Collared Triple Taper Stems Have Superior Biomechanical Characteristics in Compromised Bone.

Does Femoral Stem Design Influence Periprosthetic Fracture Incidence and Morphology in Total Hip Arthroplasty?

Risk Factors for Periprosthetic Femoral Fractures After Cementless Total Hip Arthroplasty

Cemented Femoral Stem Design Is Not Associated With Risk of Revision After Total Hip Arthroplasty in Patients Aged ≥ 65 Years: An Analysis of the American Joint Replacement Registry.

The present study aimed to investigate the prevalence and clinical consequences of occult intra-operative periprosthetic femoral fractures in total hip arthroplasty (THA). Between 2012 and 2017, a total of 113 primary THAs were enrolled. The mean age of the patients was 66.4 ± 7.6 years. We assessed occult intra-operative periprosthetic femoral fractures with the use of computed tomography (CT) and risk factors, including age, sex, body mass index, diagnosis, stem size, and radiographic parameters of proximal femoral geometry were analyzed. We also assessed the differences in thigh pain and stem subsidence and alignment between the patients with and without occult periprosthetic femoral fracture. Occult intra-operative periprosthetic femoral fractures were found in 13 of 113 hips (11.5%). In 9/13 (69.2%) of occult fractures, fracture lines were started from the region below the tip of the lesser trochanter. Six periprosthetic femoral fractures (5.3%) were found during the operation. Out of the five hips that had detected femoral fractures around the lesser trochanter intra-operatively, four hips (80%) showed concurrent occult fractures on different levels. The female sex (P = .01) and canal filling ratio at 7 cm below the tip of the lesser trochanter (P = .01) were significantly different between the patients with and without occult periprosthetic femoral fracture. The sex was significantly associated with an increased risk in predicting an occult intra-operative periprosthetic femoral fracture (odds ratio of male, 0.25 compared with the female; 95% CI, 0.08–0.85; p = .02). There was a significant difference in the incidence of thigh pain between occult fracture group and non-occult fracture group (P < .05). There were no significant differences in stem subsidence and alignment between the patients with and without occult periprosthetic femoral fracture. All 13 cases of occult intra-operative periprosthetic femoral fractures were healed at the final follow-up. Occult periprosthetic femoral fractures are common during a long, trapezoidal, double-tapered cementless femoral stem fixation in primary THA, that CT scans are helpful to identify them, and that these fractures do not adversely affect the implant’s survival if a rigid fixation of the implants has been achieved.

A direct lateral approach to the hip is described which allows adequate access for orientation of the implant, for the insertion ofthe cement and for the correction ofdiscrepancy in leg length. An anatomical observation was made that the gluteus medius muscle is inserted into the greater trochanter by a tendon and that the axis of the shaft of the femur lies anterior to the main bulk of the muscle which was left

Primary total hip arthroplasty (THA) procedures continue to increase. On the basis of data from 2000 to 2014, the frequency of THA in the U.S. is projected to grow to 635,000 procedures per year by 20301. The majority of implants from these procedures are expected to last >20 years. A study of 94,292 total hip replacements from the Finnish Arthroplasty Registry noted a survivorship of 58% at 25 years2. THA complications (especially periprosthetic joint infection [PJI] and dislocation), as well as perioperative management to optimize short stays and outpatient THA while minimizing perioperative complications, continue to draw heavy attention. Implant Design and Related Outcomes In a study evaluating 2016 data from the American Joint Replacement Registry (AJRR) compared with other national registries, the authors found that cementless stem fixation combined with the use of ceramic and 36-mm heads was the current preference in the U.S., while other registries indicated that cemented implants and metal and 32-mm heads were most commonly used3. Cemented Versus Cementless Implants There is evidence that cemented implants outperform cementless counterparts in elderly patients when early complication rates are compared. On the basis of the recent Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) annual report, Tanzer et al. reported that, among patients >75 years of age who underwent THA, those treated with the best-performing cementless femoral stems had more early revisions (<30 days postoperatively) compared with those treated with the best-performing cemented implants4. These early revisions were mainly attributable to the risk of revision for fracture or loosening. This difference disappeared after 90 days following surgery4. Bearing Surfaces Metal-on-Polyethylene (MoP) Studies show better long-term survival with a metal-on-highly-cross-linked-polyethylene (HXLPE) articulation compared with metal-on-conventional, non-cross-linked polyethylene (CPE) in younger