Total knee replacement in post-traumatic arthritic knees with limitation of flexion

Increased Revisions in Conversion Total Knee Arthroplasty After Periarticular Open Reduction Internal Fixation Compared With Primary Total Knee Arthroplasty: A Matched Cohort Analysis

BACKGROUND

Prior studies on conversion total knee arthroplasty (cTKA) have reported increased technical challenges and risk of complications compared with primary knee arthroplasty. The purpose of this study was to compare two-year postoperative complication/revision rates between patients undergoing cTKA after prior periarticular open reduction and internal fixation (ORIF) and those undergoing primary TKA.

METHODS

Patients who underwent cTKA after prior periarticular ORIF of the ipsilateral knee were identified in a national all-payer claims database from 2010 to 2018. This ORIF-cTKA cohort was propensity matched to participants undergoing primary TKA based on age, gender, Charlson comorbidity index, and obesity status. Univariate analysis was performed to analyze differences in two-year complication and revision rates.

RESULTS

After propensity matching, 823 patients were included in the ORIF-cTKA cohort and 1640 patients in the primary TKA cohort. No differences in demographics or comorbidities existed between cohorts. Relative to the primary TKA cohort, the ORIF-cTKA cohort had significantly higher incidences of all-cause revision (5.47% vs 2.47%, P = .001), periprosthetic joint infection (PJI; 4.74% vs 1.34%, P < .001), and intraoperative or postoperative periprosthetic fracture (1.58% vs 0.55%, P = .01) at two years postoperatively. There was also a nonsignificant trend toward increased rates of aseptic loosening (1.82% vs 0.91%, P = .052) in the ORIF-cTKA.

CONCLUSION

Relative to primary TKA, cTKA after periarticular ORIF is associated with significantly increased rates of all-cause revision, PJI, and periprosthetic fracture at two years postoperatively. Surgeons should counsel these patients about the increased risks of these postoperative complications and consider treating them as high risk for PJI in the perioperative period.

Custom TKA enables adequate realignment with minimal ligament release and grants satisfactory outcomes in knees that had prior osteotomies or extra-articular fracture sequelae

PURPOSE

To report the early clinical and radiographic outcomes of custom total knee arthroplasty (TKA) in knees that had prior osteotomies and/or extra-articular fracture sequelae.

METHODS

The authors retrospectively analysed a consecutive series of 444 knees that received custom TKA between 2016 and 2019 and identified 41 knees that had prior extra-articular events (osteotomies or fracture sequelae). Patients responded to pre- and post-operative (> 12 months) questionnaires, including Knee Society Score (KSS), Oxford Knee Score (OKS), Forgotten Joint Score (FJS) and Knee injury and Osteoarthritis Outcome Score (KOOS). Net improvements were calculated by subtracting pre- from post-operative scores. In addition to a preoperative CT scan, pre- and post-operative long-leg weight-bearing radiographs were obtained, on which the hip-knee-ankle (HKA) angle, femoral mechanical angle (FMA, between femoral mechanical axis and joint line) and tibial mechanical angle (TMA, between tibial mechanical axis and joint line) angles were measured, and alignment was planned within a 'target zone' of FMA and TMA within 85°-95° and HKA angle within 175°-183°. Agreements between preoperative, planned and post-operative angles were calculated using intra-class correlation coefficients (ICC).

RESULTS

From the initial 41 knees, 3 had incomplete post-operative data and 1 was revised for painful stiffness due to uncorrected rotational malunion, leaving 37 knees for analysis. Twenty had prior osteotomies (tibia, n = 18, femur, n = 2), 8 had isolated fractures (tibial, n = 3; femoral, n = 5), and 9 had both osteotomies and fractures. Postoperative coronal alignments were 90.4° ± 2.4° for FMA, 89.3° ± 2.6° for TMA and 179.9° ± 3.0° for HKA angle. Agreements between planned and achieved alignments were fair to excellent, and 29 (78%) knees were within the 'target zone'. At a mean follow-up of 15 ± 5 months, all clinical scores had improved significantly (p < 0.001).

CONCLUSIONS

Custom TKA granted satisfactory clinical outcomes and a low complication rate in knees that had prior osteotomies and/or extra-articular fracture sequelae. Using custom implants and strategies for coronal alignment, 29 (78%) of the 37 knees were successfully aligned within the 'target zone', and 35 (95%) of the 41 knees did not require ligament release.

