Tapered wedge stems decrease early postoperative subsidence following cementless total hip arthroplasty in Dorr type C femurs compared to fit-and-fill stems

doi:10.21203/rs.3.rs-948396/v1

Download PDF

Research article

Tapered wedge stems decrease early postoperative subsidence following cementless total hip arthroplasty in Dorr type C femurs compared to fit-and-fill stems

https://doi.org/10.21203/rs.3.rs-948396/v1

This work is licensed under a CC BY 4.0 License

Journal Publication

published 10 Apr, 2022

Read the published version in Journal of Orthopaedic Surgery and Research →

You are reading this latest preprint version

Background: To compare the degree of stem subsidence between two different femoral component designs and to determine the risk factors associated with stem subsidence after cementless total hip arthroplasty (THA) in Dorr type C femurs.

Methods: We retrospectively reviewed 91 consecutive hips in 87 patients with Dorr type C proximal femoral morphology who underwent primary cementless THA using a fit-and-fill stem or a tapered wedge femoral stem at our institution between January 2013 and June 2020. A fit-and-fill stem was used in 48 hips and a tapered wedge stem was used in 43 hips. Radiologically, the distance between the apex of the major trochanter and the stem shoulder were measured at three different time points (immediately [0W], one week [1W], and six weeks [6W] after surgery) and the degrees of stem subsidence were assessed by comparing the distance between 0W and 1W, 1W and 6W, and 0W and 6W, respectively.

Results: The mean degree of stem subsidence (0W vs. 1W) was 0.25 mm (standard deviation [SD] 0.58) in the fit-and-fill stem group, and 0.24 mm (SD 0.43) in the tapered wedge stem group. There was no significant difference between the two groups (P = 0.4493). However, the mean degrees of subsidence were significantly higher in the fit-and-fill stem group (1W vs. 6W, 0.38 mm [SD 0.81]; 0W vs. 6W, 0.64 mm [SD 1.17]) than in the tapered wedge stem group (1W vs. 6W, 0.17 mm [SD 0.29]; 0W vs. 6W, 0.25 mm [SD 0.35]) (P < 0.05 for both). In addition, the rates of >3 mm subsidence (in which instability can be observed) were 16.7% (8 of 48 hips) and 2.3% (1 of 43 hips), respectively. There was also a significant difference between the two stems (P = 0.0324). Multivariate analysis demonstrated that higher age and fit-and-fill stem were risk factors for >3 mm subsidence after THA in Dorr type C femurs (P = 0.0396 and 0.0227, respectively).

Conclusion: Our findings suggest that the tapered wedge stem is more suitable for Dorr type C femurs than the fit-and-fill stem to avoid early postoperative subsidence in cementless THA.

Orthopedics

Orthopedic Surgery

Cementless total hip arthroplasty

Stem subsidence

Dorr type C

Tapered wedge stem

Fit-and-fill stem

Total hip arthroplasty (THA) is one of the most successful surgeries of the twentieth century to alleviate pain and restore joint function in patients with end-stage hip arthritis [1]. The number of surgeries performed each year and the degree of durability have been increasing because of the increasing average life expectancy [2–4]. However, stem subsidence is a known cause of early failure of surgery, in addition to periprosthetic femoral fracture (PFF), instability, and infection [5–7]. Maximum stem subsidence is observed within the first six to eight weeks after cementless THA [8–10]. It can lead to unequal leg length, decreased hip stability, and implant failure. While stem subsidence of up to 3 mm is considered acceptable, migration above 5 mm is associated with early failure due to the instability of the hip joint [11, 12].

However, there is a lack of knowledge regarding reasons for subsidence [6, 9, 13]. Femoral stem type, design, and anatomical properties may play a relevant role [8, 14]. A recent study investigated early postoperative stem subsidence by comparing the fit-and-fill stem and tapered wedge stem [15]. The authors reported that an anatomically designed morphometric tapered wedge femoral stem demonstrated greater axial stability and decreased subsidence with increasing body mass index (BMI) than a traditional fit-and-fill stem after cementless THA.

