Periprosthetic fractures around total knee arthroplasty

Periprosthetic Fractures After a Total Knee Arthroplasty

As the number of total knee arthroplasties performed continues to increase, complications such as postoperative periprosthetic fractures are becoming increasingly more common. Femoral periprosthetic fractures are the most common type of fractures around a total knee arthroplasty, whereas tibial and patellar periprosthetic fractures are infrequent. Treatment principles depend on the bone the fracture is located, the status of the implant fixation, bone stock, and the type of implants available. The Vancouver classification allows for a standardized system to describe and manage these injuries, incorporating these factors. A systematic approach is vital in obtaining the best possible outcomes because complications and mortality rates mimic those of hip fractures.

Intraoperative Fractures of the Tibia and Femur in Knee Revision Surgery

Intra-operative fractures in knee revision surgery are relatively rare and have not been well studied. They may occur during joint exposition, removal of the prosthesis or cement, or implantation of trial or original components. The fractures affect both the metaphyseal area and diaphysis of the tibia and femur. Tibial fractures are slightly more common than femur fractures. On the femur, the medial condyle is most frequently affected, followed by the femur diaphysis. The use of non-cemented stems is associated with a greater risk of intra-operative diaphyseal fractures than that of cemented stems. Overall, women and patients with an osteopenic bone structure have a higher risk of fractures. It is common that fractures are diagnosed post-operatively. In these cases, conservative therapy may be successful, depending on the stability of the prosthesis and bones. The most common surgical fixation options are cerclages and screws, followed by stem extensions for bridging the fracture. Plate fixation or use of strut grafts are also sensible therapy options. Overall, intraoperative fractures have a high healing potential with stable and good joint function. The revision rate is still 15%, which is most often caused by peri-prosthetic infection.

Biomechanical Analysis of the Use of Stems in Revision Total Knee Arthroplasty

Adequate fixation is fundamental in revision total knee arthroplasty; consequently, surgeons must determine the correct set-up for each patient, choosing from numerous stem solutions. Several designs are currently available on the market, but there are no evidence-based quantitative biomechanical guideline yet. Therefore, several stems were designed and analyzed using a previously-validated finite-element model. The following parameters were studied: stem design characteristics (length and shape), added features (straight/bowed stem), fixation technique, and effect of slots/flutes. Bone stress and Risk of Fracture (RF) were analyzed in different regions of interest during a squat (up to 120°). For the femoral stem, the results indicated that all parameters influenced the bone stress distribution. The maximum von Mises stress and RF were always located near the tip of the stem. The long stems generated stress-shielding in the distal bone. Regarding the tibial stem, cemented stems showed lower micromotions at the bone-tibial tray interface and at the stem tip compared to press-fit stems, reducing the risk of implant loosening. The results demonstrated that anatomical shapes and slots reduce bone stress and risk of fracture, whereas flutes have the opposite effect; no relevant differences were found in this regard when alternating cemented and press-fit stem configurations. Cemented tibial stems reduce antero-posterior micromotions, preventing implant loosening.

Tibial periprosthetic fractures in Total Knee Arthroplasty - A scoping review

Background

Periprosthetic tibial fractures in Total Knee Arthroplasty are much less commonly seen than femoral fractures, and there is a paucity of available literature and management recommendation for these fractures. We aimed to identify the relevant and up-to-date literature on this subject to analyse the incidence, risk factors, and management recommendations.

Methods

A literature search was done on the databases of PubMed and SCOPUS using appropriate keywords. All the published literature in the English language was included for this review.

Results

We included 21 studies comprising 260 tibial periprosthetic fractures (91 intra-operative (35%) and 169 (65%) post-operative or delayed fractures). Only 5.9% of these fractures were managed conservatively. Whereas 98 cases (58%) were managed with open reduction and internal fixation (ORIF) with plating, 19 (11.2%) were managed with revision TKA. Seventeen cases (10%) were managed with minimally invasive percutaneous plate osteosynthesis (MIPPO), and 8 (4.7%) were managed with intramedullary nailing. Less than 6% of cases were managed with other means, viz. megaprosthesis (n = 4), arthrodesis (n = 5), amputation (n = 1), and external fixator (n = 1).

Conclusion

Intraoperative fractures accounted for one-third of the fractures in our review. A majority of the delayed periprosthetic fractures were treated with surgical intervention. The most preferred surgical treatment method was ORIF of fractures using locking plates (either open or MIPPO). Revision TKA or megaprosthesis was used in cases with the loosened implants in association with the fracture.

Level of evidence

IV.

A Review of Periprosthetic Tibial Fractures: Diagnosis and Treatment

Periprosthetic fracture occurring during or after total knee arthroplasty is a rare injury. Literature concerning periprosthetic tibial factures is sparse, and there is limited guidance for evidence-based management. This review aims to provide readers with an overview of the epidemiology, risk factors, and classification of these fractures. Management includes nonoperative treatment of nondisplaced fractures, fixation for those with stable implants, and revision for those with loose implants.