patients5-7. In a retrospective review of 101 hips in 84 patients ≤50 years of age, with a duration of follow-up of 15 to 20 years, cobalt-chromium (CoCr)-on-CPE showed a high rate of wear-related revision (13 of 101, 12.9%)5. In contrast, the authors of another report noted excellent 15-year survivorship and functional outcome with no wear-related revision in a cohort of 82 patients (89 hips) ≤50 years of age with CoCr-on-HXLPE6. An observational study from the AOANJRR showed that hips in which XLPE was used (199,131 procedures) had a significantly lower revision rate at 16 years following THA for osteoarthritis compared with hips in which CPE was used (41,171 procedures), regardless of the head material7. Ceramic-on-Ceramic (CoC) or Ceramic-on-Polyethylene (CoP) Clicking or squeaking continues to be present in a small percentage of patients who undergo THA with CoC components. In 1 report, audible noise was present in 6.4% of hips (48 of 749) following THA with use of fourth-generation alumina CoC bearings, although no patient underwent revision for clicking or squeaking8. The selection of CoP recently surpassed MoP as the most popular bearing surface used in THA in the U.S.9. Metal-on-Metal (MoM) A study from Korea demonstrated an acceptable rate of aseptic loosening (cup, 10.5%; stem, 6.1%) in a cohort of 114 hips treated with THA using 28-mm MoM components; the average follow-up was 20 years (range, 17 to 23 years)10. Nonetheless, the use of an MoM articulation continues to decline secondary to persistent concerns for metal debris-induced adverse local tissue reactions. Surface Treatment The authors of a prospective multicenter study reported that, at the 5-year follow-up, titanium alloy (Ti6Al4V) acetabular shells with a porous titanium coating (PTC) had a higher percentage of gaps/radiolucency compared with plasma-sprayed (PS) acetabular shells from the same manufacturer (23% versus 5%). Patients in the PTC group had more patient-reported pain, although none underwent revision for loosening11. Short Versus Standard Stems In a randomized double-blinded study, persistent mid-thigh pain was much more prevalent among patients with a short Collum Femoris Preserving (CFP) stem (LINK) (19%) compared with a full-profile wedge-tapered Alloclassic Zweymüller stem (Zimmer) (7%) at medium-term follow-up. Both cohorts, however, had a high percentage of varus malalignment (14% and 16%, respectively), and the results may not be generalizable to other cementless designs12. The association between periprosthetic femoral fracture and length/geometry of cementless implants was also studied. In a cohort study of 5,090 consecutive, direct-anterior primary THAs performed at a single institution, the incidence of periprosthetic fracture using femoral components with 4 variations in length and geometry was evaluated13. All stems were of a single-taper wedge design from the same manufacturer, with 1 of 4 configurations: full-length, standard profile; full-length, reduced distal profile; short-length, standard profile; and short-length, reduced distal profile. There was a trend toward a higher risk of periprosthetic fracture in the short-length-with-standard-profile group13. It is unclear whether the same trend would hold using other surgical approaches. Head Size In a study using data from the Nordic Arthroplasty Register Association database and including 186,231 patients who underwent MoP THA with use of a 28, 32, or 36-mm head, the authors found that the risk of dislocation was reduced with the use of 32 versus 28-mm heads, although the overall revision risk remained similar. Surprisingly, transitioning from 32 to 36-mm heads was associated with a higher risk of revision for all causes, including the risk of dislocation14. It appeared that 32-mm heads would be the optimal choice for MoP THA. Dual-Mobility Constructs Modular dual-mobility constructs employ a CoCr articular surface liner that locks into an outer shell of titanium. A systematic review of mid-term studies of dual-mobility constructs supports their efficacy in reducing the incidence of dislocation after both primary and revision THA15. The wear rate for contemporary dual-mobility constructs using an HXLPE design showed substantially larger magnitudes of initial head penetration and wear than those reported for HXLPE in fixed-bearing couples (twice the rate)16. It approaches a steady state after 2 years, making it comparable with traditional fixed bearings; future studies should address the long-term outcomes16. A propensity score-matched study showed that patients with a dual-mobility construct had a lower risk of revision due to dislocation, although there was no difference in the overall risk of revision between the dual-mobility construct group and the MoP/CoP group. The authors speculated that selection bias may have been present, as the dual-mobility construct group also showed a higher risk of revision due to infection17. Patient Factors in Relation to Outcomes Medical Comorbidities Dialysis dependence was demonstrated to be an independent risk factor for 30-day adverse events, intensive care unit (ICU) care, longer length of stay, and rehabilitation needs