Diaphyseal Stem Research Articles

Survival and complications at a minimum 5 years’ follow-up of the modular Mark-2 Extreme™ cementless femoral stem: Does the reduced modularity resolve the mechanical issues of the Mark-I stem?

IntroductionThe Extreme™ modular stem was developed for implant revision with metaphyseal-diaphyseal defect. Due to the high breakage rate, a new “reduced modularity” design has been introduced, but without reported results. We therefore conducted a retrospective assessment of (1) overall stem survival, (2) functional results, (3) osseointegration, and (4) the rate of complications, and notably of mechanical failure. HypothesisReduced modularity reduces the risk of revision surgery for mechanical failure. Material and methodsForty-five prostheses were implanted between January 2007 and December 2010 in 42 patients with severe bone defect (Paprosky≥III) or periprosthetic shaft fracture. Mean age was 69.6years (range: 44–91years). Minimum follow-up was 5years, for a mean 115.4months (range: 60–156months). The main study endpoint was femoral stem survival, counting all-cause explantation as event. Functional assessment comprised subjective rating of satisfaction, Postel Merle d’Aubigné (PMA) and Harris Hip scores, and Forgotten Joint Score (FJS). Whether the revision assembly was carried out in situ, in the patient's hip, or outside, on the operating table, was not known in 2 cases; in the other 43, assembly was in situ in 15 cases (35%) and on the operating table in 28 (65%). ResultsFive-year stem survival was 75.7% (95% CI: 61.9–89.5%), taking all causes of change together. Seventeen patients (45.9%) had complications, 13 (35.1%) requiring revision surgery, including 10 (27.0%) for stem replacement. Five patients (13.5%) had steam breakage at the junction between the metaphysis and the diaphyseal stem, 4 of which occurred within 2 years of implantation or of fixation of a periprosthetic fracture. Mean preoperative Harris score was 48.4 [IQR (25–75% interquartile range): 37–58] and PMA score 11.1 (IQR: 10–12), compared to respectively 74 (IQR: 67–89) and 13.6 (IQR: 12.5–16) at follow-up. Mean FJS at follow-up was 71.5 (IQR: 61–94.5). In the 15 in situ assemblies, there were 3 breakages (20%), compared to 2 (7.1%) in the 28 table assemblies (p=0.21). DiscussionThe stem breakage rate was high despite the reduced modularity, which concentrated all stress on a single junction but without reducing the risk of mechanical failure. Surgical technique was faulty in some cases, with in situ assembly of the metaphysis after implanting the diaphyseal stem, which does not respect the manufacturer's recommendations. Level of evidenceIV; retrospective study.

Hip Arthroplasty Femoral Stem Designs and Their Association With Early Postoperative Periprosthetic Femoral Fractures

BackgroundPeriprosthetic femoral fractures (PFFs) in total hip arthroplasty (THA), especially those in contact with the diaphyseal stem, carry high morbidity. This study evaluated how stem design influences the risk of early Vancouver B PFF or other PFF requiring operative intervention after THA. MethodsA multicenter, retrospective study of 3,433 primary cementless THAs performed from 2014 to 2021 included 2,302 single-taper (micro M/L [n = 1,169]; M/L [n = 1,133]) and 1,131 double-taper (fit-and-fill [n = 420]; compaction-collared [n = 711]) stems. Mean follow-up was 2.2 years (range, 0.3 to 6.5 years). Primary outcomes were Vancouver B and surgically treated postoperative PFFs among differing femoral stems. Secondary outcomes included rates of intraoperative and postoperative Vancouver A and C PFFs. ResultsForty five postoperative PFFs (1.3%) occurred within 8.8 weeks (median), 25 of which were Vancouver B (0.7%) and 20 total PFFs that required operative intervention (0.6%). Compaction-collared stems had a decreased risk of Vancouver B (hazard ratio 0.18, 95% confidence interval: 0.03-0.97 P = .044) and any surgically treated PFF (hazard ratio 0.10, 95% confidence interval: 0.01-0.95; P = .037). Intraoperative PFFs were most common with fit-and-fill stems (3.6%, P < .001) and Vancouver A with compaction-collared stems (1.8%, P < .001). The cohort with PFF had a higher Charlson comorbidity index (P = .004), more women (P = .001), more Dorr A or C femora (P = .013), and more posterior or lateral surgical approaches compared to those without PFF (P ≤ .001). ConclusionAfter controlling for confounding variables, compaction-collared stems had a significantly lower risk of postoperative Vancouver B and PFF requiring operative treatment than single-taper and double-taper stems.

