Reliability and validity of the Unified Classification System for postoperative periprosthetic femoral fractures around cemented polished taper-slip stems

Periprosthetic fractures around cemented hip hemiarthroplasty: Are SOFCOT-Vancouver recommendations mandatory? A comparative study with propensity score matching

INTRODUCTION

Periprosthetic hip fracture is a serious complication associated with increased mortality and impaired autonomy. When the implant is loosened, the standard treatment involves prosthetic revision. However, recent studies suggest that these cases can be successfully treated with fixation without prosthetic exchange. This strategy seems relevant for elderly and frail patients with fractures around hemiarthroplasties but it has not yet been investigated in France. Therefore we did a retrospective comparative investigation aiming to compare postoperative complications (i.e., death within one month or reintervention) between osteosynthesis and prosthetic revision in elderly patients with Vancouver B fractures around polished tapered stem hemiarthroplasties.

HYPOTHESIS

We hypothesized that there would be no significant difference between osteosynthesis and prosthetic revision.

MATERIALS AND METHODS

In a single-university-center, all patients treated between 2005 and 2024 for periprosthetic fractures after cemented hemiarthroplasty were included in a retrospective observational study. A total of 92 patients were included, with an average age of 88.7 years (range, 77-107), mostly institutionalized (58%) and with multiple comorbidities, as indicated by a mean ASA score of 2.75 (range: 2-4) and a mean Charlson Comorbidity Index of 6.4 (range: 4-10); the average time between HHA and PPF occurrence was 2.1 years (range: 7-5679 days). The primary outcome was a composite criterion including the occurrence of a complication requiring reintervention or death within one month postoperatively. Group comparability was established using a propensity score.

RESULTS

The mean follow-up was 665 days, with the longest follow-up reaching 5704 days. No significant difference was observed in the primary outcome between the osteosynthesis group (n = 19/39 patients, (48.71%)) and the revision group (n = 16/39 patients, (41.02%)) (p = 0.637). Osteosynthesis demonstrated significantly shorter operative time (96 min vs. 167 min, p < 0.001), reduced blood loss (428 mL vs. 874 mL, p < 0.001), shorter hospital stays (9.17 days vs. 13.39 days, p < 0.001), and better autonomy preservation (loss of 1.09 Parker score points vs. 1.97 points, p < 0.001) compared to revision surgery. The 1-year mortality rate was 29,3% (27/92). The reintervention rate was 27.2% (25/92). The main causes of reintervention were dislocations, accounting for 13% (12/92) of cases, (occurring in 9.4% (5/53) of patients in the osteosynthesis group and 17.9% (7/39) in the revision group. The second most common reintervention cause was infection, which accounted for 11% (10/92) of cases, (occurring in 7.5% (4/53) of patients in the osteosynthesis group and 15.4% (6/39) in the revision group).

DISCUSSION

This result supports the idea that, for HHA's PPF, the Vancouver-SOFCOT recommendations can be adapted. For all type B fractures, if the fracture can be reduced and the cement mantle is well-fixed to the bone and of good quality, osteosynthesis is also a reliable option.

LEVEL OF EVIDENCE

III; Retrospective comparative study.

The History of Classification Systems for Periprosthetic Femoral Fractures: A Literature Review

Periprosthetic femoral fractures (PPFFs) following total hip arthroplasty (THA) present a significant clinical challenge due to their increasing incidence with an aging population and evolving surgical practices. Historically, classifications were primarily based on anatomical fracture location, the stability of the implant, and bone quality surrounding the implant. We critically analyzed 25 classification systems, highlighting the emergence and adaptations of key systems such as the Vancouver classification system (VCS) and the Unified classification system (UCS), which are lauded for their simplicity and effectiveness yet require further refinement. VCS, developed in 1995, categorizes fractures based on the site, implant stability, and bone quality, and remains widely used due to its robust applicability across different clinical settings. Introduced in 2014, UCS expands the VCS to encompass all periprosthetic fractures with additional fracture types, aiming for a universal application. Despite their widespread adoption, these systems exhibit shortcomings, including the incomplete inclusion of all PPFF types and the imprecise assessment of implant stability and surrounding bone loss. These gaps can result in misclassification and suboptimal treatment outcomes. This paper suggests the necessity for ongoing improvements in classification systems to include emerging fracture types and refined diagnostic criteria, ensuring that they remain relevant to contemporary orthopedic practices and continue to facilitate the precise tailoring of treatment to patient-specific circumstances. This comprehensive historical review serves as a foundation for future innovations in classification systems, ultimately aiming to standardize PPFF treatment and improve patient prognosis.