LEVEL OF EVIDENCE

IV.

Primary total knee arthroplasty using constrained condylar knee design for severe deformity and stiffness of knee secondary to post-traumatic arthritis

Background

Key to a successful outcome of total knee arthroplasty (TKA) is to attain optimum alignment, adequate balance, and deformity correction. In primary TKA, this can be achieved efficiently by posterior stabilized (PS) design with or without the sub-periosteal release. However, certain circumstances such as post-traumatic arthritis are often associated with severe deformities with a significant bone defect, stiffness, and instability. Such deformities are extremely difficult to balance with soft tissue release only and require additionally constrained prostheses even in primary TKA. In such situation, constrained condylar knee (CCK) design is the ultimate choice. This study primarily aimed to report on clinical outcome, regain of function, and complication of patients who underwent primary CCK-TKA for severe deformity of the knee secondary to post-traumatic arthritis. The secondary aim was to find out the mid-term prostheses survival.

Methods

Between February 2007 and November 2013, 38 consecutive patients with post-traumatic arthritis of the knee received cemented primary CCK-TKA. Thirty-four patients (21 men and 13 women) who had a minimum of 3 years follow-up were included in this retrospective study. We used Knee Society Score (KSS), Hospital for Special Surgery (HSS) score, and roentgenographic evaluation form to assess the patients. Prostheses survival was assessed using Kaplan-Meier’s survival analysis.

Results

Patients were followed up for an average duration of 6.47 years. KSS knee score improved from 44 points (23–68) pre-operatively to 91 points (76–100) post-operatively [P < 0.001]. The average KSS functional score improved from 49 points (20–75) pre-operatively to 91 points (65–100) post-operatively [P < 0.001]. The average HSS score improved from 51 points (27–83) pre-operatively to 91 points (75–100) post-operatively [P < 0.001]. Similarly, the average ROM improved from 68.09° ± 35.99° (0°–120°) to 113.68° ± 8.90° (100°–130°) post-operatively [P < 0.001]. The average hip-knee-ankle (HKA) angle was 176.88° ± 14.48° (135°–199°) pre-operatively and 180.24° ± 1.77° (175°–184°) post-operatively. Radiolucencies were evident in 13 knees, mostly on the tibial side. Prostheses survival was 94.7% at a mean follow-up of 6.47 years.

Conclusion

Despite severe deformity, instability, and stiffness at a relatively young age, mid-term follow-up of primary CCK-TKA in post-traumatic arthritis provides satisfactory clinical and functional outcomes with 94.7% prostheses survival. However, it is not without complication.

Ten-year survival and complications of total knee arthroplasty for osteoarthritis secondary to trauma or surgery: A French multicentre study of 263 patients

BACKGROUND

Previous surgical procedures raise technical challenges in performing total knee arthroplasty (TKA) and may affect TKA outcomes. Survival rates of TKA done after trauma or surgery to the knee have not been accurately determined in large populations. The objectives of this retrospective study in 263 patients with TKA after knee trauma or surgery and a follow-up of 10 years were to assess survival, functional outcomes, and the nature and frequency of complications.

HYPOTHESIS

Knee trauma or surgery before TKA increases the risk of complications and decreases implant survival.

MATERIAL AND METHODS

Two hundred and sixty-three patients (122 [47%] females and 141 [53%] males) underwent TKA between 2005 and 2009 at nine centres in France. Mean age at surgery was 61 years. The patients had knee osteoarthritis secondary to a fracture (n=66), osteotomy (n=131), or ligament injury (n=66). Mean time from trauma or surgery to TKA was 145 months (range, 72-219 months).

RESULTS

Major complications were infection (n=12, 4.5%), skin problems (n=8, 3%), and stiffness (n=8, 3%). Ten-year survival to implant exchange for any reason was 89%±2.8%. Flexion range increased by 2.5°±17° (p=0.02) to a mean of 110° (range, 30° to 140°); extension range increased by 4°±7° (p<0.001) to a mean of -1.19 (range, -20° to 0°). Of the 263 patients, 157 (60%) reported little or no pain at last follow-up. Mean postoperative hip-knee-ankle angle was 179°±3.2° (range, 171°-188°).

CONCLUSION

TKA performed after knee injury or surgery carries a risk of specific complications (infection, skin problems, and stiffness) and may have a lower survival rate compared to primary TKA.

