Mid-term outcomes of pyrolytic carbon humeral resurfacing hemiarthroplasty compared with metal humeral resurfacing and metal stemmed hemiarthroplasty for osteoarthritis in young patients: analysis from the Australian Orthopaedic Association National Joint Replacement Registry.

BACKGROUND: The optimal surgical management of glenohumeral osteoarthritis in young patients remains an unsolved problem. Humeral resurfacing hemiarthroplasty and stemmed hemiarthroplasty using metallic heads are 2 surgical options that avoid the complications of loosening or wear of the glenoid component seen in total shoulder arthroplasty. Despite the potential benefits, improvement in survivorship has not been demonstrated from joint registry studies or other studies at mid-term follow-up. This is predominantly because of glenoid erosion and pain that occur when the metal resurfaced head articulates with the native glenoid. The use of pyrolytic carbon (pyrocarbon) as a resurfacing material has been proposed as an alternative bearing surface thought to reduce glenoid erosion owing to a marked reduction in wear rates in vitro. This study aimed to compare the survivorship of shoulder hemi-resurfacing using pyrocarbon with shoulder hemi-resurfacing and stemmed hemiarthroplasty using metallic heads. METHODS: Data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR) were analyzed for all patients aged <55 years who had undergone a primary shoulder replacement for osteoarthritis from April 16, 2004, to December 31, 2019. The outcomes of shoulder procedures using pyrocarbon hemi-resurfacing were compared with procedures using metal hemi-resurfacing and metal stemmed hemiarthroplasty. The reasons for revision in each arthroplasty class were analyzed. The analyses were undertaken using Kaplan-Meier estimates of survivorship and hazard ratios (HRs) from Cox proportional hazards models. RESULTS: We analyzed 393 primary shoulder procedures, of which 163 were pyrocarbon hemi-resurfacing procedures, 163 were metal hemi-resurfacing procedures, and 67 were metal stemmed hemiarthroplasties.The cumulative percentage of revision at 6 years was 8.9% for pyrocarbon hemi-resurfacing, 17.1% for metal hemi-resurfacing, and 17.5% for metal stemmed hemiarthroplasty. Pyrocarbon hemi-resurfacing prostheses had a statistically lower revision rate than other hemi-resurfacing prostheses (HR, 0.41; 95% confidence interval, 0.18-0.93; P = .032). Pain, prosthesis fracture, and infection were the key reasons for revision. No pyrocarbon hemi-resurfacing cases were revised for glenoid erosion. In male patients, pyrocarbon humeral resurfacing had a lower cumulative percentage of revision compared with metal stemmed hemiarthroplasty (HR, 0.32; 95% confidence interval, 0.11-0.93; P = .037). CONCLUSION: Pyrocarbon humeral resurfacing arthroplasty had statistically lower revision rates at mid-term follow-up in patients aged <55 years compared with other hemi-resurfacing procedures.

Acetabular complications are the most common cause for revision surgery following proximal femoral endoprosthetic replacement : what is the best bearing option in the primary and revision setting?

AIMS: Proximal femoral endoprosthetic replacements (PFEPRs) are the most common reconstruction option for osseous defects following primary and metastatic tumour resection. This study aimed to compare the rate of implant failure between PFEPRs with monopolar and bipolar hemiarthroplasties and acetabular arthroplasties, and determine the optimum articulation for revision PFEPRs. METHODS: This is a retrospective review of 233 patients who underwent PFEPR. The mean age was 54.7 years (SD 18.2), and 99 (42.5%) were male. There were 90 patients with primary bone tumours (38.6%), 122 with metastatic bone disease (52.4%), and 21 with haematological malignancy (9.0%). A total of 128 patients had monopolar (54.9%), 74 had bipolar hemiarthroplasty heads (31.8%), and 31 underwent acetabular arthroplasty (13.3%). RESULTS: At a mean 74.4 months follow-up, the overall revision rate was 15.0%. Primary malignancy (p < 0.001) and age < 50 years (p < 0.001) were risk factors for revision. The risks of death and implant failure were similar in patients with primary disease (p = 0.872), but the risk of death was significantly greater for patients who had metastatic bone disease (p < 0.001). Acetabular-related implant failures comprised 74.3% of revisions; however, no difference between hemiarthroplasty or arthroplasty groups (p = 0.209), or between monopolar or bipolar hemiarthroplasties (p = 0.307), was observed. There was greater radiological wear in patients with longer follow-up and primary bone malignancy. Re-revision rates following a revision PFEPR was 34.3%, with dual-mobility bearings having the lowest rate of instability and re-revision (15.4%). CONCLUSION: Hemiarthroplasty and arthroplasty PFEPRs carry the same risk of revision in the medium term, and is primarily due to acetabular complications. There is no difference in revision rates or erosion between monopolar and bipolar hemiarthroplasties. The main causes of failure were acetabular wear in the hemiarthroplasty group and instability in the arthroplasty group. These risks should be balanced and patient prognosis considered when contemplating the bearing choice. Dual-mobility, constrained bearings, or large diameter heads (> 32 mm) are recommended in all revision PFEPRs. Cite this article: Bone Joint J 2021;103-B(10):1633-1640.

