Periprosthetic fractures about total knee arthroplasty

Outcomes of operatively managed periprosthetic distal femur fractures compared to fractures in patients with native knees

Introduction

With the increasing incidence of total knee arthroplasty (TKA), there is an expected rise in rate of periprosthetic fractures in the coming years. It is unclear how the outcomes of patients with distal femur fractures (DFF) and a total knee arthroplasty compare to patients of the same age group with native knees (NK).

Materials and methods

A retrospective review was completed for distal femur fractures treated with surgical fixation from January 2019-March 2021. We excluded patients <50 years old, non-ambulatory patients, revision surgeries, and patients with less than 90 days of follow-up. A chart review was performed to collect age, gender, BMI, smoking status, American Society of Anesthesiology (ASA) classification, fracture type, fixation method, time to full weight bearing, and complications. Comparisons between the TKA vs native knee groups were performed using t-test, chi-square, and Fisher's exact test where appropriate.

Results

138 patients were included in our study with a mean age of 74 years. 69 DFF ipsilateral to a TKA were included in the study group and 71 DFF were included in the native knee group. Age, sex, BMI, smoking status, and ASA class were similar between the groups. All patients with periprosthetic femur fractures had 33A AO/OTA fracture classification. Patients with native knees were more likely to receive dual implant fixation, 15.5% compared to 4.3% (p = 0.02). Full weight bearing was achieved at 8.5 vs 8.6 weeks between the NK and TKA groups (p = 0.64). The complication rate was 16.9% in the NK group vs. 7.2% in the TKA group (p = 0.21).

Conclusion

Patients with periprosthetic femur fractures have similar time to weight bearing and complications rate with patients with distal femur fracture in native knees. We found a higher utilization rate of dual implant fixation in the native knee group.

Survival Rates and Patient-Reported Outcomes Support the Use of Custom Cement-Over Megaprosthesis (CCOM) in Complex Revision Lower Limb Arthroplasty

BACKGROUND

Patients presenting with periprosthetic osteolysis or fracture between ipsilateral hip and knee arthroplasties are challenging to treat successfully. Long-stem implants, osteopenic bones, and patient comorbidities all represent considerable surgical challenges. Poor results of fracture fixation in this group, coupled with the desire to retain well-performing implants and minimize soft-tissue trauma led to the developmentof the custom cement-over megaprostheses (CCOM). The aims of the study were to evaluate implant survivals, complications, and patient outcomes in those undergoing CCOM within our institution.

METHODS

A retrospective analysis of patients undergoing CCOM between 2002 and 2022 was performed. We studied 34 cases, 33 patients, one patient underwent staged bilateral surgery with 26 women and 8 men.

INDICATIONS

trauma (16), failure of implants /aseptic loosening (9), or joint pathology. The mean Charlson comorbidity index was 3.5 (range, 0 to 8). All patients were followed up (mean 75 months [range, 9 to 170]) at 6 weeks, 6 months, 1 year, and annually thereafter. The VAS, EuroQol-5D-3L and MSTS scores were collected at 1 year.

RESULTS

Implant survival defined by the primary outcome (all-cause revision of the implant at any time point) at 12 months of 97% (32 of 33). In surviving patients, implant survival was 90% (18 of 20) and all 7 survived at 5 and 10 years, respectively. Implant survival including those in the primary outcome group and those free of infection at 12 months was 84.8% (28 of 33) and in surviving patients, implant survival was 70% (14 of 20) and 7 out of 7 at 5 and 10 years, respectively.

CONCLUSIONS

The CCOM technique demonstrates good implant survivorships and satisfactory patient-reported outcomes in complex, often frail patients who have compromised bone stock. This series confirms the technique as an established alternative to total femoral replacement in these cases.

