Uncemented Stem Fixation Research Articles

Gait pattern in patients treated with a total hip arthroplasty due to an acute displaced cervical neck fracture: a randomised comparison between 29 cases with a cemented femoral stem and 16 cases with an uncemented femoral stem.

The choice between cemented or uncemented stem fixation in the treatment of a femoral neck fracture may influence patient rehabilitation and the resulting gait pattern, due to potential differences in implant positioning and fixation. We used gait analysis to study temporal gait parameters, hip kinematics and kinetics in patients who, 2 years previously, had been randomised to treatment with a cemented or uncemented stem and due to an acute femoral neck fracture. 45 Patients implanted with a cemented Lubinus SP II (n = 29) and an uncemented (n = 16) Corail stem were studied. Gait analysis was performed using a 16-camera motion capture system and force plates. 28 subjects served as controls. Temporal gait parameters, hip kinematics and kinetics were analysed. The patients had no or minimum pain (median Harris pain score 44, range 40-44) and the majority had no limp (median Harris limp score 11, range 5-11). Temporospatial gait parameters and abduction-adduction motions and moments did not differ between patients with cemented or uncemented stems (p > 0.05). Patients with cemented stems did, however, show more hip flexion and less extension during walking than those with an uncemented stem (p < 0.05). Moreover, the flexion-extension range was less in the cemented group (p < 0.04). Compared with controls, the hip fracture patients walked more slowly, with a shorter stride length and a longer stance phase. Increased hip flexion and reduced extension in patients using the Lubinus SP II cemented stem could be an effect of its anteverted neck, but this question requires further study. Despite acute treatment with THA, hip fracture patients demonstrated a change in gait pattern compared with controls 2 years after the operation. This suggests that these changes are caused by the presence of an implant, or the soft-tissue trauma partly caused by the surgery than by any degenerative disease present in patients undergoing elective surgery.ClinicalTrials.gov Identifier: NCT04791605.

Outcomes of Reverse Total Shoulder Arthroplasty for Proximal Humerus Fracture Using Uncemented Stems, a Single Center Study.

BackgroundTo evaluate the clinical, functional, radiographic, and survival outcomes in patients undergoing reverse total shoulder arthroplasty (RSA) with uncemented stem fixation for proximal humerus fractures.Materials and MethodsThis is a retrospective cohort study that evaluated a consecutive series of patients with proximal humerus fractures undergoing RSA. Clinical data, radiographs, and re-operation rates were reviewed in patients selected for uncemented stem fixation. The same parameters were compared to the remainder of the cohort undergoing cemented stem fixation.ResultsThe uncemented group (n = 16, median total follow-up = 108 weeks) and cemented group (n = 12, median total follow-up = 223 weeks, p = 0.110) did not differ statistically in pre-operative demographic, post-operative outcomes or incidence of complications. Two patients (12.5%) in the uncemented group required a reoperation (Week 52 and 180) versus none in the cemented group.ConclusionUncemented stem fixation in RSA for proximal humerus fractures does not yield worse results than cemented stem fixation in properly selected patients. Prospective non-inferiority trials comparing outcomes are recommended.

Interlocking reconstruction-mode stem-sideplates preserve at-risk hips with short residual proximal femora.

We have evaluated the survivorship, outcomes, and failures of an interlocking, reconstruction-mode stem-sideplate implant used to preserve the native hip joint and achieve proximal fixation when there is little residual femur during large endoprosthetic reconstruction of the distal femur. A total of 14 patients underwent primary or revision reconstruction of a large femoral defect with a short remaining proximal femur using an interlocking, reconstruction-mode stem-sideplate for fixation after oncological distal femoral and diaphyseal resections. The implant was attached to a standard endoprosthetic reconstruction system. The implant was attached to a standard endoprosthetic reconstruction system. None of the femoral revisions were amenable to standard cemented or uncemented stem fixation. Patient and disease characteristics, surgical history, final ambulatory status, and Musculoskeletal Tumor Society (MSTS) score were recorded. The percentage of proximal femur remaining was calculated from follow-up radiographs. All 14 at-risk native hip joints were preserved at a mean final follow-up of 6.0 years (SD 3.7), despite a short residual femur, often after proximal osteotomies through the lesser trochanter. Overall, 13 of 14 stems had long-term successful fixation. Eight patients required no reoperation. Three patients required reoperation due to implant-related issues, and three patients required reoperation for wound healing problems or infection. There were no dislocations or fractures. At final follow-up the mean MSTS score was 24.9 (SD 4.1). Nine patients required no ambulation aids, and only one had a Trendelenburg gait. This interlocking, reconstruction-mode stem-sideplate reliably preserves native hip joint anatomy and function after large femoral resection with a short remaining proximal femur, both in the primary and revision setting. This is particularly important for preventing or delaying total femoral arthroplasty in young patients after oncological reconstruction. Hip abductor strength and function could be maintained by this method, and the risk of dislocation eliminated. The success of this technique in this modest series should be verified in a larger collaborative study and will be of interest to revision surgeons and oncologists. Cite this article: Bone Joint J 2021;103-B(2):398-404.