Long-Term Results (Minimum of 20 Years) of a Pure Proximal-Loading Metaphyseal-Fitting Anatomic Cementless Stem Without Distal Stem Fixation in Hip Arthroplasty

BackgroundThere are no reported results for more than 20 years of a pure proximal-loading anatomic cementless femoral stem without diaphyseal stem fixation. The purpose of this study was to evaluate the long-term (minimum 20 years) clinical results, bone remodeling, revision rate, and survivorship of these implants in patients aged less than 60 years. MethodsWe included 523 patients (657 hips), including 319 men and 204 women. The mean body mass index was 26.7 (range, 23-29 kg/m2). The mean age of patients at index surgery was 55 years (range, 20-59 years). The Harris Hip Score, the Western Ontario and McMaster Universities Osteoarthritis Index, and the University of California, Los Angeles activity score were recorded preoperatively and at each follow-up. Mean follow-up was 23.5 years (range, 20-27 years). ResultsThe Harris Hip Score at the final follow-up was a mean 93 points (range, 70-100 points). The Western Ontario and McMaster Universities Osteoarthritis Index and University of California, Los Angeles activity scores at the final follow-up were 16 and 7.6 points, respectively. Five femoral components (0.8%) and 13 acetabular components (2.0%) were revised. All cases in the current series had grade 2 stress shielding; no hips had grade 3 or 4 stress shielding. Kaplan-Meier survivorship of the implants at 23.5 years was 98.0% (95% confidence interval 92%-100%) for the acetabular component and 99.2% (95% confidence interval 93%-100%) for the femoral component. ConclusionA pure proximal-loading metaphyseal-fitting anatomic cementless stem with alumina-on-alumina ceramic bearing couples functioned well, with no osteolysis or mild stress-shielding at an average 23.5-year follow-up.

Total hip arthroplasty in hereditary multiple exostosis patients: literature review and evaluation of 10 cases.

Acquired hip deformities in patients affected by hereditary multiple exostosis (HME) may incur in early hip osteoarthritis and functional limitation requiring primary total hip arthroplasty (THA). Characteristic coxo-femoral joint dysmorphisms in HME may pose a challenge for the orthopaedic surgeon. Here we report our experience in a series of patients with HME treated in our hospital with THA. With a mean follow-up of 5 years, 10 primary THAs were reviewed; proximal femur deformities, acetabular dysplasia and joint osteoarthritis has been assessed through x-rays and CT-scan evaluation. In all cases hemispheric press-fit cups were used; 4 stem had metaphyseal engagement, 5 had proximal diaphyseal engagement and 1, with anatomical geometry, had metaphyseal fixation. 2 cases required stem cementation, 3 modular neck and 1 lateralised. The clinical data, complications and clinical outcomes, were recorded and analysed. The mean Harris Hip Score (HHS) increased from 34 preoperative to 86 postoperative; preoperative mean neck shaft angle (NSA) was 150°, head/neck ratio 0.6, offset 31 mm; Wiberg angle 28°, Sharp angle 38°, 1 patient had subluxation grade 4 according to Crowe, 8 hips showed osteoarthritis (Tönnis grade ⩾2 ); 5 femurs were classified as Dorr type C, 2 as type B and 3 as type A. Perioperative complications were not observed. Primary THA in HME significantly improved clinical and functional outcomes. Press-fit cup fixation together with metaphyseal and proximal diaphyseal stem engagement on reliable bone quality femur, represents a valid option in HME patients with normal acetabular morphology, wide broaden neck and valgus NSA.

Metaphyseal Stem Tip Location is a Risk Factor for Aseptic Loosening of Cemented Distal Femoral Replacements