Clinical differences between periprosthetic and native distal femur fractures: a comparative observational study

INTRODUCTION

The incidence of periprosthetic distal femur fractures (PDFF) is increasing as the number of total knee replacements becomes more common. This study compared the demographics, fracture characteristics, treatment, and outcomes of periprosthetic versus native distal femur fractures (NDFF).

MATERIALS AND METHODS

This was a retrospective cohort study of patients ≥ 18 who underwent surgical fixation of NDFF or PDFF from 2012 to 2020 at a level-1 trauma center. The main variables collected included demographics, AO/OTA fracture classification, fixation construct, concomitant fractures, polytrauma rates, bone density, and reduction quality. Primary outcomes were unexpected return to the operating room (UROR), hospital length of stay, and quality of reduction. T-tests, Fisher's exact tests, and multivariate analyses were used for statistical analysis.

RESULTS

209 patients were identified, including 70 PDFF and 139 NDFF. PDFF patients were elderly females (81%) with isolated (80%) and comminuted (85%) 33 A.3 (71%) fractures. NDFF patients included 53% females, were commonly middle-aged, and displayed comminuted (92%) 33 C.2 fractures. 48% of NDFF patients had concomitant fractures. Intramedullary nailing was the primary fixation for both groups, followed by nail-plate combination (37%) for PDFF and lateral locking plates (21%) for NDFF. NDFF patients experienced significantly longer hospital stays, higher UROR rates, and worse quality of reduction (p < 0.05). PDFF patients had a significantly greater prevalence of low bone density (p < 0.05).

CONCLUSION

PDFF occur as isolated injuries with significant metaphyseal comminution in elderly females with low bone quality. NDFF commonly occurs in younger patients with less metaphyseal comminution and concomitant fractures. Intramedullary nailing was the most common treatment for both groups, although preference for nail-plate combination fixation is increasing. NDFF type 33 C fractures are at greater risk of UROR.

Risk and Epidemiology of Periprosthetic Knee Fractures After Primary Total Knee Arthroplasty: A Nationwide Cohort Study

BACKGROUND

Periprosthetic knee fractures (PPKFs) following total knee arthroplasty (TKA) are uncommon, but potentially serious injuries. We analyze the risk and risk factors for a PPKF in standard primary TKA patients who have osteoarthritis and a minimally (cruciate-retaining TKAs without a femoral box cut) or posterior-stabilized TKA. In addition, we report the risk for patients who have other underlying knee disorders and/or a higher level of TKA constraint.

METHODS

All primary TKAs were identified from the Danish National Patient Register and the Danish Knee Arthroplasty Register using data between 1997 and 2022. Subsequent fractures were identified through the International Classification of Diseases diagnosis code, Nordic Medico-Statistical Committee procedure code, or indication for revision TKA.

RESULTS

We included 120,642 standard primary TKA patients who had 1,434 PPKFs. The cumulated proportions were 0.4% (95% confidence interval (CI) 0.3 to 0.4) at 2 years 0.8% (0.7 to 0.8) at 5 years. At 10 years, the cumulated proportion was 1.7% (1.6 to 1.8), with 1.3% in the femur, 0.2% in the patella, and 0.2% in the tibia. Significant risk factors were (hazard ratio [HR] [95% CI]); ipsilateral hip arthroplasty (2.3 [2.0 to 2.6]); women (2.1 [1.8 to 2.4]), osteoporosis (1.4 [1.2 to 1.7]); age 80+ (1.4 [1.3 to 1.6]), uncemented TKA (1.3 (1.1 to 1.5) and Charlson Comorbidity Index score 3+ (1.4 [1.1 to 1.8]). An additional 22,624 primary TKA patients who had other underlying knee disorders and/or a higher level of implant constraint were included with 485 PPKFs. The 10-year cumulated proportions were 8.3% (95% CI 6.9 to 9.8) when the underlying disorder was a previous fracture, 2.8% (2.2 to 3.5) for rheumatic disorders, and 5.2% (2.6 to 10.6) for osteonecrosis. In patients who had condylar constrained knees, it was 6.9% (5.1 to 9.4), and 12.4% (8.0 to 16.04) for hinges.