in patients undergoing total joint arthroplasty (TJA)18. Patients with hepatitis C who received interferon or direct antiviral agents prior to THA appeared to have fewer postoperative complications, especially PJI19. Dorr Type In a matched comparative study, a higher incidence of femoral stem-related complications (mainly periprosthetic femoral fractures) was observed when using double-tapered wedge stems in Dorr type-A compared with type-B femora20. A study correlating proximal femoral morphology and leg length after THA showed that patients with a Dorr type-A femur and a high femoral cortical index (FCI, defined as the ratio of cortical width minus endosteal width to the cortical width at a level 100 mm below the tip of the lesser trochanter on an anteroposterior radiograph of the hip) were at increased risk of leg lengthening while patients with a Dorr type-C femur and a low FCI had an increased probability of shortening21. Body Mass Index (BMI) Several studies showed a higher risk of complications (up to 3 times) among THA patients classified as morbidly obese compared with normal controls22-24. In particular, researchers in the U.K. reported on, to our knowledge, the largest longitudinal cohort study to date analyzing the influence of BMI on THA outcomes (>410,000 patients)25. Patients who were morbidly obese (BMI of 40 to 60 kg/m2) had the highest probability of revision at 10 years (twice that of the underweight group), while 90-day mortality was significantly higher for the underweight group compared with those with normal BMI. Milder obesity (BMI of 25 to 40 kg/m2) seemed to have a protective effect against mortality25. In another study, patients classified as super obese (BMI of ≥45 kg/m2) had a greater risk of reoperation and readmission and greater 90-day costs compared with the nonobese cohort, but they had comparable quality-of-life improvements26. Patients classified as morbidly obese who underwent bariatric surgery prior to TJA showed a reduced comorbidity burden at the time of TJA, with reduced post-TJA complications; however, the risk of revision was not reduced27. While obesity seems to be a major negative predictor of adverse outcomes, some argue that THA is still cost-effective for morbidly obese and super obese groups and recommend against a cutoff threshold to avoid unnecessary loss of health-care access28. Preoperative Opioid Use Opioid use within 3 months preceding THA was an independent predictor of early revision, while obesity and anxiety/depression were also shown to predict early failure of treatment29. Significantly higher 30-day readmission and revision rates were observed among THA/TKA (total knee arthroplasty) patients with a history of long-term preoperative opioid use30. In another study, patients who used opioids preoperatively tended to have significantly lower patient-reported outcome scores and longer hospital stays, and were more likely to be discharged to a rehabilitation facility31. Tobacco Use In a recent study, smokers had a significantly higher risk of deep infection and reoperation after revision THA compared with nonsmokers, and the risk was higher than for primary THA32. The authors of a systematic review and meta-analysis found that former tobacco users had a significantly lower risk of wound complications and PJI compared with current smokers. Smoking cessation counseling prior to total joint arthroplasty is strongly advocated33. A history of smoking was also recently tied to increased risk of nerve injury in patients undergoing THA34. Surgical Approach The optimal surgical approach in primary THA remains controversial. A systematic review and meta-analysis of prospective studies showed less pain and better reported function through 90 days postoperatively for the direct anterior approach compared with the posterior approach35. However, when comparing early revision rates (<5 years from index primary surgery), the direct anterior approach was associated with a significantly higher rate of early revision due to femoral loosening compared with the posterior approach, while the posterior approach demonstrated a higher incidence of early revision due to instability36. A Dutch joint-registry study showed small improvements in the 3-month postoperative patient-reported outcome measure (PROM) for the direct anterior and posterolateral approaches compared with the direct lateral and anterolateral approaches37. Regardless of the different approaches, there are minimal differences in gait mechanics at early or late follow-up38. The long-term prognosis of lateral femoral cutaneous nerve (LFCN) neuropathy was also investigated. One study found that approximately 11% of patients had persistent LFCN neuropathic symptoms even at 6 to 8 years after direct anterior THA, and the most common presentation was numbness (37%). This, however, did not affect hip functional scores39. Complications There is substantial variation in reported THA complication rates among national databases and joint registries. The American College of Surgeons National Surgical Quality Improvement Program (NSQIP) tends to show the lowest rate of complications40. Medical Complications A study of 10-year