Contemporary Mortality Rate and Outcomes in Nonagenarians Undergoing Primary Total Hip Arthroplasty

BackgroundNonagenarians (90-99 years) have experienced the fastest percent growth in primary THA utilization recently. However, there are limited data on this population. This study aimed to determine the mortality rate, implant survivorship, clinical outcomes, and complications of primary THAs in nonagenarians. MethodsOur institutional total joint registry was used to identify 144 nonagenarians who underwent 149 primary THAs for osteoarthritis only between 1997 and 2017. The mean age was 92 years, with 63% being female. Mortality, revision, and reoperation were assessed using cumulative incidence with death as a competing risk and Cox regression methods. Clinical outcomes were assessed using Harris hip scores (HHSs). Cemented femoral components were used in 68%. The mean follow-up was 4 years. ResultsThe mortality rates were 6%, 8%, 14%, and 49% at 90 days, 1 year, 2 years, and 5 years, respectively. The 5-year cumulative incidences of any revision and reoperation were 1% and 4%, respectively. The mean HHS improved significantly from 48 preoperatively to 76 at 5 years (P < .001). The 5-year cumulative incidence of any complication was 69%, with the most common being periprosthetic femur fracture (7) intraoperatively, delirium (25) early postoperatively, and periprosthetic femur fracture (10) later postoperatively. Uncemented stem fixation was associated with a higher risk for intraoperative femur fracture (Hazard ratio 5, P = .04) but not with a higher 5-year periprosthetic postoperative femur fracture risk (P = .19). ConclusionNonagenarians undergoing primary THA had substantial mortality rates at 90 days (6%) and 1 year (8%). While the cumulative incidence of any revision and reoperations were low at 5 years, the high complication rate is mostly due to periprosthetic fractures. Level of evidenceLevel IV, retrospective cohort.

A higher degree of polyethylene irradiation is associated with a reduced risk of revision for aseptic loosening in total hip arthroplasties using cemented acetabular components: an analysis of 290,770 cases from the National Joint Registry of England, Wales, Northern Island and the Isle of Man.

AimsTo investigate the effect of polyethylene manufacturing characteristics and irradiation dose on the survival of cemented and reverse hybrid total hip arthroplasties (THAs).MethodsIn this registry study, data from the National Joint Registry of England, Wales, Northern Ireland and the Isle of Man (NJR) were linked with manufacturing data supplied by manufacturers. The primary endpoint was revision of any component. Cox proportional hazard regression was a primary analytic approach adjusting for competing risk of death, patient characteristics, head composition, and stem fixation.ResultsA total of 290,770 primary THAs were successfully linked with manufacturing characteristics. Overall 4,708 revisions were analyzed, 1,260 of which were due to aseptic loosening. Total radiation dose was identified as a risk factor and included in the Cox model. For statistical modelling of aseptic loosening, THAs were grouped into three categories: G1 (no radiation); G2 ( > 0 to < 5 Mrad); and G3 ( ≥ 5 Mrad). G1 had the worst survivorship. The Cox regression hazard ratio for revision due to aseptic loosening for G2 was 0.7 (95% confidence interval (CI) 0.58 to 0.83), and for G3 0.4 (95% CI 0.30 to 0.53). Male sex and uncemented stem fixation were associated with higher risk of revision and ceramic heads with lower risk.ConclusionPolyethylene irradiation was associated with reduced risk of revision for aseptic loosening. Radiation doses of ≥ 5 Mrad were associated with a further reduction in risk.Cite this article: Bone Joint Res 2020;9(9):563–571.

Uncemented megaprosthesis stem fixation using “Scratch Fit” to achieve improved implant fixation

