The ‘critical trochanter angle’ does not show superiority over the CCD angle in predicting varus stem alignment in cementless short-stem total hip arthroplasty

Abstract Purpose Varus positioning of the femoral stem can affect the hip offset (HO). The critical trochanter angle (CTA) was introduced in 2019 as a novel geometric angle, to predict varus stem alignment in cementless straight stem THA. The aim of this study was to evaluate the applicability of the CTA as a predictor for stem alignment in THA with a cementless neck resecting short stem. Patients and methods In this retrospective study, 106 patients (index surgery 2014–2019) with unilateral THA and a morphologically healthy contralateral hip as a reference (Kellgren–Lawrence ≤ 1) were included. A cementless short stem with meta-diaphyseal fixation and press-fit cup was implanted in all cases. Stem alignment, CCD angle, CTA and offset reconstruction were measured on preoperative and 3 months postoperative AP radiographs of the pelvis. Results Preoperative lower CTA and lower CCD angle were positively correlated (r = 0.472; p < 0.001). Higher varus stem alignment is correlated with lower CTA (r = − 0.384; p < 0.001) and lower CCD angle (r = − 0.474; p < 0.001). A CTA of 23.1° or lower showed a sensitivity of 59.1% and a specificity of 87.1% (AUC: 0.733) and a CCD angle of 132.75° or lower a sensitivity of 68.2% and a specificity of 80.6% (AUC: 0.77) for a varus stem alignment > 3°. Conclusion The CTA is also applicable in cementless THA with a neck resecting short stem to evaluate risk of intraoperative varus stem positioning. The CCD angle shows higher sensitivity with marginally lower specificity. Therefore, the CTA is not superior in predicting varus stem alignment in short-stem THA. Level of evidence IV.

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Abductor Muscle Force after Straight-Stem Compared to Short-Stem Total Hip Arthroplasty through a Modified Direct Lateral Approach: Functional Assessment of 70 Consecutive Patients of a Randomized Controlled Clinical Trial

Journal of Clinical Medicine ◽

10.3390/jcm10061235 ◽

2021 ◽

Vol 10 (6) ◽

pp. 1235

Author(s):

Michael Fuchs ◽

Marie-Anne Hein ◽

Martin Faschingbauer ◽

Mirco Sgroi ◽

Ralf Bieger ◽

...

Keyword(s):

Clinical Trial ◽

Muscle Strength ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Lateral Approach ◽

Short Stem ◽

Abductor Muscle ◽

Total Hip ◽

Straight Stem ◽

Direct Lateral Approach

Because of preservation of proximal femoral bone stock and minimized soft tissue trauma, short-stem implants are becoming increasingly important in total hip arthroplasty (THA). The postulated advantage regarding the functional outcome has not been verified. We hypothesized an increased abductor muscle strength by the use of a short-stem design. Seventy consecutive patients of a randomized clinical trial were included. Of these, 67 patients met the inclusion criteria after 12 months. Thirty-five patients received a standard straight stem and 32 patients a short-stem femoral component. All surgeries were performed by a modified direct lateral approach. Isometric muscle strength of the hip abductors was evaluated preoperatively 3 and 12 months after surgery. Harris hip score (HHS) and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores were evaluated. After three months, there were no differences between the two groups; the abductor force was comparable to the preoperative initial values. After 12 months, a significant increase in muscle strength for the short stem patient group compared to preoperative baseline values was measured (straight-stem THA, 0.09 Nm/kg ± 0.4, p = 0.32; short-stem THA, 0.2 Nm/kg ± 0.3, p = 0.004). Comparison of the 12-month postoperative total HHS and WOMAC revealed no significant differences between both groups. A significant increase in hip abductor muscle strength 12 months after short-stem THA compared to conventional-stem THA was observed.

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Short-stem total hip arthroplasty is not associated with an earlier return to work compared to a straight-stem design

Scientific Reports ◽

10.1038/s41598-021-82805-0 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Georg Hauer ◽

Maria Smolle ◽

Sabrina Zaussinger ◽

Joerg Friesenbichler ◽

Andreas Leithner ◽

...

