Cementless total hip arthroplasty (THA) has become the standard fixation option in the United States and is used in more than 90% of all THAs.1,2 This method of fixation offers biologic bone ingrowth with the potential for the bone-implant interface to remodel and has resulted in excellent outcomes even with expanded indications, which include younger, more active patients.3,4 However, despite the success observed with these components, several concerns, including thigh pain and proximal stress shielding, have been raised, particularly with stems that have primarily diaphyseal fixation.5–7
The recent increase in enthusiasm for minimally invasive surgery and the desire to obtain greater bone loading proximally has led to the evolution of implants with short, conservative, or neck-preserving stems.8–12 These stems are defined as implants that achieve fixation in the femoral neck or in the proximal metaphysis. Although this is not necessarily a new design and several implants have been available in the United States and Europe for approximately 20 years, an increasing number of reports have been published recently that demonstrate that these implants are gaining in popularity as surgeons become increasingly interested in tissue- and bone-sparing surgery.13–15
As stems become shorter, improved proximal loading may be offset by a decrease in the primary stability of the implant when compared with conventional stems. Primary stability with less than 20 μm of micromotion at the bone-implant interface is crucial for promoting bone rather than fibrous ingrowth for the long-term success of cementless fixation.16–18
Various studies have shown that retaining the femoral neck contributes to improved primary stability with these short-stem femoral implants.19–21 Thus, most short stems currently available aim to achieve primary stability through neck retention and the impaction of bone in the femoral neck cylinder or in the proximal femoral metaphysis. With the exception of the Mayo prosthesis (Zimmer, Inc, Warsaw, Indiana), which has been used in the United States for more than 20 years, the majority of these stems have not yet been approved for general use by the Food and Drug Administration (FDA) and have primarily been used for patients in Europe.
Furthermore, many of the newer stem designs, which have been introduced in the past 5 years in the United States, are currently in clinical trials and have few short- or mid-term follow-up data available (Table 1). Although excellent clinical results have been reported in some studies at these follow-ups, some authors have reported persistence of thigh pain, stem migration, aseptic loosening, and proximal stress shielding with some of the designs.22–24 Others have reported increased stem malalignment and a higher rate of intraoperative fractures, which may temper their widespread use.25
Table 1: Short Stems Currently FDA Approved for Use in the United States
Multiple studies have reported outcomes of individual short stems in THA, but few reports have analyzed these implants as a single group. The purpose of the current study was to systematically review the literature and analyze the outcomes of FDA-approved short stems. Specific outcomes evaluated were implant survivorship, Harris Hip scores, thigh pain, periprosthetic fractures, subsidence, proximal stress shielding, and the prevalence of stem malalignment and implant over- or undersizing.
Materials and Methods
A literature search was performed using the electronic medical databases PubMed, CINAHL Plus, EMBASE, and SCOPUS to identify all articles reporting the outcomes of short or conservative femoral stems in THA. Short stems were defined as those having fixation in the neck or in the proximal femoral metaphysis. The following terms were used to search the databases: short, conservative, metaphyseal, neck, sparing, stem*, and hip arthroplasty. The names of the individual prostheses were also searched. Reference lists from all retrieved manuscripts were explored to find reports that were not included in the initial search.
Inclusion criteria included all short stems that are currently approved for use in the United States and have published data. All English-language abstracts and manuscripts were reviewed. Studies reporting the clinical outcomes of hip resurfacing implants were excluded. Studies reporting the outcomes of stems unavailable in the United States or those that are currently under investigational use or in development were not included, as well as in vitro or biomechanical studies that did not report clinical outcome metrics. If multiple reports by a single author or a group of authors composing a clinical series were found, only the most recent report was included. Single-patient case reports were reviewed but not included in the final analysis.
Initial review of the literature identified 119 articles concerning short stems. Of these, 58 reported stems that are not available in the United States or are not FDA-approved, so they were excluded from this review. A further 39 reports were either single-patient case reports or biomechanical studies that did not report clinical outcome scores and were excluded. This resulted in 22 articles for review and inclusion in the data analysis.11,12,25–44 Level of evidence assessment revealed 1 study with Level II evidence, 5 studies with Level III evidence, and 16 studies with Level IV evidence. The studies included 2734 hips in 2277 patients (mean age, 59 years; range, 36–79 years) available for analysis at a mean follow-up of 4 years (range, 0.6–9.8 years). Data gathered from the individual studies were subcategorized for the Mayo stem (n=10), lateral flare design (n=6), and shortened proximally coated stem (n=6) to assess and compare the outcomes of these 3 stem designs because they have the maximum available clinical data.
