Epidemiology of periprosthetic femoral fractures in 5417 revision total hip arthroplasties: a 40-year experience

Ipsilateral pubic ramus fracture during total hip arthroplasty is not rare: does it matter?

INTRODUCTION

Periprosthetic fractures in total hip arthroplasty (THA) have been well described and studied. However, there is a lack of reports on ipsilateral pubic ramus fractures during THA due to the rare occurrence of such fractures and ambiguity of symptoms. With the use of postoperative computed tomography (CT) examinations, we have identified that asymptomatic ipsilateral pubic ramus fractures occur frequently during THA. This study aims to evaluate the incidence, location, clinical outcomes, and risk factors of ipsilateral pubic ramus fractures during THA.

METHODS

From May 2022 to March 2023, a single surgeon performed 203 THAs in 183 patients at a single institution. All patients underwent postoperative CT scans three days after THA. The patients with ipsilateral pubic ramus fractures were followed up for a minimum of six months. Basic demographics, osteoporosis, general conditions of the operations, and outcomes of THA were investigated in all patients.

RESULTS

Twenty-two cases (10.8%) of ipsilateral pubic ramus fractures were identified on postoperative CT scans. All fractures were located near the origin of the superior or inferior pubic ramus. Five fractures were detected on simple postoperative radiographs. The fractures did not cause any further complications at a minimum of six-month postoperative follow-up. Univariate and multivariate analyses did not identify any risk factors associated with these fractures.

CONCLUSIONS

Although the incidence of ipsilateral pubic ramus fractures during THA is high, treatment is not required as they do not cause any significant clinical symptoms or affect the prognosis of THA. However, the possibility of occurrence of these fractures must be explained to the patients before surgery.

Experimental periprosthetic fractures with collarless polished tapered cemented stems

PURPOSE

After cemented total hip arthroplasty, the risk of periprosthetic fracture (PPF) of taper-slip stems is higher than that of composite-beam stems. We aimed to assess the conditions resulting in PPFs of taper-slip stems using a falling weight.

METHODS

Taper-slip stems were fixed to five types of simulated bone models using bone cement, and the fractures were evaluated by dropping stainless-steel weights from a predetermined height onto the heads. The periprosthetic fracture height in 50% of the bone models (PPFH50) was calculated using the staircase method.

RESULTS

For the fixation with 0° of flexion, the values for PPFH50 were 61 ± 11, 60 ± 13, above 110, 108 ± 49, and 78 ± 12 cm for the cobalt-chromium-molybdenum alloy, stainless steel alloy (SUS), titanium alloy (Ti), smooth surface, and thick cement mantle models, respectively; for the fixation with 10° of flexion (considering flexure), the PPFH50 values were 77 ± 5, 85 ± 9, 90 ± 2, 89 ± 5, and 81 ± 11 cm, respectively. The fracture rates of the polished-surface stems were 78.6 and 35.7% at the proximal and distal sites, respectively (p < 0.05); the fracture rates of the smooth-surface stems were 14.2 and 100%, respectively (p < 0.05).

CONCLUSION

The impact tests demonstrated that the conditions that were less likely to cause PPFs were use of Ti, a smooth surface, a thick cement mantle, and probably, use of SUS.

Risk factors influencing periprosthetic fracture and mortality in elderly patients following hemiarthroplasty with a cemented collarless polished taper stem for an intracapsular hip fracture

Aims

The aims of this study were to evaluate the incidence of reoperation (all cause and specifically for periprosthetic femoral fracture (PFF)) and mortality, and associated risk factors, following a hemiarthroplasty incorporating a cemented collarless polished taper slip stem (PTS) for management of an intracapsular hip fracture.

Methods

This retrospective study included hip fracture patients aged 50 years and older treated with Exeter (PTS) bipolar hemiarthroplasty between 2019 and 2022. Patient demographics, place of domicile, fracture type, delirium status, American Society of Anesthesiologists (ASA) grade, length of stay, and mortality were collected. Reoperation and mortality were recorded up to a median follow-up of 29.5 months (interquartile range 12 to 51.4). Cox regression was performed to evaluate independent risk factors associated with reoperation and mortality.

Results

The cohort consisted of 1,619 patients with a mean age of 82.2 years (50 to 104), of whom 1,100 (67.9%) were female. In total, 29 patients (1.8%) underwent a reoperation; 12 patients (0.7%) sustained a PFF during the observation period (United Classification System (UCS)-A n = 2; UCS-B n = 5; UCS-C n = 5), of whom ten underwent surgical management. Perioperative delirium was independently associated with the occurrence of PFF (hazard ratio (HR) 5.92; p = 0.013) and surgery for UCS-B PFF (HR 21.7; p = 0.022). Neither all-cause reoperation nor PFF-related surgery was independently associated with mortality (HR 0.66; p = 0.217 and HR 0.38; p = 0.170, respectively). Perioperative delirium, male sex, older age, higher ASA grade, and pre-fracture residential status were independently associated with increased mortality risk following hemiarthroplasty (p < 0.001).

Conclusion

The cumulative incidence of PFF at four years was 1.1% in elderly patients following cemented PTS hemiarthroplasty for a hip fracture. Perioperative delirium was independently associated with a PFF. However, reoperation for PPF was not independently associated with patient mortality after adjusting for patient-specific factors.

Management of Isolated Greater Trochanter Fractures Associated With Total Hip Arthroplasty

Periprosthetic hip fractures are recognized complications associated with total hip arthroplasty. Over the past decade, there has been a 2.5-fold increase in the incidence of periprosthetic fractures which is expected to grow exponentially in the future. Most of these fractures require surgical fixation or revision arthroplasty. Fractures of the greater trochanter represent a subset of periprosthetic fractures for which there is currently no consensus in the literature regarding the optimal management. The purpose of this review was to outline the management strategies available to address these fractures, with formulation of recommendations for fractures sustained intraoperatively, postoperatively, and in the setting of primary and revision total hip arthroplasty.

Implant breakage and revision factors for modular fluted tapered stems in revision total hip arthroplasty

PURPOSE

Modular stems in revision total hip arthroplasties allow diaphyseal fixation and optimal restoration of the architecture of the proximal femur. Several studies report metaphyseal implant breakage having a negative impact on survivorship. The aim of the study was to evaluate the outcome of an uncemented modular fluted tapered stem (MFT) in revision surgery.

METHODS

In a retrospective study, 316 patients who had revision surgery using the same design of MFT implant (Modular Revision Stem [MRS], Lima Corporate, Italy) between 2012 and 2017 were identified. Patients were male in 51% of cases and mean age was 74 years. Indications were 110 periprosthetic fractures, 98 periprosthetic joint infection, 97 aseptic loosening, 10 instability and 1 other cause. Survivorship, complications, clinical and radiographic outcomes, were assessed. Mean follow-up was 5 years.

RESULTS

There was no implant breakage. At 5-year follow-up, the survivorship, free from revision for aseptic loosening and free of revision for any reason were 96% and 87%, respectively. At last follow-up (8 years), these figures were 92% and 71%, respectively. 31 implants were revised. The risk of revision for any cause was higher for extreme length metaphyseal implants, hazard ratio was 3.7 (95% CI, 1.82-7.52). A mean stem subsidence of 9 mm was noted in 37 cases; 4 were revised for aseptic loosening. The Harris Hip Score at final follow-up was 82.

CONCLUSIONS

At 5-year follow-up, the MFT implant showed a good survivorship and outcomes with no specific complications. Unlike literature reports, no specific complications occurred with this design. Stem junction positioning and therefore metaphyseal length may be key to optimise long-term survivorship. However, a longer follow-up is needed as implant breakage is more often seen after long implantation times.

Does size matter? Outcomes following revision total hip arthroplasty with long or primary stems: a systematic review and meta-analysis

BACKGROUND

Femoral reconstruction with long stems is widely accepted as the standard in revision total hip arthroplasty (rTHA). However, long stems can be technically challenging to insert and can compromise bone stock for future revision. This study aimed to identify whether there was a difference in outcomes with using a long versus primary or short femoral stem in revision.

METHODS

We performed a systematic review and meta-analysis of all articles comparing long and primary stem length in rTHA for Paprosky 1-3B femoral defects. The primary outcome measure was the reoperation rate after rTHA. Secondary outcomes included infection and dislocation rates, periprosthetic fracture, loosening, mortality, and patient-reported outcome measures (PROMs).

RESULTS

The results of 3,102 rTHAs performed in 2,982 patients were reported from 9 eligible studies in the systematic review, of which 6 were included in the meta-analysis. The mean patient age was 67.4 and the mean follow-up lasted 5 years (range, 1-15 years). There was no significant difference in the reoperation rate (odds ratio 0.78; 95% confidence interval, 0.28-2.17, P = 0.63). Similarly, there was no significant difference in dislocation or periprosthetic fracture risk. Harris Hip Score was better with primary stems by a mean difference of 14.4 points (P < 0.05). Pooled 5-year stem-related survival was 91.3% ± 3.5% (SD) for primary stems and 89.9% ± 6.7% (SD) for long stems.

