Humeral stem alignment of curved short stem in reverse shoulder arthroplasty: Varus/Valgus alignment is not a determinant for clinical outcomes.

BACKGROUND: This study aimed to investigate the influence of curved short stem alignment within the proximal humerus on the clinical outcomes of reverse shoulder arthroplasty. We hypothesized that the varus/valgus alignment would yield clinical outcomes comparable to those of a neutral alignment. METHODS: We retrospectively reviewed 167 patients who underwent reverse shoulder arthroplasty using the Aequalis Ascend Flex implant between January 2017 and December 2021. The study categorized the patients into three groups based on the angle difference between the humeral axis and the stem axis: neutral group (GN, defined as within ±5 degrees), valgus group (GL), and varus group (GR). Functional outcomes were assessed using the visual analog scale pain score, subjective shoulder value, American Shoulder and Elbow Surgeons score, University of California Los Angeles shoulder score, and active range of motion. Routine radiographic evaluations were also conducted to assess the filling ratio and bone resorption. RESULTS: Among 138 patients, 89 were in the GN group, 37 (27%) in the GL group, and 12 (9%) in the GR group. The average degree of varus alignment was 6 (range from 5 to 7 degrees), while the average degree of valgus alignment was -7 (range from -8 to -5 degrees). According to our findings, the clinical outcomes did not exhibit significant differences between the three groups. Furthermore, the radiological outcomes showed no significant differences among the three groups. CONCLUSIONS: Compared to neutral alignment, varus or valgus alignment of the humeral stem in reverse shoulder arthroplasty using a curved short stem does not significantly affect clinical outcomes.

Survivorship of the Stryker Ascend Flex uncemented metaphyseal bearing stem at a minimum 2- and 5-year follow-up.

Introduction: The Ascend Flex short stem implant has been reported to have good early clinical outcomes and low revision rates. This retrospective study aimed to evaluate the early to mid-term radiographic and clinical outcomes of patients who underwent primary shoulder arthroplasty with this implant. Methods: All consecutive patients who underwent primary shoulder arthroplasty with short uncemented Ascend Flex stems with a minimum of 24-month follow-up were included. The primary outcomes were revision and reoperation rate. The secondary outcomes included stress shielding and Oxford Shoulder Score (OSS). Results: Totally, 151 shoulders were eligible for inclusion. Out of which 73 were anatomic total shoulder arthroplasty, 77 were reverse geometry, and 1 was a hemiarthroplasty. Mean follow-up duration was 52 ± 17.2 months. The revision and reoperation rates were 0.6% and 2.6%, respectively. 1.3% anatomic total shoulder arthroplasty (aTSA) cases and 6.5% RSA cases demonstrated stress shielding. OSS improved from 16.1 ± 8.5 to 34.1 ± 12.3 in aTSA cases (Z = -3.98, p < 0.001) and from 15.6 ± 8.4 to 30.0 ± 13.5 in RSA cases (Z = -3.41, p < 0.001). Conclusion: These findings demonstrate reassuring outcomes for this implant at a mean of 52 months. Further reports are required to document the long-term outcomes for this component.

Does the calcar femorale affect the position of uncemented short stems?

BACKGROUND AND PURPOSE: Metaphyseal-stabilised short stems rely on sufficient metaphyseal fixation and are inserted by following the medial cortex. This type of stem is used extensively in our institution, and we observed on occasion unintended implant positioning with an increased distance between the implant and the medial cortex. A bony structure within the proximal femur which was first described in 1874 and named the calcar femorale, coincides with this phenomenon.The aim of this study was to investigate the impact of the calcar femorale on the position of a metaphyseal-stabilised short stem. PATIENTS AND METHODS: The frequency of cases with an increased distance between medial cortex and the implanted short stem was analysed in 52 consecutive patients. Additionally, we performed an anatomical CT study with 60 cadaveric femora to obtain more detailed information on the anatomy of the calcar femorale. Detailed measurements regarding the calcar femorale and its relationship to the proximal femur were obtained. From this, we derived implications for the implantation of a short stem prosthesis. RESULTS: In 50% of all cases, we found an increased gap between the stem and the medial cortex. An increased gap did not significantly affect stem size, position, or subsidence rate, but in cases with an increased gap we found fewer stems with a radiologically optimum fit. The calcar could be identified in all 60 cadavers. The calcar femorale angle showed a high correlation with the mechanical antetorsion (0.87, p = 0.02) and the functional antetorsion (0.86, p = 0.05) of the femur. CONCLUSIONS: The calcar femorale is a consistent anatomical structure which may be the cause for an increased gap medial to the short stem in 50% of our cases. It limits the intramedullary space and influences both stem size and orientation. The CF angle which correlates with femoral antetorsion may influence the anteversion of the stem.