BackgroundThe objective of this study was to describe the incidence of aseptic loosening (AL) of cemented stem distal femoral replacements (DFR) and to identify modifiable risk factors for its development. MethodsA retrospective review was performed of 245 consecutive primary, cemented stem DFRs implanted at a single institution over a 40-year period. The primary outcome was revision surgery for AL. A multivariate analysis was performed to identify risk factors for AL. Radiographs were reviewed to identify stem tip location, which was defined as diaphyseal or metaphyseal. Implant survival to AL was compared using Kaplan-Meier analysis. ResultsAL and structural failure were the most common causes of implant failure (incidence 11.8%, 29/245). Younger age (P = .002), male sex (P = .01), longer resection length (P = .04), and nonmodular implants (P = .002) were all significantly associated with AL. After 1:1 matching, stem tip location in metaphyseal bone was independently associated with AL (P = .04). 36% (9/25) of implants that loosened had a stem tip located in the metaphysis vs only 8% (2/25) of implants that did not fail. 30-year survival to AL was lower for implants with a metaphyseal stem tip than implants with a diaphyseal stem tip (22.7% vs 47.6%; P = .11). ConclusionA stem tip location in metaphyseal bone is associated with diminished survival to AL. When templating before DFR, stem tip location can assist in identifying high-risk reconstructions that may benefit from alternative or supplemental fixation techniques to prevent the development of AL.

Outcome of a metaphyseal reverse total shoulder replacement in rheumatoid arthritis.

To assess the clinical and radiological results of a metaphyseal reverse total shoulder arthroplasty (rTSA) without diaphyseal stem, in rheumatoid arthritis (RA) patients. Forty-five shoulders in 36 consecutive RA patients (2005-2015) underwent rTSA with a bone impaction technique. Patients were assessed clinically and radiographically preoperatively, at 3weeks, 3months, 6months, 12months post-operatively, and yearly thereafter, using constant score (CS), pain score, subjective shoulder value (SSV) and patient satisfaction score. Forty-four shoulders with mean follow-up of 67months (range 24m-146m (12y)) were available for follow-up. Mean age at surgery was 68.7years (range 39-86). CS improved from 17.5 ± 10.5(SD) (age/sex adjusted 23.9 ± 14.5(SD)) preoperatively to 60.9 ± 17.4 (SD) (age/sex adjusted 86.5 ± 24.5 (SD)) at last follow-up (P < 0.001). Pain score and SSV also significantly improved (p < 0.001). Mean range of movement improved to 140°active forwardflexion, 134°active abduction, 47°active external rotation (AER) and 70°active internal rotation (AIR). The results were maintained over time. Combined early and late complication rate was 15.6%, whichislower than described in the literature for RA. No lucencies, loosening, subsidence or stress shielding were evident radiographically. Metaphyseal rTSA without a diaphyseal stem issuccessful and safe in RA patients. Patients achievegood function and have high satisfaction rates. Case series: Level IV.

The use of cement in revision total knee arthroplasty

Despite the availability of modern implants and techniques, Revision Total Knee Arthroplasty (R-TKA) still poses a challenge to surgeons, particularly the management of bone loss/defects and the secure fixation of implants. Polymethylmethacrylate (PMMA) bone cement plays an important role for fixation as fully uncemented fixation in RTKA is rarely used. Cement can be employed as part of a full cementing construct or as a hybrid construct. While in fully cemented implants, the diaphyseal stem as well as any couplers or connectors in the metaphysis are cemented, in hybrid cementing, only the component parts at the joint surface and metaphysis are cemented, while the diaphyseal stem is fixed in a press-fit manner. In this article the literature on the in vitro as well on the in vivo results of both fixation options is reviewed.Although the fixation mechanism of both constructs are different, radiographic and clinical survivorship appear similar for both techniques. Although there appears to be a trend towards a hybrid fixation method, the choice of which technique to employ in revision total knee arthroplasty will depend on the surgeons' familiarity with each technique as well as the factors peculiar to each patients anatomy.

Survivorship of constrained polyethylene inserts in primary total knee replacements

BackgroundVarus–valgus constrained (VVC) inserts are used in primary total knee arthroplasty (TKA) when stability cannot be achieved with a traditional insert. Concern has been raised regarding premature loosening and failure of these primary TKAs due to the increased load transfer through the prosthesis. This study seeks to assess the survival, clinical outcomes and radiographic assessment of VVC total knee inserts used in a single primary TKA system without diaphyseal stem extensions. MethodsA consecutive cohort of 74 primary TKAs with VVC inserts was identified from an institutional database. A two-to-one matched group of 136 posterior-stabilized (PS) primary TKAs was generated from the same database. Survival analysis was assessed for all-cause revision surgery. Patient outcome measures were the Oxford Knee Score (OKS) and patient reported satisfaction. Radiographs were assessed in accordance with the Knee Society radiographic scoring system for radiolucency. ResultsSurvival rates at three and five years were 98.1% and 95.1% for the VVC liner group and 98.1% and 98.1% for the PS liner group, respectively. OKS improved from pre-op to post-op for both groups (p < .001). OKS was reduced in the VVC liner group compared to the PS liner group at latest available follow-up (p = .012). However, clinical satisfaction rates did not differ between the two groups. Small, non-progressive radiolucent lines existed on several radiographs; however, no components in either group were deemed radiographically loose. ConclusionThe survivorship, clinical, and radiographic outcomes of VVC knees were similar to the PS comparison group at short- to mid-term follow-up.