Cemented femoral stem design and postoperative periprosthetic fracture risk following total hip arthroplasty

Polished taper-slip (PTS) cemented stems have an excellent clinical track record and are the most common stem type used in primary total hip arthroplasty (THA) in the UK. Due to low rates of aseptic loosening, they have largely replaced more traditional composite beam (CB) cemented stems. However, there is now emerging evidence from multiple joint registries that PTS stems are associated with higher rates of postoperative periprosthetic femoral fracture (PFF) compared to their CB stem counterparts. The risk of both intraoperative and postoperative PFF remains greater with uncemented stems compared to either of these cemented stem subtypes. PFF continues to be a devastating complication following primary THA and is associated with high complication and mortality rates. Recent efforts have focused on identifying implant-related risk factors for PFF in order to guide preventative strategies, and therefore the purpose of this article is to present the current evidence on the effect of cemented femoral stem design on the risk of PFF.

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.

A cost analysis of treating postoperative periprosthetic femoral fractures following hip replacement surgery in a UK tertiary referral centre

AIM

This study aims to evaluate costs associated with periprosthetic femoral fracture (PFF) treatment at a UK tertiary referral centre.

METHODS

This study included 128 consecutive PFFs admitted from 02/04/2014-19/05/2020. Financial data were provided by Patient Level Information and Costing Systems. Primary outcomes were median cost and margin. Secondary outcomes were length of stay, blood transfusion, critical care, 30-day readmission, 2-year local complication, 2-year systemic complication, 2-year reoperation and 30-day mortality rates. Statistical comparisons were made between treatment type. Statistical significance was set at p<0.05.

RESULTS

Across the cohort, median cost was £15,644.00 (IQR £11,031.00-£22,255.00) and median loss was £3757.50 (£599.20-£8296.20). The highest costs were ward stay (£3994.00, IQR £1,765.00-£7,013.00), theatre utilisation (£2962.00, IQR £0.00-£4,286.00) and overheads (£1705.10, IQR £896.70-£2432.20). Cost (£17,455.00 [IQR, £13,194.00-£23,308.00] versus £7697.00 [IQR £3871.00-£10,847.00], p<0.001) and loss (£4890.00 [IQR £1308.00-£10,009.00] versus £1882.00 [IQR £313.00-£3851.00], p = 0.02) were greater in the operative versus the nonoperative group. There was no difference in cost (£17,634.00 [IQR £12,965.00-£22,958.00] versus £17,399.00 [IQR £13,394.00-£23,404.00], p = 0.98) or loss (£5374.00 [IQR £1950.00-£10,143.00] versus £3860.00 [IQR -£95.50-£7601.00], p = 0.21) between the open reduction and internal fixation (ORIF) and revision groups. More patients required blood transfusion in the operative versus the nonoperative group (17 [17.9%] versus 0 [0.0%], p = 0.009). There was no difference in any clinical outcome between the ORIF and revision groups (p>0.05).

CONCLUSION

PFF treatment costs are high with inadequate reimbursement from NHS tariff. Work is needed to address this disparity and reduce hospital costs. Cost should not be used to decide between ORIF and revision surgery.

A multicentre comparative analysis of fixation versus revision surgery for periprosthetic femoral fractures following total hip arthroplasty with a cemented polished taper-slip femoral component

AIMS

The aim of this study was to compare open reduction and internal fixation (ORIF) with revision surgery for the surgical management of Unified Classification System (UCS) type B periprosthetic femoral fractures around cemented polished taper-slip femoral components following primary total hip arthroplasty (THA).