Demographic, clinical, radiographic, and survivorship data were extracted from each study and analyzed to find the pooled mean for each category. Functional outcomes were analyzed on the basis of physician-based objective outcome measures, which included Harris Hip and Merle D’Aubigne scores. Implant survivorship data were substratified based on the mean survivorship at less than 2 years, between 2 years and 5 years, and more than 5 years. The incidences of aseptic loosening and osteolysis were also assessed. Complications included the frequency of periprosthetic fractures and the incidence of thigh pain. Evaluation of the reported radiographic outcomes was assessed for stem migration, malalignment, and stem over-or undersizing.
All data were extracted and incorporated into an Excel spreadsheet (Microsoft Corporation, Redmond, Washington). For each of the 3 stem types, the metrics from the individual studies were pooled to obtain a mean value for the entire group of studies. Because all of the studies except 1 in this review did not provide comparison groups with other standard stem designs,40 statistical analysis of the data to determine whether outcomes between short stems and traditional stem designs were significantly different was not possible.
Overall mean stem survivorship for all short stems was 99.5% (range, 97.5%–100%) at a mean follow-up of 3.9 years (Table 2). Mean stem survivorship at less than 2-year follow-up was 99.4% (range, 98.2%–100%). At 2- to 5-year follow-up, mean stem survivorship was 99.6% (range, 97.5%–100%), and this was maintained at more than 5-year follow-up (mean, 99.6%; range, 98.2%–100%). Mean stem survivorship for the Mayo prosthesis was 99.2% (range, 97.5%–100%) at a mean follow-up of 4.9 years, whereas the lateral flare-type prosthesis and shortened proximally coated stem prosthesis had a mean stem survivorship of 99.9% (range, 99.7%–100%) at a mean follow-up of 2 years and 99.5% (range, 98.9%–100%) at mean follow-up of 4.6 years. However, when loosening or osteolysis was taken as an endpoint, the survivorship of the Mayo stem decreased to a mean of 97.5% (range, 91%–100%) at a mean follow up of 4.6 years.
Table 2: Demographic Data and Implant Survivorship for Various Short-stem Designs
Mean postoperative Harris Hip score at final follow-up was 91 points (range, 83–96 points) among all stem designs. Mean postoperative score for the Mayo stem was 93 points (range, 90.4–96 points) at final follow-up. The stems with a lateral flare design and the shortened versions of the conventional stems each had a mean postoperative Harris Hip score of 90 points (range, 83–95 points).
Mean incidence of periprosthetic fracture across all short stems was 1.4% (range, 0%–7%) (Table 3). The Mayo stem had a mean periprosthetic fracture rate of 4.2% (range, 0%–7%). The stems with a lateral flare design and the shortened proximally coated stems had a mean periprosthetic fracture rate of 2.4% (range, 1.1%–5.7%) and 0.8% (range, 0%–2.1%), respectively.
Table 3: Demographic Data and Implant Survivorship for Various Short-stem Designs
Mean incidence of thigh pain for the entire range of short stems was 0.4% (range, 0%–2.7%) (Table 3). The Mayo stem had a mean thigh pain incidence of 1.2% (range, 0%–2.7%). Studies on the shortened proximally coated stem had a similar incidence of thigh pain, with a mean occurrence of 1% at final follow-up. However, no incidence of thigh pain was reported at follow-ups for the stems having a lateral flare design. One study noted that 9% of patients reported persisting discomfort over the greater trochanter but had no classic symptoms of thigh pain.26
Subsidence was rarely observed with short stems, with a reported mean incidence of 1.4% (range, 0%–7%) (Table 3). Subdivision of the data showed that the Mayo stems subsided more than average (mean, 3.3%; range, 2%–7%). Stem subsidence was lower with lateral flare (0.1%) and shortened proximally coated stem (0.6%) designs; however, subsidence was evaluated in only 1 study for each of these stems.26,41 Mean incidence of proximal stress shielding with short stems was 5% across all studies. Three studies with the Mayo stem report a 5.6% incidence of proximal stress shielding (range, 4%–6%).25,27,36 Five of 6 studies of lateral flare designs noted stress shielding in all patients included in the series.12,26,30,32,40 One of 6 studies on short proximally coated stems reported absence of proximal stress shielding at short-term follow-up of 2.7 years, whereas the remaining study did not comment on bone resorption.42
Mean coronal malalignment, which was defined in all studies as greater than 5° of varus or valgus, was 20.4% (range, 5.4%–68.2%) for all stems. Only 1 study reported on the incidence of varus or valgus outliers with the Mayo stems, which was observed to be 68%.25 More studies using lateral flare designs reported coronal malalignment, with a mean incidence of malalignment of 14.2% (range, 5%–32.3%) based on 6 studies.12,26,30–32,40 Only 1 study reported this radiographic evaluation for shortened proximally coated stems, which noted that 9.9% were coronally malaligned; however, no clinical relevance was noted related to the malalignment.41
Incorrect stem sizing was not reported in any studies with the Mayo prosthesis; however, these studies did not evaluate this as an outcome measure. Three studies of lateral flare designs reported a highly variable rate of inappropriate component sizing (mean, 36.6%; range, 5.1%–81%).12,26,30 None of the studies on shortened proximally coated stems reported the incidence of incorrect stem sizing.