CONCLUSIONS

A primary stem provided non-inferior outcomes compared with long stems in rTHA with Paprosky type 1-3B femoral defects. Primary stems may yield a more straightforward technique and preserve distal bone stock for future revision particularly in younger patients. In older patients with lower functional demands and who would benefit from a decreased risk of complications, a long cemented stem is recommended.

Bone remodeling and cortical thinning distal to the femoral stem: a retrospective review

INTRODUCTION

There is a paucity of information on the bone remodeling that occurs distal to the femoral stem following total hip arthroplasty as most previous studies have focused on proximal changes. In this study, we report the cortical thinning that occur distal to the femoral stem after primary total hip arthroplasty.

METHODS

A retrospective review was performed at one institution over a 5-year period. 156 primary total hip arthroplasty procedures were included. The Cortical Thickness Index (CTI) was measured on both operative and non-operative hips at 1 cm, 3 cm and 5 cm below the prosthetic stem tip on anteroposterior radiographic images pre-operatively as well as at 6 months, 12 months and 24 months post-operatively. The difference in average CTI was measured using paired t-tests.

RESULTS

There were statistically significant decreases in CTI distal to the femoral stem at 12 months and 24 months (-1.3% and -2.8%, respectively). Greater losses were seen in female patients, patients older than 75, and patients with BMI less than 35 at 6 months postoperative. There were no differences in CTI at any time point on the non-operative side.

CONCLUSION

The current study demonstrates that patients undergo bone loss as measured by CTI distal to the stem in the first 2 years following total hip arthroplasty. Comparison to the contralateral non-operative side confirms that this change is greater than expected for the natural aging process. A greater understanding of these changes will help optimize post-operative management and direct future innovations in implant design.

Surgical treatment of specific Unified Classification System B fractures: potentially destabilising lesser trochanter periprosthetic fractures

To investigate the clinical effects of specific Unified Classification System B (UCS B)-lesser trochanter periprosthetic fractures and determine whether they occur only with non-cemented stems. A retrospective analysis of 28 patients with specific UCS B2 fractures who underwent two surgical treatments, longer stem revision and internal fixation (LSRIF) and open reduction and internal fixation (ORIF), was performed. The patients were assessed at 1, 3, 6, 12, and 24 months and annually thereafter. Fracture healing, complications, Harris Hip Score (HHS), and the Short Form Health Survey questionnaire (SF-36) quality of life score were assessed at each follow-up. At the time of the last follow-up, seven patients had been lost: three were lost to contact, two died, and two were hospitalised elsewhere and unavailable for follow-up. The remaining 21 patients were followed for an average of 49.3 ± 15.4 (range: 24-74.4) months. Their average fracture healing time was 13.5 ± 1.1 (12-15.4) weeks. Complications included three cases (10.71%) of thrombus, one (3.57%) of heart failure, and one (3.57%) of pulmonary infection. There were no revisions due to prosthesis loosening, subsidence, or infection. At the last follow-up, the HHS, SF-36 mental score, and SF-36 physical score were recorded, LSRIF vs. ORIF (82.9 ± 6.6 vs. 74.7 ± 3.9, p = 0.059; 50.9 ± 7.6 vs. 38 ± 1.4, p = 0.012, and 51.7 ± 8.4 vs. 39.7 ± 3.4, p = 0.032, respectively). Specific UCS B2 fractures mostly occur with non-cemented stems. LSRIF with cables is the main treatment, while ORIF is an option for those elderly in poor condition.

Subsidence in Centraliser Sign: A Novel Tool to Help Predict Early Subsidence in Periprosthetic Femoral Fractures Around Polished Tapered Stems Treated With Internal Fixation

Background When treating periprosthetic femoral fractures (PPF) around polished taper slip stems (PTS), determining which patients can be successfully treated with internal fixation can be challenging. We have described the subsidence-in-centraliser (SINC) sign as a radiographic feature of PPF around PTS stems. We hypothesise that a positive SINC sign can help predict a poorer outcome for the fixation of these fractures. Patients and methods Retrospective identification of PPFs around cemented PTS with an appreciable centraliser on radiographs was conducted at a single centre. A positive SINC sign was defined as a post-injury radiograph demonstrating >50% reduction in the radiographic lucency representing the stem centraliser when compared to pre-injury films or complete obliteration of distal lucency when no pre-injury film was available. The primary outcome was the rate of subsequent stem subsidence on follow-up radiographs comparing SINC-positive and SINC-negative fractures, which were managed with open reduction and internal fixation (ORIF). Results Fifty-four patients were included in the analysis. The mean age was 76.8 years, and the mean follow-up for all patients was 12.7 months. Thirty-five fractures were deemed SINC-positive, and 19 were SINC-negative. 17/17 (100%) SINC-positive fractures managed with fixation underwent further subsidence (mean 5.4 mm, SD 2.8). A positive SINC sign demonstrated a sensitivity of 90.5% and specificity of 100% for subsequent stem subsidence in fractures treated without revision. SINC positive fractures underwent significantly more subsidence compared with SINC negative fractures when fixed (5.4 mm vs. 0.28 mm, U = 6.50, p<0.001) at a mean follow-up of 12.7 months. The SINC sign demonstrated strong inter- (k=0.96) and intra-rater (k=0.86) reliability. Conclusion The SINC sign can serve as a useful adjunct in the decision to fix or revise PPF around PTS. A positive SINC sign may represent a cement mantle that cannot be reconstituted anatomically, leading to subsidence after treatment with ORIF.

Which Unified Classification System type B periprosthetic fractures around cemented polished tapered stems should not be fixed?

The Unified Classification System (UCS), or Vancouver system, is a validated and widely used classification system to guide the management of periprosthetic femoral fractures. It suggests that well-fixed stems (type B1) can be treated with fixation but that loose stems (types B2 and B3) should be revised. Determining whether a stem is loose can be difficult and some authors have questioned how to apply this classification system to polished taper slip stems which are, by definition, loose within their cement mantle. Recent evidence has challenged the common perception that revision surgery is preferable to fixation surgery for UCS-B periprosthetic fractures around cemented polished taper slip stems. Indications for fixation include an anatomically reducible fracture and cement mantle, a well-fixed femoral bone-cement interface, and a well-functioning acetabular component. However, not all type B fractures can or should be managed with fixation due to the risk of early failure. This annotation details specific fracture patterns that should not be managed with fixation alone.

Periprosthetic fractures: an unrecognized osteoporosis crisis

Total joint replacement is common and increasing. Many of these patients have low bone mineral density preoperatively, and arthroplasty leads to bone loss. As falls are common before and after arthroplasty, it is unsurprising that periprosthetic fractures, defined as those associated with an orthopedic device, whether a joint replacement or other internal fixation devices, are not rare. These fractures engender morbidity and mortality comparable to osteoporosis-related hip fractures but remain largely unrecognized and untreated by osteoporosis/metabolic bone disease clinicians. Indeed, recent osteoporosis guidelines are silent regarding periprosthetic fractures. The purposes of this clinical review are to briefly describe the epidemiology of arthroplasty procedures and periprosthetic fractures, raise awareness that these fractures are osteoporosis-related, and suggest approaches likely to reduce their occurrence. Notably, bone health evaluation is essential following the occurrence of a periprosthetic fracture to reduce subsequent fracture risk. Importantly, in addition to such secondary fracture prevention, primary prevention, i.e., bone health assessment and optimization prior to elective orthopedic procedures, is appropriate.

Outcomes of osteosynthesis of periprosthetic fractures of the greater trochanter with an anatomic claw plate

Background

The treatment of periprosthetic trochanteric fractures, especially older fractures, is often a challenge. The aim of this study was to investigate the clinical and radiological outcomes of periprosthetic fracture treatment with the anatomic Peri-Plate claw plate.

Material and methods

Thirteen new fractures (≤6 weeks after occurrence) and 8 older Vancouver AG fractures (35.4 ± 26.1 weeks after occurrence) were followed radiologically and clinically with a follow-up of 44.6 ± 18.8 (24-81) months.

Results

At 6 months, osseous consolidation had occurred in 12 cases and fibrous union in 9 cases. At 12 months one additional osseous consolidation was shown. The Harris hip score (HHS) increased from 37.2 ± 10.3 preoperatively to 87.6 ± 10.3 12 months after surgery. Thirteen patients reported no, 7 mild and one patient significant local trochanteric pain.

Conclusions

The Peri-Plate claw plate can achieve reproducibly good outcomes in terms of fracture stabilization and bony consolidation, as well as with regard to clinical outcomes in the treatment of new and older periprosthetic trochanteric fractures.

Periprosthetic fracture management of the proximal femur

The most common periprosthetic fractures occur around the hip. The most widely used classification is the Vancouver classification, and management requires careful planning and skill in both arthroplasty and fracture surgery. This article presents an overview of the diagnosis, classification, and management of periprosthetic fractures of the proximal femur. This work represents a summary review from Latin American Society Members of the International Orthopaedic Trauma Association.

