Smartphone Application Helps Improve the Accuracy of Cup Placement by Young, Less-Experienced Surgeons during Primary Total Hip Arthroplasty

Document Type : RESEARCH PAPER


1 Orthopaedic Department, Qena Faculty of Medicine and University Hospital, South Valley University, Qena, Egypt

2 Orthopaedic and Traumatology Department, Assiut University Hospital, Assiut, Egypt

3 Knee & Orthopaedic Clinic, Powai, Mumbai Head of Research, AIMD Research


Background: Dislocation after total hip arthroplasty (THA) partly under the surgeon’s control, by appropriate placement 
of the components. We aimed in this study to determine the accuracy of using intra-operative smartphone applications 
(Apps) to place the acetabular cup within the safe abduction angle by less experienced surgeons during THA surgery 
when compared to the conventional freehand technique for cup placement.
Methods: Sixty primary THAs were performed, 30 using the conventional freehand technique (control group) and 30 
using the smartphone app technique (study group) to determine the acetabular cup abduction angle by the same young 
surgeon with less than one year of experience. Postoperative mean cup abduction angle, mean cup anteversion angle, 
and the percentage of cups within the safe abduction zone as measured on radiographs were compared between the 
two groups.
Results: In the study group, the mean cup abduction angle was significantly lower (P=0.0008), and the acetabular 
cup was placed within the safe zone in a significantly higher (P<0.001) percentage of patients (93% vs 63%) when 
compared to the control group. However, there was no significant difference (P=0.40) between the two groups when 
the mean cup anteversion angle was compared.
Conclusion: The smartphone app technique may help achieve an accurate acetabular cup abduction angle and a 
higher percentage of cups placed within the safe zone of abduction by a less experienced surgeon when compared to 
the conventional freehand technique. Using tools such as the smartphone app to measure the acetabular cup position
can reduce intraoperative errors by young and less experienced surgeons during THA surgery.
Level of evidence: IV