Total hip arthroplasty using short stems has generated increasing interest among orthopedic surgeons, particularly in the past 5 years as more implant designs have become available (Table 1). Authors have noted that both proximally and distally fixed stems may have proximal femoral stress shielding and thigh pain.7,45–47 Although the biomechanical principles and the design rationale underlying these stems may differ, finite element analysis studies have shown that, irrespective of the design principles, short stems appear to load the proximal femur more physiologically compared with conventional stems.48,49
Combined with the trend toward THA in younger and more active patients, these newer stem designs have also helped address the perceived need for a proximal bone–conserving option to reduce bone loss as a long-term clinical problem. Moreover, these short stems have the additional advantage of easier insertion when using minimally invasive approaches for THA.10–12,50 Although these stems have been used for more than a decade, few studies have compared the overall clinical and functional outcomes of these stems or of the various short- or conservative-stem designs that are available. For this reason, the current authors performed a systematic review of the clinical and radiographic outcomes of short stems in THA for the treatment of degenerative joint diseases.
This study has several limitations. Overall, few high-quality studies were found, and the majority of studies reported Level IV evidence. Most studies had small sample sizes (fewer than 50 hips) and no conventional stem comparison group and did not consistently report objective clinical outcomes scores. The quality of the pooled data was also dependent on the homogeneity of the study populations presented in the original study. Moreover, the indications for THA were not the same in all studies. Some reports had a greater proportion of patients with rheumatoid arthritis, osteonecrosis, or other diseases, which may have introduced study population heterogeneity and bias. Furthermore, the effect of different stem geometries and the different biomechanical principles of fixation may also lead to different outcomes; therefore, it may not be completely appropriate to include all of these stems in a broad short-stem category. Despite these limitations, the current study was able to evaluate more than 2500 hips and analyze short- to mid-term clinical outcomes and implant survivorship.
Overall, implant survivor-ship at early and mid-term follow-up with failure due to aseptic loosening as an endpoint was excellent. At less than 2-year follow-up (ie, short-term), survivorship was 99%, and this was maintained at more than 5-year follow-up (ie, mid-term), which is comparable with what has been reported for conventional stems in the literature.11,27–30 It is noteworthy that most clinical data available in the literature are on the Mayo stem, which has been available for more than 20 years.
The incidence of reported aseptic loosening with the Mayo stems appears to be low (less than 2%) at short-term follow-up. Interestingly, none of the stems with a lateral flare design or the shortened proximally coated stems had reported aseptic loosening at short-term follow-up (mean, 2.4 years). The overall functional outcomes using the Harris Hip scores for assessment appear similar across the various stem designs. The current study shows that the incidence of thigh pain appears to be low with the use of short stems (less than 3%) in comparison with conventional stems, which are reported to be as high as 10% to 20%.51,52 Short-term follow-up evidence suggests that some of the newer stem designs with an extended lateral flare can potentially eliminate thigh pain as a complication.26,30–32
The incidence of periprosthetic fractures varied among the different stems designs. The Mayo and lateral flare designs have a higher incidence of periprosthetic fractures compared with shortened proximally coated stems. This could be related to the relative ease of insertion of the shortened proximally coated stems compared with the other designs. The surgical technique for insertion of some of these short stems appears to be challenging due to the system of curved awls and rasps in contrast to the straight instruments used for insertion of conventional stems. However, the curved instruments are beneficial for preparing the femoral canal in a minimally invasive fashion.