Femoral bone quality is an important factor that affects the initial fixation of the femoral component after THA using a cementless stem. In 1993, Dorr et al. divided the morphology of the proximal femur into three types: type A (champagne-flute), type B (funnel type), and type C (stovepipe) [16]. Dorr type C femoral morphology is characterized by thin cortices, which are found predominantly in elderly patients with osteoporosis.

A number of studies have reported risk factors for stem subsidence after cementless THA such as male sex, obesity, osteoporosis, and Dorr type C femoral morphology [17–19]. However, to our knowledge, no studies have compared different types of stems in terms of stem subsidence after cementless THA while focusing on Dorr type C femurs. The purposes of this study were to compare the degree of stem subsidence between two different femoral component designs and to determine the risk factors associated with stem subsidence after cementless THA in Dorr type C femurs.

This study was approved by our institutional review board. The need for informed consent was waived due to the retrospective and anonymous study design. At our institution, a conventional fit-and-fill stem has been used for the cementless THA. However, we have been using a modern tapered wedge stem for various types of femoral morphology in THA since August 2017. This study retrospectively reviewed 91 consecutive hips in 87 patients with Dorr type C proximal femoral morphology who underwent primary cementless THA (posterolateral approach) using a fit-and-fill stem (Fig. 1a; PerFix910, Kyocera, Kyoto, Japan) or a tapered wedge femoral stem (Fig. 1b; Initia, Kyocera, Kyoto, Japan) at our institution between January 2013 and June 2020. A fit-and-fill stem was used in 48 hips, and a tapered wedge stem was used in 43 hips. The patients included 13 males and 74 females with a mean age at surgery of 67 years (range, 32-87). The primary reason for surgery was osteoarthritis (OA) in 85 hips, osteonecrosis of the femoral head (ONFH) in 4 hips, and rheumatoid arthritis (RA) in 2 hips. The mean body mass index (BMI) was 24.1 kg/m² (SD 4.4). Full weight-bearing walking was started the day after surgery in all 87 patients (91 hips).

Postoperative radiographs were assessed by two observers (S.I. and K.S.) who are orthopedic surgeons with extensive diagnostic imaging experience, using digital imaging system (Synapse Digital Imaging System, Fujifilm Medical Imaging, Tokyo, Japan), and only mean values were used for statistical analysis. Subsidence was defined as a femoral stem distalization in reference to the major trochanter, according to a previous report [19]. The distance between the apex of the major trochanter and the stem shoulder was measured at three different time points (immediately [0 W], one week [1 W], and six weeks [6 W] after surgery) and the degrees of stem subsidence were assessed by comparing the distance at each time point (0 W vs. 1 W, 1 W vs. 6 W, and 0 W vs. 6 W) in both stems (Fig. 2). After measurement of the stem subsidence from 0 W to 6 W, all 91 hips were divided into two subgroups (>3 mm subsidence positive or negative) based on the degree of subsidence [11, 12].

Statistical analyses were carried out using Fisher’s exact probability test to compare the sex, reasons for surgery, and the incidence of PFF between the two groups (fit-and-fill stem vs. tapered wedge stem and > 3mm subsidence positive vs. negative). Age, BMI, and degree of stem subsidence were compared between the fit-and-fill stem and tapered wedge stem groups using the unpaired t-test. Multivariate analysis was performed to identify parameters associated with >3 mm stem subsidence from 0 W to 6 W after THA using a stepwise logistic regression with variable selection (P < 0.2). Statistical analyses were performed using the JMP Ver. 9.0.1 software (SAS Institute Inc., Cary, NC, USA). P values < 0.05 were considered statistically significant.