CONCLUSIONS

In standard primary TKA patients, the 10-year cumulated proportion of PPKFs was 1.7%, and ipsilateral hip arthroplasty, women, osteoporosis, advanced age, uncemented TKA and higher Charlson Comorbidity Index increased the risk. Higher risks were observed in non-osteoarthritis patients and/or patients who had a higher level of TKA constraint.

Management of periprosthetic femoral fractures following total knee arthroplasties using locking plates or intramedullary nailing. Comparative study of 567 cases

INTRODUCTION

Proximal femur fractures in elderly patients pose a common problem that requires surgical management. The main objective of this study was to compare the results of treatment by locked plate (LP) and by anterograde (AIN) or retrograde (RIN) intramedullary nailing. The secondary objective was to analyze the complications related to each group. The hypothesis of this study was that the radiological and clinical results of each group were comparable.

MATERIALS AND METHODS

The data of 438 patients from 8 centers were studied retrospectively with 365 LP and 69 cases of intramedullary nailing (49 AIN and 20 RIN). The groups were comparable in terms of mean age (75±2years), mean preoperative Parker score (5.3±0.5) and mean KOOS score (74±2). Most patients lived at home before their fracture [n=375 (86%)]. At follow-up, the joint range of motion, the KOOS and Parker scores, living premises, the time required to regain full weight-bearing, the time required for consolidation as well as the reduction alignment: frontal, sagittal, horizontal.

RESULTS

The average follow-up was: 79±2weeks (65 to 82). The functional and radiological results were comparable, although nailing allowed a faster return to weight-bearing (1±2weeks for nailing versus 7±2weeks for LP, p=0.048) and a better postoperative Parker score (5.5±0.5 for nailing versus 4.7±0.2 for LP, p=0.045). Rotational malalignment in femoral nailing was often in the direction of internal rotation, compared to the LP (p=0.045). Complications were comparable with the exception of mortality, which was more frequent for LP [22.5% in the LP group versus 13% in the nailing group (p=0.045)]. Complications were categorized as: mechanical complications 6.8% of LP, 5.7% of nailing (p>0.05), infections [11% of LP, 5.8% of nailing (p>0.05)], surgical revisions [2% of LP, 10% of nailing (p>0.05)].

DISCUSSION AND CONCLUSION

The hypothesis was refuted. These results show that nailing conferred a faster recovery of weight-bearing, a better Parker score, and is associated with a lower mortality rate. The morbidity rate is comparable between the two techniques. Indeed, when the indication for osteosynthesis by LP or by nailing is made, and both choices are technically justifiable, it would be prudent to favor the technique, which carries the least risk, which in this case is nailing. This conclusion must, however, be taken in to consideration with regard to the reduced number of nailing. A larger series of nailing, particularly retrograde, would be necessary to be able to confirm this last difference between the 2 groups.

LEVEL OF EVIDENCE

IV; comparative retrospective study.

Increased risk of periprosthetic joint infection after traumatic injury in joint revision patients

BACKGROUND

Periprosthetic joint infection (PJI) is a serious complication after total joint arthroplasty (TJA). Although some risk factors of PJI were well studied, the association between trauma and PJI remains unknown in revision patients.

MATERIALS AND METHODS

Between 2015 and 2018, a total of 71 patients with trauma history before revisions (trauma cohort) were propensity score matched (PSM) at a ratio of 1 to 5 with a control cohort of revision patients without a history of trauma. Then, the cumulative incidence rate of PJI within 3 years after operation between the two groups was compared. The secondary endpoints were aseptic revisions within 3 postoperative years, complications up to 30 postoperative days, and readmission up to 90 days. During a minimal 3-year follow-up, the survival was comparatively analyzed between the trauma cohort and the control cohort.