1. Delaunay C, Hamadouche M, Girard J, Duhamel 
A. What are the causes for failures of primary hip 
arthroplasties in France? Clinical orthopaedics and 
related research. 2013;471(12):3863-9.
2. Hailer NP, Weiss RJ, Stark A, Kärrholm J. The risk of 
revision due to dislocation after total hip arthroplasty 
depends on surgical approach, femoral head size, 
sex, and primary diagnosis. Acta Orthopaedica. 
3. Noticewala M, Murtaugh TS, Danoff J, Cunn GJ, Shah 
RP, Geller J. Has the risk of dislocation after total hip 
arthroplasty performed for displaced femoral neck 
fracture improved with modern implants? Journal of 
clinical orthopaedics and trauma. 2018;9(4):281-4.
4. Ha Y-C, Yoo JJ, Lee Y-K, Kim JY, Koo K-H. Acetabular 
Component Positioning Using Anatomic Landmarks 
of the Acetabulum. Clinical Orthopaedics and Related 
Research®. 2012;470(12):3515-23.
5. Patil S, Bergula A, Chen PC, Colwell CWJ, D’Lima 
DD. Polyethylene Wear and Acetabular Component 
Orientation. JBJS. 2003;85(suppl_4):56-63.
6. Little NJ, Busch CA, Gallagher JA, Rorabeck CH, Bourne 
RB. Acetabular polyethylene wear and acetabular 
inclination and femoral offset. Clinical Orthopaedics 
and Related Research®. 2009; 467(11):2895-900.
7. Lewinnek GE, Lewis JL, Tarr R, Compere CL, 
Zimmerman JR. Dislocations after total hipreplacement arthroplasties. J Bone Joint Surg Am. 
8. Callanan MC, Jarrett B, Bragdon CR, Zurakowski D, 
Rubash HE, Freiberg AA, et al. The John Charnley 
Award: risk factors for cup malpositioning: quality 
improvement through a joint registry at a tertiary 
hospital. Clinical orthopaedics and related research. 
9. Beverland DE, O’Neill CK, Rutherford M, Molloy D, 
Hill JC. Placement of the acetabular component. Bone 
Joint J. 2016;98-b(1 Suppl A):37-43.
10.Archbold HA, Mockford B, Molloy D, McConway J, 
Ogonda L, Beverland D. The transverse acetabular 
ligament: an aid to orientation of the acetabular 
component during primary total hip replacement: 
a preliminary study of 1000 cases investigating 
postoperative stability. The Journal of bone and joint 
surgery. British volume. 2006; 88(7):883-6.
11.Gandhi R, Marchie A, Farrokhyar F, Mahomed N. 
Computer navigation in total hip replacement: 
a meta-analysis. International Orthopaedics. 
12.Tagomori H, Kaku N, Tabata T, Kubota Y, Tsumura 
H. Comparison of cementless and cemented cups 
in revision total hip arthroplasty using a computed 
tomography-based navigation system. Journal of 
clinical orthopaedics and trauma. 2020;11(Suppl 
13.Morgenstern R, Su EP. Handheld navigation for 
direct anterior total hip arthroplasty. Seminars in 
Arthroplasty. 2018;29(3):153-6.
14.Pongkunakorn A, Chatmaitri S, Diewwattanawiwat K. 
Use of smartphone to improve acetabular component  positioning in total hip athroplasty: A comparative 
clinical study. Journal of orthopaedic surgery (Hong 
Kong). 2019;27(1):2309499019825578.
15.Peters FM, Greeff R, Goldstein N, Frey CT. Improving 
Acetabular Cup Orientation in Total Hip Arthroplasty 
by Using Smartphone Technology. The Journal of 
Arthroplasty. 2012;27(7):1324-30.
16.Pai VS. A Modified Direct Lateral Approach in Total 
Hip Arthroplasty. Journal of Orthopaedic Surgery. 
17.Khalifa AA, Bakr HM, Said E, Mahran MA. Technical 
Note on Using Intraoperative Smartphone 
Applications to Adjust Cup Inclination Angle during 
Total Hip Arthroplasty (THA). Archives of Bone and 
Joint Surgery. 2020; 8(6):734.
18.Jolles BM, Zangger P, Leyvraz PF. Factors predisposing 
to dislocation after primary total hip arthroplasty: 
A multivariate analysis. The Journal of Arthroplasty. 
19.Alzohiry MA, Abdelnasser MK, Moustafa M, 
Mahran M, Bakr H, Khalifa Y, et al. Accuracy of plain 
antero-posterior radiographic-based methods for 
measurement of acetabular cup version. Int Orthop. 
20.Elkins JM, Callaghan JJ, Brown TD. The 2014 Frank 
Stinchfield Award: The ‘Landing Zone’ for Wear 
and Stability in Total Hip Arthroplasty Is Smaller 
Than We Thought: A Computational Analysis. 
Clinical Orthopaedics and Related Research®. 
21.Abdel MP, von Roth P, Jennings MT, Hanssen AD, 
Pagnano MW. What Safe Zone? The Vast Majority 
of Dislocated THAs Are Within the Lewinnek 
Safe Zone for Acetabular Component Position. 
Clinical Orthopaedics and Related Research®. 
22.Meermans G, Goetheer-Smits I, Lim RF, Van Doorn WJ, 
Kats J. The difference between the radiographic and 
the operative angle of inclination of the acetabular 
component in total hip arthroplasty: use of a digital 
protractor and the circumference of the hip to 
improve orientation. The bone & joint journal. 2015; 
23.Jolles BM, Genoud P, Hoffmeyer P. Computer-assisted 
Cup Placement Techniques in Total Hip Arthroplasty 
Improve Accuracy of Placement. Clinical Orthopaedics 
and Related Research (1976-2007). 2004;426:174-9.
24.Tay XW, Zhang BX, Gayagay G. Use of iPhone 
technology in improving acetabular component 
position in total hip arthroplasty. Arthroplasty 
Today. 2017;3(3):167-70.
25.Hill JC, Gibson DP, Pagoti R, Beverland DE. 
Photographic measurement of the inclination of the 
acetabular component in total hip replacement using 
the posterior approach. The Journal of bone and joint 
surgery. British volume. 2010; 92(9):1209-14. 
Volume 10, Issue 3
March 2022
Pages 278-285
  • Receive Date: 28 September 2020
  • Revise Date: 05 August 2021
  • Accept Date: 22 August 2021
  • First Publish Date: 30 August 2021