The patients in the fit-and-fill stem group included 4 males and 44 females with a mean age at surgery of 68.5 years (standard deviation [SD] 10.6) Patients in the tapered wedge stem group included 9 males and 34 females with a mean age of 65.3 years (SD 12.9). There were no significant differences in sex and age between the two groups (P = 0.1327 and 0.1946, respectively). The mean BMI was 24.0 kg/m² (SD 4.3) in the fit-and-fill stem group, and 24.3 kg/m² (SD 4.6) in the tapered wedge stem group. There was no significant difference between the two groups (P = 0.7915). Reasons for surgery included: 44 hips, OA; 2 hips, ONFH; and 2 hips, RA in the fit-and-fill group; and 41 hips, OA; and 2 hips, ONFH in the tapered wedge stem group. There was also no significant difference between the two groups (P = 0.6798). In the fit-and-fill stem group only, PFF occurred in 2 of 44 hips (4.2%). One hip was intraoperative calcar fracture and was treated with circumference wiring, and the other was postoperative fracture at the level of the greater trochanter (Vancouver type A_G) 8 days after surgery [20]. Restriction of weight bearing was not adopted, and thus these two hips were included in the postoperative radiological measurement. There was no significant difference in the rate of PFF between the two groups (fit-and-fill stem, 4.2%; tapered wedge stem, 0%; P = 0.4960). Neither superficial nor deep infection were observed in either stem groups. In the tapered wedge stem group, dislocation of the hip joint was observed in one hip 3 weeks after the surgery.

The results of degrees of stem subsidence are shown in Table 1. The mean degrees of stem subsidence from 1 W to 6 W and 0 W to 6 W were significantly higher in the fit-and-fill stem group than in the tapered wedge stem group. The rate of > 3 mm subsidence was 16.7% (8 of 48 hips) in the fit-and-fill stem group (Fig. 2), and 2.3% (1 of 43 hips) in the tapered wedge stem group. There was a significant difference between the two groups.

Table 1

The results of stem subsidence between fit-and-fill stem and tapered wedge stem groups in Dorr type C femurs.
Subsidence (mm)		Fit-and-fill stem	Tapered wedge stem	P values
Subsidence (mm)		(N = 48)	(N = 43)
Duration from	0W to 1W	0.25 ± 0.58	0.24 ± 0.43	0.4493
1W to 6W		0.38 ± 0.81	0.17 ± 0.29	0.0496	*
0W to 6W		0.64 ± 1.17	0.25 ± 0.35	0.0450	*
>3 mm subsidence		8 (16.7%)	1 (2.3%)	0.0324	*
Continuous variables are represented as mean ± standard deviation. Abbreviations: N, number; 0W, immediate after surgery; 1W, One week after the surgery; 6W, Six weeks after surgery
*P < 0.05 indicates significance

Nine hips were categorized as the >3 mm stem subsidence-positive group and 82 as the -negative group (Table 2). Multivariate analysis demonstrated that age and type of cementless stem were independently associated with >3 mm subsidence after THA in Dorr type C femurs (P = 0.0396 and 0.0227, respectively).

Table 2

Univariate and multivariate analyses of >3 mm stem subsidence-positive and -negative groups in Dorr type C femurs.
		>3 mm subsidence-positive	>3 mm subsidence-negative	Univariate		Multivariate		Odds Ratio
		(N = 9)	(N = 82)	P values		P values		(95% CI)
Sex (male: female)		1: 8	12: 70	0.9999		-
Age (years)		74.2 ± 8.6	66.2 ± 11.8	0.0526		0.0396	*	1.09 (1.01-1.22)
BMI (kg/m²)		23.6 ± 2.3	24.2 ± 4.6	0.7273		-
Diagnosis				0.1063		0.1289		5.45 (0.58-45.37)
OA		7	78
Other (ONFH or RA)		2	4
Stem				0.0324	*	0.0227	*	8.22 (1.30-164.61)
	Fit-and-fill	8	40
Tapered wedge		1	42
Abbreviations: BMI, body mass index; OA, osteoarthritis; ONFH, osteonecrosis of the femoral head; RA, rheumatoid arthritis; CI, confidence interval.
*P < 0.05 indicates significance