METHODS

Data were collected for patients admitted to five UK centres. The primary outcome measure was the two-year reoperation rate. Secondary outcomes were time to surgery, transfusion requirements, critical care requirements, length of stay, two-year local complication rates, six-month systemic complication rates, and mortality rates. Comparisons were made by the form of treatment (ORIF vs revision) and UCS type (B1 vs B2/B3). Kaplan-Meier survival analysis was performed with two-year reoperation for any reason as the endpoint.

RESULTS

A total of 317 periprosthetic fractures (in 317 patients) with a median follow-up of 3.6 years (interquartile range (IQR) 2.0 to 5.4) were included. The fractures were type B1 in 133 (42.0%), B2 in 170 (53.6%), and B3 in 14 patients (4.4%). ORIF was performed in 167 (52.7%) and revision in 150 patients (47.3%). The two-year reoperation rate (15.3% vs 7.2%; p = 0.021), time to surgery (4.0 days (IQR 2.0 to 7.0) vs 2.0 days (IQR 1.0 to 4.0); p < 0.001), transfusion requirements (55 patients (36.7%) vs 42 patients (25.1%); p = 0.026), critical care requirements (36 patients (24.0%) vs seven patients (4.2%); p < 0.001) and two-year local complication rates (26.7% vs 9.0%; p < 0.001) were significantly higher in the revision group. The two-year rate of survival was significantly higher for ORIF (91.9% (standard error (SE) 0.023%) vs 83.9% (SE 0.031%); p = 0.032) compared with revision. For B1 fractures, the two-year reoperation rate was significantly higher for revision compared with ORIF (29.4% vs 6.0%; p = 0.002) but this was similar for B2 and B3 fractures (9.8% vs 13.5%; p = 0.341). The most common indication for reoperation after revision was dislocation (12 patients; 8.0%).

CONCLUSION

Revision surgery has higher reoperation rates, longer surgical waiting times, higher transfusion requirements, and higher critical care requirements than ORIF in the management of periprosthetic fractures around polished taper-slip femoral components after THA. ORIF is a safe option providing anatomical reconstruction is achievable.Cite this article: Bone Joint J 2023;105-B(2):124-134.

Management and outcomes of femoral periprosthetic fractures at the hip : data from the characteristics, outcomes and management of periprosthetic fracture service evaluation (COMPOSE) cohort study

AIMS

The aim of this study was to describe the management and associated outcomes of patients sustaining a femoral hip periprosthetic fracture (PPF) in the UK population.

METHODS

This was a multicentre retrospective cohort study including adult patients who presented to 27 NHS hospitals with 539 new PPFs between 1 January 2018 and 31 December 2018. Data collected included: management strategy (operative and nonoperative), length of stay, discharge destination, and details of post-treatment outcomes (reoperation, readmission, and 30-day and 12-month mortality). Descriptive analysis by fracture type was performed, and predictors of PPF management and outcomes were assessed using mixed-effects logistic regression.

RESULTS

In all, 417 fractures (77%) were managed operatively and 122 (23%) conservatively. The median time to surgery was four days (interquartile range (IQR) 2 to 7). Of those undergoing surgery, 246 (59%) underwent revision and/or fixation and 169 (41%) fixation alone. The surgical strategy used differed by Unified Classification System for PPF type, with the highest rate of revision in B2/B3 fractures (both 77%, 176/228 and 24/31, respectively) and the highest rate of fixation alone in B1- (55/78; 71%) and C-type (49/65; 75%) fractures. Cemented stem fixation (odds ratio (OR) 2.66 (95% confidence interval (CI) 1.42 to 4.99); p = 0.002) and B2/B3 fracture type (OR 7.56 (95% CI 4.14 to 13.78); p < 0.001) were predictors of operative management. The median length of stay was 15 days (IQR 9 to 23), 12-month reoperation rate was 5.6% (n = 30), and 30-day readmission rate was 8.4% (n = 45). The 30-day and 12-month mortality rates were 5.2% (n = 28) and 21.0% (n = 113). Nonoperative treatment, older age, male sex, admission from residential or nursing care, and sustaining the PPF around a revision prosthesis were significant predictors of an increased 12-month mortality.