Hospital Episode Statistics data from the U.K. including 540,623 THAs showed that postoperative medical complications decreased year-after-year despite a steady rise in the average Charlson Comorbidity Index score. The only 2 exceptions were lower respiratory tract infection and renal failure, which continued to rise41. Venous Thromboembolism (VTE) and Anticoagulation A systematic review found that industry-funded studies assessing thromboprophylaxis reported fewer patients with pulmonary embolism (PE), major bleeding, and mortality compared with nonfunded studies42. A cross-sectional study in 5 countries found that the rate of in-hospital VTE after hip arthroplasty was 0.16% in Canada, 1.41% in France, 0.84% in New Zealand, 0.66% in the U.S. (California), and 0.37% in Switzerland, while the benchmark was 0.58%. French data showed a higher rate, potentially because of the systematic use of ultrasound, which could result in the over-detection of deep venous thrombosis (DVT) but not PE43. A retrospective analysis of the NSQIP data set from 2008 to 2016 demonstrated that the risk of DVT was not associated with obesity in patients undergoing THA. The risk of PE, however, was found to be elevated in THA patients whose BMI was ≥35 kg/m2. The authors concluded that, since current pharmacologic anticoagulation regimens can reduce the DVT rate but have not been demonstrated to affect the rate of PE or death, the data do not support increased DVT anticoagulation in THA patients who are obese but without other VTE risk factors44. Dislocation Spinopelvic pathology dominated the literature on THA dislocation, with important research focused on spine-pelvis-hip radiographs in the sagittal plane and the related functional safe zone45-52. It has been proposed that the spinopelvic relationship be categorized according to 4 groups, as assessed at the preoperative evaluation (1A: normal alignment, normal mobility; 1B: normal alignment, stiff spine; 2A: flatback deformity, normal spine; 2B: flatback deformity, stiff spine). Special attention should be paid to the 2B population, for whom surgeons may consider using a dual-mobility construct with targeted 30° of anteversion relative to the functional pelvic plane (based on standing, rather than supine, anteroposterior pelvic radiography)45. A modified classification system was recently proposed on the basis of supine anteroposterior pelvic, standing anteroposterior pelvic, and sitting and standing lateral spinopelvic radiographs46. The classification system adds a hyperlordosis spinal alignment category (pelvic incidence-lumbar lordosis [PI-LL] mismatch of <–10°) and suggests a new risk assessment tool incorporating sagittal spinal alignment (coded as a number) and spine mobility/stiffness (coded as a letter) to use in revision THA. This new assessment tool was validated in a group of 222 patients who underwent revision hip replacement for recurrent instability. Results for 111 patients who were evaluated using the new spinal function assessment were compared with a matched group of 111 patients who were not evaluated using the system. The dislocation rate was 3% among patients who had the new presurgical assessment compared with 16% for those who did not46. Patients undergoing THA with a history of lumbar spinal fusion (LSF) had a >100% increased risk of dislocation compared with those who had LSF 5 years after THA53. Another study found that fusion to the sacrum as well as multiple levels of lumbar involvement dramatically increased the risk of dislocation in primary THA54. Although there was no increased perioperative spike of dislocation in patients undergoing LSF following an otherwise stable THA, 1 study demonstrated that this population had a sustained elevated risk of dislocation (0.7% per year) compared with those without LSF (0.4% risk per year)55. PJI The past decade saw tremendous effort and focus on preventing PJI in patients undergoing TJA. Current unadjusted 1-year and 5-year risks of PJI following THA were found to be 0.69% and 1.09%, respectively. After adjustment, however, there was no detectable decline in the risk of PJI over time56. Once PJI is confirmed, the 1-year weighted mortality rate was noted to be 4.22%, and 5-year mortality, 21.12%, highlighting the devastating consequence of PJI57. A PJI consortium (International Consensus on Orthopedic Infections) recently published a guideline for comprehensive hip and knee PJI diagnosis, prevention, and treatment58-65. With the new evidence-based and validated PJI criteria in 2018, PJI diagnosis now consists of a scoring system for minor criteria in both preoperative and intraoperative diagnosis66. One recent study found that there is no difference in treatment success as defined by the Delphi criteria between patients meeting minor-only criteria and those meeting a major criterion of PJI diagnosis67. Another PJI scoring model assigns relative weights to the various risk factors for PJI following TJA. A previous open surgical procedure, drug abuse, a revision procedure, and human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) were deemed the most influential factors68. A positive association between