Keyword(s):

Total Hip Arthroplasty ◽

Sick Leave ◽

Return To Work ◽

Hip Arthroplasty ◽

Short Stem ◽

Multivariate Linear Regression Analysis ◽

Stem Design ◽

Total Hip ◽

Straight Stem ◽

Significant Difference

AbstractReturn to work (RTW) has been specifically identified as a high priority in patients undergoing total hip arthroplasty (THA). This investigation sought to assess the effect of the stem design on patients’ RTW. Secondly, the study aimed to identify risk factors that lead to a delayed RTW. Questionnaires inquiring about RTW, employment history, educational level, type of work, physical demands and joint awareness were administered by post. Further data were collected from patients’ hospital records. 176 patients who underwent THA using a short-stem and 97 patients using a straight-stem design were compared. The median return to work time was 10 weeks [IQR 7–14 weeks], with no significant difference between the two groups (short stems vs. straight stems; 10 [IQR 7–14] vs. 11 [7.5–13.5] weeks; p = 0.693). In the multivariate linear regression analysis, self-employment vs. employee (p = 0.001), dimension of preoperative workload (p = 0.001), preoperative sick leave (p < 0.001), and hospital length of stay (LOS) (p < 0.001) independently affected the period until work was resumed. The Forgotten-Joint-Score-12 showed no significant difference between the two groups. The data show that the majority of THA patients can expect to resume work and stem design has no impact on RTW. Employees with preoperative sick leave, prolonged hospital LOS and low workload are at higher risk for a delayed RTW.

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The impact of reducing the femoral stem length in total hip arthroplasty during gait

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-021-03852-w ◽

2021 ◽

Author(s):

Anatole Vilhelm Wiik ◽

Adeel Aqil ◽

Bilal Al-Obaidi ◽

Mads Brevadt ◽

Justin Peter Cobb

Keyword(s):

Total Hip Arthroplasty ◽

Gait Analysis ◽

Hip Arthroplasty ◽

Femoral Stem ◽

Short Stem ◽

Stem Length ◽

Practical Consideration ◽

Total Hip ◽

Long Stem ◽

The Impact

Abstract Aim The length of the femoral stem in total hip arthroplasty (THA) is a practical consideration to prevent gait impairment. The aim of this study was to determine if reducing the femoral stem length in THA would lead to impaired gait biomechanics. Methods Patients uniformly with the same brand implant of differing lengths (100 mm vs 140–166 mm) were taken retrospectively from a prospective trial introducing a new short stem. Twelve patients without any other disorder to alter gait besides contralateral differing length stem THA were tested at differing gradients and speed on a validated instrumented treadmill measuring ground reaction forces. An anthropometrically similar group of healthy controls were analysed to compare. Results With the same posterior surgical approach, the offset and length of both hips were reconstructed within 5 mm of each other with an identical mean head size of 36 mm. The short stem was the last procedure for all the hips with gait analysis occurring at a mean of 31 and 79 months postoperatively for the short and long stem THA, respectively. Gait analysis between limbs of both stem lengths demonstrated no statistical difference during any walking condition. In the 90 gait assessments with three loading variables, the short stem was the favoured side 51% of the time compared 49% for the long stem. Conclusion By testing a range of practical walking activities, no lower limb loading differences can be observed by reducing the femoral stem length. A shorter stem demonstrates equivalence in preference during gait when compared to a reputable conventional stem in total hip arthroplasty.

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Displacement of Femoral Stem during Closed Reduction of Total Hip Arthroplasty

Hip International ◽

10.1177/112070009700700302 ◽

1997 ◽

Vol 7 (3) ◽

pp. 125-127

Author(s):

J. Cordes ◽

K. Sperling ◽

M. Kramhøft

Keyword(s):

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Closed Reduction ◽

Femoral Stem ◽

Stem Design ◽

Total Hip ◽

Straight Stem ◽

Image Intensification

In the literature, only one case of displacement of a cemented femoral stem from its cement bed during closed reduction of a dislocation has been reported. In that case, it was suggested that the stem design may in part be the explanation for the displacement. Another case with a cemented Müller straight stem is now presented, emphasizing the use of image intensification if reduction proves difficult.