Locked compression plating versus retrograde intramedullary nailing in the treatment of periprosthetic supracondylar knee fractures: a systematic review and meta-analysis

Background

Periprosthetic fractures of the distal femur above a total knee arthroplasty (TKA) have traditionally been managed by locking compression plating (LCP). This technique is technically demanding and is associated with high rates of non-union and revision. More recently, retrograde intramedullary nailing (RIMN) has been proposed as an acceptable alternative. This meta-analysis aims to evaluate clinical outcomes in patients with periprosthetic supracondylar femoral fractures who were treated with LCP and RIMN.

Methods

An up-to-date literature search was carried out using the pre-defined search strategy. All studies that met the inclusion criteria were assessed for methodological quality with the Cochrane’s collaboration tool. Operative time, functional score, time-to-union, non-union rates and revision rates were all considered.

Conclusion

Ten studies with a total of 531 periprosthetic fractures were included. This meta-analysis has suggested that there is no significant difference in any of the outcome measures assessed. Further, more extensive literature is required on the subject to draw more robust conclusions.

An Exploratory Study of the Texture Research Investigational Platform (TRIP) to Evaluate Bone Texture Score of Distal Femur DXA Scans - A TBS-Based Approach

Poor bone status is associated with increased complications following orthopedic surgery. Therefore, assessing site-specific skeletal status prior to or after orthopedic surgery to optimize outcomes is appealing. The trabecular bone score (TBS) approach, a surrogate for microarchitecture, was adapted to the Texture Research Investigational Platform (TRIP), which allows assessment of many skeletal sites imaged by various modalities. TRIP generates a bone texture score (TBS ORTHO), which could potentially guide surgical decision-making and offer insight into postsurgical fracture risk. As distal femur bone loss occurs following total knee arthroplasty (TKA), we hypothesized that TBS ORTHO after TKA would identify poorer texture in the operated femur compared to the nonoperated. We evaluated 30 subjects (15 M/15 F) with unilateral TKA 2-5 yr previously, mean age 67.9 yr and body mass index 30 kg/m². Using a Lunar iDXA, lumbar spine and entire femur scans were obtained, the latter using the atypical femur fracture feature. Distal femur bone mineral density (BMD) and TBS ORTHO were obtained using manual regions of interest (ROI) at 15% and 25% of leg length from the intercondylar notch. TBS ORTHO was determined using distal femur DICOM images and TRIP v1.0 (Medimaps, France). Differences in operated vs nonoperated femur were evaluated by paired t test. As previously reported, operated leg BMD was approx 10% lower at 15% and 25% ROIs. Similarly, TBS ORTHO values in the operated leg were approx 5% lower (p < 0.05) at these same ROIs. Distal femur TBS ORTHO and BMD were largely unrelated. TBS ORTHO reproducibility at these ROIs was approx 3.5%. In conclusion, this pilot study documents the feasibility of reproducibly obtaining distal femur TBS ORTHO values. Lower values were observed in the surgical leg, consistent with the bone loss that follows TKA. Further work is indicated to refine TRIP use and evaluate whether such data provides guidance for surgical decision-making and improves periprosthetic fracture prediction.

Simultaneous Bilateral Patella Fracture After Single Stage Bilateral Total Knee Arthroplasty: A Report of Two Cases and Literature Review

INTRODUCTION

Periprosthetic patellar fracture after total knee arthroplasty (TKA) is an uncommon yet devastating complication, and management of these fractures is challenging with unreliable results. An isolated bilateral patellar fracture is often associated with systemic diseases, steroid usage, and repeated microtrauma. Isolated simultaneous bilateral periprosthetic patellar fracture after TKA is seldom reported in the literature.

CASE REPORT

This report consists of two cases of simultaneous isolated closed bilateral eriprosthetic patellar fracture after TKA, treated with open reduction and internal fixation of patella using tension band wiring. Union was achieved in both cases with satisfactory knee range of motion without significant extension lag.

CONCLUSION

Regardless of the fact that surgical outcome of periprosthetic fracture of the patella has unpredictable and poor results in past, it can be considered for acute traumatic periprosthetic patella fractures with less comminution and good bone stock to avoid revision arthroplasty and poor outcome.

Short-Term Follow-Up of Patellar Component Revision in Patients With Isolated Patellar Component Loosening

BACKGROUND

The etiology of patellar component loosening can be multifactorial, including component malposition, trauma, infection, and poor implant design. These cases may be managed with isolated patellar component revision or simultaneous patellar component with femoral and/or tibial component revision. Isolated patellar revision in the setting of aseptic loosening historically has had limited success with high rates of repeat revision.