Early outcomes after robotic arm-assisted bi-unicompartmental knee arthroplasty compared with total knee arthroplasty: a prospective, randomized controlled trial.

AIMS: The aim of this study was to compare the clinical outcomes of robotic arm-assisted bi-unicompartmental knee arthroplasty (bi-UKA) with conventional mechanically aligned total knee arthroplasty (TKA) during the first six weeks and at one year postoperatively. METHODS: A per protocol analysis of 76 patients, 43 of whom underwent TKA and 34 of whom underwent bi-UKA, was performed from a prospective, single-centre, randomized controlled trial. Diaries kept by the patients recorded pain, function, and the use of analgesics daily throughout the first week and weekly between the second and sixth weeks. Patient-reported outcome measures (PROMs) were compared preoperatively, and at three months and one year postoperatively. Data were also compared longitudinally and a subgroup analysis was conducted, stratified by preoperative PROM status. RESULTS: Both operations were shown to offer comparable outcomes, with no significant differences between the groups across all timepoints and outcome measures. Both groups also had similarly low rates of complications. Subgroup analysis for preoperative psychological state, activity levels, and BMI showed no difference in outcomes between the two groups. CONCLUSION: Robotic arm-assisted, cruciate-sparing bi-UKA offered similar early clinical outcomes and rates of complications to a mechanically aligned TKA, both in the immediate postoperative period and up to one year following surgery. Further work is required to identify which patients with osteoarthritis of the knee will derive benefit from a cruciate-sparing bi-UKA. Cite this article: Bone Joint J 2021;103-B(10):1561-1570.

The effect of tibial and femoral component coronal alignment on clinical outcomes and survivorship in unicompartmental knee arthroplasty.

AIMS: This study aimed to identify the tibial component and femoral component coronal angles (TCCAs and FCCAs), which concomitantly are associated with the best outcomes and survivorship in a cohort of fixed-bearing, cemented, medial unicompartmental knee arthroplasties (UKAs). We also investigated the potential two-way interactions between the TCCA and FCCA. METHODS: Prospectively collected registry data involving 264 UKAs from a single institution were analyzed. The TCCAs and FCCAs were measured on postoperative radiographs and absolute angles were analyzed. Clinical assessment at six months, two years, and ten years was undertaken using the Knee Society Knee score (KSKS) and Knee Society Function score (KSFS), the Oxford Knee Score (OKS), the 36-Item Short-Form Health Survey questionnaire (SF-36), and range of motion (ROM). Fulfilment of expectations and satisfaction was also recorded. Implant survivorship was reviewed at a mean follow-up of 14 years (12 to 16). Multivariate regression models included covariates, TCCA, FCCA, and two-way interactions between them. Partial residual graphs were generated to identify angles associated with the best outcomes. Kaplan-Meier analysis was used to compare implant survivorship between groups. RESULTS: Significant two-way interaction effects between TCCA and FCCA were identified. Adjusted for each other and their interaction, a TCCA of between 2° and 4° and a FCCA of between 0° and 2° were found to be associated with the greatest improvements in knee scores and the probability of fulfilling expectations and satisfaction at ten years. Patients in the optimal group whose TCCA and FCCA were between 2° and 4°, and 0° and 2°, respectively, had a significant survival benefit at 15 years compared with the non-optimal group (optimal: survival = 100% vs non-optimal: survival = 92%, 95% confidence interval (CI) 88% to 96%). CONCLUSION: Significant two-way interactions between the TCCA and FCCA demonstrate the importance of evaluating the alignment of the components concomitantly in future studies. By doing so, we found that patients who concomitantly had both a TCCA of between 2° and 4° and a FCCA of between 0° and 2° had the best patient-reported outcome measures at ten years and better survivorship at 15 years. Cite this article: Bone Joint J 2021;103-B(2):338-346.