Ten-Year Results of the Fitmore® Hip Stem with a Focus on Varus/Valgus Alignment and Subsidence-A Retrospective Monocentric Analysis.

Background: Hip arthroplasty is a common elective surgery worldwide, with rising numbers due to demographic changes and an emphasis on maintaining physical activity in the elderly. The development of new implant designs, especially shorter uncemented stems, has contributed to the advancement of minimally invasive implantation techniques. However, the long-term in vivo behaviour of these implants, particularly regarding subsidence, stability, and stress shielding, remains to be fully understood. Methods: This retrospective, monocentric cohort study analyses the long-term radiographic outcomes of the first 141 patients who underwent total hip arthroplasty with the Fitmore® Hip Stem between June 2007 and December 2008. It focuses on subsidence, stability, varus-valgus alignment, and the influence of patient-related, anatomical, and surgical factors on implant behaviour over a 10-year follow-up period. Results: The average change in varus/valgus alignment was 0.7° into varus and the average subsidence was 1.7 mm over 10 years, with most changes occurring within the first six weeks postoperatively. The varus-valgus alignment and subsidence did not significantly change after the first year, indicating stable osteointegration of the implant. Neither patient factors (gender, age) nor surgical and implant factors (implantation angle, approach, stem family, size, total offset) had a significant influence on the long-term behaviour of the implant. Conclusions: The Fitmore® Hip Stem shows highly reliable long-term stability and integration, unaffected by various patient, surgical, and implant factors, as confirmed by excellent register data. Nevertheless, monitoring of this and other new implants should be continued in order to determine implant behaviour, possible weaknesses, and indication limits at an early stage for the benefit of the patient.

Uncemented Customized Hollow Stems in Tumor Endoprosthetic Replacement-A Good Opportunity to Protect the Adjacent Joint in Children?

This study aimed to retrospectively analyze the follow-up results of cases in which the adjacent joint was preserved using a custom-made uncemented short-stem design (hollow stem) with optional external flanches in tumor endoprosthetic replacement due to bone sarcomas in 13 patients (with an average age of 9.6 years) between 2017 and 2023. Reconstructions were proximal femur (n = 6), intercalary femur (n = 4), intercalary tibia (n = 2), and proximal humerus (n = 1) tumor prostheses. The hollow body was used distally in 10 of the megaprotheses, proximally in 1, and both proximally and distally in 2 of them. The average distance from the joints was 6 cm in stems with flanches and 11.8 cm in stems without flanches. No aseptic loosening or deep infection was observed during an average follow-up of 34 months. Except for one case with a tibial intercalary prosthesis that needed a revision, all cases were well osteointegrated and all lower extremity cases could bear full weight without pain. In cases where the remaining bone stock after bone resection is insufficient for a standard stem implantation, reconstruction with a patient-specific short hollow-stem design appears to be a good alternative to protect healthy joints with high prosthesis survival and low revision rates in the short-term follow-up.

Learning curve comparison between switching approach and switching implant in cementless short stem total hip arthroplasty.