RESULTS

The cumulative incidence of PJI was 40.85% in patients with trauma history against 27.04% in the controls (P = 0.02). Correspondingly, the cumulative incidence of aseptic re-revisions was 12.68% in patients with trauma history compared with 5.07% in the control cohort (P = 0.028). Cox regression revealed that trauma history was a risk factor of PJI (HR, 1.533 [95%CI, (1.019,2.306)]; P = 0.04) and aseptic re-revisions (HR, 3.285 [95%CI, (1.790,6.028)]; P < 0.0001).

CONCLUSIONS

Our study demonstrated that revision patients with trauma history carried a higher risk of PJI compared to those without trauma history. Moreover, after revisions, the trauma patients were still at higher risk for treatment failure due to PJI, periprosthetic joint fracture, and mechanical complications.

Patella Fracture After Total Knee Arthroplasty: A Review

The management and underlying causes of patellar periprosthetic fractures (PPF) after total knee arthroplasty (TKA) constitute an issue of growing importance given the rising frequency of these procedures. Patella periprosthetic fractures, though relatively rare, pose significant challenges and are a frequent indication for revision surgeries. Despite a decrease in overall incidence, PPFs remain the second most common type of periprosthetic fractures after TKA. Several factors have been identified and associated with patient-specific factors, surgical technique errors, and implant-related causes. Currently extensor apparatus integrity, bone stock, and component loosening are the major concerns and indications for the selective treatment approach. In this study, a thorough review of the existing literature was performed summarizing the epidemiology, clinical manifestation, treatment approach, and functional outcome of PPF. This review aims to underline the significance of such predisposing factors, point out the severity of PPF, and offer insights into the optimal intra- and post-operative management of the patella.

Optimal surgical treatment for periprosthetic distal femoral fractures after total knee arthroplasty: a Bayesian-based network analysis

BACKGROUND

The surgical methods for periprosthetic distal femoral fractures (PDFFs) after total knee arthroplasty included locking compression plate (LCP), retrograde intramedullary nailing (RIMN), and distal femoral replacement (DFR). However, the optimal treatment remains controversial. We performed a network meta-analysis (NMA) to provide the optimal surgical method for PDFFs.

MATERIALS AND METHODS

Electronic databases, including Embase, Web of Science, Cochrane Library, and PubMed, were searched for studies that compared LCP, RIMN, and DFR for PDFFs. The quality of the included studies was assessed according to the Newcastle-Ottawa scale. Pairwise meta-analysis was performed by Review Manager version 5.4. The NMA was conducted in Aggregate Data Drug Information System software version 1.16.5. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) for postoperative complications and reoperations.

RESULTS

A total of 19 studies and 1198 patients were included, of whom 733 for LCP, 282 for RIMN, and 183 for DFR. Pairwise meta-analysis comparing LCP to RIMN and LCP to DFR showed no significant difference in complications and reoperations except that RIMN had a higher risk of malunion comparing to LCP (OR 3.05; 95% CI 1.46-6.34; P = 0.003). No statistically significant effects were found in the NMA of overall complications, infection, and reoperation. However, results of rank probabilities showed that DFR ranked best in overall complications and reoperation, RIMN ranked best in infection but worst in reoperation, and LCP ranked worst in infection and middle in reoperation.

DISCUSSION

We found similar complication rate and reoperation rate between LCP, RIMN, and DFR. The results of rank probabilities favored DFR, and further studies with high-level evidence are expected to verify the optimal surgical method for PDFFs.

LEVEL OF EVIDENCE

Level II; network meta-analysis.