Metaphyseal vs. diaphyseal fixed-stem hemiarthroplasty in treating unstable intertrochanteric fractures in elderly patients.

BACKGROUND: Various surgical techniques have been defined for hip hemiarthroplasty (HA), including metaphyseal vs. diaphyseal and short stem vs. long stem. The present study aims to compare outcomes of metaphyseal fixed short-stem vs. diaphyseal fixed long-stem HA in treating unstable intertrochanteric fractures in elderly patients. METHODS: This study was conducted retrospectively and included 129 patients ≥65 years of age, having unstable intertrochanteric fractures and undergoing HA. Outcome measures were the 2-year Harris hip score and the mobility score of Parker and Palmer; comorbidities as well as mortality rates of the groups were compared. RESULTS: Mean operation time and median full weight-bearing time were significantly shorter in group B (p<0.05 for both). As for the Harris hip scores, group B showed better outcomes for the third-month evaluation (p=0.006). However, 2-year assessments were similar (p=0.067). In addition, higher Parker and Palmer mobility scores were obtained in group B at the 2-year assessment (p<0.001). The frequencies of prosthetic dislocation, cortical porosis and subsidence were higher in group A (p<0.05 for all). CONCLUSION: The findings obtained in this study suggest that diaphyseal fixed long-stem HA seems to be superior to the metaphyseal fixed short-stem HA because the former is related to better functional scores, earlier mobilization, and lower complication rates.

The Role of Stem Modularity in the Failure of Internal Fixation in Geriatric Patients With Distally Fixed Hemiarthroplasty.

The aim of this study was to compare the radiological and clinical outcomes of the same make of modular and monoblock tapered fluted stems in patients with failure of internal fixation following osteoporotic intertrochanteric fracture. This retrospective, comparative study included patients older than 65 years who underwent hemiarthroplasty with a modular or monoblock distally fixed fluted stem and had failed treatment with proximal femoral nailing between 2012 and 2017, with at least a 2-year follow-up period. Radiographic and clinical evaluations of the groups were compared. The modular group comprised 22 males and 18 females with a mean age of 85.05±7.1 years, and the monoblock group comprised 27 males and 17 females with a mean age of 83.27±7.0 years. No significant difference was observed between the groups regarding the preoperative and final-visit Harris Hip Score and Parker and Palmer Mobility Score values (P>.05 for both). More patients showed osseous restoration in the monoblock group, but not to a significant level. The groups were similar regarding mortality rates. Stem length was greater in the modular group, but the proximal femoral part and stem size were similar in the groups (P<.05 for all). Canal filling at levels A, B, and C was negatively correlated (weak) with the proximal femoral bone restoration (P<.001 for all). Canal filling at level B was negatively correlated (weak) with the stress shielding of the femur (P<.05 for all). When comparing the modularity of the stem by minimizing the variations of both prostheses, such as brand and geometric design, there was no significant difference in either clinical or radiological evaluations. [Orthopedics. 2021;44(1):e119-e124.].

Hemiarthroplasty for Femoral Neck Fractures in the Elderly: A Comparison of Cemented and Uncemented Femoral Stems.

The incidence of displaced femoral neck fractures among elderly patients is increasing as the population ages.Historically, the preferred treatment for displaced femoral neck fractures in elderly patients has been hemiarthroplasty with use of cemented fixation of the implant. However, there is evidence that this technique may be associated with fat embolization and subsequent cardiopulmonary arrest in the early postoperative period. Cementing techniques are also associated with increased operative time when compared with cementless techniques.There is increasing evidence that, among elderly patients, the use of uncemented hemiarthroplasty has equivalent functional outcomes and overall mortality rates when compared with the use of hemiarthroplasty with cemented fixation. The main complication associated with uncemented hemiarthroplasty is intraoperative periprosthetic fracture.

Constrained or unconstrained shoulder replacement for musculoskeletal tumor resections?