Another reason for the higher intraoperative fracture incidence, particularly for the Mayo stem, may be the use of the proximal lateral femoral cortex as a guide during insertion. This critical step requires careful broaching to avoid cortical penetration of the lateral femoral cortex, especially when poor bone quality is encountered. This may explain the higher reported incidence of periprosthetic fractures with the Mayo stem in some series.25,27,33
Stem malalignment has been found to vary markedly. The Mayo and lateral flare designs have a seemingly higher incidence of malalignment compared with shortened proximally coated stems. Currently, limited data are available regarding the incidence of stem malalignment with short stems. The unusual insertion angle of 20° to 30° varus for introduction of broaches and rasps using the round-the-corner technique has a steep learning curve to avoid stem malalignment. Stem malalignment has been associated with poor functional outcomes with conventional cemented stems, despite the fact that these stems are limited in the amount of varus/valgus malposition due to the presence of the diaphyseal component.53,54 However, the effect of malalignment on the outcomes of cementless conventional stems remains controversial and is likely related to the stem design and geometry.55 Some authors have reported instability secondary to improper seating,56,57 whereas others have reported no adverse effects from coronal malalignment.44 Long-term follow-up studies are needed to assess the effect of stem malposition on functional outcomes and survivorship for these short-stem designs.
Despite the proposed advantage of proximal load distribution with short stems, literature evidence suggests that grade 1 or 2 bone resorption, as defined by Engh et al58 can be expected with some of these stems designs.12,26,30,59 However, no reported long-term follow-up studies exist, so the clinical significance of these findings is unknown. Generally, the Mayo stems have shown a higher incidence of stem subsidence when compared with lateral flare designs and shortened proximally coated stems (mean, 3% and less than 1%, respectively).
Incorrect stem sizing has also been reported with some of the short stems with a lateral flare design. Insufficient data are available on the Mayo and shortened proximally coated stems with regard to stem sizing to draw any conclusions. Stem undersizing could be secondary to inadvertent varus stem malalignment, which was done to reduce the risk of intraoperative fracture.
Short stems have shown promise with excellent short-term survivorship; however, the surgical technique for insertion of these stems may be technically demanding. Insertion of these stems requires an exacting technique to avoid the potential pitfalls of malalignment, incorrect stem sizing, and intraoperative fracture. Proximal stress shielding has been reported to some extent with all short-stem designs. Mid-term survivorship data for these short stems has thus far been comparable with those for traditional stems.
Multiple stem designs are currently undergoing clinical trials, and the coming years will likely see an increase the number of stems available commercially, which emphasizes the need to evaluate the clinical outcomes of these stems at long-term follow-up. However, it is important to realize that the broad term short stems is inherently misleading because the multiple stem designs currently available differ in their morphological, biomechanical, and tribological principles. Due to these differences, a classification system categorizing these stems may help differentiate the various designs and improve future reporting of clinical and functional outcomes based on stems of similar design and principle.
- Kolb A, Grubl A, Schneckener CD, et al. Cementless total hip arthroplasty with the Rectangular Titanium Zweymuller Stem: a concise follow-up, at a minimum of twenty years, of previous reports. J Bone Joint Surg Am. 2012; 94(18):1681–1684. doi:10.2106/JBJS.K.01574 [CrossRef]
- McLaughlin JR, Lee KR. Total hip arthroplasty with an uncemented femoral component. Excellent results at ten-year follow-up. J Bone Joint Surg Br. 1997; 79(6):900–907. doi:10.1302/0301-620X.79B6.7482 [CrossRef]
- Bordini B, Stea S, De Clerico M, Strazzari S, Sasdelli A, Toni A. Factors affecting aseptic loosening of 4750 total hip arthroplasties: multivariate survival analysis. BMC Musculoskelet Disord. 2007; 8:69. doi:10.1186/1471-2474-8-69 [CrossRef]
- Khanuja HS, Vakil JJ, Goddard MS, Mont MA. Cementless femoral fixation in total hip arthroplasty. J Bone Joint Surg Am. 2011; 93(5):500–509. doi:10.2106/JBJS.J.00774 [CrossRef]
- Brown TE, Larson B, Shen F, Moskal JT. Thigh pain after cementless total hip arthroplasty: evaluation and management. J Am Acad Orthop Surg. 2002; 10(6):385–392.
- Engh CA Jr, Young AM, Engh CA Sr, Hopper RH Jr, . Clinical consequences of stress shielding after porous-coated total hip arthroplasty. Clin Orthop Relat Res. 2003; (417):157–163.
- Bugbee WD, Culpepper WJ II, Engh CA Jr, Engh CA Sr, . Long-term clinical consequences of stress-shielding after total hip arthroplasty without cement. J Bone Joint Surg Am. 1997; 79(7):1007–1012.
