF. Factors predisposing to dislocation after primary total hip arthroplasty: a multivariate analysis. J Arthroplasty. 2002 Apr;17(3):282-288.
  4. Callanan MC, Jarrett B, Bragdon CR, et al. The John Charnley Award: risk factors for cup malpositioning: quality improvement through a joint registry at a tertiary hospital. Clin Orthop Relat Res. 2011 Feb;469(2):319-329.
  5. Wylde V, Blom AW, Bolink S, et al. Assessing function in patients undergoing joint replacement: a study protocol for a cohort study. BMC Musculoskelet Disord. 2012 Nov;13:220.
  6. Bahadori S, Immins T, Wainwright TW. A review of wearable motion tracking systems used in rehabilitation following hip and knee replacement. Journal of Rehabilitation and Assistive Technologies Engineering. 2018 Jan. https://doi.org/10.1177/2055668318771816.
  7. Ng VY, Kean JR, Glassman AH. Limb-length discrepancy after hip arthroplasty. J Bone Joint Surg Am. 2013 Aug 7;95(15):1426–1436.
  8. Lenguerrand E, Whitehouse MR, Beswick AD, et al. Risk factors associated with revision for prosthetic joint infection after hip replacement: a prospective observational cohort study. Lancet Infect Dis. 2018 Sep;18(9):1004–1014.
  9. Scully W, Piuzzi NS, Sodhi N, et al. The effect of body mass index on 30-day complications after total hip arthroplasty. Hip Int. 2019 Feb 5. doi:1120700019826482.
  10. Werner BC, Higgins MD, Pehlivan HC, et al. Super Obesity Is an Independent Risk Factor for Complications After Primary Total Hip Arthroplasty. J Arthroplasty. 2017 Feb;32(2):402-406.
  11. Viramontes O, Luan Erfe BM, Erfe JM, et al. Cognitive impairment and postoperative outcomes in patients undergoing primary total hip arthroplasty: A systematic review. J Clin Anesth. 2019 Jan;28(56):65-76.
  12. Curtis GL, Hammad A, Anis HK, et al. Dependent Functional Status is a Risk Factor for Perioperative and Postoperative Complications After Total Hip Arthroplasty. J Arthroplasty. 2019 Jan. doi: 10.1016/j.arth.2018.12.037
  13. Veltre DR, Sing DC, Yi PH, et al. Insurance Status Affects Complication Rates After Total Hip Arthroplasty. J Am Acad Orthop Surg. 2018 Nov. doi: 10.5435/JAAOS-D-17-00635.
  14. Riddle DL, Stratford PW, Bowman DH. Findings of extensive variation in the types of outcome measures used in hip and knee replacement clinical trials: a systematic review. Arthritis Rheum. 2008;59(6):876–883.
  15. Foucher KC, Freels S. Preoperative factors associated with postoperative gait kinematics and kinetics after total hip arthroplasty. Osteoarthritis Cartilage. 2015 Oct;23(10):1685-1694.
  16. Macheras GA, Lepetsos P, Anastasopoulos PP, et al. The necessity to restore the anatomic hip centre in congenital hip disease. Ann Transl Med. 2016 Dec;4(23):470.
  17. Stefl M, Lundergan W, Heckmann N, et al. Spinopelvic mobility and acetabular component position for total hip arthroplasty. Bone Joint J. 2017 Jan;99-B(1 Supple A):37–45.
  18. Kanawade V, Dorr LD, Wan Z. Predictability of acetabular component angular change with postural shift from standing to sitting position. J Bone Joint Surg. 2014 Jun;96(12):978–986.
  19. Ochi H, Homma Y, Baba T, et al. Sagittal spinopelvic alignment predicts hip function after total hip arthroplasty. Gait Posture. 2017 Feb;52:293-300.
  20. Rivière C, Lazic S, Villet L, et al. Kinematic alignment technique for total hip and knee arthroplasty: The personalized implant positioning surgery. EFORT Open Rev. 2018 Mar;3(3):98-105.
  21. Gia VV, Sivakumar BS, Levy YD, et al. Practical implications of the lumbar spine and its function on total hip arthroplasty. J Spine Surg. 2016 Dec;2(4):334–337.
  22. Malkani AL, Himschoot KJ, Ong KL, et al. Does Timing of Primary Total Hip Arthroplasty Prior to or After Lumbar Spine Fusion Have an Effect on Dislocation and Revision Rates? J Arthroplasty. 2019 Jan. doi: 10.1016/j.arth.2019.01.009.
  23. Malkani AL, Garber AT, Ong KL, et al. Total Hip Arthroplasty in Patients With Previous Lumbar Fusion Surgery: Are There More Dislocations and Revisions? J Arthroplasty. 2018 Apr;33(4):1189-1193.
  24. Salib CG, Reina N, Perry KI, et al. Lumbar fusion involving the sacrum increases dislocation risk in primary total hip arthroplasty. Bone Joint J. 2019 Feb;101-B(2):198-206.