METHODS

We performed a retrospective cohort study of 75 cases diagnosed with patellar component loosening that underwent revision. Patients were followed for a minimum of 2 years. Cases were categorized as either isolated patellar (IP) revision or patellar with femoral and/or tibial component (P + O) revisions. Survivorship and re-revision causes were compared between groups. Secondary outcomes included surgical time, estimated blood loss, range of motion, and length of stay.

RESULTS

Fifty patients underwent IP revision, and 25 patients had P + O revision. Overall survivorship at the 2-year follow-up interval was 94.6%. Survivorship of IP revision undertaken for aseptic loosening was 94%. Survivorship of P + O revision was 96%. Eight percent of patients required reoperation from the P + O revision group, while 12% of patients in the IP revision group underwent a reoperation. Patients undergoing IP revision had better postoperative range of motion, lower surgical times, lower estimated blood loss, and decreased length of stay.

CONCLUSION

IP revision demonstrates excellent survivorship and clinical outcomes comparable to P + O revision. When appropriate, IP revision should be considered as a potential treatment option.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

Outcomes and Review of Periprosthetic Tibial Fractures

Periprosthetic fractures around total knee arthroplasties (TKA) are well documented in the literature. Fractures of the tibial side occur least frequently and often pose reconstructive challenges to the treating surgeon. As use of arthroplasty continues to rise, periprosthetic fractures of the tibia will likely become more prevalent. Periprosthetic fracture management is based on recommendations (Mayo classification) made 20 years ago. With newer design technology, the adjuvant use of locking plates in the presence of implant stable periprosthetic tibial fractures (Felix types IIA and IIIA) is unknown. The authors retrospectively reviewed 19 patients who sustained periprosthetic Felix type IIA or IIIA fractures that were treated with operative stabilization using plate and screw constructs. Union rate, time to union, incidence of need for revision on an acute or delayed basis, and restoration of ambulation were investigated. Fourteen patients were followed for the entire course of treatment. Preoperative range of motion was unable to be obtained due to the nature of the injuries. After primary surgical stabilization, 78.6% of the patients obtained successful union of their fracture at a mean of 25 months, but no arthroplasty component revision was necessary in any patient. Three (21.4%) patients required revision surgery, resulting in an overall union rate of 92.9%. Mean time to union in this cohort was 8.4±3.4 months, and the overall complication rate was 28.6%. Treatment of periprosthetic (TKA) tibial fractures carries a relatively high risk of complications and nonunion after primary stabilization, and patients should be counseled accordingly. [Orthopedics. 2020;43(3):182-186.].

Management of periprosthetic fractures of knee arthroplasty with revision surgery

Objective

As periprosthetic knee fractures are becoming common with the increase in incidence of primary and revision total knee arthroplasty, their management and treatment have become important. The current study aims to evaluate the revision knee arthroplasty carried out due to the failure of primary treatment of periprosthetic femoral fractures.

Methods

The study was conducted from May 2012 to September 2019 at Orthopedics department of Xinjiang Medical University; out of 21 patients 11 were women and 10 men aged 44 to 80 (mean, 70.76 ± 8.31) years who underwent revision surgery for periprosthetic fractures of 19 distal femur, 1 patellar, and 1 proximal tibial fracture. Nineteen cases had definite trauma history leading to periprosthetic fracture, and 2 cases had fracture during post-operative functional exercise. All patients had revision surgery with extended stems with either constrained or limited condylar knee prosthesis.

Results

The duration of follow-up averaged 4.3 years. The Hospital for Special Surgery (HSS) knee score before fracture averaged 91 + 7.01 points (89-95 points) and 85.5 + 6.18 points (81-90 points) at the last follow-up. The average range of motion of knee joint before fracture was 115.7 [+7.6] (110 [~126]), and 101.3 [+9.8] (85 [~115]) at the last follow-up. There was no significant statistical difference. No complications such as infection, component loosening or nonunion. 2 patients had lower extremity vein thrombosis.

Conclusion

Revision surgery of the knee for the periprosthetic fractures with proper prosthetic selection can attain good outcomes after primary total knee arthroplasty. Reasonable and correct procedure is the main principle for a successful operation. The benefits and applicability of revision TKA is the reconstructive solution for the issues of prosthetic knee fractures, is highly recommended.

Management of periprosthetic fracture following total knee arthroplasty- a retrospective study to decide when to fix or when to revise?

PURPOSE

Periprosthetic fractures around total knee arthroplasty are relatively rare complication comprises to 0.3-2.5%. But these injuries are often complex and challenging for the surgeons due to ageing population in conjunction with severe osteoporosis. The management option varies from conservative to internal fixation or revision surgery. Thus this study was conducted to analyze the results of various methods of treatment of periprosthetic fractures following TKA and to form the optimal treatment guidelines for fixation or revision.