- McElroy MJ, Johnson AJ, Mont MA, Bonutti PM. Short and standard stem prostheses are both viable options for minimally invasive total hip arthroplasty. Bull NYU Hosp Jt Dis. 2011; 69(suppl 1):S68–S76.
- Kim YH, Kim JS, Park JW, Joo JH. Total hip replacement with a short metaphyseal-fitting anatomical cementless femoral component in patients aged 70 years or older. J Bone Joint Surg Br. 2011; 93(5):587–592.
- Lazovic D, Zigan R. Navigation of short-stem implants. Orthopedics. 2006; 29(10 suppl):S125–S129.
- Lombardi AV Jr, Berend KR, Adams JB. A short stem solution: through small portals. Orthopedics. 2009; 32(9). doi:10.3928/01477447-20090728-09 [CrossRef]
- Ghera S, Pavan L. The DePuy Proxima hip: a short stem for total hip arthroplasty. Early experience and technical considerations. Hip Int. 2009; 19(3):215–220.
- Lerch M, Kurtz A, Stukenborg-Colsman C, et al. Bone remodeling after total hip arthroplasty with a short stemmed metaphyseal loading implant: finite element analysis validated by a prospective dexa investigation. J Orthop Res. 2012; 30(11):1822–1829. doi:10.1002/jor.22120 [CrossRef]
- Pipino F, Keller A. Tissue-sparing surgery: 25 years’ experience with femoral neck preserving hip arthroplasty. J Orthop Traumatol. 2006; 7(1):36–41. doi:10.1007/s10195-006-0120-2 [CrossRef]
- Pipino F, Calderale PM. Biodynamic total hip prosthesis. Ital J Orthop Traumatol. 1987; 13(3):289–297.
- Engh CA, O’Connor D, Jasty M, McGovern TF, Bobyn JD, Harris WH. Quantification of implant micromotion, strain shielding, and bone resorption with porous-coated anatomic medullary locking femoral prostheses. Clin Orthop Relat Res. 1992; (285):13–29.
- Pilliar RM, Lee JM, Maniatopoulos C. Observations on the effect of movement on bone ingrowth into porous-surfaced implants. Clin Orthop Relat Res. 1986; (208):108–113.
- Jasty M, Bragdon C, Burke D, O’Connor D, Lowenstein J, Harris WH. In vivo skeletal responses to porous-surfaced implants subjected to small induced motions. J Bone Joint Surg Am. 1997; 79(5):707–714.
- Whiteside LA, White SE, McCarthy DS. Effect of neck resection on torsional stability of cementless total hip replacement. Am J Orthop (Belle Mead NJ). 1995; 24(10):766–770.
- Carlson L, Albrektsson B, Freeman MA. Femoral neck retention in hip arthroplasty. A cadaver study of mechanical effects. Acta Orthop Scand. 1988; 59(1):6–8. doi:10.3109/17453678809149333 [CrossRef]
- Tanner KE, Yettram AL, Loeffler M, Goodier WD, Freeman MA, Bonfield W. Is stem length important in uncemented endoprostheses?Med Eng Phys. 1995; 17(4):291–296. doi:10.1016/1350-4533(95)90854-5 [CrossRef]
- Ender SA, Machner A, Pap G, Hubbe J, Grashoff H, Neumann HW. Cementless CUT femoral neck prosthesis: increased rate of aseptic loosening after 5 years. Acta Orthop. 2007; 78(5):616–621.
- Ishaque BA, Donle E, Gils J, Wienbeck S, Basad E, Sturz H. Eight-year results of the femoral neck prosthesis ESKA-CUT [in German]. Z Orthop Unfall. 2009; 147(2):158–165. doi:10.1055/s-0029-1185527 [CrossRef]
- Niggemeyer O, Steinhagen J, Ruether W. Long-term results of the thrust plate prosthesis in patients with rheumatoid arthritis: a minimum 10-year follow-up. J Orthop Sci. 2010; 15(6):772–780. doi:10.1007/s00776-010-1548-z [CrossRef]
- Gilbert RE, Salehi-Bird S, Gallacher PD, Shaylor P. The Mayo Conservative Hip: experience from a district general hospital. Hip Int. 2009; 19(3):211–214.