LEVEL OF EVIDENCE

IV, retrospective cohort study.

Quality of life after total knee arthroplasty

Total knee arthroplasty (TKA) results in a high degree of patient satisfaction, as it provides patients with considerable medium- and long-term benefits in terms of quality of life, pain relief and function. Nevertheless, the literature reports that up to 30% of patients are dissatisfied. This dissatisfaction is directly related to the patients' quality of life, which they deem insufficient. Their quality of life depends on many physical, behavioural, social and psychological factors that are not taken into account by functional outcome scores. After describing the principles of quality of life evaluation after TKA, we will assess the effects of patient-related factors, the surgical technique and postoperative program through an exhaustive review of the literature. Patient expectations after TKA will then be outlined, particularly return to work and return to sports.

Concurrent femoral and tibial osteotomies versus soft tissue balance in total knee arthroplasty: A technical case report

This case report outlines some of the challenges as well as limitations in correction of osteoarthritis of the knee in combination with extra-articular deformities,and provides a novel and straightforward surgical solution in overcoming these challenges. We describe the case of a 37-year-old male who suffered from advanced bilateral tri-compartmental knee arthritis due to untreated bloodstream-sourced osteomyelitis after birth. Radiographs and surgery confirmed extremely severe deformities. We performed two different surgical techniques in order to correct extra-articular deformities (one-stage approach of concurrent tibial and femoral osteotomy and total knee arthroplasty on one side, and soft tissue balancing with "pie-crusting technique" plus total knee arthroplasty on the other side), with description of subsequent results at 36-months follow-up.

Knee replacement in chronic post-traumatic cases

Post-traumatic knee arthritis is a challenging condition. Prosthetic surgery is demanding and the risk of complications is relatively high.

Planning is an essential element of this surgery; correct diagnosis (to exclude latent infection) and adequate considerations regarding approach, axis, bone loss, choice of implant and level of constraint are indispensable.

There are two main categories of post-traumatic arthritis: extra-articular deformities and articular deformities.

Use of an algorithms can support the surgeon’s choice of implant.

Correct implant positioning and limb alignment restoration is associated with very good results, similar to those achieved with standard total knee arthroplasty.

Cite this article: Benazzo F, Rossi SMP, Combi A, Meena S, Ghiara M. Knee replacement in chronic post-traumatic cases. EFORT Open Rev 2016:1:211-218. DOI: 10.1302/2058-5241.1.000025.

Development and Validation of a Preoperative Surgical Site Infection Risk Score for Primary or Revision Knee and Hip Arthroplasty

BACKGROUND

Surgical site infection (SSI) is a major complication following total joint arthroplasty. Host susceptibility to infection has emerged as an important predictor of SSI. The purpose of this study was to develop and validate a preoperative SSI risk-assessment tool for primary or revision knee and hip arthroplasty.

METHODS

Data for 6,789 patients who underwent total joint arthroplasty (from the years 2000 to 2011) were obtained from a single hospital system. SSI was defined as a superficial infection within 30 days or deep infection within 1 year. Logistic regression modeling was utilized to create a risk scoring system for a derivation sample (n = 5,789; 199 SSIs), with validation performed on a hold-out sample (a subset of observations chosen randomly from the initial sample to form a testing set; n = 1,000; 41 SSIs).

RESULTS

On the basis of logistic regression modeling, we created a scoring system to assess SSI risk (range, 0 to 35 points) that is the point sum of the following: primary hip arthroplasty (0 points); primary knee (1); revision hip (3); revision knee (3); non-insulin-dependent diabetes (1); insulin-dependent diabetes (1.5); chronic obstructive pulmonary disease (COPD) (1); inflammatory arthropathy (1.5); tobacco use (1.5); lower-extremity osteomyelitis or pyogenic arthritis (2); pelvis, thigh, or leg traumatic fracture (2); lower-extremity pathologic fracture (2.5); morbid obesity (2.5); primary bone cancer (4); reaction to prosthesis in the last 3 years (4); and history of staphylococcal septicemia (4.5). The risk score had good discriminatory capability (area under the ROC [receiver operating characteristic] curve = 0.77) and calibration (Hosmer-Lemeshow chi-square test, p = 0.34) and was validated using the independent sample (area under the ROC curve = 0.72). A small subset of patients (5.9%) had a >10% estimated infection risk.