MATERIAL AND METHODS

51 cases diagnosed with periprosthetic fracture were enrolled and underwent surgical intervention. Type of primary prosthesis, interval between TKA and periprosthetic fracture, type of fracture, prosthesis stability and mode of fixation of fracture, any revision surgery and complication were noted.

RESULTS

The mean age of all patients was 65.89 years. The mean interval between the index surgery and periprosthetic fracture was 6 years (Range 2 months to 10 years) in male and 18.5 months (Range 4 days to 7 years) in female. 44 (86%) fractures were femoral, 4 (8%) fractures were tibial and 3 (6%) fractures were of patella. The mean knee society score (KSS) & oxford knee score (OKS) were found to be good for revision group as compared to the fixation group at final follow up.

CONCLUSION

In presence of poor bone stock, far distal fracture configuration, comminution, severe osteoporosis, difficulty in achieving stability with plates & old age-revision TKA is a viable option with stemmed components.

Regional differences between the US, Scandinavia, and South Korea in patient demographics and patient-reported outcomes for primary total knee arthroplasty

INTRODUCTION

Differences in total knee arthroplasty (TKA) patient demographics and clinical outcomes may exist between international regions, yet research is limited. The aim of this study was, therefore, to compare TKA patient demographics and patient-reported outcome measure (PROM) scores between the US, Scandinavia, and South Korea.

MATERIALS AND METHODS

A total of 398 TKA patients from three regions were assessed: 169 in Scandinavia (3 centers), 129 in the US (3 centers), and 100 patients in South Korea (2 centers). Regional variation in patient demographics was assessed using Kruskal-Wallis H tests. Regional variation in PROM scores from preoperative, 1-, 3- and 5-year visits was assessed using piecewise linear mixed effect models. The PROMs analyzed were a numerical rating scale for satisfaction and the Knee Osteoarthritis Outcome Score.

RESULTS

South Korean patients were the oldest (p < 0.001) and had the highest Charnley class (p < 0.001); US patients had the highest BMI (p < 0.001); Scandinavian patients had the lowest preoperative KL grade (p < 0.001). Scandinavian patients were associated with better preoperative and worse postoperative PROM scores. Scandinavian patients were also associated with moderately lower levels of satisfaction. These differences were lessened but remained significant after controlling for relevant demographic and surgical factors.

CONCLUSIONS

Regional differences were found in TKA patient demographics and PROMs between the US, Scandinavia, and South Korea. The regional differences in patient demographics support the need for more research and clear guidelines related to TKA appropriateness criteria. The better preoperative and worse postoperative Scandinavian PROM scores may have been related to their less severe KL grade but might also reflect cultural differences in how patients reflect on their health state when answering PROMs. Clinicians should be aware of these international differences in PROM scores when interpreting studies conducted in different international regions. Future studies should investigate TKA variation between more international regions and assess intraregional variation.

LEVEL OF EVIDENCE

Level III.

Surgical Technique to Manage Periprosthetic Fractures of the Knee in Patients with Infected Leg Ulcers: A Report of Two Cases

CASES

We describe 2 cases of nonagenarians with periprosthetic knee fractures that were not amenable to either standard internal fixation nor prosthesis revision because of infected leg ulcers in the same limb. The fractures were internally fixed by percutaneous insertion of medial and lateral plates that spanned the knee. Both patients returned to their baseline level of activity without developing surgical site infections.

CONCLUSIONS

Percutaneous bridging plates that span the knee are a useful option for treating these difficult cases.

Patellar complications following total knee arthroplasty: a review of the current literature

Total knee arthroplasty is a common operation for treating patients with end-stage knee osteoarthritis and generally has a good outcome. There are several complications that may necessitate revision of the implants. Patella-related complications are difficult to treat, and their consequences impact the longevity of the implanted joint and functional outcomes. In this review, we explore the current literature on patellar complications in total knee arthroplasty and identify risk factors as well as strategies that can help in preventing these complications. We present pertinent findings relating to patellar complications. They can be classified into bony or soft tissue complications and include bone loss, aseptic loosening, periprosthetic fractures, patella fracture, patellar clunk syndrome, patellofemoral instability, extensor mechanism complications, maltracking, patella baja and malrotation. We conclude that patellar complications in total knee arthroplasty are common and have significant implications for the functional outcome of total knee arthroplasty. A high index of suspicion should be maintained in order to avoid them. Implant malpositioning and other forms of intraoperative technical error are the main cause of these complications, and therefore, primary prevention is crucial. When dealing with these established problems, a clear plan of action should be formulated in advance to allow appropriate management as well as anticipation of adverse outcomes.

Periprosthetic Tibial Fracture with Nonunion and Ascending Prosthetic Joint Infection: A Case Report of an Individual Treatment Strategy

Introduction:

Periprosthetic fractures are severe injuries that demand the surgeon’s full expertise and special diagnostic and therapeutic strategies. A major complication is the occurrence of an infectious nonunion, including an ascending infection from the fracture site to the arthroplasty.