[Strategies for stem revision : Surgery planning, implant removal and reimplantation]

BACKGROUND AND PLANNING

Femoral revision represents a challenging procedure in its surgical planning and technical execution. The results are mainly dependent on the bone loss present, the quality of the implant removal and the choice of revision system. Patient-specific factors such as age, comorbidities, bone quality or even the localization of the cement have a decisive influence on the surgical strategy. Appropriate preoperative preparation, including the presence of the necessary special instruments, which are essential for gentle implant removal, is indispensable to achieve the best possible result.

THERAPY

A bone-sparing implant removal can be particularly challenging, especially in the case of well-fixed stems and cement residues, which may extend far beyond the isthmus. In such situations, a transfemoral approach should be considered. Cementless reimplantation using modular or non-modular titanium stems is currently the preferred treatment of choice for most revisions. In elderly, low-demand patients or with poor bone quality, cemented revision remains a good alternative treatment option.

Does intraoperative periprosthetic occult fracture of the acetabulum affect clinical outcomes after primary total hip arthroplasty?

INTRODUCTION

The frequency of intraoperative periprosthetic occult fracture of the acetabulum (IPOA) in primary total hip arthroplasty (THA) is relatively high. However, the effect of this fracture on clinical outcome and survival of primary THA remains unknown. This study aimed to determine the impact of IPOA on the outcomes of primary THA during a minimum follow-up of 5 years.

MATERIALS AND METHODS

This retrospective case-control study compared the outcomes of primary THA with or without IPOA during a minimum 5-year follow-up. Thirty-eight patients who underwent primary THA with IPOA (O group) were matched to 76 patients without IPOA (C group) between 2004 and 2013 based on age, sex, body mass index, primary diseases, cup diameter, cup design, and additional dome screw. Both groups underwent the same rehabilitation programs after surgery. We evaluated the Japanese Orthopaedic Association clinical outcomes score; postoperative complications, such as nerve injury, dislocation, heterotopic ossification, iliopsoas impingement, or infection; and radiographic outcomes. Additionally, we performed Kaplan-Meier survival analysis with cup aseptic loosening, cup failure revision, and all-cause revision as the endpoints.

RESULTS

There were no significant differences in the pre- and postoperative clinical scores, postoperative complication rates, and cup sagittal rotation between the two groups. Radiographic evaluations showed no aggravation of cases to overt fractures. Bone ingrowth was observed in all cases, and none of the acetabular cups had a progressive radiolucent line ≥ 2 mm in all the 3 acetabular zones. Ten-year survival rates for cup aseptic loosening and cup failure revision were 100% in both groups; those for all-cause revision were 97.4% (92.0-100%) and 100% in the O and C groups, respectively (p = 0.157).

CONCLUSIONS

Primary THA with IPOA provides favorable mid- to long-term outcomes. On IPOA diagnosis, although radiographic follow-up is necessary, additional treatments or rehabilitation programs are not required. Furthermore, postoperative computed tomography images for the detection of IPOA may be unnecessary.

Periprosthetic Infection in the Setting of Periprosthetic Total Hip Fractures: Evaluation and Management

The incidences of periprosthetic fracture and periprosthetic joint infection after total hip arthroplasty are expected to increase exponentially over the coming decades. Epidemiologic data suggest that many periprosthetic fractures after THA occur concurrently with a loose femoral implant. Recent studies suggest an approximately 8% incidence of indolent infection in cases of suspected aseptic loosening. The available data, therefore, suggest that periprosthetic fracture and infection may coexist, and this possibility should be considered, particularly in patients with a loose femoral stem and high pretest possibility. Although currently limited, the available literature provides some guidance as how to manage this complex issue.

[Effectiveness of shape memory alloy embracing device in treatment of Vancouver B2 periprosthetic femoral fracture]

OBJECTIVE

To analyze the effectiveness of shape memory alloy embracing device in the treatment of Vancouver B2 periprosthetic femoral fracture after primary hip arthroplasty.

METHODS

The clinical data of 30 patients (30 hips) with Vancouver B2 periprosthetic femoral fracture after primary hip arthroplasty between January 2019 and January 2021 were analyzed retrospectively. Among them, 15 cases were treated with shape memory alloy embracing device for fracture fixation (group A) and 15 cases with titanium cable cerclage (group B). There was no significant difference in general data such as gender, age, body mass index, the cause of primary arthroplasty and surgical method, prosthesis type, the cause and side of femoral fracture, the time from injury to operation, and comorbidities between the two groups ( P>0.05). The operation time, intraoperative blood loss, and hospital stay of the two groups were recorded. The fracture healing was examined by X-ray film, and the hip joint function was evaluated by Harris score.

RESULTS

The operations in both groups were completed successfully, and the incisions healed by first intention after operation with no vascular or nerve injury. The operation time and hospital stay in group A were significantly shorter than those in group B ( P<0.05), but there was no significant difference in intraoperative blood loss between group A and group B ( t=-0.518， P=0.609). Patients were followed up 12-20 months (mean, 16.3 months) in group A and 12-22 months (mean, 16.7 months) in group B. X-ray film showed that all fractures healed, the healing time was (14.73±2.05) weeks in group A and (17.27±2.60) weeks in group B, and there was a significant difference between the two groups ( t=-2.960， P=0.006). During follow-up, there was no complication such as prosthesis loosening, periprosthetic infection, joint stiffness, or internal fixator loosening. The Harris score of group A was significantly better than that of group B at 3, 6, and 12 months after operation ( P<0.05).

CONCLUSION

Compared with titanium cable cerclage, using shape memory alloy embracing device to fix Vancouver B2 periprosthetic femoral fracture can accelerate fracture healing, shorten operation time, and reduce intraoperative blood loss. Patients can perform functional exercise earlier and restore joint function better.

The insidious risk of periprosthetic fracture in clinically functional total hip arthroplasties: A biomechanical study of willed joints

Femoral bone quality is a major risk factor of periprosthetic fracture after total hip arthroplasty (THA), which has mortality similar to native hip fractures but higher short-term morbidity. The goal of this study was to quantify cortical strains at the site of expected Vancouver Type-B periprosthetic fracture as a function of bone mineral density, femoral stem material, and fixation method using a series of 29 autopsy-retrieved, clinically asymptomatic hip joints with THA. Periprosthetic bone mineral content and density was assessed using dual-energy X-ray absorptiometry by Gruen Zone. Specimens then underwent combined cyclic axial and torsional loading, increasing incrementally from 100 N and ±1 Nm to peaks of 700 N and ±5 Nm. All specimens experienced significantly higher strains on the lateral surface than on the anterior surface, indicating that the bending loads in the frontal plane, rather than axial/torsional loads, had the predominant effect. Multiple significant relationships (p = 0.04, p = 0.02) were found between predicted periprosthetic strains calculated from radiographic measurements and observed principal strains. Though THA in the present study were in successful clinical service, the produced results indicated that some femurs with rigid cemented or noncemented implants were potentially at high risk for Vancouver Type-B fractures, which may be predicted radiographically.

Comparison of axial-rotational postoperative periprosthetic fracture of the femur in composite osteoporotic femur versus human cadaveric specimens: A validation study

Postoperative periprosthetic femoral fracture following hip replacement has been the subject of many varied experimental approaches. Cadaveric samples offer realistic fit and fracture patterns but are subject to large between-sample variation. Composite femurs have not yet been validated for this purpose. We compared the results of composite femurs to cadaveric femurs using an established methodology. In vitro postoperative periprosthetic fracture results using axial-rotational loading were compared between 12 composite femurs and nine fresh frozen femurs, which were implanted with an otherwise identical collarless (6 composite vs 4 cadaveric) or collared (6 composite vs 5 cadaveric) cementless femoral stem using identical methodology. Fracture torque and rotational displacement were measured and torsional stiffness and rotational work prior to fracture were estimated. Fractures patterns were graded according to the Unified Classification System. Fracture torque, displacement, torsional stiffness and fracture patterns for cadaveric and composite femurs were similar between groups. There was a trend for a greater rotational displacement in the cadaveric groups, which lead to a decrease in torsional stiffness and a significantly greater rotational work prior to fracture for all cadaveric specimens (collarless stems: 10.51 [9.71 to 12.57] vs 5.21 [4.25 to 6.04], p = 0.01 and for collared stems: 15.38 [14.01 to 17.05] vs 5.76 [4.92 to 6.64], p = 0.01). Given comparable fracture torque and the similarity in fracture patterns for fracture trials using composite samples versus cadaveric femurs, the use of composite femur models may be a reasonable choice for postoperative periprosthetic femoral fracture studies within certain limitations.