An Ultra-Short Femoral Neck-Preserving Hip Prosthesis: A 2-Year Follow-up Study with Radiostereometric Analysis and Dual X-Ray Absorptiometry in a Stepwise Introduction.

Total hip arthroplasty (THA) with a diaphyseal stem may risk bone loss. In order to save proximal bone stock in young patients with a high activity level and a long life expectancy, the interest in short stems has evolved. The purpose of this prospective observational cohort study was to evaluate the fixation of, and bone remodeling around, the Primoris femoral neck-preserving hip implant. Fifty younger patients with end-stage osteoarthritis were managed with the Primoris hip implant. We evaluated bone mineral density (BMD) using dual x-ray absorptiometry (DXA) and implant migration using radiostereometric analysis (RSA). A region-of-interest (ROI) protocol for 4 ROIs was applied to assess BMD. The association between BMD and migration was evaluated to determine the fixation of the Primoris implant and bone remodeling in the proximal part of the femur. Follow-up evaluation was performed at regular intervals from day 1 (baseline) until 24 months after surgery. The major stem migrations were subsidence (Y axis; mean, 0.38 mm) at 6 weeks and varus tilt (rotation) (Z axis; mean, 0.93°) at 6 to 12 months. In ROI4 (the calcar area), a significant gain in bone was found with a mean difference of 4.1% (95% confidence interval [CI], 0.8% to 7.4%; p < 0.02) at 24 months postoperatively. Significant bone loss was found in ROI1 and ROI2, with a mean difference of -4.9% (95% CI, -7.4% to -2.4%; p = 0.0003) and -8.9% (95% CI, -11.5% to -6.2%; p = 0.0001), respectively. Linear regression and multivariate regression analysis showed a significant negative association between maximal total point motion and BMD (p = 0.02, R = 15%; and p < 0.05, R = 26%, respectively). The Primoris component showed satisfactory primary stability with promising results at the 24-month follow-up. DXA scans showed limited stress-shielding with the proximal loading pattern of the Primoris. Better bone quality was associated with less implant migration. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Reverse shoulder arthroplasty with a cementless short metaphyseal humeral prosthesis without a stem: survivorship, early to mid-termclinical and radiological outcomes in a prospective study from an independent centre.

The use of reverse total shoulder arthroplasty has increased for the management of cuff-deficient glenohumeral joint arthritis and fractures. With bone preservation being a major target in reverse shoulder arthroplasty, metaphyseal humeral components without a stem were developed. The aim of this study is to present the survivorship, functional and radiological outcomes of a novel short metaphyseal prosthesis without a diaphyseal stem from an independent centre. Clinical function and radiological features of patients undergoing stemless reverse shoulder arthroplasty were prospectively recorded. Patients' demographics, indications for surgery, complications, functional and radiological assessment at the final follow-up as well as survivorship with the end point of revision for any reason were recorded. Between 2009 and 2016, 36 patients received 37 reverse shoulder arthroplasties with the stemless Verso prosthesis. Mean age of the patients was 76.9years. The most common indication for surgery was cuff tear arthropathy. Mean follow-up was 3years (range 1-7years). Oxford shoulder score improved from an average of 11 pre-operatively (range 2-19) to 44 post-operatively (range 29-48) (p < 0.0001). There was one case of a deep post-operative infection that needed washout, liner exchange with retention of the prosthesis. Radiographic analysis showed no lucencies, or stress shielding around the humeral or glenoid components. Constant score at the final follow-up was on average 63 (range 35-86). Activities of daily living with requirement for internal and external rotation score (ADLEIR) was on average 12 pre-operatively (range 0-27) and 31 post-operatively (range 18-36) (p < 0.0001). There was 100% survivorship of the prosthesis in this early to mid-term study. This early to mid-term prospective study demonstrates excellent survivorship and radiological results of the Versoreverse shoulder replacement. It needs a simple reproducible technique, and the results have been replicated at an independent centre. This study underlines its survivorship in the early to mid-term and confirms lower incidence of complications such as instability, notching, loosening and the need for revision surgery. Most importantly, it conserves the humeral bone stock for revision arthroplasties in the future. Our results are similar to those of the currently published literature.