INTRODUCTION: Implementing new approaches or new implants is always related with a certain learning curve in total hip arthroplasty (THA). Currently, many surgeons are switching to minimally invasive approaches combined with short stems for performing THA. Therefore, we aimed to asses and compare the learning curve of switching from an anterolateral Watson Jones approach (ALA) to a direct anterior approach (DAA) with the learning curve of switching from a neck-resecting to a partially neck-sparing short stem in cementless THA. MATERIALS AND METHODS: The first 150 consecutive THA performed through a DAA (Group A) and the first 150 consecutive THA using a partially neck-sparing short stem (Group B) performed by a single surgeon were evaluated within this retrospective cohort study. All cases were screened for surgery related adverse events (AE). Furthermore, the operative time of each surgery was evaluated and the learning curve assessed performing a cumulative sum (CUSUM) analysis. RESULTS: Overall, significantly more AE occurred in Group A compared to Group B (18.0% vs. 10.0%; p = 0.046). The sub-analysis of the AE revealed higher rates of periprosthetic joint infections (2.7% vs. 0.7%; p = 0.176), periprosthetic fractures (4.0% vs. 2.0%; p = 0.310) and overall revisions (4.7% vs. 1.3% p = 0.091) within Group A without statistical significance. The CUSUM analysis revealed a consistent reduction of operative time after 97 cases in Group A and 79 cases in Group B. CONCLUSION: A significantly higher overall rate of AE was detected while switching approach compared to switching implant for performing THA. However, according to the results of this study, surgeons should be aware of the learning curve of the adoption to a new implant with different fixation philosophy as well.

Native hip geometry restoration in total hip arthroplasty: a retrospective analysis of eight different short stems.

PURPOSE: To compare different types of short stems (SS) in terms of native hip geometry reproducibility, analyzing centrum-collum-diaphyseal angle (CCD) and femoral offset (FO). These parameters allow the SS to be adapted to patient's anatomy in order to ensure better functional outcomes in total hip arthroplasty (THA). METHODS: A total of 387 cases of SS met the inclusion criteria. CCD and FO were measured using MediCAD® software Version 6 in preoperative (preop-) and postoperative (postop-) X-rays at 6-12 months after surgery. Considering preop-CCD, the sample was divided into three groups: ≤ 124.9° (A); 125°-129.9° (B); and ≥ 130°(C). Preop- and postop-CCD and FO and the respective average difference (Δ) were examined considering the SS individually and within groups, to verify reproducibility of these parameters. RESULTS: The SS considered were eight: Fitmore Zimmer, Pulchra Adler, TRIS Adler, Trifit Corin, Trilock Depuy, Actis Depuy, Profemur Microport, and SMF Smith&Nephew. Groups A, B, and C consisted, respectively, of 113, 124, and 150 cases. Considering all cases, there was a statistically significant (p < 0.05) increase in CCD and FO with surgery. Overall, Trifit and Trilock stems were the best in reproducing preop-CCD, Trifit itself followed by Pulchra and Profemur for preop-FO. In groups A and C, the reproduction of preop-CCD was better than preop-FO, in contrast in group B. With regard to preop-CCD reproduction, in group A Trifit and Pulchra, in group B Fitmore and Trifit, and in group C Fitmore and Pulchra were the best. Fitmore in group A, SMF in group B, Pulchra and Trilock in group C were the worst in reproducing preop-FO. CONCLUSION: Each hip anatomy is unique, and reproduction of preop-CCD and preop-FO can be achieved with different SS characteristics. Accurate knowledge of the stems and performing correct preop- planning are crucial to allow the best restoration of the patient's native hip geometry in THA.

The medullary cavity morphology of the proximal femur influences the fixation pattern of the rectangular tapered short stem in total hip arthroplasty.

INTRODUCTION: This study aimed to evaluate differences in the pattern of fixation with a rectangular tapered short stem (Fitmore stem) due to proximal femoral medullary cavity morphology based on periprosthetic bone mineral density (BMD) and radiological findings. MATERIALS AND METHODS: We analyzed 105 consecutive patients (Dorr type A, 18; Dorr type B, 66; Dorr type C, 21) who underwent total hip arthroplasty using a Fitmore stem. Periprosthetic BMD was measured using dual-energy X-ray absorptiometry from 1 to 24 months postoperatively and radiological analysis was performed. Clinical outcomes were evaluated using the Harris hip score (HHS) and the University of California Los Angeles (UCLA) activity score preoperatively and 24 months postoperatively. RESULTS: At 24 months postoperatively, Dorr type C had significantly decreased BMD changes in Gruen zones 2, 6, and 7 compared to Dorr types A and B, and conversely, significantly increased BMD changes in zone 4 (p < 0.05). Dorr type C had significantly greater subsidence than the other types (p < 0.01) and significantly higher cortical hypertrophy in zone 3 (p < 0.01). Stress shielding was not significantly different between Dorr types. The preoperative and postoperative HHS and UCLA activity scores showed no significant differences between the Dorr types. CONCLUSIONS: In Dorr type C, BMD significantly decreased in the proximal femur with a rectangular tapered short stem, suggesting that the stem was fixed at the distal part. Careful observation of this prosthesis over time is needed in patients with Dorr type C.