postoperative urinary tract infection and PJI after THA or TKA was established in a population-based, retrospective cohort study of 113,061 patients (≥66 years old). No association was found between acute postoperative urinary retention and PJI69. Debate continues regarding the merits of 1-stage versus 2-stage revision for PJI. In a recent Danish study, the authors reported an encouraging 91% infection-free survival rate at a minimum of 2 years of follow-up when using 1-stage cementless revision in the treatment of patients with chronic periprosthetic hip joint infection70. In another study, about 30% of revisions had an increase in the vancomycin minimum inhibitory concentration (MIC) between 2 stages, raising concerns about the potential for the emergence of resistant organisms between the stages of a 2-stage revision71. Postoperative Urinary Retention Risk factors for postoperative urinary retention have been defined, including an age of >60 years, intraoperative fluid administration of >1,350 mL, and intraoperative of an of risk factors related to postoperative urinary retention are and should be Although the percentage probability of periprosthetic femoral fracture using cementless stems was demonstrated to be only at 10 years, this dramatically increased to at years after primary another study the incidence of periprosthetic femoral fracture in stems found that the incidence of periprosthetic femoral fracture continued to increase after the decade and the incidence of aseptic loosening in the decade A study using data from the national found that the annual incidence of periprosthetic femoral fracture in primary THAs increased from of to of the of to In the report, type-C 4 more than and they were more commonly in cemented The incidence of with MoP is and an average of 5 years to metal the ratio have been shown to be higher in MoP (range, or compared with MoM (range, to Another study a level of and a ratio of to be a cutoff threshold for important MoP The levels of and to decline by and 3 months after potential in the femoral nerve was observed in 17 of patients who underwent the direct anterior approach in THA when were against the anterior of the although this was The authors of another recent study of the anterior in a relative safe to the to avoid In a recent retrospective cohort study using the A data was found to be associated with significantly lower rates of dislocation and aseptic revision of the acetabular following primary The authors when their results because of potential by In a double-blinded study in the U.K. that patients undergoing THA or the use of with an and to show a in the rate of surgical infection Current and The past decade has a rise in the incidence of both outpatient and THA, according to a recent comparative and have been for or to be while also patient supports a trend toward better postoperative outcomes when hip replacement is performed by While the majority of primary THAs are performed at surgeons are the majority of these A more relationship was by a New data set of of the was associated with a 2 to increase in the risk of complications, mortality, and revision relative to while hospital was associated with a increase in complications and a 4 to increase in The opioid has has more attention in recent years. regarding opioid after joint replacement surgery show that to of patients continue opioid use even at 1 year have been to reduce opioid without of A study indicated that fewer compared with 90 was associated with a in opioid and decreased opioid without pain scores and patient-reported In a retrospective review of patients who underwent THA and TKA reported a history of those reported and including respiratory and In this study, no patient with a who was an adverse It was also found that, for the patients with a who were or no differences could be found in the rate of Use is now an of the THA to reduce loss and the risk of by including the American Association of and Surgeons and the American of Orthopaedic Surgeons state that no of or time of administration have been shown to A recent randomized study did that multiple postoperative of reduced loss compared with a single preoperative The of 1 preoperative of 2 by 3 postoperative of of loss in Smoking A study from the demonstrated that level of 8 within 1 of TJA could significantly rates of smokers It also to of patients who reported as continued smoking and as more than after surgery among those who and A from demonstrated that the administration of could to for among patients undergoing THA, by a in postoperative pain scores of was also in reducing opioid and The of use in patients with undergoing THA or TKA was recently in a retrospective study of 2 of patients in the group and in the patients who received were not found to have a significantly higher infection rate than to the that PJI is an this study have been with the of with a a mainly a spinal using significantly the length of of patients undergoing THA by 1 Postoperative Current evidence that the postoperative of and levels following THA in patients with a normal preoperative level is the should be by risk factors and Preoperative and levels of and 4 have been