- Kim YH, Park JW, Kim JS. Is diaphyseal stem fixation necessary for primary total hip arthroplasty in patients with osteoporotic bone (class C bone)?J Arthroplasty. 2013; 28(1):139.e1–146.e1. doi:10.1016/j.arth.2012.04.002 [CrossRef]
- Morrey BF, Adams RA, Kessler M. A conservative femoral replacement for total hip arthroplasty. A prospective study. J Bone Joint Surg Br. 2000; 82(7):952–958. doi:10.1302/0301-620X.82B7.10420 [CrossRef]
- Falez F, Casella F, Panegrossi G, Favetti F, Barresi C. Perspectives on metaphyseal conservative stems. J Orthop Traumatol. 2008; 9(1):49–54. doi:10.1007/s10195-008-0105-4 [CrossRef]
- Molli RG, Lombardi AV Jr, Berend KR, Adams JB, Sneller MA. A short tapered stem reduces intraoperative complications in primary total hip arthroplasty. Clin Orthop Relat Res. 2012; 470(2):450–461. doi:10.1007/s11999-011-2068-7 [CrossRef]
- Santori FS, Santori N. Mid-term results of a custom-made short proximal loading femoral component. J Bone Joint Surg Br. 2010; 92(9):1231–1237.
- Toth K, Mecs L, Kellermann P. Early experience with the Depuy Proxima short stem in total hip arthroplasty. Acta Orthop Belg. 2010; 76(5):613–618.
- Kim YH, Kim JS, Park JW, Joo JH. Total hip replacement with a short metaphyseal-fitting anatomical cementless femoral component in patients aged 70 years or older. J Bone Joint Surg Br. 2011; 93(5):587–592.
- Cruz-Vazquez FJ, De la Rosa-Aguilar M, Gomez-Lopez CA. Evaluation of the uncemented Mayo femoral stem. The first 10 years [in Spanish]. Acta Ortop Mex. 2011; 25(2):108–113.
- Zeh A, Weise A, Vasarhelyi A, Bach AG, Wohlrab D. Medium-term results of the Mayo short-stem hip prosthesis after avascular necrosis of the femoral head [in German]. Z Orthop Unfall. 2011; 149(2):200–205. doi:10.1055/s-0030-1270710 [CrossRef]
- Gagala J, Mazurkiewicz T. Early experiences in the use of Mayo stem in hip arthroplasty [in Polish]. Chir Narzadow Ruchu Ortop Pol. 2009; 74(3):152–156.
- Goebel D, Schultz W. The Mayo cementless femoral component in active patients with osteoarthritis. Hip Int. 2009; 19(3):206–210.
- Hagel A, Hein W, Wohlrab D. Experience with the Mayo conservative hip system. Acta Chir Orthop Traumatol Cech. 2008; 75(4):288–292.
- Hube R, Zaage M, Hein W, Reichel H. Early functional results with the Mayo-hip, a short stem system with metaphyseal-intertrochanteric fixation [in German]. Orthopade. 2004; 33(11):1249–1258. doi:10.1007/s00132-004-0711-7 [CrossRef]
- Tadeusz N, Adam N, Lukasz N. Total hip replacement in young patients with use of MAYO prosthesis—early result of treatment [in Polish]. Chir Narzadow Ruchu Ortop Pol. 2007; 72(5):319–321.
- Kim YH, Oh JH. A comparison of a conventional versus a short, anatomical metaphyseal-fitting cementless femoral stem in the treatment of patients with a fracture of the femoral neck. J Bone Joint Surg Br. 2012; 94(6):774–781.
- Patel RM, Smith MC, Woodward CC, Stulberg SD. Stable fixation of short-stem femoral implants in patients 70 years and older. Clin Orthop Relat Res. 2012; 470(2):442–449. doi:10.1007/s11999-011-2063-z [CrossRef]
- Stulberg SD, Dolan M. The short stem: a thinking man’s alternative to surface replacement. Orthopedics. 2008; 31(9):885–886. doi:10.3928/01477447-20080901-37 [CrossRef]
- Finn H. Cementless total hip arthroplasty with a short femoral component. http://www.biomet.com/orthopedics/productDetail.cfm?category=2&product=239. Accessed on November 15, 2012.
- Emerson RJ, Jones K, Kavolus CH, Peyton RS, Pietrzak WS. Short-term clinical outcomes of the taperloc microplasty stem. http://www.biomet.com/orthopedics/productDetail.cfm?category=2&product=239. Accessed on November 15, 2012.