CONCLUSIONS

The patient comorbidities composing the risk score heavily influenced SSI risk for primary or revision knee and hip arthroplasty. We believe that infection risk can be objectively determined in a preoperative setting with the proposed SSI risk score.

Total knee arthroplasty for treatment of post-traumatic arthritis: Systematic review

AIM

To review and report functional outcomes, complications, and survivorship associated with total knee arthroplasty (TKA) in the treatment of post-traumatic arthritis (PTA).

METHODS

We conducted a systematic review according to the PRISMA guidelines. We searched PubMed, Cochrane Library, and SCOPUS in December 2015 for English-language clinical research studies, both prospective and retrospective, examining the use of TKA for the treatment of PTA. All relevant articles were accessed in full. The manual search included references of retrieved articles. We extracted data on patients’ demographics and clinical outcomes, including preoperative diagnosis and pre- and post-operative functional scores. We summarized the data and reported the results in tables and text.

RESULTS

Sixteen studies, four prospective and ten retrospective, examined patients who underwent TKA for PTA due to fractures of the proximal tibia, patella, and/or distal femur. Eleven studies utilized the Knee Society Scores criteria to assess functional outcomes. All studies utilizing these criteria reported an improvement in functional and knee scores of patients following TKA. Further, studies reported an increased range of motion (ROM) and reduction of pain following surgery. The most commonly reported complications with TKA included infection, stiffness, wound complications, intraoperative rupture of tendons, and osteolysis/polyethylene wear. The overwhelming majority of these complications occurred within the first two years following surgery. Six studies examined the survivorship of TKA with subsequent revision for any reason as an endpoint. Compared to patients with osteoarthritis, patients with PTA required more revisions, the majority for polyethylene wear.

CONCLUSION

Although associated with higher complication rates, TKA is an effective treatment for PTA, as it improves ROM, pain and functional outcomes.

TKA for Posttraumatic Osteoarthritis Is More Complex and Needs More Surgical Resources

The purpose of this study was to evaluate the surgical effort of total knee arthroplasty (TKA) for posttraumatic osteoarthritis (PTOA) compared with primary osteoarthritis (OA). A total of 1841 TKAs were analyzed, including 170 patients with PTOA, that resulted from soft tissue trauma in 83 patients and fractures in 87 patients. Results showed that patients were significantly younger at the time of surgery in the posttraumatic group (62 vs 71 years; P<.001). Furthermore, fracture was associated with 3.7 years earlier need of TKA compared with soft tissue trauma. Operation time was significantly longer for both of the posttraumatic groups compared with OA (P<.001). Patients undergoing TKA after knee injuries are younger and surgical treatment is more challenging compared with TKA for OA. Extended operation time and implant systems with higher constraint and modular options are required. [Orthopedics. 2016; 39(3):S36-S40.].

Does primary total knee arthroplasty for acute knee joint fracture maintain autonomy in the elderly? A retrospective study of 21 cases

INTRODUCTION

Due to poor results and failure encountered in osteosynthesis of peri-articular fracture of the knee, arthroplasty may be suggested to osteopenic elderly subjects. All osteosynthesis techniques entail loss of independence and are associated with elevated mortality. No studies definitively establish better management of such fractures.

HYPOTHESIS

Total arthroplasty provides better autonomy after peri-articular fracture of the knee.

MATERIAL AND METHOD

Seventy-nine patients aged over 65years were operated on for peri-articular fracture of the knee between April 2008 and March 2013. In 21 cases, treated by a single surgeon, total knee arthroplasty was performed in view of osteopenia or osteoarthritis. Mean age was 79years (range, 68-96years). There were 10 distal femoral and 11 proximal tibial fractures. Mean follow-up was 31months (range, 9-68months). Cases of pathologic fracture, failed osteosynthesis and non-operative management were excluded. All patients showed severe osteopenia on radiology and half already had advanced osteoarthritis.

RESULTS

One-year mortality was 14%. At last follow-up, the revision rate was 9.5%. Fifteen patients were followed up. Mean Parker score fell from 7.2 (range, 2-9) preoperatively to 4.6 (range, 0-9) at last follow-up, indicating loss of independence. At follow-up, mean IKS score was 116.6 (range, 0-192) with mean IKS knee score of 78.4 (range, 0-100) and IKS function score of 38.2 (range, 0-100). Mean Oxford score was 36/60 (range, 18-53). Global IKS and IKS function scores were significantly better in case of ASA-2 than ASA-3 (P<0.05). There was no difference between femoral and tibial fractures in terms of IKS or Oxford score or loss of independence.