Case Report:

This case report presents on a patient with a well-functioning revision total knee arthroplasty (TKA) who suffered a periprosthetic tibia fracture. Initial treatment with plating failed and the fracture had to be revised due to an infectious non-union with a multidrug-resistant Staphylococcus epidermidis, and its eradication was complicated by septic loosening of the patient’s knee arthroplasty. After multiple revisions of the nonunion, a two-stage exchange arthroplasty with a partial replacement of the distal femur due to a bone defect was necessary to obtain an acceptable result.

Conclusion:

The objective of this case report is to present an individual surgical strategy in a complex case of periprosthetic fracture and TKA with major complications. It is shown that the infection of the bone and implants is a challenging situation for surgical treatment. There is still no optimal management strategy due to missing standards as well as controversies in treatment.

DXA evaluation of femoral bone mineral density and cortical width in patients with prior total knee arthroplasty

Periprosthetic fractures after total knee arthroplasty (TKA) have devastating consequences. Osteoporosis increases periprosthetic fracture risk, but distal femur bone mineral density (BMD) is not measured post-TKA. This study measured distal femur BMD and cortical width; both were lower in the TKA compared to the non-operated leg. BMD measurement reproducibility was good. Standardized DXA regions of interest are proposed.

INTRODUCTION

Periprosthetic fractures following total knee arthroplasty (TKA) are not rare. We hypothesized that TKA is associated with low BMD, potentially increasing periprosthetic fracture risk. However, distal femur dual energy x-ray (DXA) measurement is virtually never performed after TKA due to lack of standardized approaches. Thus, this study's aims were to develop standard DXA femur regions of interest (ROIs), assess cortical width, and determine measurement reproducibility in TKA patients.

METHODS

Thirty adults (15 M/15 F) age 59-80 years with unilateral, primary TKA within 2-5 years had femoral DXA scans performed in duplicate using a Lunar iDXA densitometer. In prior work, we established that femur BMD was lowest in the distal metaphysis and highest in mid-shaft. Thus, BMD and cortical width were measured at 15%, 25%, and 60% of the femur length measured from the distal notch. Femur BMD and cortical width were compared between limbs (TKA vs. non-operated side) by paired t test.

RESULTS

BMD was 3.2-9.9% lower (p < 0.001) in the operated femur at all custom ROIs; substantial between individual differences existed with some up to 30% lower. Cortical width was lower (p < 0.05) at the 25% ROI on the TKA side. BMD reproducibility was excellent; CV 0.85-1.33%.

CONCLUSIONS

Distal femur BMD can be reproducibly measured using DXA and is ~ 10% lower on the TKA leg. Similarly, medial and lateral cortices are thinner at the 25% ROI. These bone changes likely increase periprosthetic fracture risk. Further work to define and mitigate periprosthetic fracture risk after TKA is needed.

DXA Measured Distal Femur Bone Mineral Density in Patients After Total Knee Arthroplasty: Method Development and Reproducibility

INTRODUCTION

Total knee arthroplasty (TKA) is increasingly being performed. Distal femur periprosthetic fracture is a potentially catastrophic complication following TKA and existing data document substantial distal femur bone mineral density (BMD) loss following TKA. However, distal femur BMD is virtually never measured clinically as no consensus approach exists. This pilot study's purpose was to define regional BMD variation throughout the femur, suggest standard dual-energy X-ray absorptiometry (DXA) regions of interest (ROIs) and evaluate BMD reproducibility at these ROIs.

METHODS

Thirty volunteers 2-5 yr post TKA had both entire femurs imaged twice using a Lunar iDXA with subject repositioning between scans; the atypical femur fracture feature of enCORE software was utilized. To define femoral BMD distribution, custom 1 cm ROIs were stacked one atop the other starting at the intercondylar notch and continuing to the base of the lesser trochanter. Femur length was measured with the ruler tool to calculate distance at 5% increments. ROIs encompassing each 5% increment were utilized to measure BMD at each location. Descriptive statistics were used to determine mean BMD at each ROI and reproducibility at the 15%, 25%, 45%, 60%, and 80% ROIs.

RESULTS

The 5 and 10% ROIs included prosthetic and/or patella, causing high BMD values. Distal femur BMD was lowest at the 15% ROI and was higher (p < 0.05) at each more proximal ROI to 45%, then plateaued from 45% to 75%. BMD reproducibility at these regions was excellent; coefficient of variation (CV) from ∼1% to 3.5%. As periprosthetic fractures generally occur in the distal femur, we propose measuring femur BMD using ROIs placed at 15% and 25%. A 60% region could also be used as a highly cortical site.

CONCLUSION

Existing DXA capabilities allow distal femur BMD measurement with good reproducibility. Further research using standardized ROIs to assess distal femur BMD loss after TKA, and interventions to mitigate this loss, is indicated.