Subsidence is a known complication of THA. Walker et al. found that subsidence of the femoral stem can predict clinical outcomes, and that decreased subsidence leads to better results [21]. Additionally, significant subsidence may contribute to postoperative instability and leg length discrepancy [11, 12]. A number of studies focusing on stem subsidence have been reported, since excessive subsidence can lead to early failure after surgery [5–12, 15, 17–19, 21]. However, there have been few reports on subsidence comparing different types of stems. Grant et al. compared the subsidence of a cementless fit-and-fill stem with that of a cementless tapered wedge stem [15]. The mean degree of subsidence 4 weeks after THA was significantly lower in 65 patients treated with a tapered wedge stem (0.3 mm) than in 61 patients treated with a fit-and-fill stem (1.1 mm) [15]. Their findings were consistent with our results (taper wedge, 0.25 mm; fit-and-fill, 0.64 mm), although their study did not analyze subsidence based on femoral morphology such as types of Dorr [15].

The advantages of cementless implantation including shorter operative times and lower risk of potential cardiopulmonary event, may favor the use of this stem [22, 23]. However, cemented stems are generally recommended for patients with Dorr type C femurs because of concerns about achieving immediate fixation and occurring of fracture around the cementless stem [22, 23]. An investigation by Pentlow and Heal showed a significantly higher subsidence rate of hydroxyapatite (HA)-coated cementless stem in traumatic patients who mostly had Dorr type C femurs [24]. Song et al. reported that Dorr type C femurs had a higher risk of subsidence when using uncemented collarless HA-coated stem [19]. In contrast, Reis et al. concluded in their investigation that no anatomic parameter could be detected as a predisposing factor for cementless stem subsidence [12]. Dalury et al. also reported that a proximally coated cementless stem was safely and successfully used for type C bone [25]. In the current study, the mean stem subsidence in the duration from immediate to 6 weeks after surgery was within 1 mm in both cementless stems, which supports previous reports in which cementless stems have been used safely for THA even for Dorr type C femurs. In addition, our study may be the first to report that a tapered wedge stem is more suitable for immediate fixation than a fit-and-fill stem in Dorr type C femurs by comparing the degrees of stem subsidence between two different types of stems.

Regarding the lower degree of stem subsidence in the tapered wedge stem group than in the fit-and-fill stem group observed in our study, a recent comparative study mentioned that tapered wedge stems are designed to achieve more congruent cortical fit in the coronal plane and have demonstrated excellent long-term results of 25 years with a small 1.4% loosening rate [15, 26]. We consider that mediolateral cortical bone quality at the level of initial fixation in the tapered wedge stem (bellow the lesser trochanter) is better than that in the fit-and-fill stem (above the lesser trochanter) (Fig. 2) in the majority of Dorr type C femurs, which may be related to the differences in the degree of subsidence between the two groups in this study. In addition, the taper wedge stem has the advantage of more accurate stem size prediction in preoperative three-dimensional (3D) planning, since the mediolateral cortical bone is clear (Fig. 2).

There were several limitations to the current study. First, this study evaluated stem subsidence only early (up to 6 W) after surgery in both fit-and-fill and tapered wedge stems. However, Dalury et al. reported that subsidence was apparent at 6 weeks and remained stable at an average of 6 years of follow-up [25]. Second, the current study was retrospective, with a small number of cases. Therefore, further prospective studies with a large number of cases are necessary.

Our findings suggest that cementless stems can be used safely for THA, even for Dorr type C femurs. In addition, the tapered wedge stem appears to be more suitable for Dorr type C femurs than the fit-and-fill stem to avoid early postoperative subsidence in cementless THA.