CONCLUSION

Femoral hip PPFs have mortality, reoperation, and readmission rates comparable with hip fracture patients. However, they have a longer wait for surgery, and surgical treatment is more complex. There is a need to create a national framework for data collection for this heterogeneous group of patients in order to understand the outcomes of different approaches to treatment. Cite this article: Bone Joint J 2022;104-B(8):997-1008 .

Epidemiology and characteristics of femoral periprosthetic fractures : data from the characteristics, outcomes and management of periprosthetic fracture service evaluation (COMPOSE) cohort study

AIMS

The aim of this study was to describe the demographic details of patients who sustain a femoral periprosthetic fracture (PPF), the epidemiology of PPFs, PPF characteristics, and the predictors of PPF types in the UK population.

METHODS

This is a multicentre retrospective cohort study including adult patients presenting to hospital with a new PPF between 1 January 2018 and 31 December 2018. Data collected included: patient characteristics, comorbidities, anticoagulant use, social circumstances, level of mobility, fracture characteristics, Unified Classification System (UCS) type, and details of the original implant. Descriptive analysis by fracture location was performed, and predictors of PPF type were assessed using mixed-effects logistic regression models.

RESULTS

In total, 720 femoral PPFs from 27 NHS sites were included. PPF patients were typically elderly (mean 79.9 years (SD 10.6)), female (n = 455; 63.2%), had at least one comorbidity (n = 670; 93.1%), and were reliant on walking aids or bed-/chair-bound prior to admission (n = 419; 61.7%). The study population included 539 (74.9%) hip PPFs, 151 (21.0%) knee PPFs, and 30 (4.2%) dividing type PPFs. For hip (n = 407; 75.5%) and knee (n = 88; 58.3%) arthroplasty UCS B type fractures were most common. Overall, 556 (86.2%) were treated in the presenting hospital and 89 (13.8%) required transfer for treatment. Female sex was the only significant predictor of fracture type (A/B1/C type versus B2/B3) for femoral hip PPFs (odds ratio 0.61 (95% confidence interval 0.41 to 0.91); p = 0.014). Sex, residence type, primary versus revision implant PPF, implant fixation, and time between arthroplasty and PPF were not found to predict fracture type for hip PPFs.

CONCLUSION

This multicentre analysis describes patient and injury factors for patients presenting with femoral PPFs to centres across the UK. These patients are generally elderly and frail, comparable to those sustaining a hip fracture. These data can be useful in planning future services and clinical trials. Cite this article: Bone Joint J 2022;104-B(8):987-996 .

Periprosthetic femoral fracture type and location are influenced by the presence of an ipsilateral knee arthroplasty implant: A case-control study of 84 interprosthetic femoral fractures

BACKGROUND

This multicentre case-control study compares Vancouver Classification System (VCS) grade and Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) fracture type in interprosthetic femoral fractures (IPFFs) between primary total hip arthroplasty (THA) and ipsilateral total knee arthroplasty (TKA) to periprosthetic femoral fracture (PFF) without ipsilateral TKA.

METHODS

Data were collected following institutional approval. Eighty-four IPFFs were assessed for VCS grade and AO/OTA type. Each IPFF case (84) was matched to five PFF controls (360) by age, gender and stem fixation philosophy (SMD<0.1). VCS grade and AO/OTA type were compared between the IPFF and PFF groups using weighted proportions and medians.

RESULTS

Median (IQR) age of IPFF patients was 81.75 (76.57-85.33) years and 61 (72.6%) were female. The commonest VCS grade was B1 (34, 40.5%). The commonest AO/OTA type was spiral (51.8% of VCS B fractures; 50.0% of VCS C fractures). A greater proportion of fractures occurred distal to the stem in IPFF patients versus PFF patients (33.3% versus 18.2%, p = 0.003). VCS grade was significantly different between groups (p = 0.015). For VCS C fractures, twice as many AO/OTA transverse and wedge fractures occurred in the IPFF group compared to the PFF group (25.0% versus 12.6% and 7.1% versus 3.3%, respectively) although the overall difference was not statistically significant (p = 0.407).

CONCLUSION

The presence of an ipsilateral TKA affects the location of PFF with more fractures occurring distal to the stem. A greater proportion of bending type fractures occurred when an ipsilateral TKA was present. These unstable fractures often require more complex surgery.