BACKGROUND: Many options exist for reconstructing the shoulder after large bony resections of the proximal humerus. One of the more widely used is endoprosthetic replacement. Proximal migration of unconstrained hemiarthroplasty articulations may cause difficulties particularly in the setting of loss of the rotator cuff and/or deltoid musculature. To attempt to overcome these issues, a fixed-fulcrum constrained reverse shoulder replacement option may be considered. METHODS: A retrospective review of prospectively collected data from the Queensland Bone and Soft Tissue Sarcoma Service was undertaken to compare the function, implant survivorship, and reoperation rate of constrained reverse and unconstrained hemiarthroplasty-type endoprostheses in patients with tumors. RESULTS: We retrospectively reviewed data on 41 consecutive proximal or total humeral endoprosthetic replacements undertaken between January 2003 and July 2018. One patient was excluded as lost to follow-up prior to 24 months. There were 21 unconstrained implants and 19 constrained shoulder replacements (Stanmore Modular Endoprosthesis Tumour System with Bayley-Walker articulation). Proximal migration of the unconstrained hemiarthroplasty articulation occurred in 8 patients (38%), and dislocation or failure of the constrained mechanism occurred in 5 (26%). Reoperation for implant-related issues was required in 5 patients in the constrained group and none in the unconstrained group. Of the 18 patients alive at the time of review, 12 provided functional scores. The mean follow-up period for surviving patients was 4.2 years (standard deviation, 2.7 years), with a minimum of 2 years' follow-up. Functional scores were similar between the 2 groups. CONCLUSION: Constrained reverse prostheses were associated with a higher reoperation rate in this series without any functional benefit compared with unconstrained hemiarthroplasty-type articulations. We favor the use of unconstrained hemiarthroplasty-type endoprostheses for reconstruction after resection of destructive lesions of the proximal humerus.

Cemented versus uncemented hemiarthroplasty for displaced femoral neck fractures: A randomized controlled trial with two years follow-up.

OBJECTIVE: The aim of this prospective randomized trial was to compare cemented (CHA) and uncemented bipolar hemiarthroplasty (UCH) in patients with femoral neck fractures (FNF). METHODS: The study included 158 patients aged ≥76 years who underwent bipolar HA for displaced FNF. Patients were randomized in two groups: the cemented group (CHA, n=79) was treated with cement and the uncemented group (UCH, n=79) without cement. The groups were compared for operating time, blood loss and peroperative morbidity and mortality rates. RESULTS: Both the CHA and the UCH group did not differ significantly in terms of age (86±5 vs. 84±4 years), sex (58.3% male vs. 60.7% female), and comorbidities (p=0.49). The CHA group had a significantly longer operating time (p=0.038) and a greater intraoperative blood loss (p=0.024). In the CHA group there were 8 (10.1%) events of intraoperative drop in the oxygen saturation (SaO2), whereas no such events were noted in the UCH group (p=0.009). Despite no significant difference between these two groups, we found that the CHA group was associated with a higher early postoperative mortality (8.8% in the CHA group versus 3.8% in the UCH group, p=0.009). Intraoperative fracture occurred in two patients (2.5%) of the UCH group. Over a 2-year follow-up period there were no significant differences between the groups regarding the rate of dislocation (p=0.56) or rate of postoperative periprosthetic fracture (p=0.56). There was a trend towards a better postoperative functional recovery at 6 week for the CHA group (77.1±13.1 versus 71.3±16.3), although the mean Harris Hip Score (HHS) at the end of 2 years was comparable (p=0.55). CONCLUSION: Both CHA and UCH are acceptable methods for treating displaced femoral neck fractures. However, based on our results perioperative cardiovascular disturbances are less frequent and resulting in a potential lower early mortality with UCH. Therefore, UCH is particularly appropriate for elderly patients with pre-existing cardiovascular comorbidities. LEVEL OF EVIDENCE: Level II, Randomized Controlled Trial.

Timing of hip hemiarthroplasty and the influence on prosthetic joint infection.