DISCUSSION

Total knee arthroplasty can be considered for peri-articular fracture of the knee in osteopenic geriatric patients. Although surgical revision was less frequent than after osteosynthesis and resumption of weight-bearing was immediate, autonomy was still impaired. Mortality was comparable to other reports.

LEVEL OF EVIDENCE

IV, retrospective study.

Long-term outcomes of primary constrained condylar knee arthroplasty

BACKGROUND

Although constrained condylar knee (CCK) inserts are widely used for total knee arthroplasty (TKA), their long-term outcomes remain unclear. We sought to evaluate patients with at least 10 years' follow-up after CCK TKA to identify potential adverse events (osteolysis, loosening, constraint-mechanism failure), assess functional outcomes with special emphasis on range of motion, and determine prosthesis survival.

HYPOTHESIS

Increasing constraint by implantation of a CCK insert does not increase the long-term frequencies of osteolysis or mechanical loosening.

MATERIAL AND METHODS

We studied 43 knees after Legacy(®) CCK TKA. The indication was severe deformity (n=20), pre-operative laxity (n=6), or failure to achieve intra-operative balancing (n=17). There were 41 patients with a mean age of 66 years (21-88). A history of one or more surgical procedures was noted for 27 (63%) knees. Outcome measures were the Hospital for Special Surgery (HSS) knee score, Knee Society Score (KSS), and change in the hip-knee-ankle (HKA) angle. Prosthesis survival was assessed using revision surgery for any reason or for reasons other than infection as the censoring criterion.

RESULTS

Complications other than venous thrombosis occurred in 16% of patients, including 3 who required revision surgery (septic loosening, n=2; and major instability in a patient with ipsilateral hip arthrodesis). No cases of osteolysis or aseptic loosening were recorded. Mean follow-up was 12.7 years (range, 10-14). At last follow-up, the HSS score had improved from 53 (26-83) pre-operatively to 80 (55-93), the KSS knee component from 42 (16-77) to 90 (77-99), and the KSS function component from 31 (0-80) to 61 (10-90) (P<0.001). Mean range of flexion increased from 109° (50°-140°) to 112° (90°-130°) (P=0.12). The HKA angle changed from 182°±15.5° (150°-210°) to 179.5°±2.5° (174°-184°) (P=0.5). The 11-year prosthesis survival rate was 88.5% (95% confidence interval, 0.69-0.94) overall and 97.7% (0.76-0.99) after excluding the cases of infection.

DISCUSSION

Long-term functional gains after CCK TKA were similar to those reported after standard posterior-stabilised TKA, with no cases of constraint-mechanism failure or osteolysis. The complication rate was higher, with decreased survival compared to standard TKA, but the knee deformities and/or instability were particularly severe and two-thirds of knees had a history of one or more surgical procedures.

Lower function, quality of life, and survival rate after total knee arthroplasty for posttraumatic arthritis than for primary arthritis

BACKGROUND AND PURPOSE

Total knee arthroplasty (TKA) for treatment of end-stage posttraumatic arthritis (PTA) has specific technical difficulties and complications. We compared clinical outcome, postoperative quality of life (QOL), and survivorship after TKA done for PTA with those after TKA performed for primary arthritis (PA).

PATIENTS AND METHODS

We retrospectively reviewed patients who were operated on at our institution for PTA between 1998 and 2005 (33 knees), and compared them to a matched group of patients who were operated on for PA during the same period (407 knees). Clinical outcomes and postoperative QOL were compared in the 2 groups using Knee Society score (KSS), range of motion (ROM) of the knee, and the knee osteoarthritis outcomes score (KOOS). Implant survival rate was calculated using Kaplan-Meier analysis.