Cemented Calcar-Guided Short-Stem Prostheses in Geriatric Patients: Short-Term Results from a Prospective Observational Study.

Both cementless and cemented stems have exhibited favorable long-term outcomes in total hip arthroplasty. Nonetheless, in elderly patients, cemented hips offer an advantage due to their reduced risk of periprosthetic fractures. This study aimed to assess the initial outcomes of 28 patients who underwent unilateral cemented total hip arthroplasty utilizing a calcar-guided A2 stem (ARTIQO GmbH, Lüdinghausen, Germany). Various types of antibiotic-loaded bone cement were employed. During follow-up, we recorded demographic data and comorbidities and employed standardized clinical assessment tools, including the Harris Hip Score. Radiographic assessments included preoperative, postoperative, and follow-up imaging to evaluate subsidence, osteolysis, and bone resorption. The results indicated that among the 28 patients, 5 withdrew consent and 2 patients passed away from unrelated causes. Additionally, one prosthesis was explanted due to the undersizing of the cement stopper, which resulted in an inadequate cement mantle. As a result, 20 patients underwent a 1-year follow-up, revealing noteworthy enhancements in clinical scores, with no instances of radiolucent lines or osteolysis. No infections were detected. In summary, our short-term experience with this particular cemented short-stem design yielded promising results, exhibiting excellent functional outcomes, no aseptic loosening attributable to the stem, and no infections. Further clinical studies and registry data are essential to corroborate these findings.

Analysis of Postoperative Complication and Revision Rates and Mid- to Long-Term Implant Survival in Primary Short-Stem Total Hip Arthroplasty.

Background/Objectives: Short-stem prostheses were introduced as an alternative to conventional straight-stem prostheses. Despite their benefits, including minimally invasive approaches, soft-tissue- and bone-sparing implantation, and physiological load transfer to the metaphysis, data on postoperative complication and revision rates as well as on implant survival are scarce. Methods: A retrospective analysis of 1327 patients who underwent primary total hip arthroplasty (THA) using the Metha® short stem between 2006 and 2023 was conducted. Complication and revision rates were analysed for the intraoperative, direct postoperative, and follow-up episodes. Implant survival was analysed with the endpoint of all-cause stem revision. Results: Intraoperative complications were observed in 3.77% of the cases and included 44 hairline cracks and 6 fractures. In 15 cases (30.0%), conversion to a straight-stem or revision implant was necessary. The direct postoperative complication rate was 2.44%, and 11 revision procedures were performed during inpatient stay (0.84%). Mean follow-up was 7 years (range 1-17). During follow-up, femoral component revision was performed in 60 cases. Aseptic loosening and stem subsidence accounted for a combined percentage of 80% of all indications. Implant survival rate was 95.66% after 5 years, 95.58% after 10 years, and 95.50% after 15 years. Conclusions: Our study provides a comprehensive analysis of postoperative complication and revision rates in a large sample undergoing primary short-stem THA. Postoperative complication rates were favourable, and the long-term implant survival rates were comparable to conventional straight-stem prostheses. Therefore, short-stem THA may be considered an alternative for younger patients.

Cementless short stem total hip arthroplasty in patients older than 75 years: is it feasible?