INTRODUCTION: Previous research suggested that patients have increased risk of infection with increased time from presentation with a femoral neck fracture to treatment with a hip hemiarthroplasty (HHA). The purpose of this study was to determine if rates of prosthetic joint infections within 3 months of surgery was affected by the time from patient presentation with a femoral neck fracture to the time of treatment with HHA. MATERIALS AND METHODS: Acute hip fractures treated with HHA between 2005 and 2017 at three centres in Norway were enrolled in the study. Multi-trauma patients were excluded. Univariable analysis was performed to determine any significant effect of pre-operative waiting time on infection rate. Two pre-planned analyses dichotomizing pre-operative waiting time cut-offs were performed. RESULTS: There were 2300 patients with an average age of 82 (range, 48-100) years included of which 3.4% experienced a prosthetic joint infection within 3 months. The primary analysis found no significant difference in infection rate depending on time to surgery (OR = 1.06 (95% CI 0.94-1.20, p = 0.33)). The secondary analyses showed no significant differences in infection rates when comparing pre-operative waiting time of <24 hours vs ≥24 hours (OR = 0.92 (95% CI 0.58-1.46, p = 0.73)) and <48 hours vs ≥48 hours (OR = 1.39 (95% CI 0.81-2.38, p = 0.23)). CONCLUSION: Based off of a large retrospective Norwegian database of hip fractures there did not appear to be a significant difference in infection rate based on pre-operative wait time to surgery.

Radiological subsidence and acetabular erosion after tapered uncemented hemiarthroplasty in femoral neck fractures a 10- to 13- year follow-up study.

BACKGROUND: Contemporary uncemented hemiarthroplasties are being used after displaced femoral neck fractures, however, their functional and radiological results remain controversial. The aim of this study was to evaluate the clinical and radiological results of a tapered uncemented stem combined with a uni- or bipolar hemiarthroplasty after a minimum follow-up of ten years. PATIENTS AND METHODS: 135 patients underwent uncemented hip hemiarthroplasty after a displaced femoral neck fracture between 2004 and 2007. Their mean age was 81.5 years old (range, 70 to 90). 38 patients were evaluated with a minimum follow-up of ten years. We analysed the complications and the postoperative clinical result according to the Merle D´Aubigné and Postel scale. Radiological femoral type according to Dorr et al., femoral canal filling and the appearance of stem loosening, subsidence and acetabular erosion according to Baker et al., were also assessed. RESULTS: There were two early periprosthetic femoral fractures. The mean clinical score was 15.8 (range, 9 to 17). Six hips were converted to a total hip arthroplasty due to acetabular erosion, and three stems were revised due to an infection, a late periprosthetic fracture and one aseptic loosening. The survival rate for any cause was 85.4% (Confidence interval (CI) 76 - 92.4%). The survival rate for revision surgery on the acetabular side at 10 years was 92.6% (CI 85 - 100%) and on the femoral side was 97.6% (CI 94.4 - 100%). 14 hips showed non-progressive radiological subsidence and 9 acetabular erosion. Stem subsidence was related to a femoral canal filling < 80% (p = 0.035) and acetabular erosion to a cylindrical femur (p = 0.024). CONCLUSION: Bone fixation can be obtained with a contemporary uncemented stem in hemiarthroplasty for patients over 70 years old with a femoral neck fracture. Acetabular erosion was frequent after ten years, however, the rate of revision surgery was low.

Hemiarthroplasty implants should have very low stiffness to optimize cartilage contact stress.

Hemiarthroplasty is often preferred to total arthroplasty as it preserves native tissue; however, accelerated wear of the opposing cartilage is problematic. This is thought to be caused by the stiffness mismatch between the implant and cartilage-bone construct. Reducing the stiffness of the implant by changing the material has been hypothesized as a potential solution. This study employs a finite element model to study a concave-convex hemiarthroplasty articulation for various implant materials (cobalt-chrome, pyrolytic carbon, polyether ether ketone, ultra-high-molecular-weight polyethylene, Bionate-55D, Bionate-75D, and Bionate-80A). The effect of the radius of curvature and the degree of flexion-extension was also investigated to ensure any relationships found between materials were generalizable. The implant material had a significant effect (P < .001) for both contact area and maximum contact pressure on the cartilage surface. All of the materials were different from the native state except for Bionate-80A at two of the different flexion angles. Bionate-80A and Bionate-75D, the materials with the lowest stiffnesses, were the closest to the native state for all flexion angles and radii of curvature. No evident difference between materials occurred unless the modulus was below that of Bionate-55D (288 MPa), suggesting that hemiarthroplasty materials need to be less stiff than this material if they are to protect the opposing cartilage. This is clinically significant as the findings suggest that the development of new hemiarthroplasty implants should use materials with stiffnesses much lower than currently available devices.