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Impact of stem design and cementation on postoperative femoral antetorsion in 227 patients with total hip arthroplasty (THA)

Skeletal Radiology ◽

10.1007/s00256-020-03483-z ◽

2020 ◽

Vol 49 (12) ◽

pp. 2001-2009

Author(s):

Tim Fischer ◽

Christoph Stern ◽

Benjamin Fritz ◽

Patrick O. Zingg ◽

Christian W. A. Pfirrmann ◽

...

Keyword(s):

Retrospective Study ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Hip Prosthesis ◽

Femoral Stem ◽

Stem Design ◽

Femoral Antetorsion ◽

Total Hip ◽

Posterior Condylar ◽

Lower Variability

Abstract Objective In total hip arthroplasty (THA), surgeons attempt to achieve a physiological antetorsion. However, postoperative antetorsion of the femoral stem is known to show large variabilities. The purpose of this study was to assess whether postoperative antetorsion is influenced by stem design or cementation. Materials and methods This retrospective study included 227 patients with a hip prosthesis with five different stem designs (S1: short curved, S2 and S3: standard straight, S4: standard straight collared, S5: cemented straight), who had metal suppressed 1.5T-MRI of the hip between February 2015 and October 2019. Measurement of femoral antetorsion was done independently by two fellowship-trained radiologists on axial images by measuring the angle between the long axis of the femoral neck and the posterior condylar tangent of the knee. Measured angles in the different groups were compared using the t test for independent samples. Results The cementless collared stem S4 showed the highest antetorsion with 18.1° (± 10.5°; range –10°–45°), which was significantly higher than the antetorsion of the collarless S3 with 13.3° (± 8.4°; − 4°–29°) and the cemented S5 with 12.7° (± 7.7°; − 3°–27°) with p = 0.012 and p = 0.007, respectively. S1 and S2 showed an antetorsion of 14.8° (± 10.0°; 1°–37°) and 14.1° (± 12.2°; − 20°–41°). The torsional variability of the cementless stems (S1–4) was significantly higher compared with that of the cemented S5 with a combined standard deviation of 10.5° and 7.7° (p = 0.019). Conclusion Prosthesis design impacts the postoperative femoral antetorsion, with the cementless collared stem showing the highest antetorsion. Cemented stems demonstrated significantly lower variability, suggesting the lowest rate of inadvertent malrotation.

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Value of preoperative three-dimensional planning software (AI-HIP) in primary total hip arthroplasty: a retrospective study

Journal of International Medical Research ◽

10.1177/03000605211058874 ◽

2021 ◽

Vol 49 (11) ◽

pp. 030006052110588

Author(s):

Xuzhuang Ding ◽

Bingshi Zhang ◽

Wenao Li ◽

Jia Huo ◽

Sikai Liu ◽

...

Keyword(s):

Retrospective Study ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Preoperative Planning ◽

Intraclass Correlation ◽

Three Dimensional ◽

Femoral Stem ◽

Stem Size ◽

Total Hip ◽

Primary Total Hip Arthroplasty

Objective We performed a retrospective study to compare the accuracy of preoperative planning using three-dimensional AI-HIP software and traditional two-dimensional manual templating to predict the size and position of prostheses. The purpose of this study was to evaluate the accuracy of AI-HIP in preoperative planning for primary total hip arthroplasty. Methods In total, 316 hips treated from April 2019 to June 2020 were retrospectively reviewed. A typical preoperative planning process for patients was implemented to compare the accuracy of the two preoperative planning methods with respect to prosthetic size and position. Intraclass correlation coefficients (ICCs) were used to evaluate the homogeneity between the actual prosthetic size and position and the preoperative planning method. Results When AI-HIP software and manual templating were used for preoperative planning, the stem agreement was 87.7% and 58.9%, respectively, and the cup agreement was 94.0% and 65.2%, respectively. The results showed that when AI-HIP software was used, an extremely high level of consistency (ICC > 0.95) was achieved for the femoral stem size, cup size, and femoral osteotomy level (ICC = 0.972, 0.962, and 0.961, respectively). Conclusion AI-HIP software showed excellent reliability for predicting the component size and implant position in primary total hip arthroplasty.