Combination-type periprosthetic tibial fracture: Felix type (II+IV)A

Tibial periprosthetic fractures are rare but present a complicated problem for orthopaedic surgeons. Literature in relation to combination-type periprosthetic fractures is extremely scarce, and there is limited guidance available on its treatment. We report the case of a woman in her 60s, whose radiographs revealed a periprosthetic fracture of the tibia, which was a Felix type (II+IV)A fracture. The tibial tuberosity fragment was fixed with a cannulated cancellous screw. The fracture adjacent to the stem was managed conservatively as the prosthesis was stable. Follow-up radiographs revealed both fractures to have healed completely by 12 weeks. The patient returned to preinjury functional levels by 4 months. Our demonstrated treatment of a Felix type II+IV periprosthetic fracture could be a viable treatment option for such fractures.

Comparison of locking compression plate and distal femoral replacement for periprosthetic distal femoral fractures: a retrospective study

OBJECTIVE

To compare the clinical outcomes of locking compression plate (LCP) and distal femoral replacement (DFR) for periprosthetic distal femoral fractures (PDFFs) after total knee arthroplasty.

METHODS

This retrospective study identified patients with PDFFs in an institutional database between January 2012 and December 2021. Demographic data and clinical outcomes, including postoperative complications, reoperation, 1-year mortality, Knee Society Scores (KSS) and Knee Society Functional Score (KSFS) were analysed.

RESULTS

In total, 12 patients treated with LCP and six patients treated with DFR were included. There was no significant difference between the LCP and DFR groups in terms of postoperative complications (25.0% versus 33.3%, respectively), reoperation (8.3% versus 0.0%), respectively, 1-year mortality (8.3% versus 16.7%, respectively) or mean ± SD KSS (80.3 ± 8.3 versus 78.0 ± 2.5, respectively). However, the mean ± SD KSFS was significantly better for patients with LCP than for those with DFR (51.8 ± 12.5 versus 37.0 ± 6.7, respectively).

CONCLUSION

DFR provides similar clinical outcomes compared with LCP for PDFFs. Patients with advanced age may benefit from DFR to allow early weight bearing.

Successful Plate Fixation with Long Intramedullary Fibula Bone Graft for Periprosthetic Femur Fracture: A Case Report

Background and objectives: Treatment of a displaced or comminuted periprosthetic distal femur fracture is challenging, especially in patients with osteoporosis. In this case report, we shared our successful surgical experience of using a long intramedullary fibula bone graft in a plate fixation surgery for a periprosthetic distal femur fracture in an extremely elderly patient with osteoporosis. Case report: A 95-year-old woman with severe osteoporosis (bone mineral density level: −3.0) presented with right knee pain and deformity after a fall, and a right periprosthetic distal femur fracture was identified. The patient underwent an open reduction and an internal plate fixation surgery with the application of a long intramedullary fibular bone graft. Due to a solid fixation, immediate weight-bearing was allowed after the surgery. She could walk independently without any valgus or varus malalignment or shortening 3 months after the surgery. A solid union was achieved 4 months postoperatively. Conclusions: We present a case wherein a long intramedullary allogenous fibula strut bone graft was used successfully to treat a right periprosthetic femur fracture in an extremely elderly patient. A long allogenous fibula bone graft can act not only as a firm structure for bridging the bone defect but also as a guide for precise component alignment. We believe this treatment option for periprosthetic fractures is beneficial for achieving biological and mechanical stability and facilitates early mobilization and weight-bearing for the patient.

Comparable Outcomes Between Native and Periprosthetic Fractures of the Distal Femur