Hemiarthroplasties: the choice of prosthetic material causes different levels of damage in the articular cartilage.

BACKGROUND: Hemiarthroplasty has clear advantages over alternative procedures and is used in 20% of all shoulder joint replacements. Because of cartilage wear, the clinical outcome of hemiarthroplasty is unreliable and controversial. This paper suggests that the optimal choice of prosthetic material may reduce cartilage degeneration and improve the reliability of the procedure. The specific objectives were to assess 3 materials and assess how the severity of arthritis might affect the choice of prosthetic material. METHODS: A CoCr alloy, an AL2O3 ceramic, and a polycarbonate urethane polymer (PCU) were mechanically tested against 5 levels of human osteoarthritic cartilage (from intact to severely arthritic, n = 45). A high friction coefficient, a decrease in Young's modulus, an increase in permeability, a decrease in relaxation time, an increase in surface roughness, and a disrupted appearance of the cartilage after testing were used as measures of cartilage damage. The biomaterial that caused minimal cartilage damage was defined as superior. RESULTS: The CoCr caused the most damage. This was followed by the AL2O3 ceramic, whereas the PCU caused the least amount of damage. Although the degree of arthritis had an effect on the results, it did not change the trend that CoCr performed worst and PCU the best. DISCUSSION AND CONCLUSION: This study indicates that ceramic implants may be a better choice than metals, and the articulating surface should be as smooth as possible. Although our results indicate that the degree of arthritis should not affect the choice of prosthetic material, this suggestion needs to be further investigated.

Factors affecting dislocation after bipolar hemiarthroplasty in patients with femoral neck fracture.

PURPOSE: This study aimed to investigate the anatomic risk factors associated with dislocation following bipolar hemiarthroplasty for the treatment of femoral neck fracture. MATERIALS AND METHODS: We retrospectively reviewed 208 consecutive patients (133 women, 75 men) with femoral neck fractures who were treated with bipolar hemiarthroplasty between 2015 and 2018. A comparative analysis was performed between dislocation (n = 18) and non-dislocation (n = 190) groups in terms of patient demographics, surgical and pelvic morphologic factors, and clinical outcomes, including postoperative Harris and modified Harris hip scores. Independent risk factors affecting dislocation were also evaluated. RESULTS: The mean follow-up period was 30.8 ± 2.0 (range, 12-48) months. The mean age was 79.2 ± 7.4 (range, 71-94) years. The dislocation rate was 8.6% (18/208), and the mean dislocation time after operation was 2.0 ± 1.1 (range, 1-4) months. Patient-related factors did not differ between the dislocated and non-dislocated groups. As regards dislocation, statistically significant difference was observed in surgical and pelvic morphologic factors, including femoral offset, residual femoral neck length, trochanter upper end and femoral head center distance, and height of the hip center of the operated side (p = 0.025, p = 0.013, p = 0.002, p = 0.008, respectively). Moreover, the femoral offset, height of the hip center, and femoral neck-shaft angle of the non-operated side are significantly different between the groups (p = 0.007, p = 0.001, p = 0.027, respectively). Decrease in the center edge (CE) angle, offset of prosthesis, and increase in femoral head extrusion index (FHEI) of the operated side and decrease in the height of the hip center of the non-operated side increased the risk of dislocation (p = 0.030, OR: 1,306; p = 0.041, OR: 8.15; p = 0.020, OR: 1.038; p = 0.010, OR: 2.02, respectively). CONCLUSIONS: Pelvic morphologic features and surgical factors were found to affect dislocation. Patients with smaller OP, CE angle of the operated side, and higher FHEI and smaller height of the hip center of the non-operated side should be carefully monitored to decrease postoperative dislocation.

Undersizing the Exeter stem in hip hemiarthroplasty increases the risk of periprosthetic fracture.