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Total Hip Arthroplasty With the Wagner Cone Femoral Stem in Patients With Crowe IV Developmental Dysplasia of the Hip: A Retrospective Study

The Journal of Arthroplasty ◽

10.1016/j.arth.2021.09.007 ◽

2021 ◽

Author(s):

Cagri Ors ◽

Remzi Caylak ◽

Emre Togrul

Keyword(s):

Retrospective Study ◽

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Femoral Stem ◽

Developmental Dysplasia ◽

Total Hip ◽

Dysplasia Of The Hip

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More than a feeling?—Overruling the preoperatively templated offset option leads to a minor offset increase in short stem total hip arthroplasty

Archives of Orthopaedic and Trauma Surgery ◽

10.1007/s00402-021-04331-y ◽

2022 ◽

Author(s):

Matthias Luger ◽

Christian Stadler ◽

Rainer Hochgatterer ◽

Jakob Allerstorfer ◽

Tobias Gotterbarm ◽

...

Keyword(s):

Total Hip Arthroplasty ◽

Hip Arthroplasty ◽

Short Stem ◽

Leg Length ◽

Digital Templating ◽

Stem Size ◽

Total Hip ◽

Press Fit ◽

A Minor ◽

Short Stems

Abstract Purpose Short stems are increasingly used in total hip arthroplasty (THA) because of advantages in bone and soft tissue preservation and reconstruction of hip geometry. Digital templating is essential in determining the correct offset option and stem size in THA. However, the preoperative template sizes might be intraoperatively overruled. Patients and methods We evaluated the effect of intraoperative overruling of the preoperatively templated offset option of a short curved stem on hip offset, leg length, implant positioning, and femoral canal fill index. The overruling was performed in case of intraoperative instability, telescoping, or both. A series of 1052 consecutive THAs with a cementless short curved stem and press-fit cup was retrospectively screened. One hundred patients with unilateral THA and a contralateral native and morphologically healthy hip as a reference met the inclusion criteria. Measurements were carried out on preoperative and 3 months anterior–posterior postoperative radiographs. Patients were divided according to the overruling by offset option or stem size. Results Hip offset was increased in all groups, but only with significant increase if an offset option + 1 was used intraoperatively (p = 0.025). LLD was restored without significance in all groups (p = 0.323; p = 0.157). Conclusion Intraoperative overruling of the preoperative digital template in cementless short stem total hip arthroplasty results in an increase of hip offset compared to a contralateral healthy hip. However, the increase is marginal and clearly under 5 mm compared to the contralateral healthy hip.

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Comparison of radiographic changes in rectangular curved short stem with thin versus thick porous coating for cementless total hip arthroplasty: a retrospective study with a propensity score matching

Journal of Orthopaedic Surgery and Research ◽

10.1186/s13018-021-02397-3 ◽

2021 ◽

Vol 16 (1) ◽

Author(s):

Yutaro Munakata ◽

Yujiro Kuramitsu ◽

Yutaka Usui ◽

Ken Okazaki

Keyword(s):

Retrospective Study ◽

Total Hip Arthroplasty ◽

Propensity Score ◽

Propensity Score Matching ◽

Hip Arthroplasty ◽

Short Stem ◽

Porous Coating ◽

Significant Difference ◽

Short Stems ◽

Radiographic Changes

Abstract Background Radiographic changes that appear relatively quickly after fixation of cementless stem in total hip arthroplasty (THA) vary depending on the stem design and fixation style. The present study compared radiographic changes between two types of rectangular curved short stems of similar shape. Methods This retrospective study included 118 hips that underwent primary cementless THA with an anterolateral supine approach using a rectangular, curved, short stem performed by the same surgeon between June 2015 and June 2019. Among the examined hips, 39 had a thicker porous coating stem (thicker group) and 66 had a thinner porous coating and reduced tip stem (thinner group) and at least 12-month follow-up. Radiographs taken during the final course observation were assessed. Propensity score matching was performed based on demographic data and comparisons were made using pairs of 25 hips each. Statistical analysis was performed using chi-square test and p values ≤ 0.05 indicated statistical significance. Results The pattern of the radiolucent lines showed a significant difference after matching (p = 0.0044). A “proximal and distal” pattern was most common in the thicker group and a “distal only” pattern was most common in the thinner group. There was notable and significant difference in cortical hypertrophy in the thicker group after matching (p = 0.024). Conclusions Although the two short stems were similar shapes, the short-term radiographic changes were different. The thinner group showed fewer radiographic changes than the thicker group, making it a more “silent” stem.

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