as below which should consider postoperative and It has been that consider the use of the in for THA including of patients with THA with a had significantly higher than those without a and among the THA with a was greater for those The of The a of recently published studies related to the system that received a higher of In to in this 4 other with a higher of to hip replacement are to this review after the standard with a about to in an evidence-based in this treatment and risk of or after total hip a cohort study from national Danish Joint This to the knowledge, the largest study using the Danish databases to address the association between perioperative treatment and postoperative 30-day PE, and from all among patients who underwent THA. A total of patients were the study from to among received perioperative and did After use was not found to significantly increase the risk of PE, or The authors were to the of using on patients with previous and other in this of on outcomes after primary and revision total hip at the a cohort study patients who underwent primary or revision THA from through A using 32 factors found in the medical including 17 and of was used to the study population as index of of to and of With to in-hospital complications, differences were found only for wound complications and the and with patients had a significantly higher risk of mortality ratio of dislocation, wound and reoperation within 90 days and 1 year after primary THA. The authors did not a association of with aseptic periprosthetic or prior bariatric surgery outcomes following total joint arthroplasty in the morbidly A This meta-analysis studies from to 2018, with a total of patients who underwent THA or underwent bariatric surgery prior to TJA and the patients with obesity as the group. The study found that bariatric surgery prior to TJA was associated with reduced risks of medical complications, length of stay, and The risks of wound infection or and the long-term risks of dislocation, periprosthetic and revision were not the THA and TKA bariatric surgery was associated with a in the risk of PJI after but not after THA. of of and on in the after total hip the randomized The and in is a Danish study the and of 4 regimens or after THA. The was 1 surgery and 6 for for a total of 4 of the on the postoperative and patients were in the The authors found that significantly reduced compared with in the after The surgical approach versus for the study cohort was not which have the postoperative for

Many femur fractures in total hip arthroplasty (THA) occur during advancement of the final stem, especially during a direct anterior approach (DAA). Calcar collars are a re-emerging trend among cementless stem designs which may reduce fracture risk by both preventing subsidence and acting as an intraoperative cue for sufficient stem advancement. We hypothesize that collared femoral stems have lower risk of intraoperative and post-op periprosthetic fracture and stem subsidence compared to collarless designs in DAA THA at 6 months. A retrospective review of 348 DAA THAs on a Hana table performed from 2017–2020 by a single surgeon, fellowship trained in arthroplasty, was done. Three cementless stems with similar broach systems were studied: Zimmer ML Taper, Avenir &amp; the Avenir-Complete with a collar. Only patients with Dorr A or B femurs received cementless THA. Incidence of intraoperative fractures and post-operative Vancouver AL/B fractures within 6 months were recorded. Radiographic stem subsidence was measured and compared at 6-months by the attending surgeon and 2 independent observers. Routine 3-dimensional post-operative imaging to quantify subsidence was not feasible at our institution. Fisher-Exact test was used to compare outcomes between the collared vs non-collared designs with p 3mm was deemed clinically significant based on prior studies for similar broached stems. Both groups were comparable in sex, smoking history, diabetes, Dorr type and BMI. Patients with the collared stem had significantly fewer femur fractures compared to collarless stem designs (0/99 vs. 11/249) (p=0.043). 3 patients had intra-operative calcar cracks requiring cerclage and 8 required revision post-op. Radiographic subsidence &gt;3 mm was also significantly lower in the collared stem group (p &lt; 0.001) at 6 months. No statistically significant differences were observed in infection (p=0.55), hematoma formation (p=0.10), or wound complications (p=0.47). The use of collared cementless femoral stems in DAA THA resulted in significant reduction in periprosthetic femur fractures and subsidence compared to collarless stems. This was likely due to the collar acting as an intraoperative and post-operative calcar stop against over-advancement in the canal. There were no cases of early loosening with any of the stems. A prospective multi-surgeon study comparing collared and collarless versions of the Avenir-complete stem would yield stronger data. Subsidence would be more reliably measured with 3D imaging and radiostereometry. Implementing collared femoral stem designs may lead to further cost-savings and lower fracture rate in patients undergoing DAA THA.