INTRODUCTION: Whether under- or oversizing of the femoral component of cemented hip hemiarthroplasties impacts the risk of periprosthetic fractures (PPF) has only been examined experimentally. This study was carried out to add more knowledge about the risks of PPF in cemented polished tapered hemiarthroplasties. METHODS: 20 patients with PPF following hip hemiarthroplasty with cemented Exeter V40 stems were compared to 50 controls who never suffered PPF having received the same type of Exeter hemiprosthesis for the same indication. The difference between stem size and post-hoc radiographic ideal templated size was investigated as a predictor of PPF. RESULTS: Cases had a median size difference to post-hoc templating of -2, while controls had a median size difference of -1 (p = 0.09). An ROC curve constructed to find an optimal cutoff point in size difference between cases and controls arrived at an area under curve of 63%, with -1.5 as the cutoff. Patients with size differences exceeding -1.5 had a statistically significant increased PPF risk (odds ratio = 3.8, 95% confidence interval, 1.1-13.3, p < 0.05). This group covered 55% of all cases. CONCLUSION: An implanted femoral component that is 2 or more sizes smaller than the template that is shown to be appropriate will increase the risk of PPF in Exeter hip hemiarthroplasties.

Comparative analysis for five fixations of Pauwels-I by the biomechanical finite-element method.

Background: Little is known about how biomechanics govern the five fixtures such as DHS, MLS, DHS + LS, LP, and HA are accepted as common therapeutic techniques. Aims and objectives: A series of numerical models for a femoral neck fracture of Pauwels-I will be constructed by innovative approach of finite element in order to determine the most optimized option in comparison with biomechanical performance. Method: Twenty sets of computer tomography scanned femora were imported onto Mimics to extract 3 D models; these specimens were transferred to Geomagic-Studio for a simulative osteotomy and kyrtograph; then, they underwent UG to fit simulative solid models; 5 sorts of fixture were then expressed by Pro-Engineer virtually. After processing with HyperMesh, all compartments (fracture model + internal implant) were assembled onto 5 systems: "Dynamic Hip Screw (DHS), Multiple Lag screw (MLS), DHS + LS, femoral Locking Plate (LP) and HemiArthroplasty (HA)." Eventually, numerical models of the finite-elemental analysis were exported to AnSys to determine the solution. Result: Four models of fixation and a simulation of HA for Pauwels-I were established, validated, and analyzed with the following findings: In term of displacement, these 5 fixtures ranged between 0.3801 and 0.7536 mm have no significant difference; in term of stress, the averages of peaks for integral assemblage are b(MLS) = 43.5766 ≈< d(LP) = 43.6657 ≈< e(Ha) = 43.6657 < c(DHS + LS) = 66.5494 < a(DHS) = 105.617 in MPa indicate that MLS, LP and HA are not significantly different, but less than DHS + LS or DHS in each. Conclusion: A fixture of MLS or LP with optional HA should be recommended to clinically optimize a Pauwels-I facture.

Reconstruction with Custom Unicondylar Hemiarthroplasty following Tumor Resection: A Case Series and Review of the Literature.

For patients with tumors of the distal femur, options for limb salvage include tumor resection followed by reconstruction. While reconstruction commonly involves a distal femoral replacement, careful selection of patients with tumor involvement limited to a single condyle may be candidates for reconstruction with distal femur hemiarthroplasty. In these procedures, resection spares considerably more native anatomy. Three consecutive patients who underwent resection and reconstruction at the distal femur with custom unicondylar hemiarthroplasty are presented in this case series at a mean follow-up of 45 months (range, 26-78). In two cases, prostheses were utilized as a secondary procedure after failure of initial reconstruction. In one case, the custom prosthesis was utilized as the primary method of reconstruction. Mean Musculoskeletal Tumor Society disease-specific scores were 26.7 (range, 25-28). All patients achieved a return to full weight bearing, activities of daily living, and functional range of motion. In appropriately selected patients with tumors of the distal femur, reconstruction with custom unicondylar hemiarthroplasty provides benefits including optimal function postoperatively via preservation of tumor-free bone and ligamentous structures. Additionally, maintenance of greater bone stock may confer benefits to patients with pathology at a high likelihood for recurrence and need for subsequent procedures.

The optimal approach in hip hemiarthroplasty: a cohort of 1009 patients.