BACKGROUND: In recent years, the indication for cementless short stem total hip arthroplasty (THA) has been widened to elderly patients as they might profit by the advantages of the short-curved implant design as well. Therefore, this study was conducted to evaluate the clinical and radiological outcome of a cementless short stem in elderly patients (≥ 75 years) compared to a young control group (≤ 60 years). METHODS: A retrospective cohort of 316 THAs performed between 2014 and 2017 was prospectively examined. In all patients a cementless, curved short stem and press-fit cup (Fitmore® stem; Allofit®/-S cup; both ZimmerBiomet, Warsaw, IN, USA) were implanted via a minimally-invasive anterolateral approach. Clinical and radiological outcome as well as rate of complications and revision were assessed. RESULTS: In total, 292 patients have been included for analysis of complications and revisions (Øfollow-up: 4.5 years) and 208 patients for clinical and radiological outcome (Øfollow-up: 4.4 years). Complication rate was significantly increased in elderly patients (13.7% vs. 5.8%, p = 0.023), while the revision rate was increased without statistical significance (5.2% vs. 2.2%, p = 0.169). Periprosthetic fractures occurred significantly higher in the elderly patients (5.2% vs. 0.7%; p = 0.026). Both groups showed a comparable clinical outcome in the Harris Hip Score (93.7 vs. 91.9; p = 0.224), Oxford Hip Score (44.5 vs. 43.7; p = 0.350), Forgotten Joint Score (81.7 vs. 81.5; p = 0.952) and WOMAC (7.4 vs. 9.3; p = 0.334). CONCLUSION: Cementless short stem total hip arthroplasty shows a comparable clinical and radiological outcome in patients over 75 years of age compared to younger patients under 60 years of age. However, cementless shorts stem THA shows an increased rate of overall complications and periprosthetic fractures in elderly patients over 75 years of age. Cemented fixation of the femoral component should be considered in patients over 75 years of age. LEVEL OF EVIDENCE: III Case-controlled study. TRIAL REGISTRATION: Observational study without need for trial registration due to ICMJE criteria.

The Migration Pattern of a Short-Tapered Femoral Stem Correlates with the Occurrence of Cortical Hypertrophies: A 10-Year Longitudinal Study Using Ein Bild Röntgen Analyse-Femoral Component Analysis.

Background: Shorter hip stems have shown promising mid-term results but lack long-term data. High rates of distal cortical hypertrophy (CH) have been described, suggesting a more diaphyseal load transmission. This study aimed to determine patient-specific and surgery-related factors influencing CH and their impact on 10-year outcomes. Methods: It included 100 consecutive total hip arthroplasties (THAs) using the Fitmore stem (Zimmer, Warsaw, Indiana), with clinical and radiographic follow-ups at 1, 2, 5, and at least 10 years post-surgery. Results: No revisions were performed due to aseptic loosening after a mean of 11.6 years (range: 10-13.5 years). CH was observed in 26% of hips, primarily in Gruen zones 3 and 5. There was no significant difference in the Harris Hip Score between patients with and without CH. Larger stem sizes and greater axial subsidence significantly correlated with CH occurrence (OD 1.80, (1.13-1.92), p = 0.004; OD 1.47, (1.04-2.08), p = 0.028). The Fitmore stem demonstrated excellent survival rates and favorable outcomes over 10 years. Conclusions: Despite a lower CH rate compared to other studies, significant correlations with stem size and subsidence were identified. This study underscores the importance of patient selection and achieving high primary stability to maintain the metaphyseal anchoring concept.

The assessment of canal flare index and proximal femoral bone density can improve stem selection for peri-prosthetic bone maintenance after total hip arthroplasty.

INTRODUCTION: Bone maintenance after total hip arthroplasty (THA) is important for implant success. This study aimed to investigate the relationship between patient characteristics and periprosthetic bone maintenance after THA for better implant selection. MATERIALS AND METHODS: This retrospective cohort study enrolled 112 consecutive patients who underwent THA using full hydroxyapatite (HA) compaction with short (n = 55) or short-tapered wedge (n = 61) stems. Periprosthetic bone mineral density (BMD) was compared between the two groups after propensity score matching, and the relationship between periprosthetic BMD changes and patient background was analyzed. RESULTS: Both groups showed similar periprosthetic BMD changes after adjusting for patient background using propensity score matching. Canal flare index > 3.7 in patients that underwent THA using tapered-wedge stem (odds ratio (OR), 3.2; 95% confidence interval (CI), 1.3-7.9, p = 0.013) and baseline zone 1 BMD > 0.65 in patients that received with short HA compaction stems (OR, 430.0; 95% CI 1.3-1420, p = 0.040) were associated with proximal periprosthetic bone maintenance after THA. CONCLUSION: Considering their predictive value, canal flare index and zone 1 BMD assessment might be useful strategies for implant selection during THA.

Long-term outcomes of the mayo conservative hip system in patients aged 30 years or less with osteonecrosis of the femoral head: mean follow-up of more than 10 years.