Despite the rising prevalence of arthroplasty and aging population, limited data exist regarding differences in periprosthetic fracture clinical outcomes compared with native counterparts. This study compares differences in hospital treatment, morbidity, and mortality associated with periprosthetic distal femur fractures at an urban level 1 trauma center. We retrospectively reviewed all adult AO/OTA type 33 fractures (526) that presented to our institution between 2009 and 2018. In total, 54 native and 54 periprosthetic fractures were matched by age and gender. We recorded demographics, operative measures, length of stay (LOS), discharge disposition, and mortality. We used McNemar's and paired t-tests for analysis where appropriate (p < 0.05) (IBM SPSS Statistics for Windows, Version 26.0. Armonk, NY; IBM Corp.). The average age at injury was 74 years ± 12 (native) compared with 73 years ± 12 (periprosthetic). After 1:1 matching, the groups had similar body mass index (31.01 vs. 32.98, p = 0.966 for native and periprosthetic, respectively) and mechanisms of injury with 38 native and 44 periprosthetic (p = 0.198) fractures from low-energy falls. Both groups had 51/54 fractures managed with open reduction internal fixation with a locking plate. The remaining were managed via amputation or intramedullary nail fixation. Mean operative time (144 minutes (±64) vs. 132 minutes (±62), p = 0.96) and estimated blood loss (319 mL (±362) vs. 289 mL (±231), p = 0.44) were comparable between the native and periprosthetic groups, respectively. LOS: 9 days ± 7 (native) versus 7 days ± 5 (periprosthetic, p = 0.31); discharge disposition (to skilled nursing facility/rehab): n = 47 (native) versus n = 43 (periprosthetic, p = 0.61); and mortality: n = 6 (native) versus n = 8 (periprosthetic, p = 0.55). No significant differences were observed. We found no statistical differences in morbidity and mortality in periprosthetic distal femur fractures treated over 10 years at a level 1 trauma center. Native and periprosthetic AO/OTA type 33 distal femur fractures are serious injuries with similar outcomes at a level 1 trauma center.

Impact of patient and prosthesis characteristics on common reasons for total knee replacement revision: a registry study of 36,626 revision cases from Australia, Sweden, and USA

BACKGROUND AND PURPOSE

Total knee replacement (TKR) studies usually analyze all-cause revision when considering relationships with patient and prosthesis factors. We studied how these factors impact different revision diagnoses.

PATIENTS AND METHODS

We used data from 2003 to 2019 of TKR for osteoarthritis from the arthroplasty registries of Sweden, Australia, and Kaiser Permanente, USA to study patient and prosthesis characteristics for specific revision diagnoses. There were 1,072,924 primary TKR included and 36,626 were revised. Factors studied included age, sex, prosthesis constraint, fixation method, bearing mobility, polyethylene type, and patellar component use. Revision diagnoses were arthrofibrosis, fracture, infection, instability, loosening, pain, patellar reasons, and wear. Odds ratios (ORs) for revision were estimated and summary effects were calculated using a meta-analytic approach.

RESULTS

We found between-registry consistency in 15 factor/reason analyses. Risk factors for revision for arthrofibrosis were age < 65 years (OR 2.0; 95% CI 1.4-2.7) and mobile bearing designs (MB) (OR 1.7; CI 1.1-2.5), for fracture were female sex (OR 3.2; CI 2.2-4.8), age ≥ 65 years (OR 2.8; CI 1.9-4) and posterior stabilized prostheses (PS) (OR 2.1; CI 1.3-3.5), for infection were male sex (OR 1.9; CI 1.7-2.0) and PS (OR 1.5; CI 1.2-1.8), for instability were age < 65 years (OR 1.5; CI 1.3-1.8) and MB (OR 1.5; CI 1.1-2.2), for loosening were PS (OR 1.5; CI 1.4-1.6), MB (OR 2.2; CI 1.6-3.0) and use of ultra-high molecular weight polyethylene (OR 2.3; CI 1.8-2.9), for patellar reasons were not resurfacing the patella (OR 13.6; CI 2.1-87.2) and MB (OR 2.0; CI 1.2-3.3) and for wear was cementless fixation (OR 4.9; CI 4.3-5.5).

INTERPRETATION

Patients could be counselled regarding specific age and sex risks. Use of minimally stabilized, fixed bearing, cemented prostheses, and patellar components is encouraged to minimize revision risk.

Outcomes of the Surgical Treatment of Periprosthetic Fractures Around the Knee with Locking Plates: A Single Centre Experience

Introduction:

Surgical treatment options for periprosthetic fractures (PPF) include internal fixation with plate, intramedullary nailing and revision arthroplasty. We aimed at evaluating the surgical outcomes of patients who we had treated PPF with locking compression plates (LCP).