Background: Despite a proposed lower incidence of aseptic loosening, uncemented distal femoral implants present challenges with the intra-operative assessment of the adequacy of stem fixation within the femoral canal. Our biomechanical study was intended to assess the adequacy of oncologic implant press-fit stem fixation within the reamed canal of the distal femur for the Stryker GMRS oncologic distal femoral implant. We hoped to answer the following: #1 Does the initial stem placement in the femoral canal using a standardized force (50 N) (i.e., “Scratch Fit”) predict the (adequacy)stability of the final stem placement (and implant fixation) within the femoral canal? #2 Is there a difference in the uncemented stem fixation and stability within the femur for different stem (Stryker GMRS) diameters (13, 14, and 15 mm) for the Stryker GMRS uncemented press-fit stems/(Stryker Global Orthopaedics) Methods: Femoral cadaveric specimens were thawed and cut at the distal end of the femur, at 13 cm from the distal joint line, to e represent a distal femoral tumor resection. Stryker GMRS uncemented stems were placed, after femoral reaming, into the distal femoral canal with firm, hand pressure applied via a customized, spring-based insertion tool positioned over the standard Stryker insertion tool and calibrated to apply a standard stem insertion force of 50 N (11.2 lbs). Initial stem placement, utilizing this method, resulted in a stem that was only partially implanted into the femur with a recorded distance (defined as “Scratch Fit”) between the stem collar and the cut surface of the femoral shaft. After completing final stem impaction into the femur, stem torsional testing was performed on a multi-axis biomechanical test frame with a 3-D Vicon motion-capture system with axial torsion applied to the stems with the proximal femur fixed to a potted base. Kinematics of both the implant and the distal femur were captured using the Vicon system which tracked reflective infrared targets at a 60 Hz sampling rate. The peak torsional moment at failure was compared to “Scratch Fit” metrics for each implant diameter to address the proposed research questions. Results: Scratch fit distances ranged from 7–46 mm with a mean of 29.1±12.7 mm. Peak torques ranged from 11.5 to 57.5 Nm with a mean of 33.6±17.0 Nm. Figure shows peak (max.) torque plotted against scratch fit for all stems/specimens with good correlation (r 2 =0.6404). When separated by stem diameters, figure shows strong correlations between peak torque and scratch fit. Conclusions: while there may be multiple metrics that affect uncemented stem implant placement and stability (i.e., femoral canal size, femoral reaming, and implant type/size (diameter), there appears to be some correlation between initial stem placement (i.e., “Scratch Fit”) after femoral reaming to implant torsional (rotational) stability; this correlation is stronger when controlled for stem diameter. This suggests that a greater initial “Scratch Fit” distance may provide improved press-fit stem fixation and may provide a better operative standard for making decisions regarding the fixation or stability of these implants.

Hemiarthroplasty and total hip arthroplasty in 30,830 patients with hip fractures: data from the Dutch Arthroplasty Register on revision and risk factors for revision

Background and purpose — In the Netherlands about 40% of hip fractures are treated with a hemiarthroplasty (HA) or a total hip arthroplasty (THA). Although these procedures are claimed to have fewer complications than osteosynthesis (i.e., reoperation), complications still occur. Analyses of data from national registries with adequate completeness of revision surgery are important to establish guidelines to diminish the risk for revision. We identified risk factors for revision.Patients and methods — All patients older than 50 years of age with a hip fracture treated with arthroplasty by orthopedic surgeons and registered in the (national) Dutch arthroplasty register (LROI) were included in the study. In this register, patient characteristics and surgical details were prospectively collected. Revision surgery and reasons for revision were evaluated. A proportional hazard ratio model for revision was created using competing risk analysis (with death as competing risk).Results — 1-year revision rate of HA was (cumulative incidence function [CIF] 1.6% (95% CI 1.4–1.8) and THA 2.4% (CI 2.0–2.7). Dislocation was the most common reason for revision in both groups (HA 29%, THA 41%). Male sex, age under 80 years, posterolateral approach, and uncemented stem fixation were risk factors for revision in both THA and HA. THA patients with ASA classification III/IV were revised more often, whereas revision in the HA cohort was performed more often in ASA I/II patients.Interpretation — After arthroplasty of hip fractures, both a posterolateral approach and an uncemented hip stem have higher risks for revision surgery compared with an anterolateral approach and an cemented stem.

Satisfactory Results of the Exeter Revision Femoral Stem Used for Primary Total Hip Arthroplasty

BackgroundThe Exeter cemented femoral stem has demonstrated excellent clinical and radiographic outcomes as well as long-term survivorship free from aseptic loosening. A shorter revision stem (125 mm) with a 44 offset became available for the purpose of cement-in-cement revision situations. In certain cases, this shorter revision stem may be used for various primary total hip arthroplasties (THAs) where the standard length stem would require distally reaming the femoral canal. We sought to report on the early to midterm results of this specific stem when used for primary THA regarding (1) clinical and radiographic outcomes, (2) complications, and (3) survivorship. MethodsTwenty-nine patients (33 hips) underwent a hybrid THA using the smaller revision Exeter cemented femoral stem. Twenty-five patients (28 hips) had at least 2 years of follow-up and were assessed for clinical and radiographic outcomes. All 33 hips were included in the analysis of complications and survivorship. The Kaplan-Meier survivorship was performed using revision for all causes and for aseptic loosening as the end points. ResultsThe average clinical follow-up was 4 years (range, 2-7). Harris Hip Scores improved from a mean preoperative value of 56 (range, 23-96) to 90 (range, 51-100) at the latest follow-up. All patients demonstrated superior cement mantles with no signs of loosening. One patient suffered a B2 periprosthetic fracture and 1 patient experienced 2 episodes of instability. The 5-year Kaplan-Meier survivorship was 96.7% for all causes of revision and was 100% using aseptic loosening as the end point. ConclusionThe shorter Exeter revision cemented femoral stem has favorable early to midterm clinical and radiographic outcomes when used for primary THA with a low complication rate and is a viable option in patients with narrow femoral canals where uncemented stem fixation is not desired.