Treatment Algorithm of Periprosthetic Femoral Fracturens

Introduction. The ever-expanding indications for total hip arthroplasty are leading to more implants being placed in younger as well as in older patients with high functional demand. Also, prolonged life expectancy is contributing to an overall increment of periprosthetic femoral fractures. The Vancouver classification has been the most used for guiding the surgeon choice since its proposal in 1995. Fractures occurring over a hip femoral implant can be divided into intra-operative and post-operative PFFs, and their treatment depends on factors that may severely affect the outcome: level of fracture, implant stability, quality of bone stock, patients’ functional demand, age and comorbidities, and surgeon expertise. There are many different treatment techniques available which include osteosynthesis and revision surgery or a combination of both. The goals of surgical treatment are patients’ early mobilization, restoration of anatomical alignment and length with a stable prosthesis and maintenance of bone stock. Significance. The aim of this review is to describe the state-of-the-art treatment and outcomes in the management of PFFs. We performed a systematic literature review of studies reporting on the management of PFFs around hip stems and inter-prosthetic fractures identifying 45 manuscripts eligible for the analysis. Conclusions. PFFs present peculiar characteristic that must be considered and special features that must be addressed. Their management is complex due to the extreme variability of stem designs, the possibility of having cemented or uncemented stems, the difficulty in identifying the “real” level of the fracture and the actual stability of the stem. As a result, the definition of a standardized treatment is unlikely, thereby high expertise is fundamental for the surgical management of PPFs, so this kind of fractures should be treated only in specialized centres with both high volume of revision joint arthroplasty and trauma surgery.

The race for the classification of proximal periprosthetic femoral fractures : Vancouver vs Unified Classification System (UCS) - a systematic review

Background

Periprosthetic femoral fractures (PFFs) represent a major cause for surgical revision after hip arthroplasty with detrimental consequences for patients. The Vancouver classification has been traditionally used since its introduction in 1995. The Unified Classification System (UCS) was described in 2014, to widen the spectrum by aiming for a more comprehensive approach. The UCS also aimed to replace the Vancouver classification by expanding the idea of the Vancouver classification to the whole musculoskeletal apparatus. After introduction of the UCS, the question was raised, whether the UCS found its place in the field of analysing PFFs. Therefore, this systematic review was performed to investigate, the use of the UCS compared to the established Vancouver classification.

Methods

Medline was searched for reports published between 1 January 2016 and 31 November 2020, without language restriction. Included were original articles, irrespective of the level of evidence and case reports reporting on a PFF and using either the Vancouver or the UCS to classify the fractures. Excluded were reviews and systematic reviews.

Results

One hundred forty-six studies were included in the analysis. UCS has not been used in a single registry study, giving a pooled cohort size of 3299 patients, compared to 59,178 patients in studies using the Vancouver classification. Since 2016, one study using UCS was published in a top journal, compared to 37 studies using the Vancouver classification (p=0.29). During the study period, the number of yearly publications remained stagnant (p=0.899).

Conclusions

Despite valuable improvement and expansion of the latter UCS, to date, the Vancouver system clearly leads the field of classifying PFFs in the sense of the common use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05240-w.

Revision Total Hip Arthroplasty with Primary Stem or Full-Porous-Coated Long Stem for Aseptic Femoral Component Loosening: A Matched-Pair Study

Background

Revision total hip arthroplasty (RTHA) for loosening the femoral stem is a technical challenge. Distally fixed, full-porous-coated long stems are widely accepted as the standard selection for these revisions. However, the success of primary stems in RTHA is not well known.

Methods

This study enrolled 24 patients with aseptic loosening of the femoral stem who underwent RTHA using primary stems. Another 72 patients with aseptic loosening who underwent RTHA using full-porous-coated long stems were matched in terms of operation date, proximal femoral bone stock (Paprosky classification), sex, and age. The primary and secondary outcomes of failure were the need for revision for any reason and the radiographic change in the stem respectively.

Results

In the primary stem group, one patient had a periprosthetic fracture and received a second RTHA 2 years after the previous one. The primary outcome’s 5-and 10-year survival rates were both 95.8%. For the matched comparison group, one patient had an immediate periprosthetic fracture of the femoral shaft requiring further open reduction internal fixation surgery. Another patient had a full-porous-coated long stem breakage 6 years postoperatively, which required a second RTHA. The primary outcome’s 5-and 10-year survival rates were 98.6% and 97.2%, respectively.

Conclusion

Primary stems can achieve non-inferior clinical success compared to a full-porous-coated long stem for aseptic stem loosening RTHA in patients with adequate proximal femoral bone stock.

Experimental analysis of early periprosthetic femoral fractures with uncemented straight hip stems

BACKGROUND

The periprosthetic femoral fracture is one of the most severe complications after total hip arthroplasty and is associated with an increased mortality. The underlying causes and the patient- and implant-specific risk factors of periprosthetic femoral fractures remain insufficiently understood. The aim of this study was to gain a more profound understanding of the underlying fracture mechanisms and to provide experimental datasets for validation of computational models.

METHODS

Six cadaveric femurs were implanted with straight hip stems (Zweymueller design) and loaded until fracture reproducing the clinically relevant load cases stumbling and sideways fall. Displacements and the strain distribution on the surface of the femurs and implants, as well as the fracture load and implant subsidence were measured.

FINDINGS

For the load case stumbling the mean fracture load was 6743 N and two different mechanisms leading to fracture could be identified: high subsidence with low femoral bending and small subsidence with high femoral bending. For the load case sideways fall the mean fracture load was 1757 N and both tested femurs fractured due to a rotation of the hip stem around its own axis. The detailed datasets provided by this study can be used in future computational models.

INTERPRETATION

We demonstrated that the underlying fracture mechanisms of periprosthetic femoral fractures can be fundamentally different in the load case stumbling. The seating and exact position of the hip stem in the femur may correlate with implant subsidence and therefore lead to different types of fracture mechanisms resulting in different patient-specific fracture risks.

Management of Vancouver B2 Periprosthetic Femoral Fractures, Revision Total Hip Arthroplasty Versus Open Reduction and Internal Fixation: A Systematic Review and Meta-Analysis

OBJECTIVE

To identify and analyze the current evidence for the use of open reduction and internal fixation (ORIF) constructs compared with conventional revision total hip arthroplasty (rTHA) for the management of Vancouver B2 periprosthetic femoral fractures (PFFs).

DATA SOURCES

A systematic literature search of the MEDLINE, CINAHL, and EMBASE databases was conducted. Prospective and retrospective studies were eligible. No limitation was placed on publication date, with only articles printed in English eligible.

STUDY SELECTION

Included studies were retrospective studies comparing ORIF and rTHA for the management of Vancouver B2 PFFs.

DATA EXTRACTION

The primary outcome was the overall complication rate. Other outcomes included as rate of dislocation, revision operation, refracture, infection, nonunion, and subsidence/loosening. Twenty-four studies were included totaling 1621 patients, of which 331 were treated with ORIF and 1280 with rTHA.

CONCLUSION

The 1621 patients included comprised a mixture of different fracture patterns, prostheses, and patient comorbidities. The overall complication rate for ORIF was 24% versus 18% for rTHA (P = 0.13). The results demonstrate that rTHA has a similar revision rate to ORIF in PFFs with a loose femoral component and adequate bone stock. ORIF was superior to rTHA in prevention of postoperative dislocation; however, there was no difference between other complications. This review suggests a potential role of both ORIF and rTHA in the management of Vancouver B2 PFFs.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Combined Surgical and Medical Treatment for Vancouver B1 and C Periprosthetic Femoral Fractures: A Proposal of a Therapeutic Algorithm While Retaining the Original Stable Stem

INTRODUCTION

There is lack of consensus regarding best operative fixation strategy for periprosthetic femoral fractures (PFFs) around a stable stem. Evidence exists that some patterns of fracture around a stable stem are better treated with revision surgery than with standard fixation. Anyway, a more aggressive surgical procedure together with medical treatment could allow for stem retention, and reduced risk of nonunion/hardware failure, even in these cases.

SIGNIFICANCE

This paper is placed in a broader context of lack of studies on the matter, and its aim is to shed some light on the management of PFFs around a stable stem, when peculiar mechanical and biological aspects are present.

RESULTS

Based on our casuistry in the treatment of nonunions after PFF successfully treated with original stem retention, and on review of Literature about risk factors for fixation failure, an algorithm is proposed that can guide in choosing the ideal surgical technique even for first-time PFFs with a stable stem, without resorting to revision. Mechanical (major and minor) and biological (local and systemic) factors that may influence fracture healing, leading to nonunion and hardware failure, and subsequent need for re-operation, are considered. The proposed surgical technique consists of rigid fixation with absolute stability (using a plate and structural allograft) plus local biological support (structural allograft and autologous bone marrow concentrate over a platelet-rich plasma-based scaffold) at fracture site. Systemic anabolic treatment (Teriparatide) is also administered in the post-operative period.

CONCLUSION

Mechanical factors are not the only issues to be considered when choosing the surgical approach to PFFs over a stable stem. Systemic and local biological conditions should be taken into account, as well. A therapeutic algorithm is proposed, given the prosthetic stem to be stable, considering mechanical and biological criteria.