BACKGROUND: A hip hemiarthroplasty is the treatment of choice for a displaced femoral neck fracture in elderly patients not eligible for total hip arthroplasty. There is continuing debate about the optimal surgical approach for this operation, with the most commonly used approaches being posterior and lateral. OBJECTIVE: To compare the outcomes of the posterior and the lateral approaches in patients with a displaced femoral neck fracture treated by hemiarthroplasty. METHOD: A retrospective study was carried out in two high-volume teaching hospitals in the Netherlands. Electronic patient records were searched for patient characteristics, the operative approach and adverse outcomes. RESULTS: A total of 1009 patients with a median age of 86 years were included. The posterior approach was used in 51.1% of patients. There were no differences in surgical site infection and periprosthetic fracture rates. There was a trend towards more dislocations in the posterior approach (2.9% vs. 1.4% with an OR of 2.1, 95% CI 0.8-5.1). An uncemented hemiprosthesis was used in 62.7% of patients. Deep surgical site infections and periprosthetic fractures occurred more often in the uncemented group (OR 2.9 and 7.4, respectively). CONCLUSION: No differences in adverse outcomes between both approaches could be shown. This study did confirm the relatively high incidence of post-operative complications in uncemented prostheses. Therefore, the cemented prosthesis should be the treatment of choice, with the approach dependent on surgeon preference and experience.

The effects of cement fixation on survival in elderly patients with hip hemiarthroplasty: a nationwide cohort study.

BACKGROUND: Hip hemiarthroplasty (HHA) is a common treatment for hip fractures in the elderly population. Because of the fatal effects of bone cement implantation syndrome, the safety of cement utilization to enhance implant firmness in the femur is controversial. The aim of this study was to investigate the postoperative survival of elderly patients receiving HHA with and without cement fixation. METHODS: Claim data from the National Health Insurance Database and the National Register of Deaths Database were used for analysis in this retrospective cohort study. From 2008 to 2014, 25,862 patients aged 80 years or older treated with hip hemiarthroplasty were included in the analysis. A Cox proportional risk model was used to analyse the effects of cement utilization on postoperative mortality. RESULTS: The cemented group had a significantly higher mortality risk than the non-cemented group within 7, 30, 180 days and 1 year after the operation. The effect of bone cement on postoperative mortality was significantly stronger within 7 days than within 30, 180 days and 1 year. In addition, the male gender, age > 85 years and higher score on the Charlson Comorbidity Index were also risk factors for mortality (p < 0.05). Patients who received HHA in lower-volume hospitals had higher mortality rates within 180 days and 1 year than those in higher-volume hospitals. Compared with patients who were operated on by high-volume surgeons, those who received surgery performed by lower-volume surgeons were more likely to die within 30 days (aHR = 1.22), 180 days (aHR = 1.16) and 1 year (aHR = 1.19), respectively. CONCLUSIONS: The postoperative mortality rate of elderly patients undergoing HHA was significantly higher in the cemented group than in the non-cemented group.

Comparing the efficacy of Cartiva synthetic cartilage implant hemiarthroplasty vs osteotomy for the treatment of conditions affecting the second metatarsal head.

BACKGROUND: Cartiva synthetic cartilage implants (SCI) have been designed for treatment of conditions affecting the second metatarsal head. Osteotomies are regularly performed for the treatment of conditions affecting the second metatarsal head such as Freiburg's disease. A comparative study between these two procedures has not yet been performed. METHODS: Patients at a single centre with symptomatic conditions affecting the second metatarsal head who received Cartiva SCI or a primary Osteotomy were identified, and patient-reported outcomes were evaluated using MOXFQ and the FAAM questionnaires. RESULTS: Six Cartiva SCI and 7 Osteotomy patients were identified and included in this study. All patients were female and were followed up for an average of 19 months (SD +/- 5.6) and 27 months (SD +/- 10.9) respectively. Cartiva SCI MOXFQ Index scores improved by 13 points from 57 to 44 (33%). Walking/and Pain domain scores improved, however, Social interaction deteriorated. Mean FAAM scores improved by 10% from 65% to 75%, and subjective FAAM scores improved by 7% from 48% to 55%. Four of the six Cartiva patients (3 Freiberg's disease and 1 Osteochondral defect) had revisions to Weil osteotomies at a mean of 15 months post-operatively. The Osteotomy group had improved MOXFQ Index and 3 Domain scores. FAAM scores improved by 26% from 66% to 92% and subjective FAAM scores improved by 28% from 60% to 88%. CONCLUSIONS: Second metatarsal head osteotomies result in high functional outcomes and should be the mainstay of treatment, especially when there is avascular necrosis of the metatarsal head.