Early Clinical and Radiological Outcomes of the Metaphyseally Fixed Totally Stabilized Knee Prosthesis in Primary Total Knee Arthroplasty.

The use of valgus-varus constrained (VVC) implant designs in primary total knee arthroplasty (TKA) is considered in situations of severe deformities, bone loss, and inadequate soft tissue balance. It is not known whether the use of such prosthesis designs may predispose to reduced function owing to its constraining design. The components are usually implanted with diaphyseal stem extensions to dissipate the increased forces. The totally stabilized (TS) implant is a contemporary VVC design with metaphyseal fixation only. It has a conforming articulation with increased rotational freedom compared with conventional VVC designs. The aim of this study was to assess whether the use of the contemporary TS implant with its metaphyseally fixed components would be associated with inferior outcomes compared with conventional standard primary posterior stabilized (PS) implants. We reviewed 38 consecutive complex primary TKAs performed using the metaphyseally fixed TS implant and 76 matched patients receiving primary PS TKA, at a minimum follow-up of 24 months. The mean follow-up was 61.1 months (24-102). Only patients with osteoarthritis were included. Clinical outcome was assessed using range of motion (ROM) and Oxford knee score (OKS). Radiographic assessment was performed using the femorotibial angle (FTA) at 6 weeks followed by assessment of bone-implant interface lucencies at final follow-up. There were no major early postoperative complications. The mean postoperative ROM in the TS and PS groups were 114.1 and 112.0, respectively. There was no difference in the mean ROM and OKS between the two groups. The mean FTA for patients in both groups was within 3° of the expected. There was no evidence of progressive lucencies or implant migration at final follow-up. The metaphyseally fixed TS knee design achieves comparable short-term functional outcomes when compared with conventional PS designs in primary knee arthroplasty. Long-term follow-up studies are required to assess survivorship.

Stemless reverse shoulder arthroplasty: indications, technique and European experience

Reverse shoulder prostheses are increasingly used in recent years for treatment of glenohumeral arthropathy with deficient rotator cuff such as: rotator cuff arthropathy, rheumatoid arthritis, proximal humeral fractures sequela, irreparable rotator cuff tears, and failed shoulder replacement. Good mid-term and long-term results with restoration of active elevation have been reported. However, early studies showed relatively high rates of complications (24–50%) and many of them require further surgery. Most of the current designs of rTSA are with a humeral diaphyseal stem. A significant part of the reported intra-operative and postoperative complications, as well as difficulties arising during revision surgery, are related to the diaphyseal humeral component. Therefore, preservation of bone stock has become a major goal. Metaphyseal cementless implants without a diaphyseal stem have been developed to preserve bone and resect only minimal amount of bone. In 2005 the first stemless reverse TSAs were introduced for clinical use in Europe, with the Verso shoulder [Innovative Design Orthopaedics, London, UK (formerly Biomet, UK)] in UK and the TESS reverse shoulder (Biomet, France) in France. This review examines the European experience with stemless metaphyseal reverse TSAs, the history, the design rationale, the indications and the clinical and radiological outcome. The European experience with stemless metaphyseal reverse TSAs now spans over 13 years, with results that are at least equal with the stemmed implants. Specific design biomechanical considerations will be discussed.

Influence of varying stem and metaphyseal sleeve size on the primary stability of cementless revision tibial trays used to reconstruct AORI IIA defects. A simulation study.

Traditionally, diaphyseal stems have been utilized to augment the stability of revision total knee replacement (rTKR) implants. More recently metaphyseal augments, such as sleeves, have been introduced to further augment component fixation. The effect of augments such as stems and sleeves have on the primary stability of a rTKR implant is poorly understood, however it has important implications on the complexity, costs and survivorship of the procedure. Finite element analysis was used to investigate the primary stability and strain distribution of various size stems and sleeves used in conjunction with a cementless revision tibial tray. The model was built from computer tomography images of a single healthy tibia obtained from an 81-year-old patient to which an Anderson Orthopaedic Research Institute (AORI) IIA defect was virtually added. The influences of varying body mass index (BMI) and bone modulus were also investigated. Stemless sleeves were found to provided adequate primary implant stability (average implant micro-motion <50 μm) for the studied defect. Addition of a stem did not enhance the primary stability. Furthermore, this study found that varying BMI and bone modulus had a considerable effect on strain distribution but negligible effect on micro-motion in the sleeve area. In conclusion, the addition of diaphyseal stem to a metaphyseal sleeve had little benefit in enhancing the primary stability of tibial trays augmented when simulating reconstructions of AORI IIA tibial defects. Additional studies are required to determine the relative benefit of the diaphyseal stem when using metaphyseal sleeves defects with more extensive bone loss. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1876-1886, 2018.