A Comparison of Risks and Benefits Regarding Hip Arthroplasty Fixation

Since the field-changing invention of noncemented hip arthroplasty fixation in the 1980s, noncemented fixation has been progressively replacing cemented fixation. However, analyses of fixation frequencies reveal new patterns in cement versus noncemented preferences. Although cementation is again gaining ground in the United States, noncemented models remain the dominant fixation mode, seen in more than 90% of all hip arthroplasties. This stark preference is likely driven by concerns regarding implant durability and patient safety. Although advances in surgical techniques, intensive perioperative care, and improved instrument have evolved in both methods, data from large arthroplasty registries reveal shifting risks in contemporary hip arthroplasty, calling the use of noncemented fixation into question. Varying risk profiles regarding sex, age, or health comorbidities and morphological and functional differences necessitate personalized risk assessments. Furthermore, certain patient populations, based on the literature and data from large registries, have superior outcomes from cemented hip arthroplasty techniques. Therefore, we wanted to critically evaluate the method of arthroplasty fixation in primary hip arthroplasties for unique patient populations.

Revision hip arthroplasty using a porous tantalum acetabular component

INTRODUCTION

Reconstruction of acetabulum in case of bone defects can be challenging. The aim of this retrospective study was to investigate the 10-year survival of trabecular tantalum metal (TM) acetabulum component in revision hip arthroplasty operations and to evaluate complications.

METHODS

A total of 100 consecutive acetabulum revision hip arthroplasties (100 patients) were operated on between May 2004 and October 2006 at Kuopio University Hospital. The mean follow-up time was 9.4 years and the median was 11.5 years (SD 4.118; range 0.1-13.4 years). Kaplan-Meier survival analysis was performed to study the survival of patients to re-revision surgery. Intra- and postoperative complications and reasons for re-revision were evaluated.

RESULTS

The Kaplan-Meier analysis showed a cumulative proportion of revision hip survivorship of 66% at 13.4 years (SE 0.403, 95% CI, 10.886-12.466) based on the need for further re-revision surgery for any major reason. The Kaplan-Meier survival analysis of time to re-revision surgery due acetabular component loosening showed a cumulative proportion of survivorship of 98.9% at 13.4 years (SE 0.136; 95% CI, 12.998-13.529). There were a total of 41/100 complications and the most common complication was dislocation (24/100). Re-revision for any major reason was performed on 18/100 of the revision arthroplasties. The mean time to re-revision was 4.9 years (SD 5.247; range 0.1-13.2 years).

DISCUSSION

The trabecular TM acetabular component gives excellent outcomes regarding stability and fixation to the acetabulum in acetabulum revision hip arthroplasty at a minimum of ten years of follow-up. However, acetabular component malposition and the small head size (28 mm) are risk factors for dislocation.

Revision Arthroplasty Versus Open Reduction and Internal Fixation of Vancouver Type-B2 and B3 Periprosthetic Femoral Fractures

»

Revision arthroplasty (RA) continues to be considered the gold standard in the surgical treatment of Vancouver type-B2 and B3 periprosthetic femoral fractures. However, open reduction and internal fixation (ORIF) has been associated with satisfactory outcomes. Thus, there is an ongoing discussion regarding the optimal surgical strategy for the treatment of these fractures.

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In this systematic review and meta-analysis, no significant differences in clinical and radiographic outcome were observed between ORIF and RA in the treatment of Vancouver type-B2 periprosthetic femoral fractures.

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ORIF of Vancouver type-B3 periprosthetic femoral fractures was associated with higher revision and reoperation rates than those after RA.

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Compared with RA, a significantly higher rate of subsidence was found in the ORIF group in Vancouver type-B2 periprosthetic femoral fractures whereas no significant difference in terms of loosening was observed.

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In the comparison of RA and ORIF for the treatment of Vancouver type-B2 and B3 fractures, the percentage of patients achieving full weight-bearing did not differ significantly.

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Mortality rates did not differ between RA and ORIF in the treatment of Vancouver type-B2 and B3 fractures.

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Overall complication rates did not differ between RA and ORIF in the treatment of Vancouver type-B2 and B3 fractures.

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We found a high heterogeneity in applied surgical and fixation techniques in the ORIF group.

Atypical periprosthetic femoral fractures of the hip: A PRISMA compliant systematic review

INTRODUCTION

Long-term use of bisphosphonates (BPs) is associated with Atypical Femoral Fracture (AFF). Theoretically, periprosthetic femoral fractures (PFF) should be excluded from the diagnosis of AFF. However, recently several studies reported the occurrence of PPFs around a hip arthroplasty presenting features of an AFF. The present study describes the characteristics of Atypical Periprosthetic Femoral Fracture (APFF) and evaluates the effectiveness of their management through a PRISMA compliant systematic review of the published case reports and series.

MATERIALS AND METHODS

A literature search was performed using "periprosthetic fracture" and "atypical femoral fracture" as keywords. Patients demographics, drug use, clinical and imaging characteristics, stem fixation and classification, management strategies for APFF and patients' outcomes, were also collected.

RESULTS

The present review included and analysed 17 patients from 12 studies. All APFFs occurred in females with a mean age of 75.9 years of age (range 43-87). In 11 patients, APFFs occurred around an uncemented stem, and in 6 around a cemented stem. Ten fractures were incomplete, and 7 complete. Conservative management was effective in 4 of 10 patients with incomplete fracture, while all patients with complete fractures underwent open reduction and internal fixation. A fracture non-union was observed in 5 patients and further surgery was required.

DISCUSSIONS

APFFs share several clinical and imaging characteristics with AFF. An appropriate and early diagnosis may allow to improve the outcome of these fractures, the management of which should be based on the same principles of that of AFFs.

CONCLUSIONS

Considering the low quality of published articles and the heterogeneity of the treatment used, a clear recommendation of the most appropriate treatment cannot be formulated.

Periprosthetic Atypical Femoral Fractures Exist: A Retrospective Study at a Single Institution. Prevalence on 115 Periprosthetic Femoral Fractures Around a Primary Hip Stem

BACKGROUND

Some periprosthetic femoral fractures (PFFs) present history and radiographic aspect consistent with an atypical femoral fracture (AFF), fulfilling the criteria for AFF except that PFFs by themselves are excluded from the diagnosis of AFFs. The aim of this study is to evaluate in a single institution series of PFFs if any of them could be considered a periprosthetic atypical femoral fracture (PAFF), and their prevalence.

METHODS

Surgical records were searched for PFFs around a primary hip stem from January 2013 to December 2019. Cases were classified according to Vancouver classification. Demographic and medical history was extracted. Fisher's exact test was used for statistical analysis.

RESULTS

One hundred fifteen PFFs were identified, 59 of them were type B1 and 16 were type C. Radiographs and medical records were available for all patients. Twenty-four patients (32%) have been treated with bisphosphonates (BPs) for longer than 4 years. Four patients presented a fracture with characteristics of PAFF. When enlarged to all PFFs of the series, no other PAFF was found: prevalence of PAFFs was 5.3% for type B1 and C cases and 3.5% for all surgically treated PFFs. Statistical significative difference between PAFFs and PFFs was found for prolonged BP assumption and for the level of fracture clear of the stem.

CONCLUSION

Fracture with characteristics of AFFs can also happen over a prosthetic stem, configuring themselves as PAFFs, and they are related to prolonged BP use. As a correct diagnosis is mandatory for proper treatment, a revision of criteria for AFFs should be considered, accepting that PAFFs exist.

Interprosthetic Femoral Fractures Surgical Treatment in Geriatric Patients

Background

Total hip (THA) and total knee arthroplasty (TKA) are becoming an increasingly standard procedure in the whole world. In conjunction with an aging population and increased prevalence of osteoporosis, proper management of periprosthetic, and interprosthetic fractures is of great interest to orthopedic surgeons. This study aims to report the clinical and radiographic outcomes, complications and reoperations of IFFs in geriatric patients.

Methods

A retrospective single-institution case series study was conducted. Between 2011 and 2019, 83 patients underwent surgical treatment for periprosthetic femoral fractures. Thirteen fractures were identified as IFFs. Patient demographics and comorbidities were collected preoperatively, and fractures were classified with the Vancouver and AO unified classification system (AO-UCS).

Results

We included 12 patients (13 hips) with IFFs (AO-UCS type IV.3 B (2/13) type IV.3 C (3/13), type IV.3 D (8/13)). The average patient age was 86.54 (range, 79-89) years. There were 10 females and 2 males. Perioperative morbidity has been identified in 10 of the 12 patients, and the 3-month and 1-year mortality were reported in 2 and 3 patients, respectively. Cerclage cables were used in 9 of 12 patients. One of 12 patients showed a local complication, with no documented implant failure or revision. Patients achieved complete union and returned to their preoperative ambulatory status, and full weight-bearing at an average of 5 (range, 2 to 7) months later.