INTRODUCTION: Historically, total hip arthroplasty (THA) in very young patients has been associated with lower survivorship. However, the long-term outcomes of THA using short stems for osteonecrosis of the femoral head (ONFH) in very young patients remain unclear. Therefore, this study aimed to investigate the long-term outcomes of the Mayo conservative hip system, a short metaphyseal stabilised stem, in patients with ONFH aged ≦30 years. MATERIALS AND METHODS: We retrospectively reviewed 104 joints in 76 patients with ONFH who underwent THA using the Mayo conservative hip system with a minimum follow-up of 8 years. The mean follow-up period was 12.5 (range, 8-19) years. Patients were categorised into two age groups (≦30 years, n = 21 and > 30 years, n = 83). Radiographic evaluation was used to assess stem sinking, stress shielding, and spot welds. The clinical evaluations were performed using the Japanese Orthopedic Association (JOA) hip score. Postoperative major complication and revision surgery rates were also assessed. RESULTS: The patient characteristics were similar between the two groups, except for the age. Revision surgeries were performed in five cases, with similar implant survival rates between the groups. Dislocations occurred in the older age group alone (four joints). One case of intra-operative periprosthetic femoral fracture was found in the younger age group. Stem sinking of > 3 mm occurred in one and seven joints in the younger and older age groups, respectively. Spot welds were observed in most joints (93.2%) in modified Gruen zones 2 and 6 without significant differences between the groups. Stress shielding showed no significant differences in the frequency of occurrence or location between the two groups. Furthermore,the JOA score showed no significant difference between the two groups. CONCLUSION: The use of short stems in patients aged ≤ 30 years with ONFH showed favourable long-term outcomes.

Revision of Failed Short Stems in Total Hip Arthroplasty.

Background: The current literature lacks studies which evaluate the failure of short stems in total hip arthroplasty (THA). Therefore, the present clinical investigation reported our experience with the failure of short stems in THA, evaluating the causes of failure, survivorship, and the clinical outcomes of revision arthroplasty. Methods: The present study was performed according to the STROBE guidelines. This study was conducted at the Department of Orthopaedic Surgery of the Humanitas Clinical Institute, Milan, Italy, between 2017 and 2022. All patients who underwent revision surgery of a previously implanted THA using a short stem were prospectively included in the present study. Surgeries were performed with patients in lateral position, using a minimally invasive posterolateral approach. The outcomes of interest were to report information on the type and survivorship of implants used for the revision surgery and evaluate the clinical outcomes and the rate of complications. The following patient-reported outcome measures (PROMs) used for the clinical assessment were the Western Ontario McMaster Osteo-Arthritis Index (WOMAC) and related subscales of pain, stiffness, and function, and the visual analogue scale (VAS). Results: Data from 45 patients were retrieved. Of them, 31% (14 of 45 patients) were women. The mean age was 63.7 ± 13.9 years. The mean length of the implant survivorship was 6.2 ± 5.7 years. In total, 58% (26 of 45 patients) underwent revision of all components, 36% (16 of 45 patients) revised only the stem, and 1% (3 of 45 patients) received a two-stage revision. The mean length of the follow-up was 4.4 ± 1.5 years. The cup was revised in 58% (26 of 45) of patients. At 4.4 ± 1.5 years of follow-up, the WOMAC score was 3.5 ± 1.3 and the VAS was 1.2 ± 1.3. In total, 9% (4 of 45) of patients experienced minor complications. One patient used a walking aid because of reduced function. One patient evidenced muscular hypotrophy. Two patients experienced hip dislocations. All two dislocations were managed conservatively with repositioning in the emergency room under fluoroscopy. No patient needed additional revision surgery or experienced further dislocations. Conclusions: Revision surgery is effective and safe when a short stem THA fails. At approximately four years of follow-up, all patients were highly satisfied with their clinical outcomes. Despite the relatively high number (9%), complications were of a minor entity and were successfully managed conservatively.

Total Hip Replacement with a Fully Hydroxyapatite-Coated Shortened Stem: Five- to Thirteen-Year Follow-Up Results.