Ultra-Short Versus Conventional Uncemented Stems for Hip Replacement in Octogenarians.

The aim of this study was to determine how an ultra-short anatomic uncemented stem vs a diaphyseal filling five-eighths porous coated uncemented femoral stem (conventional stem) affects the survival of primary total hip arthroplasties in octogenarians. The current study consisted of 52 patients (55 hips) in the ultra-short stem group (mean age, 85.5±5.3 years) and 61 patients (72 hips) in the diaphyseal (conventional) stem group (mean age, 84.1±4.8 years). The predominant diagnosis was osteoarthritis, followed by osteonecrosis of the femoral head, in both groups. Average follow-up was 6.1 years (range, 5-8 years) in the ultra-short stem group and 6.3 years (range, 5-9 years) in the conventional stem group. Pre- (41 vs 39 points) and postoperative (85 vs 86 points) Harris hip scores were similar between groups (P=.131 and .129, respectively). The incidence of thigh pain was 0% (0 of 52 patients) in the ultra-short stem group and 15% (9 of 61 patients) in the conventional stem group. The revision rate was 1.8% (1 hip) in the ultra-short stem group and 1.4% (1 hip) in the conventional stem group. Survivorship of the femoral stem was 98.2% in the ultra-short stem group at 6.1 years and 98.6% in the conventional stem group at 6.3 years. Ultra-short anatomic and diaphyseal filling uncemented stems obtained osseointegration in all hips. However, the prevalence of thigh pain and periprosthetic fracture were significantly higher in the patients with a conventional stem than in those with an ultra-short stem. [Orthopedics. 2018; 41(1):28-34.].

Short-Term Results of Ultra-Short Anatomic vs Ultra-Short Non-Anatomic Proximal Loading Uncemented Femoral Stems

BackgroundQuestion arises as to whether rigid fixation of ultra-short anatomic or ultra-short non-anatomic proximal loading uncemented femoral stem can be obtained without diaphyseal stem fixation. The purpose of this study is to compare the short-term clinical results, radiographic results, revision and survival rates, and complication rates of ultra-short anatomic versus ultra-short non-anatomic uncemented femoral stems. MethodsThis study consisted of 50 patients (56 hips) in the ultra-short anatomic uncemented stem group (mean age 61.4 ± 14.7 years) and 50 patients (56 hips) in the ultra-short non-anatomic uncemented stem group (mean age 59.5 ± 15.2 years). The mean follow-up was 3.4 years (range 3-4) in the ultra-short anatomic stem group and 3.5 years (range 3-4) in the ultra-short non-anatomic stem group. ResultsAt the final follow-up, the mean Harris hip scores (92 vs 93 points), Western Ontario and McMaster Universities Osteoarthritis scores (16 vs 15 points), University of California at Los Angeles activity scores (6.5 vs 6.8 points), the incidence of thigh pain (0% vs 4%), revision rates (0% vs 4%), aseptic loosening rate (0% vs 2%), and complication rates (2% vs 4%) were not significantly different between 2 groups. ConclusionBoth ultra-short anatomic and ultra-short non-anatomic proximal loading uncemented femoral stems obtained rigid fixation without diaphyseal stem fixation in the short-term follow-up. This finding suggests that an ultra-short anatomic uncemented femoral stem can be replaced with an ultra-short non-anatomic uncemented stem to reduce inventory of the femoral stems, and consequently reduce manufacturing and delivery cost of these femoral stems.

Tibial Tubercle Osteotomy to Aid Exposure for Revision Total Knee Arthroplasty.