Impact of time to surgery from injury on postoperative infection and deep vein thrombosis in periprosthetic knee fractures

PURPOSE

Periprosthetic fracture (PPF) is a serious complication that occurs in 0.3%-2.5% of all total knee arthroplasties used to treat end-stage arthritis. To our knowledge, there are no studies in the literature that evaluate the association between time to surgery after PPF and early postoperative infections or deep vein thrombosis (DVT). This study tests our hypothesis that delayed time to surgery increases rates of postoperative infection and DVT after PPF surgery.

METHODS

Our study cohort included patients undergoing PPF surgery in the American College of Surgeons National Surgical Quality Improvement Program database (2006-2015). The patients were dichotomized based on time to surgery: group 1 with time ≤2 days and group 2 with time >2 days. A 2-by-2 contingency table and Fisher's exact test were used to evaluate the association between complications and time to surgery groups, and multivariate logistic regression was used to adjust for demographics and known risk factors.

RESULTS

A total of 263 patients (80% females) with a mean age of 73.9 ± 12.0 years were identified receiving PPF surgery, among which 216 patients were in group 1 and 47 patients in group 2. Complications in group 1 included 3 (1.4%) superficial infections (SI), 1 (0.5%) organ space infection (OSI), 1 (0.5%) wound dehiscence (WD), and 4 (1.9%) deep vein thrombosis (DVT); while complications in group 2 included 1 (2.1%) SI, 1 (2.1%) OSI, 1 (2.1%) DVT, and no WD. No significant difference was detected in postoperative complications between the two groups. However, patients in group 2 were more likely (p = 0.0013) to receive blood transfusions (57.5%) than those in group 1 (32.4%).

CONCLUSION

Our study indicates patients with delayed time to surgery have higher chance to receive blood transfusions, but no significant difference in postoperative complications (SI, OSI, WD, or DVT) between the two groups.

Is the fracture pattern in periprosthetic fractures around the knee related with the anterior femoral notch?

INTRODUCTION

Periprosthetic fractures around the knee (PPF) are a devastating complication of total knee arthroplasty (TKA). Anterior femoral notching during TKA is considered a risk factor for PPF. The aim of this paper is to determine if an anterior femoral notch after total knee arthroplasty may affect the fracture pattern when a PPF appears postoperatively.

MATERIAL AND METHODS

50 patients diagnosed in our centre of a PPF from January 2010 to December 2013 were retrospectively enrolled. 100 patients who underwent a total knee arthroplasty without fracture were randomly obtained as a control group. Evidence of the notch was searched in both groups in postoperative X-rays. In the PPF group, distance from the shield of the femoral component to the most distal (d) and proximal (D) point of the fracture were measured.

RESULTS

Two different groups were obtained: 1) d = 0 (33 out of 50 patients); the fracture is supposed to be related with the notch as it's a theoretically weaker area. 2) d > 0 (17 out of 50 patients); the fracture pattern has no relationship with the notch. Prevalence of patients suffering a fracture in the shield of the prosthesis (d = 0), was similar in both patients with notch (66,7%) and without it (68%).

CONCLUSIONS

In conclusion, fracture pattern is not related with the existence of a femoral notch in the clinical setting.

Periprosthetic femoral fractures following total hip and total knee arthroplasty

Total joint arthroplasties are increasing worldwide in both frequency and prevalence. When successful, they offer great improvements in quality of life. However, fractures around implants are often difficult to manage and require prolonged inpatient stays in tertiary hospitals. Management may differ between surgeons, but most patients will be managed surgically if mobility or joint stability is threatened. Those affected are often at higher risk from surgery, are frailer and at higher risk of mortality and a lifelong reduction in mobility. The incidence of these fractures is increasing, and patients should appreciate the risk and implications of this recognised complication of joint arthroplasty.

[Patella fractures in knee arthroplasty]

Periprosthetic patella fractures occur both with and without retropatellar joint replacement. A non-operative treatment yields satisfactory results with low morbidity. It can be applied in minimally displaced fractures that have an intact retropatellar component and an intact extensor mechanism, combined with an initial immobilization. The surgical treatment is associated with relatively poor results and with high complication rates. There was only minor improvement of functional results, no matter which surgical technique was used. Surgical intervention is still required in fractures with a loosening of the patellar component, considerable dislocations of fragments, and damage to or rupture of the extensor mechanism. In particular, type II fractures require repair of the extensor mechanism and the fracture or patellectomy. Type III fractures require a revision or resection of the patella, a patelloplasty or total patellectomy. In addition, early or late reconstruction using allograft to restore the extensor mechanism can be taken in consideration.

What Are the Preoperative Outcome Measures That Predispose to Periprosthetic Fractures After Primary Total Knee Arthroplasty?