Conclusion

Management of IFF can be challenging because these fractures require extensive surgical expertise. Locking plate seems to be a valuable treatment option for geriatric patients with IFFs. Despite the complexity of this type of fracture, the overall complication and revision rate, as well as the radiographic outcome are good to excellent.

Level of Evidence

Level III, Therapeutic study.

The reliability and validity of the modified Unified Classification System for periprosthetic femoral fractures after hip arthroplasty

BACKGROUND

This study assessed the reliability and validity of the modified Unified Classification System for femur fractures after hip arthroplasty.

METHODS

Four hundred and two cases were evaluated by 6 observers, 3 experts and 3 trainee surgeons. Each observer read the radiographs on 2 separate occasions and classified each case as to its type. Reliability was assessed by looking at the intraobserver and interobserver agreement using the Kappa statistic. Validity was assessed within the B group by looking at the agreement between the radiographic classification and the intraoperative findings. Interobserver and intraobserver agreement and validity were analyzed, using weighted kappa statistics.

RESULTS

The mean k value for interobserver agreement was found to be 0.882 (0.833-0.929) for consultants (almost perfect agreement) and 0.776 (0.706-0.836) for the trainees (substantial agreement). Intraobserver k values ranged from 0.701 to 0.972, showing substantial to almost perfect agreement. Validity analysis of 299 type B cases revealed 89.854% agreement with a mean k value of 0.849 (0.770-0.946) (almost perfect agreement).

CONCLUSIONS

This study has shown that the modified Unified Classification System is reliable and valid. We believe it is useful to improve the judgment of the implant stability, and establish the therapeutic strategy for periprosthetic femoral fracture.

Biomechanics of periprosthetic femur fractures and early weightbearing

PURPOSE

The incidence of periprosthetic fractures is expected to rise increase by 4.6% every 10 years between 2015 and 2060. There are few large series examining optimal fixation constructs or the influence of early ambulation on outcome. The purpose of this narrative review is to investigate the published biomechanical considerations for periprosthetic fracture fixation, with specific consideration of early postoperative weightbearing.

METHODS

A literature review was performed to identify fracture incidences, etiology, and current trends in weightbearing after fixation. Benefits of early weightbearing, current constructs, and biomechanics are reviewed.

RESULTS

The limited data available support medical benefits and increased union rates with early mobilization. Optimal fixation constructs are not agreed upon, but mechanical studies suggest that dual implant constructs can support physiologic weightbearing loads.

CONCLUSION

Further clinical trials are required to investigate fracture union and hardware complications in dual implant construct.

Periprosthetic occult acetabular fracture: an unknown side effect of press-fit techniques in primary cementless total hip arthroplasty

BACKGROUND

This study sought to investigate the prevalence and risk factors of periprosthetic occult acetabular fracture occurring during cementless acetabular cup insertion in patients undergoing primary total hip arthroplasty (THA) and to assess the clinical consequences of these fractures.

METHODS

A total of 232 hips (n = 205 patients) were included in this study. A periprosthetic occult acetabular fracture was defined as that which was unrecognised intraoperatively and was undetectable on post-operative radiographs yet was successfully diagnosed on post-operative computed tomography (CT) images. Clinical (age, sex, body mass index, and preoperative diagnosis) and surgical (additional screw fixation, cup rim size, and cup type) variables were analysed to identify risk factors for periprosthetic occult acetabular fracture.

RESULTS

Sixteen (6.9%) periprosthetic occult intraoperative acetabular fractures were identified. In addition, one (0.4%) periprosthetic acetabular fracture was found during operation. The superolateral wall (9/16 hips; 56.3%) was the most frequent location. In addition, one (0.4%) periprosthetic acetabular fracture was found during operation. Male sex was the only factor associated with an increased risk for periprosthetic occult intraoperative acetabular fracture (odds ratio for male versus female sex: 4.28; p = 0.04). There was no significant association between cup type and the occurrence of periprosthetic occult acetabular fracture. All 16 hips with periprosthetic occult intraoperative acetabular fracture were healed at the final follow-up visit without the requirement for any additional surgical interventions.

CONCLUSION

The results of the current study suggest that periprosthetic occult acetabular fractures are common during press-fit acetabular cup insertion in primary THA. Surgeons should have a high index of suspicion and early CT imaging referral in male patients who present with unexplained early post-operative groin pain in primary THA using cementless acetabular cups.

Factors affecting the incidence of postoperative periprosthetic fractures following primary and revision hip arthroplasty: a systematic review and meta-analysis

Objectives

The increasing number of hip arthroplasties (HA), due to the growing elderly population, is associated with the risk of femoral periprosthetic fractures (FPFs). The purpose of this study was to identify potential risk factors for the development of FPFs after HA.

Methods

A systematic review was conducted in five data bases (Medline, Embase, Cochrane, Cinahl, ICTRP) according to the Preferred Reporting Items for Systematic reviews and Meta-analysis (PRISMA) guidelines up to May 2019, using the key words “risk factor,” “periprosthetic fracture,” and “hip replacement or arthroplasty.” Meta-analysis of the clinical outcomes of HA and subgroup analysis based on the factors that were implicated in FPFs was performed.

Results

Sixteen studies were included (sample size: 599,551 HA patients, 4253 FPFs, incidence 0.71%). Risk factors statistically associated with increased incidence of FPFs were female gender (+ 40%), previous revision arthroplasty surgery (× 3 times), and the presence of rheumatoid arthritis (× 2.1 times), while osteoarthritis (− 57%), cement application (− 59%), and insertion of Biomet (− 68%) or Thompson’s prosthesis (− 75%) were correlated with low prevalence of FPFs. Obesity, cardiac diseases, advanced age, bad general health (ASA grade ≥ 3), and use of Exeter or Lubinus prosthesis were not linked to the appearance of FPFs.

Conclusion

This meta-analysis suggested that female gender, rheumatoid arthritis, and revision arthroplasty are major risk factors for the development of FPFs after a HA. In those patients, frequent follow-ups should be planned. Further prospective studies are necessary to clarify all the risk factors contributing to the appearance of FPFs after HA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-020-02152-0.

Nationwide Analysis of Lower Extremity Periprosthetic Fractures

BACKGROUND

Although the annual incidence of primary total joint arthroplasty is increasing, trends in the annual incidence of periprosthetic fractures have not been established. This study aimed to define the annual incidence of periprosthetic fractures in the United States.

METHODS

Inpatient admission data for 60,887 surgically treated lower extremity periprosthetic fractures between 2006 and 2015 were obtained from the National Inpatient Sample database. The annual incidence of periprosthetic fractures was defined as the number of new cases per year and presented as a population-adjusted rate per 100,000 US individuals. Univariable methods were used for trend analysis and comparisons between groups.

RESULTS

The national annual incidence of periprosthetic fractures presented as a population-adjusted rate of new cases per year peaked in 2008 (2.72; 95% confidence interval [95% CI], 2.39-3.05), remained stable from 2010 (1.65; 95% CI, 1.45-1.86) through 2013 (1.67; 95% CI, 1.55-1.8) and increased in 2014 (1.99; 95% CI, 1.85-2.13) and 2015 (2.47; 95% CI, 2.31-2.62). The proportion of femoral periprosthetic fractures managed with total knee arthroplasty revision remained stable (P_trend = .97) with an increase in total hip arthroplasty (THA) revision (P_trend < .001) and concurrent decrease in open reduction and internal fixation (ORIF) (P_trend < .001). Revision THA was significantly more costly than revision total knee arthroplasty (P = .004), and both were significantly more costly than ORIF (P < .001 for both).

CONCLUSION

The annual incidence of periprosthetic fractures remained relatively stable throughout our study period. The proportion of periprosthetic fractures managed with revision THA increased, whereas ORIF decreased. Our findings are encouraging considering the significant burden an increase in periprosthetic fracture incidence would present to the health care system in terms of both expense and patient morbidity.

Introduction of a New Treatment Algorithm Reduces the Number of Periprosthetic Femoral Fractures After Primary Total Hip Arthroplasty in Elderly Females

BACKGROUND

Increasing global usage of cementless prostheses in total hip arthroplasty (THA) presents a challenge, especially for elderly patients. To reduce the risk of early periprosthetic femoral fractures (PFFs), a new treatment algorithm for females older than 60 years undergoing primary THA was introduced. The aim of this study was to determine the impact of the new treatment algorithm on the early risk of perioperative and postoperative PFFs and guideline compliance.

METHODS

A total of 2405 consecutive THAs that underwent primary unilateral THA at our institution were retrospectively identified in the period January 1, 2013-December 31, 2018. A new treatment algorithm was introduced on April 1, 2017 with female patients aged older than 60 years intended to receive cemented femoral components. Before this, all patients were scheduled to receive cementless femoral components. Demographic data, number of perioperative and postoperative PFFs, and surgical compliance were recorded, analyzed, and intergroup differences compared.