A tibial tubercle osteotomy can provide reliable and safe exposure during revision total knee arthroplasty with a high union rate, low complication rate, and predictable outcomes. Determine the need for an extensile approach on the basis of the preoperative knee range of motion; position of the patella; bone quality; medical comorbidities; and cement mantle, tibial keel or stem, and thickness of the anterior tibial cortex. Create full-thickness subcutaneous flaps and perform a medial parapatellar arthrotomy with complete synovectomy and careful excision of scar tissue from the medial and lateral gutters. Extend the skin and subcutaneous dissection distal to the tibial tubercle and mark the chevron osteotomy using electrocautery. Perform the osseous cut for the tibial tubercle osteotomy with a thin saw blade in a medial-to-lateral direction, such that the fragment hinges on the lateral soft tissue and musculature. With the knee maximally flexed and lateral subluxation of the extensor mechanism, for full visualization of the femoral and tibial components, remove the components and perform the knee revision. The final tibial component should have a diaphyseal stem long enough to bypass the distal extent of the tibial tubercle osteotomy by at least 2 cortical diameters. When cementing the final tibial component, take care to remove cement anterior to the tibial stem that would otherwise impede complete reduction of the osteotomy fragment and interfere with osseous union at the osteotomy site. Manually position the osteotomized bone fragment over the tibia and obtain an anatomic reduction either freehand or using bone clamps, depending on the soft-tissue tension. Obtain rigid fixation with a 6.5-mm screw proximally and 2 sets of doubled-over 18-gauge wires distally. Stress the osteotomy site by flexing the knee 90°, deflate the tourniquet, place a drain if needed, and close. Allow weight-bearing as tolerated and a 0° to 90° range of motion in a hinged knee brace. Tibial tubercle osteotomy to aid in exposure during revision total knee arthroplasty has been reported to yield favorable outcomes in the orthopaedic literature7-18.

Reverse shoulder arthroplasty with a cementless short metaphyseal humeral implant without a stem: clinical and radiologic outcomes in prospective 2- to 7-year follow-up study

Reverse shoulder prostheses are increasingly used in recent years for treatment of glenohumeral arthropathy with deficient rotator cuff. Bone preservation is becoming a major goal in shoulder replacement surgery. Metaphyseal humeral components without a stem were developed to minimize bone resection and preserve bone. This study evaluated the clinical and radiologic outcomes at 2 to 7 years using a novel short metaphyseal reverse total shoulder arthroplasty (rTSA) prosthesis without a diaphyseal stem. Between 2005 and 2010, 102 consecutive patients underwent rTSA with this implant, and 98 (20 men, 78 women) were available for follow-up. Mean age was 74.4 years (range, 38-93 years). Indications were cuff tear arthropathy, 65; fracture sequelae, 12; rheumatoid arthritis, 13; failed rotator cuff repair, 3; cuff deficiency with loosening of anatomic prosthesis, 3; and acute trauma, 2; with 17 of these as revisions. Patients' satisfaction (Subjective Shoulder Value) improved from 8 of 100 to 85 of 100. The Constant score improved from 14 to 59 (age- and sex-adjusted, 86; P < .0001). Range of motion improved from 47° to 129° in elevation, 10° to 51° in external rotation, and 21° to 65° in internal rotation. Radiographic analysis showed no lucencies, subsidence, or stress shielding around the humeral or glenoid components. Glenoid notching was found in 21 patients (18 grade 1-2; 3 grade 3). The short metaphyseal rTSA design without a diaphyseal stem shows encouraging short- to midterm results, with excellent pain relief and shoulder function, restoration of good active range of motion, and high patient satisfaction scores. The design of this implant seems to result in improved rotational movements, low incidence of glenoid notching, and no implant loosening, subsidence, or stress shielding.

CORR Insights(®): Are Complications Associated With the Repiphysis(®) Expandable Distal Femoral Prosthesis Acceptable for Its Continued Use?

CORR Insights(®): Are Complications Associated With the Repiphysis(®) Expandable Distal Femoral Prosthesis Acceptable for Its Continued Use?