Materials and methods:

Twenty patients with PPF after primary total knee arthroplasty (TKA) between 2009 and 2016 were included in to the study. Knee Society Knee Scoring System (KSKSS) was used in the evaluation of radiologic and functional outcomes. There were periprosthetic supracondylar femoral fractures in 15 patients, and that of tibial fractures in 5 patients. For internal fixation, locking compression plate was preferred.

Results:

The mean age was 69 (range 61 to 78) years and the mean follow-up period was 72.25 (range 24 to 110) months. Union was achieved by 15.8 weeks in all the cases. Superficial infection and implant fracture were each seen in two patients. Revision operations were done to those patients with implant fracture. Mean KSKSS was 81.4 (75-87) and the mean functional score was 78.75 (75-85). Degenerative osteoarthritis patients were found to have higher age values than post-traumatic osteoarthritis patients (p = 0.001). When the union times were compared, it was found that the degenerative osteoarthritis patient group had a significantly shorter union than the post-traumatic osteoarthritis patient group (p = 0.036).

Conclusion:

Internal fixation with LCP is an effective treatment method in managing of PPF for patients with good bone stock. Rigid fixation should be done with the right surgical technique and an early movement must be initiated so that a good function can be achieved.

Current Reconstruction Options in Periprosthetic Fractures Around the Knee

Background:

Periprosthetic fractures are a rare complication after total knee arthroplasty (TKA). However, the incidence of these fractures is growing after the increasing number of TKAs performed every year and the progressive aging of the population. In addition, the surgical treatment and peri-operative management of these complications are demanding, representing a challenge for the orthopedic surgeon.

Significance:

A thorough understanding of these fractures and a correct classification are necessary in order to select the most suitable surgical treatment. The aim of this review was to analyze the epidemiology, classification, diagnosis, surgical treatment, and outcomes of periprosthetic knee fractures in order to give an exhaustive overview.

Results:

Reduction and internal fixation with locking plates or intramedullary nails represents the preferred option in case of a stable prosthetic implant. Conversely, in case of loose tibial and/or femoral component, implant revision is mandatory. Conservative treatment is rarely indicated.

Conclusion:

A deep understanding of the characteristics and patterns of periprosthetic knee fractures, and the determination of the stability of the prosthetic implant are necessary in order to establish the correct treatment.

The autoclaving and re-implantation of an infected prosthesis as a spacer during resection knee arthroplasty: a systematic review

Background

Hofmann et al., in 1995, first described an articulating spacer made by cleaning and autoclaving the original femoral component, which is then re-implanted with a new tibial polyethylene. This systematic review aims to assess the state of existing evidence on the intraoperative autoclaving and re-use of an infected prosthesis, as a spacer, during a two-stage revision following Periprosthetic Joint Infections (PJI).

Methods

A systematic review was conducted with methods described in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. OVID-MEDLINE^®, EMBASE, Cochrane Library, SCOPUS, Web of Science, Google Scholar and PubMed were searched from 1995 to April 2020 to identify relevant studies.

Results

Fourteen studies were included in this systematic review: two prospective case series; six retrospective comparative studies and six retrospective case series. The reviewed studies included 567 patients (571 knees): 394 patients treated with autoclaved components and 173 with a spacer made of new components. The cumulative re-infection rate in patients treated with re-used autoclaved components was 13.7% (54 re-infections in 394 patients), whereas in control patients the re-infection rate was 13.3% (23 re-infections in 173 patients). The final Range of Movement in patients treated using the autoclaved components as a spacer, compared with patients receiving static spacers, was significantly higher in three out of four comparative studies.

Conclusion

There is a moderate level of evidence that the intraoperative autoclaving and re-use of an infected prosthesis as a spacer, during a knee resection arthroplasty, is an effective procedure in the management of knee PJI.