THA, total hip arthroplasty; W, week; SD, standard deviation; BMI, body mass index; PFF, periprosthetic femoral fracture; OA, osteoarthritis; ONFH, osteonecrosis of the femoral head; RA, rheumatoid arthritis; HA, hydroxyapatite; 3D, three-dimensional

Acknowledgements

Not applicable

Authors’ contributions

SI performed the literature review and drafted the manuscript. YN supervised writing of the manuscript. SI, GM, SH, MF, SK, TS, DH, and KS contributed to the data collection. SI and KS analyzed the data. All authors read and approved the final manuscript.

Funding

This work was supported in part by a Grant-in-Aid in Scientific Research (No. JP19K09628) from the Japan Society for the Promotion of Science.

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.

Ethics approval and consent to participate

This retrospective study was approved by Kyushu University institutional review board for clinical research (NO.30-91). The need for informed consent was waived due to the retrospective and anonymous study design.

Consent for publication

Not applicable

Competing interests

The authors declare that they have no competing interests.

Learmonth ID, Young C, Rorabeck C. The operation of the century: total hip replacement. Lancet. 2007;370:1508–19.
Erivan R, Villatte G, Dartus J, Reina N, Descamps S, Boisgard S. Progression and projection for hip surgery in France, 2008-2070: epidemiologic study with trend and projection analysis. Orthop Traumatol Surg Res. 2019;105:1227–35.
Singh JA, Yu S, Chen L, Cleveland JD. Rates of total joint replacement in the United States: future projections to 2020-2040 using the National Inpatient Sample. J Rheumatol. 2019;46:1134–40.
Ackerman IN, Bohensky MA, Zomer E, Tacey M, Gorelik A, Brand CA, et al. The projected burden of primary total knee and hip replacement for osteoarthritis in Australia to the year 2030. BMC Musculoskelet Disord. 2019;20:90.
Kärrholm J, Borssén B, Löwenhielm G, Snorrason F. Does early micromotion of femoral stem prostheses matter? 4–7-year stereoradiographic follow-up of 84 cemented prostheses. J Bone Joint Surg Br. 1994;76:912–7.
Campbell D, Mercer G, Nilsson KG, Wells V, Field JR, Callary SA. Early migration characteristics of a hydroxyapatite-coated femoral stem: an RSA study. Int Orthop. 2011;35:483–8.
Gwam CU, Mistry JB, Mohamed NS, Thomas M, Bigart KC, Mont MA, et al. Current epidemiology of revision total hip arthroplasty in the United States: National Inpatient Sample 2009 to 2013. J Arthroplasty. 2017;32:2088–92.
Al-Najjim M, Khattak U, Sim J, Chambers I. Differences in subsidence rate between alternative designs of a commonly used uncemented femoral stem. J Orthop. 2016;13:322–6.
Ström H, Nilsson O, Milbrink J, Mallmin H, Larsson S. Early migration pattern of the uncemented CLS stem in total hip arthroplasties. Clin Orthop Relat Res. 2007;454:127–32.
Selvaratnam V, Shetty V, Sahni V. Subsidence in collarless Corail hip replacement. Open Orthop J. 2015;29:194–7.
Sudhahar TA, Morapudi S, Branes K. Evaluation of subsidence between collarless and collared Corail femoral cement less total hip replacement. J Orthopaedics. 2009;6(2):e3 URL. http://www. jortho.org/2009/6/2/e3.
Ries C, Boese CK, Dietrich F, Miehlke W, Heisel C. Femoral stem subsidence in cementless total hip arthroplasty: a retrospective single-centre study. Int Orthop. 2019;43:307–14.
Ström H, Mallmin H, Milbrink J, Petrén-Mallmin M, Nivbrant B, Kolstad K. The cone hip stem: aprospective study of 13 patients followed for 5 years with RSA. Acta Orthop Scand. 2003;74:525–30.