RESULTS

The utilization of cemented components in female patients older than 60 years increased from 12.3% (n = 102) to 82.5% (n = 264). In females older than 60 years, a significant reduction in the risk in early postoperative and intraoperative PFF after introduction of the new treatment algorithm was seen (4.57% vs 1.25%; P = .007 and 2.29% vs 0.31%; P = .02, respectively). Overall risk for postoperative and intraoperative fractures combined was also reduced in the entire cohort (4.1% vs 2.0%; P = .01).

CONCLUSION

Use of cemented fixation of the femoral component in female patients older than 60 years significantly reduces the number of PFFs. Our findings support use of cemented femoral fixation in elderly female patients.

Contribution of the remaining attachment index in the management of Vancouver B1 periprosthetic hip fracture

INTRODUCTION

Implant fixation assessment following Vancouver B1 periprosthetic hip fracture is a major decision factor for internal fixation and/or implant revision. The main aim of the present study was to assess the correlation between radiographic Remaining Attachment Index (RAI) and risk of implant loosening at last follow-up following internal fixation of Vancouver B1 periprosthetic hip fracture.

MATERIAL AND METHOD

A multicentre retrospective study included 50 patients with Vancouver B1 periprosthetic hip fracture with uncemented femoral stem between 2013 and 2019. Preoperative radiographs were analysed independently by 2 senior orthopedic surgeons, distinguishing 2 groups: RAI>2/3 versus<2/3. Postoperative and last follow-up radiographs were then screened for signs of complete femoral component loosening.

RESULTS

Median age was 89 years (range: 36-99 years). Two RAI>2/3 patients showed implant loosening (8%) versus 9 RAI<2/3 patients (36%), disclosing a significant correlation between early loosening and RAI<2/3 (p=0.005). Interobserver agreement for both radiographic RAI and radiographic loosening assessment at last follow-up was 98% with kappa correlation coefficient 0.96 [range: 0.88-1].

CONCLUSION

Remaining Attachment Index<2/3 in Vancouver B1 periprosthetic hip fracture was a risk factor for early implant loosening after isolated internal fixation. In these often frail elderly patients, first-line implant exchange is to be considered in the light of the risk/benefit ratio. The present results confirm the need for rigorous preoperative radiographic work-up of the remaining attachment area in Vancouver B1 fracture.

LEVEL OF EVIDENCE

IV.

Periprosthetic fractures of the proximal femur: beyond the Vancouver classification

The majority of periprosthetic femoral fractures are treated surgically.

Surgical treatment may be revision only, revision in combination with open reduction and internal fixation (ORIF), or ORIF only.

The treatment decision is dependent on whether the stem is loose or not, but loose stems are not always identified, resulting in unsatisfactory treatments.

This article presents an algorithmic approach to identifying loose stems around proximal femoral periprosthetic fractures, taking patient history, stem design, and plain radiographs into consideration. This approach may help identifying loose stems and increase the probability of effective treatments.

Cite this article: EFORT Open Rev 2020;5:449-456. DOI: 10.1302/2058-5241.5.190086

Validity and reliability of the Unified Classification System applied to periprosthetic femur fractures: a comparison with the Vancouver system

Objective: The Unified Classification System (UCS) presents itself as an evolution of the Vancouver Classification (VCS) for the evaluation of periprosthetic fractures of the proximal femur (PPF). The aim of our study was to highlight any loss of reproducibility or validity of the new classification system, compared to the previous one.Material and methods: We tested the interobserver and intraobserver agreement using 40 PPF clinical cases. Each classifying subtype of the UCS and VCS was present in at least two cases. Six experienced hip surgeons (Senior Surgeon, SS) and 5 surgeons in training (Junior Surgeon, JS) classified the clinical cases, using VCS and UCS. The validity of both classifications was then tested with intraoperative surveys.Results: The mean κ value for interobserver agreement for the VCS in the JS group was 0.65 and 0.81 for the SS group. The mean κ value for interobserver agreement for the UCS in the JS group was 0.63 and 0.65 for the SS group. The mean κ value for intraobserver agreement for the VCS in the JS group was 0.71 and 0.73 for the SS group. The mean κ value for intraobserver agreement for the UCS in the JS group was 0.72 and 0.7 for the SS group. Validity analysis showed a moderate agreement for the VCS and a good agreement for the UCS.Conclusion: The UCS completes the Vancouver classification, expanding it. It is reliable, despite the increase in classification categories and number of parameters to evaluate, with a slightly higher validity.

[Periprosthetic fractures of the proximal femur]

The incidence of periprosthetic fractures of the proximal femur is increasing due to the growing numbers of hip replacements in old age. The treatment of these fractures is a challenge for the treating physician and standardized procedures are necessary. The unified classification system (UCS) is a suitable tool to establish treatment strategies: On the basis of the fracture localization and extent, bone quality, stability of the prosthesis and the presence of further implants, the fractures can be classified according to the UCS and a treatment algorithm can be derived. This article gives an overview of the diagnostics, classification and characteristics of the various periprosthetic fracture types as well as the treatment.

Has the Use of Fixation Techniques in THA Changed in This Decade? The Uncemented Paradox Revisited

BACKGROUND

Despite existing studies favoring cemented fixation for patients older than 75 years, a trend toward increased use of uncemented fixation has been described in a 2013 study that used arthroplasty registry data from 2006 to 2010. Updated summarized data are needed beyond 2010 to investigate contemporary trends in the usage of uncemented fixation, especially in patients older than 75 years, and to draw attention to a potential continuing conflict between trends in fixation choice and reported revision risk. Thus, healthcare policy and practice can change and surgeons can make better implant fixation choices.

QUESTIONS/PURPOSES

(1) Has the percentage of primary THAs performed with uncemented fixation changed since 2010? (2) Has the percentage of primary THAs performed in patients older than 75 years performed with uncemented fixation changed since 2010? (3) After stratifying by age, which fixation strategy (cemented versus uncemented and hybrid versus uncemented) is associated with the lowest risk of revision?

METHODS

National annual reports from hip arthroplasty registers were identified, and data were extracted from registers published in English or a Scandinavian language, with at least 3 years of reported data in the period from 2010 to 2017. These included Australia, Denmark, England-Wales, Finland, the Netherlands, New Zealand, Romania, Norway, Sweden, and Switzerland, which are all countries with high completeness rates. Data regarding rates of revisions (all causes) related to fixation methods and secondary to different age groups, were taken directly from the registers and no re-analysis was done. The risk estimates were presented as either hazard ratios, rate per 100 component years or as Kaplan-Meier estimates of revision. The age groups compared for Denmark were younger than 50, 50-59, 60-69,70-79, and older than 80 years, and for Australia, New Zealand, England-Wales, and Finland, they were younger than 55, 55-64, 65-74, and older than 75 years. No data were pooled across the registers.

RESULTS

The current use of uncemented fixation in primary THAs varies between 24% (Sweden) and 71% (Denmark). Increasing use of uncemented fixation has been reported in Norway, Denmark, and Sweden, whereas decreasing use of uncemented fixation has been reported in England-Wales, Australia, New Zealand, and Finland. Examining the group of patients older than 75 years, we found that the use of uncemented fixation has been stable in Netherlands, Sweden, New Zealand, and England-Wales. The use of uncemented fixation is still increasing in Denmark and Australia. In Finland, the use of uncemented fixation has decreased (from 43 % to 24 %) from 2010 to 2017. When compared with uncemented fixation, the risk of revision for hips using cemented fixation was lower in patients older than 75 years for all registers surveyed, except for the oldest males in the Finnish register. In this group, no difference was found between cemented and uncemented fixation.

CONCLUSION

Our findings should be used in healthcare policy as feedback on current THAs being performed so as to direct surgeons to choose the right implant fixation, especially in patients older than 75 years, thereby reducing revision risk and increasing the long-term survival of primary THAs. It appears that femoral stem fixation may be the most important revision risk factor in older patients, and future studies should examine this perspective.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Perceived occurrence of an adverse event affects patient-reported outcomes after total hip replacement

Background

Dislocation, periprosthetic fracture and infection are serious complications of total hip replacement (THR) and which negatively impact on patients’ outcomes including satisfaction, quality of life, mental health and function. The accuracy with which patients report adverse events (AEs) after surgery varies. The impact of patient self-reporting of AEs on patient-reported outcome measures (PROMs) after THR is yet to be investigated. Our aim was to determine the effect of confirmed and perceived AEs on PROMs after primary THR.

Methods

A prospective single-centre cohort study of patients undergoing primary THR, with one-year follow-up, was performed. Participants completed forms pre-operatively and 3, 6, 9 and 12 months post-operatively, including Work Productivity and Activity Impairment (WPAI), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), EuroQol-5D-3 L (EQ5D), Self-Administered Patient Satisfaction (SAPS) and AE reporting questionnaires. Results were reported in three groups: No AE, reported but not confirmed AE and confirmed AE. A generalised linear model was used to compare among groups using robust standard errors (SE).