  25. Buckland AJ, Puvanesarajah V, Vigdorchik J, et al. Dislocation of a primary total hip arthroplasty is more common in patients with a lumbar spinal fusion. Bone Joint J. 2017 May;99-B(5):585-591.
  26. Furuhashi H, Togawa D, Koyama H, et al. Repeated posterior dislocation of total hip arthroplasty after spinal corrective long fusion with pelvic fixation. Eur Spine J. 2017 May;26(Suppl 1):100-106.
  27. Haldane CE, Ekhtiari S, de Sa D, et al. Preoperative physical examination and imaging of femoroacetabular impingement prior to hip arthroscopy-a systematic review. J Hip Preserv Surg. 2017 Jun;4(3):201-213.
  28. Shaikh AH. Preoperative Planning of Total Hip Arthroplasty. 2018. 10.5772/intechopen.76368. Available at: https://www.researchgate.net/publication/328797039_Preoperative_Planning_of_Total_Hip_Arthroplasty.
  29. Schmitz HC, Egidy CC, Al-Khateeb H, et al. Importance of Preoperative Imaging in Acetabular Revision Surgery - A Case Report. Open Orthop J. 2012 May;6:215–219.
  30. Kavalerskiy GM, Murylev VY, Rukin YA, et al. Three-Dimensional Models in Planning of Revision Hip Arthroplasty with Complex Acetabular Defects. Indian J Orthop. 2018 Nov-Dec;52(6):625-630.
  31. Direito-Santos B, França G, Nunes J, et al. Acetabular retroversion: Diagnosis and treatment. EFORT Open Rev. 2018 Nov;12;3(11):595-603.
  32. Domb BG, Watson JN, Gupta A. Acetabular Retroversion. In: Nho S, et al. (eds). Hip Arthroscopy and Hip Joint Preservation Surgery. Springer, New York, NY. 2015. 619-636.
  33. Charnley J. Low friction arthroplasty of the hip: Theory and Practice. Vol. 246. Berlin Heidelberg: Springer-Verlag; 1979.
  34. Müller ME. Lessons of 30 years of total hip arthroplasty. Clin Orthop Relat Res. 1992 Jan;(274):12-21.
  35. Kearney R, Shaikh AH, O'Byrne JM. The accuracy and inter-observer reliability of acetate templating in total hip arthroplasty. Ir J Med Sci. 2013 Sep;182(3):409-414.
  36. Miashiro EH, Fujiki EN, Yamaguchi EN, et al. Preoperative planning of primary total hip arthroplasty using conventional radiographs. Rev Bras Ortop. 2014 Apr;49(2):140-148.
  37. Bono J. Digital templating in total hip arthroplasty. Bone Joint Surg Am. 2004;86-A(Suppl 2):118-122.
  38. Stigler SK, Müller FJ, Pfaud S, et al. Digital templating in total hip arthroplasty: Additional anteroposterior hip view increases the accuracy. World J Orthop. 2017 Jan;8(1):30–35.
  39. Boese CK, Wilhelm S, Haneder S, et al. Influence of calibration on digital templating of hip arthroplasty. Int Orthop. 2018 Aug.1-7.
  40. González Della Valle A, Comba F, Taveras N, et al. The utility and precision of analogue and digital preoperative planning for total hip arthroplasty. Int Orthop. 2008 Jun;32(3):289-294.
  41. Shemesh SS, Robinson J, Keswani A, et al. The Accuracy of Digital Templating for Primary Total Hip Arthroplasty: Is There a Difference Between Direct Anterior and Posterior Approaches? J Arthroplasty. 2017 Jun;32(6):1884-1889.
  42. Holzer LA, Scholler G, Wagner S Arch, et al. The accuracy of digital templating in uncemented total hip arthroplasty. Orthop Trauma Surg. 2019 Feb;139(2):263-268.
  43. Petretta B, Strelzow J, Ohly NE, et al. Acetate Templating on Digital Images Is More Accurate Than Computer-based Templating for Total Hip Arthroplasty. Clin Orthop Relat Res. 2015 Dec;473(12):3752–3759.
  44. Karkenny AJ, Mendelis JR, Geller DS, et al. The Role of Intraoperative Navigation in Orthopaedic Surgery. J Am Acad Orthop Surg. 2019 Feb. doi: 10.5435/JAAOS-D-18-00478.
  45. Scheerlinck T. Primary hip arthroplasty templating on standard radiographs. A stepwise approach. Acta Orthop Belg. 2010 Aug;76(4):432-442.
  46. GoodReads. Planning Quotes. Available at: https://www.goodreads.com/quotes/tag/planning. Accessed March 2, 2019.
  47. Donnelly WJ, Crawford RW, Rimmington TD, et al. Acetabular Cup Placement, Are We Accurate? Orthopedic Proceedings. 2004 Apr;86-B(SUPP_IV):474.