Background: Shortened femoral stems aim to mimic the biomechanical performance of traditional stems while preserving more bone and minimizing soft tissue damage. Our objective is to assess the outcomes of patients treated with a shortened stem (Furlong Evolution, JRI Orthopaedics, Sheffield, UK) to analyze the implant's efficacy and survivorship. Methods: This retrospective observational study included all patients aged 18 to 70 undergoing uncemented shortened stem total hip replacement at Hospital del Mar between 2010 and 2018. Hip function and pain were assessed with the Merle d'Aubigné-Postel scale and visual analog scale, respectively. A radiographic analysis measured stem and cup orientation, leg length discrepancy, stem subsidence, and radiolucencies around the cup. Perioperative complications, prosthetic failures, and reoperations were documented. Results: A total of 109 patients (74 male, 35 female) of a mean age of 51.8 ± 8.8 years were included. The average follow-up was 91 ± 17.4 months. Radiographically, 71 (65.1%) of the stems had been inserted at the appropriate angulation (±3°), and 102 (93.6%) of the cups had been placed in the Lewinnek safety zone. Leg length discrepancy was observed in 19 (17.4%) cases. The mean Merle d'Aubigné-Postel score improved from 13.1 ± 1.39 preoperatively to 17.8 ± 0.49 at 6 months postoperatively (p < 0.001). Merle d'Aubigné-Postel subscales also reflected a statistically significant improvement (p < 0.001). The mean pain score 12 months postoperatively was 0.52 ± 1.22, with 95.4% of patients declaring themselves satisfied or highly satisfied. The expected 13-year survival according to a Kaplan-Meier analysis was 100% in the absence of infection and 91.3% if revision for any cause is taken as a survival endpoint. Conclusions: The shortened stem under analysis provides excellent functional results and long-term survival rates.

Mid-Term Outcomes of a Short Modular Neck-Preserving Cementless Hip Stem: A Retrospective Study With a 6-Year Minimum Follow-Up.

Background: The neck-preserving cementless short stem represents a valid therapeutic option for total hip replacement in high-functional-demand patients, but few studies are available about the use of modularity in the last-generation short stem. The aim of the study was to evaluate the mid-term survival of a specific implant design that combines partial collum short hip stem with neck modularity; assessing the functional status was the second endpoint. Methods: A retrospective single-center cohort study was conducted on 75 patients aged 35 to 80 years, with a minimum 6-year follow-up. Patients with neurological/rheumatic pathologies and previous hip surgeries were excluded. All the patients underwent total hip replacement with a short modular neck-preserving cementless hip stem. Clinical outcomes, complications, revisions, and the Western Ontario and McMaster Universities Osteoarthritis Index, Harris hip score, and Short Form 12-Item Health Survey (SF-12) questionnaires were evaluated. The results were compared with healthy population's data extracted from the literature, stratified by age. Results: The Kaplan-Meier analysis revealed a 10-year implant survival rate of 96.7%, coupled with a revision rate of 1.3%. Results showed a Harris hip score and physical SF-12 significantly lower and a mental SF-12 higher when compared to healthy population. No statistically significant differences emerged when comparing groups based on neck modularity. Conclusions: The short modular neck-preserving cementless hip stem emerged as a reasonable choice for patients with elevated functional demands, ensuring good clinical outcomes while preserving bone integrity. The use of a modular neck in short stems didn't show any mechanical problems in the mid-term.

Equivalent revision rates and patient reported outcomes with routine use of a short (125mm) cemented stem for total hip arthroplasty compared to a standard length (150mm) cemented stem. A two surgeon series of 1335 patients.

BACKGROUND: Routine total hip arthroplasty (THA) using a short cemented stem as compared with a standard length cemented stem may have benefits in terms of stress distribution, bone preservation, stem subsidence and ease of revision surgery. Two senior arthroplasty surgeons transitioned their routine femoral implant from a standard 150 mm Exeter V40 cemented stem to a short 125 mm Exeter V40 cemented stem for all patients over the course of several years. We analysed revision rates, adjusted survival, and PROMS scores for patients who received a standard stem and a short stem in routine THA. METHODS: All THAs performed by the two surgeons between January 2011 and December 2021 were included. All procedures were performed using either a 150 mm or 125 mm Exeter V40 stem. Demographic data, acetabular implant type, and outcome data including implant survival, reason for revision, and post-operative Oxford Hip Scores were obtained from the New Zealand Joint Registry (NZJR), and detailed survival analyses were performed. Primary outcome was revision for any reason. Reason for revision, including femoral or acetabular failure, and time to revision were also recorded. RESULTS: 1335 THAs were included. 516 using the 150 mm stem and 819 using the 125 mm stem. There were 4055.5 and 3227.8 component years analysed in the standard stem and short stem groups respectively due to a longer mean follow up in the 150 mm group. Patient reported outcomes were comparable across all groups. Revision rates were comparable between the standard 150 mm stem (0.44 revisions/100 component years) and the short 125 mm stem (0.56 revisions/100 component years) with no statistically significant difference found (p = 0.240). CONCLUSION: Routine use of a short 125 mm stem had no statistically significant impact on revision rate or PROMS scores when compared to a standard 150 mm stem. There may be benefits to routine use of a short cemented femoral implant.