- MacDonald SJ, Rosenzweig S, Guerin JS, et al. Proximally versus fully porous-coated femoral stems: a multicenter randomized trial. Clin Orthop Relat Res. 2010; 468(2):424–432. doi:10.1007/s11999-009-1092-3 [CrossRef]
- Nishino T, Mishima H, Miyakawa S, Kawamura H, Ochiai N. Midterm results of the Synergy cementless tapered stem: stress shielding and bone quality. J Orthop Sci. 2008; 13(6):498–503. doi:10.1007/s00776-008-1272-0 [CrossRef]
- Kilgus DJ, Shimaoka EE, Tipton JS, Eberle RW. Dual-energy X-ray absorptiometry measurement of bone mineral density around porous-coated cementless femoral implants. Methods and preliminary results. J Bone Joint Surg Br. 1993; 75(2):279–287.
- Aamodt A, Lund-Larsen J, Eine J, Andersen E, Benum P, Husby OS. Changes in proximal femoral strain after insertion of uncemented standard and customised femoral stems. An experimental study in human femora. J Bone Joint Surg Br. 2001; 83(6):921–929. doi:10.1302/0301-620X.83B6.9726 [CrossRef]
- Bieger R, Ignatius A, Decking R, Claes L, Reichel H, Durselen L. Primary stability and strain distribution of cementless hip stems as a function of implant design. Clin Biomech (Bristol, Avon). 2012; 27(2):158–164. doi:10.1016/j.clinbiomech.2011.08.004 [CrossRef]
- Walde HJ, Walde TA. Minimally invasive orthopedic surgery: first results in navigated total hip arthroplasty. Orthopedics. 2006; 29(10 suppl):S139–S141.
- Vresilovic EJ, Hozack WJ, Rothman RH. Incidence of thigh pain after uncemented total hip arthroplasty as a function of femoral stem size. J Arthroplasty. 1996; 11(3):304–311. doi:10.1016/S0883-5403(96)80083-0 [CrossRef]
- Pierannunzii LM. Thigh pain after total hip replacement: a pathophysiological review and a comprehensive classification. Orthopedics. 2008; 31(7):691–699. doi:10.3928/01477447-20110505-05 [CrossRef]
- Gill TJ, Sledge JB, Orler R, Ganz R. Lateral insufficiency fractures of the femur caused by osteopenia and varus angulation: a complication of total hip arthroplasty. J Arthroplasty. 1999; 14(8):982–987. doi:10.1016/S0883-5403(99)90014-1 [CrossRef]
- Woolson ST, Maloney WJ. Cementless total hip arthroplasty using a porous-coated prosthesis for bone ingrowth fixation. 3 1/2-year follow-up. J Arthroplasty. 1992; (7 suppl):381–388. doi:10.1016/S0883-5403(07)80028-3 [CrossRef]
- Min BW, Song KS, Bae KC, Cho CH, Kang CH, Kim SY. The effect of stem alignment on results of total hip arthroplasty with a cementless tapered-wedge femoral component. J Arthroplasty. 2008; 23(3):418–423. doi:10.1016/j.arth.2007.04.002 [CrossRef]
- Vresilovic EJ, Hozack WJ, Rothman RH. Radiographic assessment of cementless femoral components. Correlation with intraoperative mechanical stability. J Arthroplasty. 1994; 9(2):137–141. doi:10.1016/0883-5403(94)90062-0 [CrossRef]
- Ries MD, Lynch F, Jenkins P, Mick C, Richman J. Varus migration of PCA stems. Orthopedics. 1996; 19(7):581–585.
- Engh CA, Bobyn JD, Galssman AH. Porous-coated hip replacement. The factors governing bone ingrowth, stress shielding, and clinical results. J Bone Joint Surg Br. 1987; 69(1):45–55.
- Engh CA, Bobyn JD. The influence of stem size and extent of porous coating on femoral bone resorption after primary cementless hip arthroplasty. Clin Orthop Relat Res. 1988; (231):7–28.