Impaction grafting in the femur in cementless modular revision total hip arthroplasty: a descriptive outcome analysis of 243 cases with the MRP-TITAN revision implant

BackgroundWe present a descriptive and retrospective analysis of revision total hip arthroplasties (THA) using the MRP-TITAN stem (Peter Brehm, Weisendorf, GER) with distal diaphyseal fixation and metaphyseal defect augmentation. Our hypothesis was that the metaphyseal defect augmentation (Impaction Bone Grafting) improves the stem survival.MethodsWe retrospectively analyzed the aggregated and anonymized data of 243 femoral stem revisions. 68 patients with 70 implants (28.8%) received an allograft augmentation for metaphyseal defects; 165 patients with 173 implants (71.2%) did not, and served as controls. The mean follow-up was 4.4 ± 1.8 years (range, 2.1–9.6 years). There were no significant differences (p > 0.05) between the study and control group regarding age, body mass index (BMI), femoral defects (types I-III as described by Paprosky), and preoperative Harris Hip Score (HHS). Postoperative clinical function was evaluated using the HHS. Postoperative radiologic examination evaluated implant stability, axial implant migration, signs of implant loosening, periprosthetic radiolucencies, as well as bone regeneration and resorption.ResultsThere were comparable rates of intraoperative and postoperative complications in the study and control groups (p > 0.05). Clinical function, expressed as the increase in the postoperative HHS over the preoperative score, showed significantly greater improvement in the group with Impaction Bone Grafting (35.6 ± 14.3 vs. 30.8 ± 15.8; p ≤ 0.05). The study group showed better outcome especially for larger defects (types II C and III as described by Paprosky) and stem diameters ≥ 17 mm. The two groups did not show significant differences in the rate of aseptic loosening (1.4% vs. 2.9%) and the rate of revisions (8.6% vs. 11%). The Kaplan-Meier survival for the MRP-TITAN stem in both groups together was 93.8% after 8.8 years. [Study group 95.7% after 8.54 years ; control group 93.1% after 8.7 years]. Radiologic evaluation showed no significant change in axial implant migration (4.3% vs. 9.3%; p = 0.19) but a significant reduction in proximal stress shielding (5.7% vs. 17.9%; p < 0.05) in the study group. Periprosthetic radiolucencies were detected in 5.7% of the study group and in 9.8% of the control group (p = 0.30). Radiolucencies in the proximal zones 1 and 7 according to Gruen occurred significantly more often in the control group without allograft augmentation (p ≤ 0.05).ConclusionWe present the largest analysis of the impaction grafting technique in combination with cementless distal diaphyseal stem fixation published so far. Our data provides initial evidence of improved bone regeneration after graft augmentation of metaphyseal bone defects. The data suggests that proximal metaphyseal graft augmentation is beneficial for large metaphyseal bone defects (Paprosky types IIC and III) and stem diameters of 17 mm and above. Due to the limitations of a retrospective and descriptive study the level of evidence remains low and prospective trials should be conducted.

5-year clinical and radiostereometric analysis (RSA) follow-up of 39 CUT femoral neck total hip prostheses in young osteoarthritis patients

Background As the number of young patients receiving total hip arthroplasty increases, bone-saving implantations facilitating possible future revision, such as the CUT femoral neck prosthesis, are gaining importance. There have been few medium-term results reported for this prosthesis, however, and its migration pattern has not been analyzed.Patients and methods 39 consecutive CUT femoral neck prostheses were implanted in 32 patients, mean age 37 (17–58) years, with symptomatic osteoarthritis and either less than 55 years of age or with an anatomic anomaly preventing implantation of a diaphyseal stem (n = 1). Patients were followed prospectively using routine clinical examination and radiostereometric analysis (RSA) at 6, 12, 26, and 52 weeks postoperatively and annually thereafter. This study evaluated the 5-year follow-up results.Results The mean Harris hip score increased from 26 (3–51) points preoperatively to 84 (66–98), 86 (55–98), and 87 (47–98) points at 3, 12, and 60 months. 3 stems were revised: 1 after luxation following excessive subsidence due to an undersized component and 2 due to persistent strong thigh pain. 5-year survival was 95% (95% CI: 87–100). Initial migration varied widely in magnitude; median total tip migration was 0.42 mm (0.09–9.4) at 6 weeks, 0.92 mm (0.18–5.9) at 1 year, and 1.10 mm (0.13–6.4) at 5 years. Even after high initial migration, stabilization was achieved in 31 of the 35 RSA-evaluable implants. 3 prostheses showed progressive continuous migration throughout the entire follow-up period, and were considered to be loose, suggesting reduced long-term survival.Interpretation Currently, we cannot recommend the CUT femoral neck prosthesis as a routine treatment option in (young) patients requiring THA. The CUT prosthesis may not reach the 90% survival benchmark at 10 years, and the prosthesis is difficult to implant. If initial stabilization is achieved, however, aseptic loosening is unlikely. A good clinical outcome was seen in the surviving prostheses. We will continue to follow this patient group.