Results

Forty-one AEs were reported in a cohort of 417 patients (234 females), with 30 AEs reported by 3 months. Eleven (27 reported) infections, two (six reported) periprosthetic fractures and two (eight reported) dislocations were confirmed. Those in the no AE group reported significantly better outcomes that the reported AE group as measured by WOMAC Co-Eff 14.27 (p = 0.01), EQ5D − 0.128 (p = 0.02) and SAPS − 9.926 (p = 0.036) and the combined reported and confirmed AE groups as measured by WOMAC Co-Eff 13.72 (p = 0.002), EQ5D − 0.129 (p = 0.036) and SAPS − 11.512 (p = 0.004). No significant differences were seen in WPAI among groups.

Conclusions

Patients who report AEs have worse outcomes than those who do not, regardless of whether the AEs can be confirmed by standard medical record review methods. The observed negative trends suggest that patient perception of AEs may influence patient outcome in a similar way to those with confirmed AEs.

Treatment of Complex Femoral Fractures with the Long Intramedullary Gamma Nail

The purpose of the current study was to present the authors’ experiences with the long intramedullary Gamma nail in the treatment of patients with complex femoral fractures. Th is retrospective study included 48 patients with complex femoral fractures. All patients had received fracture fixation treatments with long intramedullary Gamma nails from January 2007 to December 2015. The complex fractures of all patients were classified into 3 types, according to the anatomical locations of the fractures. Type I included combined fractures of the shaft and the proximal femur. Type II included segmental fractures. Type III included combined fractures of the shaft and distal femur. According to the Harris Hip Score, 85.4% of our patients had excellent and very good functional outcomes of the operative procedure. Complications occurred in 7 (14.58%) patients. The most common complications occurred in patients with combined fractures of the shaft and distal femur (50%). Based on the findings of this study, we conclude that the clinical and radiological results after the treatment of complex femoral fractures with the long intramedullary Gamma nail show good outcomes, with a high rate of bone union and minimal soft tissue damage. Experience with this procedure is important to prevent and minimise technical complications.

Cable plate fixation for Vancouver Type-B1 periprosthetic femoral fractures-Our experience and identification of a subset at risk of non-union

INTRODUCTION

Management of periprosthetic femoral fractures is challenging. Vancouver classification is universally accepted for fracture description and management algorithm. Guidelines for the treatment of type B1 fracture is open reduction and internal fixation. The difficulty involved in managing this group is evidenced by the array of treatment options described in the literature.

METHODS

Thirty two patients with Vancouver type B1 fracture treated with osteosynthesis using cable plate (between 2007 and 2015) were reviewed retrospectively. There were 21 females and 11 males with an average age of 81yrs (56-96 years). The average follow-up was 21 months. All patients were reviewed clinically and radiologically until fracture united or patient re-operated. Postoperative protocol followed was six weeks toe touch weight bearing, 6 weeks partial weight bearing and then full weight bearing if there was no displacement. Post-operative radiographs were evaluated for fracture union. Statistical analysis was done using contingency tables with Fishers exact test and a p-value < 0.05 for significance.

RESULTS

In twenty four patients fracture union was achieved. Non-union was recorded in four patients. Comparing the different fracture patterns all non-unions occurred in the fractures which were short oblique or transverse at the cemented stem tip (p = 0.001). Fractures were more common in female patients and associated more with the uncemented femoral stems, but it was not associated with increased rate of non-union (p = 0.68). All failed osteosynthesis were revised successfully using long stem prosthesis. Two patients died within 2 months, one patient died within 4 months, one patient was lost to follow-up.

CONCLUSION

Transverse or short oblique periprosthetic fractures around tip of cemented femoral stems can have high failure rates with just internal fixation. Revision arthroplasty may be the preferred option if possible otherwise may need to supplement fixation with cortical onlay graft. We should consider subcategorising Vancouver type B1 periprosthetic fractures into groups based on the pattern and fracture level in relation to the femoral stem.

Risk Factors for Intraoperative Periprosthetic Femoral Fractures During Primary Total Hip Arthroplasty. An Analysis From the National Joint Registry for England and Wales and the Isle of Man

BACKGROUND

The aim of this study is to estimate risk factors for intraoperative periprosthetic femoral fractures (IOPFF) and each anatomic subtype (calcar crack, trochanteric fracture, femoral shaft fracture) during primary total hip arthroplasty.

METHODS

This retrospective cohort study included 793,823 primary total hip arthroplasties between 2004 and 2016. Multivariable regression modeling was used to estimate relative risk of patient, surgical, and implant factors for any IOPFF and for all anatomic subtypes of IOPFF. Clinically important interactions were assessed using multivariable regression.

RESULTS

Patient factors significantly increasing the risk of fracture were female gender, American Society of Anesthesiologists grade 3 to 5, and preoperative diagnosis including avascular necrosis of the hip, previous trauma, inflammatory disease, pediatric disease, and previous infection. Overall risk of IOPFF associated with age was greatest in patients below 50 years and above 80 years. Risk of any fracture reduced with computer-guided surgery and in non-National Health Service hospitals. Nonposterior approaches increased the risk of shaft and trochanteric fracture only. Cementless implants significantly increased the risk of only calcar cracks and shaft fractures and not trochanteric fractures.

CONCLUSION

Fracture risk increases in patients younger than 50 and older than 80 years, females, American Society of Anesthesiologists grade 3 to 5, and indications other than primary osteoarthritis. Large cumulative reduction in IOPFF risk may occur with use of cemented implants, posterior approach, and computer-guided surgery.

LEVEL OF EVIDENCE

Level 3b (cohort study).

Risk factors for periprosthetic femoral fractures around total hip arthroplasty: a systematic review and meta-analysis

BACKGROUND

Periprosthetic fractures are becoming increasingly common, often leading to poor patient outcomes. The aim of this study was to identify risk factors associated with periprosthetic femoral fractures (PPFFx).

METHODS

Two independent reviewers conducted a systematic review of the databases MEDLINE, Embase and Cochrane Library according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, from the earliest available date to December 2017. We included all clinical articles reporting more than 100 post-operative PPFFx around total hip arthroplasty (THA). Outcomes included demographics, fracture type, risk factors and time to fracture.

RESULTS

A total of 12 868 PPFFx were reported across 18 eligible studies; 64% occurred following primary THA and 36% occurred after revision THA, and 66% of all fractures were in females. Vancouver B2 fractures were the most common type (39%). We found the odds of sustaining a PPFFx is significantly lower after a primary THA compared to revision THA (odds ratio 0.31, 95% confidence interval 0.24-0.40, P < 0.00001). The incidence of PPFFx is 2.96 per 1000 person-years following primary THA compared to 9.08 per 1000 person-years following revision THA (odds ratio 0.33, 95% confidence interval 0.27-0.40). The time to fracture was 6.03 years following primary THA and 4.08 years following revision THA. Gender and cementation did not significantly affect the odds of fracture.

CONCLUSION

The odds of sustaining a PPFFx following revision THA is three times greater compared to primary THA. Other risk factors including gender and cementation did not affect the odds of fracture.

Use of Natural Language Processing Tools to Identify and Classify Periprosthetic Femur Fractures

BACKGROUND

Manual chart review is labor-intensive and requires specialized knowledge possessed by highly trained medical professionals. The cost and infrastructure challenges required to implement this is prohibitive for most hospitals. Natural language processing (NLP) tools are distinctive in their ability to extract critical information from unstructured text in the electronic health records. As a simple proof-of-concept for the potential application of NLP technology in total hip arthroplasty (THA), we examined its ability to identify periprosthetic femur fractures (PPFFx) followed by more complex Vancouver classification.

METHODS

PPFFx were identified among all THAs performed at a single academic institution between 1998 and 2016. A randomly selected training cohort (1538 THAs with 89 PPFFx cases) was used to develop the prototype NLP algorithm and an additional randomly selected cohort (2982 THAs with 84 PPFFx cases) was used to further validate the algorithm. Keywords to identify, and subsequently classify, Vancouver type PPFFx about THA were defined. The gold standard was confirmed by experienced orthopedic surgeons using chart and radiographic review. The algorithm was applied to consult and operative notes to evaluate language used by surgeons as a means to predict the correct pathology in the absence of a listed, precise diagnosis. Given the variability inherent to fracture descriptions by different surgeons, an iterative process was used to improve the algorithm during the training phase following error identification. Validation statistics were calculated using manual chart review as the gold standard.

RESULTS

In distinguishing PPFFx, the NLP algorithm demonstrated 100% sensitivity and 99.8% specificity. Among 84 PPFFx test cases, the algorithm demonstrated 78.6% sensitivity and 94.8% specificity in determining the correct Vancouver classification.

CONCLUSION

NLP-enabled algorithms are a promising alternative to manual chart review for identifying THA outcomes. NLP algorithms applied to surgeon notes demonstrated excellent accuracy in delineating PPFFx, but accuracy was low for Vancouver classification subtype. This proof-of-concept study supports the use of NLP technology to extract THA-specific data elements from the unstructured text in electronic health records in an expeditious and cost-effective manner.

LEVEL OF EVIDENCE

Level III.