Short Stems Currently FDA Approved for Use in the United States
|Stem Design||Manufacturer||Implant Name||Year Introduced|
|Mayo||Zimmer, Inc, Warsaw, Indiana||Mayo||1984|
|Short proximally coated||Zimmer, Inc||Fitmore||1999|
|Short proximally coated||Stryker, Mahwah, New Jersey||Citation||2000|
|Lateral flare design||DePuy Orthopaedics, Inc, Warsaw, Indiana||Proxima||2006|
|Short proximally coated||Biomet, Inc, Warsaw, Indiana||Taperloc Microplasty||2007|
|Short proximally coated||Biomet, Inc||Balance Microplasty||2007|
|Short proximally coated||Corin, Group PLC, Cirencester, United Kingdom||MiniHipa||2009|
|Short proximally coated||Smith & Nephew, Inc, Memphis, Tennessee||SMFa||2011|
|Short proximally coated||OMNI Life Science, Inc, East Taunton, Massachusetts||Apex ARCa||2011|
Demographic Data and Implant Survivorship for Various Short-stem Designs
|Study||Level of Evidence||No. of Hips||No. of Patients||Mean Age, y||Mean Follow-up, y||Mean Harris Hip Score, points||Survivorship, %|
| Zeh et al34||III||21||21||45||7.9||93.5||100|
| Cruz-Vazquez et al33||IV||42||39||52||5||NR||100|
| Gilbert et al25||IV||49||42||57.8||3.1||19.4a||NR|
| Gagala & Mazurkiewicz35||IV||38||35||51||2||96||100|
| Goebel & Schultz36||IV||30||26||57.4||6.8||16b||100|
| Hagel et al37||IV||270||NR||NR||NR||93.6||98.2|
| Hube et al38||III||45||45||59||1||NR||100|
| Falez et al28||IV||160||140||63.4||4.7||NR||97.5|
| Tadeusz et al39||IV||34||32||32.7||7||NR||NR|
| Morrey et al27||IV||159||146||50.8||6.5||90.4||98.2|
|Lateral flare designs|
| Kim et al26||II||70||70||74.9||4.1||85.7||100|
| Kim & Oh 40||III||256||230||65||5.6||93||99.7|
| Kim et al32||IV||84||84||78.9||4.6||89||100|
| Santori & Santori30||IV||129||109||51||9.8||95||100|
| Toth et al31||IV||41||41||49||2.2||88||100|
| Ghera & Pavan12||IV||65||65||70.1||1.7||91||100|
|Shortened proximally coated stems|
| Patel et al41||III||160||149||75||2.9||90.5||100|
| Molli et al29||III||269||246||63||2.5||83.1||99.6|
| Lombardi et al11||IV||640||591||62.7||0.6||NR||99.1|
| Stulberg & Dolan 42||IV||65||60||56||2.7||93||100|
| Emerson et al44,c||IV||93||93||71||1||93.1||98.9|
Demographic Data and Implant Survivorship for Various Short-stem Designs
|AL||PF||Dislocation||Thigh Pain||Mal||Inappropriate SS||Neck Res||Stem Sub|
| Zeh et al34||NR||NR||NR||NR||NR||NR||NR||0|
| Cruz-Vazquez et al33||0||7.1||2.3||2.7||NR||NR||NR||NR|
| Gilbert et al25||2.0||4.1||2.0||2.0||68.2||NR||4.1||2.0|
| Goebel & Schultz36||0||3.3||0||NR||NR||3.3||6.6a||3.3|
| Gagala & Mazurkiewicz 35||NR||NR||2.6||NR||NR||NR||NR||2.6|
| Falez et al28||1.2||4.4 (3.8 b)||NR||NR||NR||NR||NR||NR|
| Hagel et al37||1.9||NR||NR||NR||NR||NR||NR||NR|
| Hube et al38||0||0||NR||0||NR||NR||NR||NR|
| Tadeusz et al39||NR||NR||NR||NR||NR||NR||NR||NR|
| Morrey et al27||7.5||6.2b||NR||0||NR||NR||6%||7|
|Lateral flare designs|
| Kim et al26||0||NR||0.7||0||5.4||5.1||Grade 1c||0.7|
| Kim & Oh40||0||2.8 (1.4 b)||1.4||0 (9d)||7||NR||Grade 1c||NR|
| Kim et al32||0||1.1||1.1||0||5||NR||Grade 1c||NR|
| Santori & Santori30||0||5.7b||1.5||0||11||23.1||8.5||NR|
| Toth et al31||0||2.4b||2.4||NR||24.3||NR||NR||NR|
| Ghera & Pavan12||0||1.5||0||0||32.3||81.5||Grade 1 (75%)c; Grade 2 (25%)c||NR|
|Shortened proximally coated stems|
| Patel et al41||0||0.6b||NR||0||9.9||NR||NR||0.6|
| Molli et al29||0||0.4||NR||NR||NR||NR||NR||NR|
| Emerson et al 44,e||0||2.1||NR||2.1||NR||NR||NR||NR|
| Lombardi et al11||NR||1.1||NR||NR||NR||NR||NR||NR|
| Stulberg & Dolan42||0||0||3.1||NR||NR||NR||0||NR|