IntroductionThe present study evaluated whether patient demographic characteristics influence the subsidence of the stem in total hip arthroplasty (THA). The following characteristics were evaluated: age, height, weight, and sex. The association between the time elapsed from the THA implantation and the amount of stem subsidence was also investigated.MethodsThe records of patients who underwent THA in the period between 2016 and 2023 were accessed. All patients underwent two-staged bilateral THA using cementless DePuy collarless Corail (DePuy Synthes, Raynham, MA, USA) stems. The following parameters were measured and compared to assess stem subsidence: distance from the proximal femur at the stem bone interface and the medial apex of the regular triangle built within the trochanter minor (point A); distance from the medial apex of the regular triangle built within the trochanter minor and the distal portion of the femoral stem (point B).ResultsOverall, 294 patients were included. 62% (182 of 294 patients) were women. 45% (134 of 296 THAs) were on the right side. The mean age was 64.9 ± 10.4 years. The mean BMI was 28.3 ± 5.1 kg/m2. The mean length of the follow-up was 14.4 ± 11.0 months. The mean subsidence in point A was 2.1 mm (P < 0.0001), and that in point B was 3.1 mm (P < 0.0001). There was evidence of a weak positive association between patient weight (P < 0.0001), age (P = 0.03), follow-up (P = 0.002) and the amount of stem subsidence. Patient height did not demonstrate any association with the amount of stem subsidence (P = 0.07). There was no difference in stem subsidence between women and men (P = 0.9).ConclusionStem subsidence in THA using cementless DePuy collarless Corail implants is approximately 2.6 mm after 14.4 months. Greater patient weight, age, and longer time elapsed from THA implantation were associated with greater stem subsidence. Patient height and sex did not demonstrate any influence on the amount of stem subsidence. These results must be considered in light of the limitations of the present study.

Periprosthetic femoral fractures (PFFs) are an increasingly common indication for revision total hip arthroplasty (THA). While patient-related risk factors are well documented, the influence of femoral stem design on PFF risk remains poorly characterized. In this study using nationwide data, we assessed the association between stem design and PFF risk. We analyzed 182,118 primary THAs (performed from 2015 to 2023) from the Swiss National Joint Registry (SIRIS). Cementless stems were categorized according to the Kheir classification, and cemented stems were categorized as double-tapered polished, triple-tapered polished, composite-beam, or custom. A multivariable Cox regression model, including variables such as age, sex, American Society of Anesthesiologists (ASA) class, body mass index (BMI), surgical indication, prior ipsilateral hip surgery, stem design, collar, dual-mobility cup, bearing, and head size, was analyzed. Hazard ratios (HRs) with 95% confidence intervals (CIs) are reported. Among 182,118 THAs (mean patient age, 68.9 ± 11.5 years; female sex in 53.1% of cases), 1,226 (0.7%) were complicated by PFF. The cumulative incidence of PFF reached 0.7% at 5 years and 1.3% at 10 years. Higher PFF risk was associated with an age of 75 to 84 years (HR = 1.68 [95% CI = 1.44 to 1.96]) and ≥85 years (HR = 1.86 [95% CI = 1.47 to 2.35]), ASA class of 3 to 5 (females, HR = 1.70; males, HR = 1.73), BMI of <18.5 kg/m2 (HR = 1.61) or ≥40 kg/m2 (HR = 1.64), prior ipsilateral hip surgery (HR = 1.32), and use of a dual-mobility cup (HR = 1.56). Elective procedures (HR = 0.36) and collared stems (HR = 0.26) were associated with a lower risk. Compared with cementless type-3 stems, cementless type-7 (anatomic) stems showed a higher risk of PFF (HR = 1.88), whereas cementless type-1B (HR = 0.62) and composite-beam cemented stems (HR = 0.45) were protective. In this large nationwide registry study, femoral stem design independently influenced PFF risk after primary THA. Cementless anatomic stems increased the risk, whereas composite-beam cemented stems and the presence of a collar conferred a protective effect. These findings support personalized implant selection, particularly for older patients or those with frailty. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Postoperative periprosthetic femur fractures are an increasing concern after primary total hip arthroplasty (THA). Identifying and understanding predisposing factors are important to mitigating future risk. Femoral stem design may be one such factor. The goals of our study were to compare the (1) frequency of periprosthetic femur fracture and implant survivorship; (2) time to fracture in those patients who experienced periprosthetic femur fracture; and (3) predictive risk factors for periprosthetic femur fracture between a unique stem design with an exaggerated proximal taper angle and other contemporary cementless, proximally fixed, tapered stems. We reviewed all hips in which a femoral hip component with a uniquely exaggerated proximal taper angle (ProxiLock) was implanted during primary THA at a single academic institution. That group of patients was compared with a cohort of patients who underwent primary THA during the same time interval (1995-2008) in which any other cementless, proximally fixed, tapered stem design was used. The two groups differed somewhat in terms of sex, age, and body mass index, although these differences were of unclear clinical significance. During the study, 3964 primary THAs were performed using six different designs of cementless, proximally fixed, tapered femoral hip prostheses. There were 736 stems in the ProxiLock (PL) patient group and 3228 stems in the non-ProxiLock (non-PL) group. In general, the stem highlighted in this study became the routine cementless stem used for primary THA for three arthroplasty surgeons without specific patient or radiographic indications. Periprosthetic fractures were identified within each group. The incidence, timing, type, and treatment required for each fracture were analyzed. The Kaplan-Meier method was used to determine study patient survival free of any postoperative fracture. Radiographs and the electronic medical record of each patient who sustained a fracture were reviewed. Followup was comparable between groups at all time points. The Kaplan-Meier estimate for fracture-free patient survival was worse in the PL group at all time points with survival of 98.4% (range, 97.4%-99.3%), 97.1% (range, 95.9%-98.3%), 95.4% (range, 93.8%-97.0%), and 92.6% (range, 89.6%-95.3%) at 30days, 1year, 5years, and 10years, respectively, for the PL patient group compared with 99.8% (range, 99.7%-99.9%), 99.6% (range, 99.3%-99.8%), 99.3% (range, 99.0%-99.6%), and 98.4% (range, 97.5%-99.1%) in the non-PL patient group (p<0.001). Patients in the PL group had increased cumulative probability of both early and late fractures with cumulative probabilities of fracture of 2.5% (range, 1.3%-3.6%) at 90days and 7.4% (range, 4.7%-10.4%) at 10years compared with probabilities of 0.3% (range, 0.1%-0.5%) at 90days and 1.6% (range, 0.8%-2.5%) at 10years in the non-PL group (p<0.001). Patients in the PL group had an increased risk of postoperative periprosthetic femur fracture (hazard ratio [HR], 5.6; 95% confidence interval [CI], 3.4-9.1; p<0.001); fracture requiring reoperation (HR, 8.4; 95% CI, 4.4-15.9); p<0.001); and fracture requiring stem revision (HR, 9.1; 95% CI, 4.5-18.5; p<0.001). Age older than 60years was also a risk factor for fracture (HR, 3.7; 95% CI, 2.1-6.4), but sex, body mass index, and preoperative diagnosis were not predictive. Hips implanted with an uncemented femoral stem, which has a uniquely exaggerated proximal taper angle, had an increased risk of both early and late postoperative periprosthetic femur fracture. The majority of patients with a fracture underwent reoperation or stem revision. The unique proximal geometry, lack of axial support from the smooth cylindrical distal stem as well as resorption of the hydroxyapatite coating and poor ongrowth with subsequent subsidence may contribute to increased risk of fracture. Although this particular stem has recently been discontinued by the manufacturer, these findings are important in regard to followup care for patients with this stem implanted as well as for future cementless stem design in general. Level III, therapeutic study.

Periprosthetic femur fracture (PFF) is a major complication following total hip arthroplasty (THA) that carries significant morbidity, mortality, and economic burden. Currently, uncemented stems are highly preferred in primary THA, but have been associated with higher risk of PFF compared to cemented stems. The use of collared stems in uncemented primary THA has shown promise in reducing PFF rates postoperatively.This retrospective study included 2,294 uncemented primary THAs using the posterior approach performed by two attending surgeons from January 2016 to December 2022. Both surgeons switched from a collarless femoral stem design to a collared design in May 2020. Data was collected regarding stem design, frequency of PFF, and requirement for revision surgery. Periprosthetic fractures were identified and confirmed using medical records and/or radiographic imaging. Fracture rates and percentages between collared and collarless stems were then analyzed. A Fisher's Exact Test was performed to determine if there was a significant association between collared and collarless stem use on PFF rates.A total of 2,294 uncemented primary THAs performed by 2 surgeons were eligible for analysis. 903 (39.4%) patients received a collared stem, and 1,391 (60.6%) patients received a collarless stem. In total, 14 (0.6%) PFFs occurred over the study period. There was 1 fracture (0.1%) out of 903 collared stems, and 13 fractures (0.9%) out of 1,391 collarless stems (p = 0.012).Collared stems were associated with a significant decrease in PFF rate when compared to collarless stems in uncemented primary THA. Future studies are encouraged to continue to investigate PFF and other complication rates with the use of a collared stem design.

Mid-Term Survival of Total Hip Arthroplasty in Patients Younger Than 55-year-old.

The treatment of fractions of the shaft of the femur using nylon cerclage.

Does Stem Design Affect the Incidence of Periprosthetic Femoral Fractures in Arthroplasty for Femoral Neck Fractures? A Secondary Analysis of the HEALTH Trial.

Does Powered Femoral Broaching Compromise Patient Safety in Total Hip Arthroplasty?