RESULTS

At a mean follow-up of 11 (5-15) years, KSS knee increased from mean 39 (SD 18) to 87 (SD 16) in the PA group (p = 0.003), and from 31 (SD 11) to 77 (SD 15) in the PTA group (p = 0.003). KSS function increased from 55 (12) to 89 (25) in the PA group (p = 0.008) and from 44 (SD 14) to 81 (SD 10) in the PTA group (p = 0.008). Postoperative ROM also improved in both groups, from 83° to 108° in the PTA group (p < 0.001) as opposed to 116° to 127° in the PA group (p = 0.001), with lower results in the PTA group (p < 0.001). KOOS was lower in the PTA group (p < 0.001). The survival rate of TKA at 10 years with an endpoint defined as "any surgery on the operated knee" showed better results in the PA group (99%, CI: 98-100 vs. 79%, CI: 69-89; p < 0.001).

INTERPRETATION

Patients and surgeons should be aware that clinical outcome and implant survival after TKA for PTA are lower than after TKA done for PA.

Total knee replacement in acute and chronic traumatic events

Total knee replacement (TKR) is a widely used procedure for the treatment of post-traumatic arthritis. This type of solution has also been used recently for the treatment of acute fractures around the knee, particularly in joints that were already arthritic before the trauma. The purpose of this paper is to present our experience with TKR in both acute and chronic traumatic events, highlighting the main problems associated with these conditions and focussing on the indications, principles of technique, tips, tricks and pitfalls of this procedure. The main issues related to post-traumatic arthritis and the problem of TKR in acute fractures are discussed, and our case series of both groups of patients is presented.

Total knee arthroplasty of the stiff knee: three hundred and four cases

PURPOSE

The purpose of this study was to analyse the results of total knee arthroplasty (TKA) in stiff knees (flexion ≤90° and/or flexion contracture ≥20°). Our hypothesis was that despite having poorer results than those obtained in a "standard" population and a high rate of complications, TKA was a satisfactory treatment in patients with osteoarthritis of the knee associated with significant stiffness.

METHODS

Three hundred and four consecutive primary HLS TKAs (Tornier), whose data were prospectively collected between October 1987 and October 2012, were retrospectively analysed at a mean of 60 months (range, 12-239) postoperatively. Two groups, those with a "flexion contracture" and those with a "flexion deficit", were assessed for postoperative range of motion (as integrated to the Knee Society score [KSS]), physical activity level and patient satisfaction.

RESULTS

At the latest follow-up, range of motion was significantly improved, as was the KSS. Ninety-four percent of patients were satisfied or very satisfied, and activity levels were increased after surgery. The complication rate, however, was high in patients with a preoperative flexion deficit (17%). Pain and residual stiffness were the most common complications.

CONCLUSION

TKA provides satisfactory results in patients with knee osteoarthritis associated with significant pre-operative stiffness. The surgical plan should be adapted to anticipate complications, which are particularly frequent in the presence of a flexion deficit.

Primary total knee arthroplasty in the management of epiphyseal fracture around the knee

INTRODUCTION

Over the past few years the use of arthroplasty was broadened to treating complex epiphyseal fractures at the shoulder and elbow joints. Similar trends to treat this type of fractures at the knee are less documented. Based on a multicenter retrospective series study, the aims of this work is to evaluate the short term clinical results of total knee prostheses in the management of comminuted epiphyseal fractures around the knee, to identify the technical issues and fine tune the indications.

MATERIAL AND METHODS

Following the initiative of the French Hip and Knee Society (SFHG) and the Traumatology Study Group (GETRAUM), 26 charts from eight different centers in France were included in this multicenter retrospective series. Inclusion criteria were: primary total knee arthroplasty (TKA) in the management of complex articular fractures involving the proximal end of the tibia or distal end of the femur. Surgical features were identified and complications were analyzed. The assessment protocol at last follow-up was standardized and included patient demographic data, analysis of the Parker and IKS scores.

RESULTS

During the immediate postoperative period, six patients (23%) reported a general complication and four patients (15%) a local arthroplasty-related complication. At last follow-up (mean 16.2 months), the overall final Parker score was 6.3 (a mean decrease of 1.7) and the mean IKS knee score was 82 points for a mean function score of 54 points.

DISCUSSION

Primary TKA is a suitable management option for complex fractures in autonomous elderly patients suffering from knee osteoarthritis. The key technical details of this procedure should be respected and meticulously planned to achieve optimal results and limit the risk of complications. This risk in these acute complex fractures remains higher than after conventional TKA but comparable to that observed after TKA for post-traumatic arthritis.

LEVEL OF EVIDENCE

IV; retrospective cohort study.