Published: 2022-04-25

A prospective comparative study of functional outcome of 28 mm versus 36 mm femoral head sizes in uncemented total hip arthroplasty

Avinash Parthasarathy, T. H. Prakashappa, Achyutha S. Nayaka, Varun Kuttikara Odhayoth


Background: Incidence of dislocation is about 1% to 6% for primary total hip arthroplasty (THA) and 4.8% to 13% for revision THA. The diameter of the femoral head is one of the important variables under the control of a surgeon. Larger heads with modern necks improve the head-to-neck ratio, increase jump distance, reduce component impingement, instability and increase ROM. Objective were to compare the functional outcome of 28 mm versus 36 mm head sizes in uncemented THA in terms of ROM and functional status.

Methods: In this prospective comparative study conducted on 30 patients with 36 diseased hips undergoing primary THA with 28 mm and 36 mm femoral head sizes for degenerative arthritis aged between 20-70 years, in Sanjay Gandhi institute of trauma and orthopaedics, Bangalore from November 2019 to April 2021. All patients were followed up at 6, 12 and 24 weeks postoperatively and assessed for ROM and functional status using modified Harris hip score (HHS).

Results: The flexion was 9.31 degrees, extension was 4.0 degrees, adduction was 3.35 degrees, abduction was 4.31 degrees, internal rotation was 6.13 degrees, external rotation was 9.06 degrees and modified HHS was more in patients who received 36 mm femoral head as compared to the patients who received 28 mm femoral head at the end of follow up.

Conclusions: We conclude that the use of 36 mm femoral head provides better improvement in the range of motion, functional outcome, and better patient and surgeon satisfaction than 28 mm femoral head in THA.



28 mm vs 36 mm femoral head, 36 mm femoral head, Uncemented THA

Full Text:



Magee T, Schaeffer J, Buck D, Gililland J, Hofmann A. Effect of Femoral Head Diameter on Risk of Dislocation after Primary Total Hip arthroplasty. J Arthritis. 2013;2(1):2167-7921.

American Joint Replacement Registry-Annual Report. 2016;16-20.

Amlie E, Høvik Ø, Reikerås O. Dislocation after total hip arthroplasty with 28- and 32-mm femoral head. J Orthop Traumatol. 2010;11:111-5.

Bystrom S, Espehaug B, Furnes O, Havelin L. Femoral head size is a risk factor for total hip luxation: a study of 42,987 primary hip arthroplasties from the Norwegian Arthroplasty Register. Acta Orthop Scan. 2003;74(5):514-24.

Kelley SS, Lachiewicz PF, Hickman JM, Paterno SM. Relationship of femoral head and acetabular size to the prevalence of dislocation. Clin Orthop Rel Res. 1998;355:163-70.

Burroughs B, Hallstrom B, Golladay G, Hoeffel D, Harris W. Range of Motion and Stability in Total Hip Arthroplasty With 28-, 32-, 38-, and 44-mm Femoral Head Sizes. J Arthroplasty. 2005;20(1):11-9.

Eftekhar N. Dislocation and Instability Complicating Low Friction Arthroplasty of the Hip Joint. Clin Orthop Rel Res. 1976;(121):120-5.

Harkess J, Crockarell Jr J. Campbell's Operative Textbook for Orthopaedics. 13th ed. Elsevier. 2017;167-313.

Singh S, Bhalodiya H. Head size and dislocation rate in primary total hip arthroplasty. Indian J Orthop. 2013;47(5):443-8.

Cho M, Choi W, Kim J. Current Concepts of Using Large Femoral Heads in Total Hip Arthroplasty. Hip Pelvis. 2016;28(3):134.

Phillips CB, Barrett JA, Losina E. Incidence rates of dislocation, pulmonary embolism, and deep infection during the first six months after elective total hip replacement. J Bone Joint Surg Am. 2003;85-A(1):20.

Bystrom S, Espehaug B, Furnes O. Femoral head size is a risk factor for total hip luxation: a study of 42,987 primary hip arthroplasties from the Norwegian Arthroplasty Register. Acta Orthop Scand 2003;74(5):514.

Berry DJ, von Knoch M, Schleck CD. Effect of femoral head diameter and the approach on risk of dislocation after primary total hip arthroplasty. J Bone Joint Surg Am. 2005;87(11):2456.

Von Knoch M, Berry DJ, Harmsen WS. Late dislocation after total hip arthroplasty. J Bone Joint Surg Am 1949;84-A(11):2002.

Haddad FS. Even the winners are losers. Bone Joint J. 2017;99eB:561e2.

Brooks PJ. Dislocation following total hip replacement: causes and cures. Bone Joint J. 2013;95-B(11A):67-9.

Howie D, Holubowycz O, Middleton R. Large Femoral Heads Decrease the Incidence of Dislocation After Total Hip Arthroplasty. J Bone Joint Surgery-Am Vol. 2012;94(12):1095-103.

Kim M, Chung Y, Lee J, Kim C. Measuring the Impact of Femoral Head Size on Dislocation Rates Following Total Hip Arthroplasty. Hip Pelvis. 2017;29(2):91-6.

Sultan P, Tan V, Lai M, Garino J. Independent contribution of elevated-rim acetabular liner and femoral head size to the stability of total hip implants. J Arthroplasty. 2002;17(3):289-92.

Bartz RL, Noble PC, Kadakia NR, Tullos HS. The effect of femoral component head size on posterior dislocation of the artificial hip joint. J Bone Joint Surg Am. 2000;82-A:1300-07.

Geller JA, Malchau H, Bragdon C, Greene M, Harris WH, Freiberg AA. Large diameter femoral heads on highly cross-linked polyethylene: minimum 3-year results. Clin Orthop Relat Res. 2006;447:53-9.

Hammerberg E, Wan Z, Dastane M, Dorr L. Wear and Range of Motion of Different Femoral Head Sizes. J Arthroplasty. 2010;25(6):839-43.