Outcomes of a cementless onlay short stem reverse shoulder arthroplasty in elderly patients: a comprehensive analysis of clinical and radiological findings.

OBJECTIVE: The objective of this study was to evaluate clinical and radiological outcomes of a short stem reverse shoulder prosthesis with metaphyseal fixation specifically in older patients. METHODS: All patients, older than 70 years, submitted to a Reverse Shoulder Arthroplasty (RSA) using a cementless onlay short stem (Aequalis Ascend™ Flex Convertible Shoulder System (Stryker®)) from January 2017 to December 2021, with a minimum follow-up of 2 years, were included. Postoperative radiographs were assessed for stem loosening, subsidence, and varus-valgus tilt. Range of motion, visual analogue scale for pain, constant score, complication rate and revision rate were also analysed. RESULTS: A total of 34 patients with a mean age of 75 years (range 71-83 years) were submitted to a cementless onlay short stem RSA with a Bone Increased Off-Set (BIO-RSA) construct. The mean follow-up period was 61 months (range 54-87). Significant improvements (p < 0.001) were observed for the constant score and range of motion from the preoperative state to final follow-up. One case exhibited a significant varus deviation (> 5˚) during the follow-up period. No case of stem loosening was identified. There was only one case of complication because of post-traumatic dislocation, but the stem didn't need revision. CONCLUSION: Short stem RSA, even in patients older than 70 years, can yield a stable fixation with a good clinical and radiological outcome at short-medium term follow-up. LEVEL OF EVIDENCE: Level III; Retrospective Study.

Do all short stem types restore biomechanical parameters of the hip? Comparison according to femoral neck osteotomy levels.

PURPOSE: There is no consensus on ideal short femoral stem design. A classification system proposed by Feyen and Shimmin divides short stems in two types according to femoral neck osteotomy levels: subcapital (IIIA) and standard (IIIB). The study aims to determine which design type is more successful in restoring native biomechanical parameters and whether stem type has an impact on clinical results. METHODS: In this retrospective comparative study, patients that have undergone short stem hip arthroplasty were evaluated according to stem types: type IIIA (n = 52, 66.7%) (Mathys Optimys) and IIIB (n = 26, 33.3%) (Implantcast Aida and Smith & Nephew SMF). Pelvis X-rays were assessed in terms of femoral neck length, horizontal and vertical hip centres of rotation, horizontal and vertical femoral offsets, abductor lever arm lengths, leg lengths, and stem-shaft angles. Improvement in Harris hip scores, differences between post-operative and pre-operative measurements, and stem-shaft angles were evaluated and compared between two groups. RESULTS: Mean femoral neck resection (8.27 ± 6.68 mm in IIIA and 15 ± 6.33 mm in IIIB) was significantly different between both groups (p < 0.001). Harris hip scores were increased at post-operative six months in both groups with no difference (84.4 ± 6.4 and 84.6 ± 5.5, p = 0.4). The absolute values of differences between pre-operative and post-operative horizontal centres of rotation (p = 0.63), vertical centers of rotation (p = 0.75), horizontal femoral offsets (p = 0.78), vertical femoral offsets (p = 0.83), abductor lever arm distances (p = 0.63), and leg length (p = 0.21) measurements were not different between both groups. Stem positions were both varus with no statistically significant difference between groups (p = 0.14). CONCLUSION: We found no difference regarding restoration of biomechanical parameters between short stem designs with different levels of neck osteotomy. Additionally, short stem can mostly result in varus component positioning regardless of the level of neck osteotomy.