Early periprosthetic bone remodelling around cemented and uncemented custom-made femoral components and their uncemented acetabular cups

Periprosthetic bone remodelling after total hip replacement may contribute to aseptic loosening of the prosthesis. The selection between cemented and uncemented fixation of the stem is mainly determined by patient's age, general constitution and CT scan-estimated bone quality; intra-operative observation may ultimately influence the choice of the fixation method. The influence of cemented versus uncemented stem fixation on periprosthetic bone remodelling around the uncemented cup has, to our knowledge, never been studied until now. A total of 75 patients received intra-operatively manufactured stem prostheses and a standard hydroxy apatite-coated pinnacle cup. The pre-operative CT scans provides guidance for the bone quality and hence the type of stem fixation: cemented or uncemented. The influence of either type of stem fixation on periprosthetic bone remodelling around the cup and the stem was measured by bone mineral density at 6 weeks, and 3, 6 and 12 months after surgery. Early changes in bone mineral density were noted. The type of stem fixation had an influence on the bone remodelling of the femur and also of the pelvis. The caudal part of the acetabulum was subject to a greater loss in BMD at 12 months in the group with cemented stem fixation. Changes at 12 months correlated with the changes measured at any time point. The selection of the stem implant and its type of fixation in the femoral cavity (cemented or uncemented fixation) seems to have an impact on the bone mineral density of the acetabulum. Long-term clinical follow-up is required to draw conclusions regarding the influence on prosthesis survival.

Algorithm for the Surgical Treatment of Malignant Lesions of the Proximal Tibia

Complications are common among patients treated for malignant lesions of the proximal tibia and can be difficult to manage. This investigation was a retrospective review of 40 patients treated with total knee replacements after proximal tibial resections. Various reconstructive methods were used to fix the prosthetic stems, reestablish the extensor mechanism, and provide soft tissue coverage. Thirty-one patients had adequate followup to allow for review of prosthetic outcome (means, 78 months; range, 25-193 months). Seven patients died with less than 2 years followup, and two patients had postoperative acute infections treated by early amputation to allow chemotherapy to resume promptly. The overall 5-, 8-, and 12-year event free prostheses survival rates were 62%, 33%, and 16%, respectively. Prognostic factors for prosthetic survival were analyzed (age, gender, type of excision, type of prosthesis, type of fixation, and percent of bone resected). None were statistically significant. Patients with less than 40% of the tibia resected had better prosthetic survival at 5 years. The durability of uncemented stem fixation exceeded that of cemented stems. Expected survival of prostheses after revision was 52% at 8 years. The major cause of limb loss was infection. Failure to reconstruct soft tissues satisfactorily caused most failures. Aggressive multistage management of infection is needed. Prosthetic knee replacement is most suitable for patients with cancers that require chemotherapy and for those patients who have short potential survival.

Host—bone response to porous-coated cobalt—chrome and hydroxyapatite-coated titanium femoral components in hip arthroplasty: Dual-energy X-ray Absorptiometry Analysis of Paired Bilateral Cases at 5 to 7 Years

Uncemented porous-coated cobalt—chrome femoral stems have produced satisfactory short-term clinical results, although slightly inferior to the results of cemented total hip arthroplasty. Proximal femoral bone resorption, osteolysis, and fibrous ingrowth have been reported with porous-coated stems. Hydroxyapatite-coated stems and titanium stems have been introduced to avoid these findings through improved fixation. Dual-energy x-ray absorptiometry allows quantitative examination of bone density changes after uncemented total hip arthroplasty. This study examines the host—bone response to hydroxyapatite-coated titanium and porous-coated cobalt—chrome stems of identical geometry in three paired bilateral cases at 5 to 7 years. Distinctly different patterns of femoral bone mineral density changes were observed with the two stem designs. The authors conclude that dual-energy x-ray absorptiometry is a promising technique allowing noninvasive analysis of uncemented stem fixation, and that the data from this study suggest improved fixation and stress transfer with hydroxyapatite-coated titanium stems.