Incidence and Risk Factors of In-Hospital Prosthesis-Related Complications Following Total Knee Arthroplasty: A Retrospective Nationwide Inpatient Sample Database Study

Objective

To examine the incidence and risk factors of in‐hospital prosthesis‐related complications (PRCs) following total knee arthroplasty (TKA) using a large‐scale national database.

Methods

A retrospective database analysis was performed based on Nationwide Inpatient Sample (NIS) from 2005–2014. Patients who underwent TKA were included. The recruited cases were divided into two groups according to the occurrence of PRCs. Patient demographics (age, sex, and race), hospital characteristics (type of admission and payer, and bedsize, teaching status, location, and region of hospital), length of stay (LOS), total charges during hospitalization, in‐hospital mortality, comorbidities, and perioperative complications were analyzed.

Results

A total of 1,227,244 TKAs were captured from the NIS database. There were 8484 cases of in‐hospital PRCs after TKA and the overall incidence was 0.69%, with a slight downward trend annually. Periprosthetic joint infection (PJI) was the main category among PRCs (0.20%), followed by mechanical loosening (0.04%), dislocation (0.02%), and periprosthetic fracture (PPF) (0.01%). Patients suffered from in‐hospital PRCs were 3 years younger (64 years vs 67 years) and 6.51% more likely to be male (43.60% vs 37.09%) compared to the nonaffected population (P < 0.0001). Additionally, patients experiencing in‐hospital PRCs after TKA were 2.11% less likely through elective admission (92.07% vs 94.18%) while 2.34% more likely in teaching hospital (45.53% vs 43.19%) than those without these complications (P < 0.0001). Furthermore, the occurrence of in‐hospital PRCs was associated with longer LOS (4 days vs 3 days; P < 0.0001), more total charges ($53,418 vs $41,204, P < 0.0001), and higher in‐hospital mortality (0.30% vs 0.07%; P < 0.0001). Multivariate logistic regression was performed to identify independent risk factors of in‐hospital PRCs after TKA which included younger age, male, non‐elective admission, teaching hospital, deficiency and chronic blood loss anemia, coagulopathy, congestive heart failure, depression, diabetes with chronic complications, fluid and electrolyte disorders, pulmonary circulation disorders, metastatic cancer, and weight loss. Besides, in‐hospital PRCs after TKA were associated with secondary osteoarthritis, inflammatory arthritis, prior knee arthroscopy, acute renal failure, acute myocardial infarction, deep vein thrombosis, sepsis, transfusion, and wound dehiscence.

Conclusion

It is beneficial to study the risk factors of in‐hospital PRCs after TKA to ensure the appropriate management and optimize consequences although a relatively low incidence was identified.

[Periprosthetic fractures around the knee]

BACKGROUND

Periprosthetic fractures of the knee joint are complex injuries and frequently represent a challenge for the surgeon.

OBJECTIVE

The aim of this review is to present and discuss the current classification and treatment options for periprosthetic knee fractures.

MATERIAL AND METHODS

A selective review of the existing literature on periprosthetic fractures around the knee was performed in PubMed. The various classifications and treatment regimens are discussed with respect to the advantages and disadvantages and from this knowledge a new algorithm was developed.

RESULTS

The classifications of periprosthetic fractures have changed in recent years and have been replaced by a uniform fracture classification; however, not only the radiological evaluation of the fractures is crucial to determine the treatment regimen for periprosthetic fractures. A thorough evaluation of the inserted endoprosthesis should be carried out in order to be able to decide between the treatment options of osteosynthesis and revision arthroplasty. Treatment options are available for osteosynthesis and revision arthroplasty that enable a safe treatment of these complex injuries.

CONCLUSION

Periprosthetic fractures of the knee joint are complex injuries, requiring a thorough preoperative planning and an interdisciplinary treatment with trauma and endoprosthetic expertise.