BACKGROUND

There is little known in the literature about whether preoperative patient-reported outcome measures (PROMs) would affect the risk of periprosthetic fractures (PPFs) after primary total knee arthroplasty (TKA). Our study aims to evaluate the predictive values of PROMs on PPF after primary TKA. We hypothesize that poorer PROMs are associated with a higher risk of PPF after primary TKA.

METHODS

We reviewed prospectively collected data in our hospital arthroplasty registry. Patients who sustained PPF after primary TKA between 2000 and 2015 were identified. Forty-two patients were identified and matched for gender, age, and body mass index to a control group of 84 patients who had primary TKA without PPF in a 2:1 ratio. Preoperative demographics, Short Form-36 (SF-36) scores, Oxford Knee score and Knee Society Score were evaluated. Variables of PROMs were entered into a multivariate logistic regression model. A variable was considered to be a significant predictor if its odds ratio was significant at P < .05.

RESULTS

After multivariate regression analysis, SF-36 subdomains of physical functioning (PF) and vitality (VT) were identified as significant predictors for PPFs after primary TKA. A lower SF-36 PF and VT scores were associated with higher risks of sustaining a PPF after primary TKA.

CONCLUSION

From our study, low preoperative SF-36 PF and VT scores are associated with a higher risk of PPFs after primary TKA. These results can allow the preoperative identification of patients at higher risk of PPF, and appropriate preoperative counseling, optimization, and close follow-up can be instituted for this at-risk group.

Circular hexapod external fixation for periprosthetic tibial fracture

A poor soft tissue envelope often accompanies periprosthetic tibia fracture around a well-fixed total knee arthroplasty and the tibial stem leaves little room for screw fixation. This article describes the practicability and effectiveness of a novel surgical technique using circular hexapod external fixation, in patients with this clinical scenario. It was applied for fixation of periprosthetic tibia fracture in 2 patients. Contact between the external fixation pins and the prosthesis was avoided. Using a web-based software program, a gradual reduction in all planes was achieved. Adequate fixation, stability, reduction, and quick healing were obtained in the 2 cases, with minimal complications. The patients returned to their activity level a few months after external fixation removal.

The painful knee after total knee arthroplasty: evaluation and management

Total knee arthroplasty (TKA) is the treatment of choice for end-stage osteoarthritis of the knee. The aging of population and the need to maintain high quality of life have increased the demand for TKA. Although considered a successful procedure, 15-30% of patients presenting persistent pain. The management of these patients requires a clinical, laboratory and radiological assessment in order to address the underlying aetiology. There are several causes of pain, divided in joint and non-joint related, which should be diagnosed and treated promptly. Patients with unexplained pain should be treated conservatively since a plausible reason has been identified. (www.actabiomedica.it)

The painful knee after total knee arthroplasty: evaluation and management

Total knee arthroplasty (TKA) is the treatment of choice for end-stage osteoarthritis of the knee. The aging of population and the need to maintain high quality of life have increased the demand for TKA. Although considered a successful procedure, 15-30% of patients presenting persistent pain. The management of these patients requires a clinical, laboratory and radiological assessment in order to address the underlying aetiology. There are several causes of pain, divided in joint and non-joint related, which should be diagnosed and treated promptly. Patients with unexplained pain should be treated conservatively since a plausible reason has been identified.

Towards an understanding of the painful total knee: what is the role of patient biology?

Total knee arthroplasty (TKA) remains the treatment of choice for end-stage osteoarthritis of the knee. With an aging population, the demand for TKA continues to increase, placing a significant burden on a health care system that must function with limited resources. Although generally accepted as a successful procedure, 15-30 % of patients report persistent pain following TKA. Classically, pain generators have been divided into intra-articular and extra-articular causes. However, there remains a significant subset of patients for whom pain remains unexplained. Recent studies have questioned the role of biology (inflammation) in the persistence of pain following TKA. This article aims to serve as a review of previously identified causes of knee pain following TKA, as well as to explore the potential role of biology as a predictor of pain following knee replacement surgery.

Megaprostheses in the management of trauma of the knee

OBJECTIVE

Review the outcome of patients with complex fractures around the knee treated with megaprosthesis.

METHOD

Retrospective observational study of 10 patients was undertaken.

RESULTS

Six patients were treated with a distal femoral endoprosthesis (DEFPR) and four with an augmented rotating hinge knee replacement (RHK). The mean post-operative Toronto Extremity Salvage Score (TESS) was 62.5 for the whole cohort (RHK group 79.3, compared with 49.2 in the DFEPR group (p = 0.038), peri-prosthetic fracture group was 46.3, compared with 75.6 in native knee fracture group (p = 0.04)).

CONCLUSION

A megaprosthesis is a viable option in complex fractures around the knee.

Systematic review of periprosthetic tibia fracture after total knee arthroplasties

AIM: To investigate the known incidences, treatment options, and related outcomes of periprosthetic tibia fractures after total knee arthroplasty (TKA).