Noble PC, Alexander JW, Lindahl LJ, Yew DT, Granberry WM, Tullos HS. The anatomic basis of femoral component design. Clin Orthop Relat Res. 1988;235:148–65.
Grant TW, Lovro LR, Licini DJ, Warth LC, Ziemba-Davis M, Meneghini RM. Cementless Tapered Wedge Femoral Stems Decrease Subsidence in Obese Patients Compared to Traditional Fit-and-Fill Stems. J Arthroplasty. 2017;32:891–7.
Dorr LD, Faugere MC, Mackel AM, Gruen TA, Bognar B, Malluche HH. Structural and cellular assessment of bone quality of proximal femur. Bone. 1993;14:231–42.
Johanson PE, Antonsson M, Shareghi B, Kärrholm J. Early Subsidence Predicts Failure of a Cemented Femoral Stem With Minor Design Changes. Clin Orthop Relat Res. 2016;474:2221–9.
Rattanaprichavej P, Laoruengthana A, Chotanaphuti T, Khuangsirikul S, Phreethanutt C, Pongpirul K. Subsidence of Hydroxyapatite-Coated Femoral Stem in Dorr Type C Proximal Femoral Morphology. J Arthroplasty. 2019;34:2011–5.
Song JH, Jo WL, Lee KH, Cho YJ, Park J, Oh S. Subsidence and perioperative periprosthetic fractures using collarless hydroxyapatite-coated stem for displaced femoral neck fractures according to Dorr type. J Orthop Surg (Hong Kong). 2019;27:2309499019877530.
Duncan CP, Masri BA. Fractures of the femur after hip replacement. Instr Course Lect. 1995;44:293–304.
Walker PS, Mai SF, Cobb AG, Bentley G, Hua J. Prediction of clinical outcome of THR from migration measurements on standard radiographs. A study of cemented Charnley and Stanmore femoral stems. J Bone Joint Surg Br. 1995;77:705–14.
Ahmad A, Mirza Y, Evans AR, Teoh KH. A comparative study between uncemented and hybrid total hip arthroplasty in octogenarians. J Arthroplasty. 2018;33:3719–23.
Jämsen E, Eskelinen A, Peltola M, Keijo M. High early failure rate after cementless hip replacement in the octogenarian. Clin Orthop Relat Res. 2014;472:2779–89.
Pentlow AK, Heal JS. Subsidence of collarless uncemented femoral stems in total hips replacements performed for trauma. Injury. 2012;43:882–5.
Dalury DF, Kelley TC, Adams MJ. Modern proximally tapered uncemented stems can be safely used in Dorr type C femoral bone. J Arthroplasty. 2012;27:1014–8.
McCalden RW, Korczak A, Somerville L, Yuan X, Naudie DD. A randomised trial comparing a short and a standard-length metaphyseal engaging cementless femoral stem using radiostereometric analysis. Bone Joint J. 2015;97:595–602.

Download PDF

Journal Publication

published 10 Apr, 2022

Read the published version in Journal of Orthopaedic Surgery and Research →

Editorial decision: Major revision
14 Oct, 2021
Review #1 received at journal
14 Oct, 2021
Reviewer #3 agreed at journal
09 Oct, 2021
Review #3 received at journal
09 Oct, 2021
Review #2 received at journal
09 Oct, 2021
Reviewer #2 agreed at journal
08 Oct, 2021
Reviewers invited by journal
05 Oct, 2021
Reviewer #1 agreed at journal
05 Oct, 2021
Editor assigned by journal
29 Sep, 2021
Submission checks completed at journal
28 Sep, 2021
Editor invited by journal
28 Sep, 2021
First submitted to journal
28 Sep, 2021

You are reading this latest preprint version

Tapered wedge stems decrease early postoperative subsidence following cementless total hip arthroplasty in Dorr type C femurs compared to fit-and-fill stems

Status:

Journal Publication

Version 1

Abstract

Figures

Background

Methods

Results

Discussion

Conclusion

Abbreviations

Declarations

References

Status:

Journal Publication

Version 1