METHODS: A literature search was done to identify studies that fit the inclusion criteria. The database search yielded 185 results, which were further reduced by the exclusion criteria to 13 papers, totaling 157 patients that met these criteria. Incidence rates of the different types of periprosthetic tibia fractures were determined and their treatments were subsequently analyzed based on the fracture’s subclass, with patient outcomes being overall favorable.

RESULTS: Of the 144 documented patients, 54 (37.5%) had a subclass C fracture, which are frequently seen in revision arthroplasties or when using cement intraoperatively. The fractures of subclasses A and B occur postoperatively. There were 90 subclass A and B fractures with incidences of 18.75% and 43.75% respectively. When broken down by type, 62 (55.36%) were type 1, 24 (21.4%) were type 2, 24 (21.4%) were type 3, and 2 (1.8%) were type 4. Furthermore, from the studies that included origin of injury, the types were further classified as having non-traumatic or traumatic origins. Type 1 had 78% (40/51) non-traumatic origin and 22% (11/51) traumatic origin. Fifteen fractures were type 2, but 5 were falls and 1 through a motor vehicle accident, giving a trauma causation of 40% (6/15). Of the 24 type 3 fractures, 12 were falls and 2 vehicular accidents, leading to a trauma causation of 58% (14/24).

CONCLUSION: Type 1 fractures were the most common. Subclass A was treated with locking plates, B required a revision TKA, and C was treated intraoperatively or nonoperatively.

Field testing the Unified Classification System for periprosthetic fractures of the femur, tibia and patella in association with knee replacement: an international collaboration

The Unified Classification System (UCS) was introduced because of a growing need to have a standardised universal classification system of periprosthetic fractures. It combines and simplifies many existing classification systems, and can be applied to any fracture around any partial or total joint replacement occurring during or after operation. Our goal was to assess the inter- and intra-observer reliability of the UCS in association with knee replacement when classifying fractures affecting one or more of the femur, tibia or patella. We used an international panel of ten orthopaedic surgeons with subspecialty fellowship training and expertise in adult hip and knee reconstruction ('experts') and ten residents of orthopaedic surgery in the last two years of training ('pre-experts'). They each received 15 radiographs for evaluation. After six weeks they evaluated the same radiographs again but in a different order. The reliability was assessed using the Kappa and weighted Kappa values. The Kappa values for inter-observer reliability for the experts and the pre-experts were 0.741 (95% confidence interval (CI) 0.707 to 0.774) and 0.765 (95% CI 0.733 to 0.797), respectively. The weighted Kappa values for intra-observer reliability for the experts and pre-experts were 0.898 (95% CI 0.846 to 0.950) and 0.878 (95% CI 0.815 to 0.942) respectively. The UCS has substantial inter-observer reliability and 'near perfect' intra-observer reliability when used for periprosthetic fractures in association with knee replacement in the hands of experienced and inexperienced users.

The treatment of periprosthetic femur fractures after total knee arthroplasty

Periprosthetic femur fractures after total knee arthroplasty are a rising concern; however, when properly diagnosed, they can be managed nonoperatively or operatively in the form of locking plate fixation, intramedullary nailing, and arthroplasty. The degree of osteoporosis, stability of the femoral implant, and goals of the patient are a few critical variables in determining the ideal treatment. Despite excellent outcomes from each of these operative choices, the risk of nonunion, malunion, instability, and refracture cannot be ignored.

Revision total knee arthroplasty for failure of primary treatment of periprosthetic knee fractures

Periprosthetic knee fractures and their complications are expected to increase as the numbers of knee arthroplasties continue to rise. We report our experience with revision knee arthroplasty for failure of primary fracture treatment. Five periprosthetic knee non-unions and 1 mal-union in 6 patients, with ages ranging from 65 to 83years (average 74.6years) were treated with revision total knee arthroplasty, and were followed up for 3 to 10years (average 4.5years). Union occurred in 8 to 18weeks (average 12.5weeks). All patients were ambulatory at the latest follow-up, with a range of motion averaging 84.2° (P = 0.03), and an Oxford Knee Score averaging 35 (P = 0.03). We conclude that union complications of periprosthetic knee fractures can be satisfactorily addressed with revision arthroplasty.

Periprosthetic fractures around the knee: current concepts and advances in management

Knee replacement is an effective treatment for pain and functional impairment secondary to degenerative joint conditions. The number of knee replacements performed continues to rise. Periprosthetic fractures around total knee arthroplasties are a relatively rare complication but are complex injuries that require the treating surgeon to be familiar with and proficient at arthroplasty and trauma reconstructive techniques. An increase in life expectancy and in the functional demands of elderly patients may lead to an increased incidence of periprosthetic fractures. Supracondylar fractures of the femur are the most common type and this review will focus on the incidence, risk factors, classification, investigation, and treatment options for periprosthetic fractures around total knee arthroplasties.