Extensor Mechanism Reconstruction Using Marlex Mesh: Is Postoperative Casting Mandatory?

A unique case report of a revision extensor mechanism reconstruction using Marlex mesh in the setting of proximal tibial bone deficiency: The tantalum clamshell technique

Extensor mechanism (EM) disruption is a rare but severe complication of total knee arthroplasty (TKA) that can greatly impair function. Treatment options for chronic patella tendon ruptures include primary repair, autograft augmentation, and reconstruction with allograft or synthetic material. Despite various techniques, failures can occur, and options for reconstruction after a failed allograft or mesh are limited, especially if the tibial component is well-fixed and cannot be easily removed, and if there is proximal tibial deficiency from a previous failed EM allograft. This case report presents a novel solution for revision EM reconstruction in a 72y.o. female patient with a history of multiple EM failures using an off-label Trabecular Metal Cone-Mesh-Cone (TM CMC) clamshell construct. The surgical procedure involved the removal of a non-viable allograft from the knee joint and the creation of a custom trabecular metal (TM) clamshell construct with a Marlex mesh graft in between the two TM implants. The customized TM cone was designed to cover the deficient anterior tibia and wrap around the ingrown TM cone. The Marlex mesh was cemented between the existing implant and the customized TM cone, and the construct was secured in place with two cancellous screws. The mesh was tunneled between soft tissue to prevent contact with the implant and rotated scar tissue was interposed to prevent abrasion of the mesh on the implant surfaces. The patient tolerated the procedure well and no complications were noted postoperatively. At a follow-up 12 months after the operation the patient remains satisfied with the result.

The Infected Polypropylene Mesh: When Does Biofilm Form and Which Antiseptic Solution Most Effectively Removes It?

BACKGROUND

Polypropylene (PPE) mesh is commonly utilized to reconstruct catastrophic extensor mechanism disruptions in revision total knee arthroplasty. Unfortunately, these procedures are associated with a high rate of periprosthetic joint infection. The purpose of the current study was to: 1) visualize and quantify the progression of bacterial biofilm growth on PPE-mesh; and 2) determine which antiseptic solutions effectively remove viable bacteria.

METHODS

Knitted PPE mesh samples were cultured with either methicillin-sensitive Staphylococcus aureus (MSSA) or Escherichia coli (E. coli) for 7 days, with regular quantification of colony forming units (CFUs) and visualization using scanning electron microscopy to identify maturity. Immature (24 hour) and mature (72 hour) biofilm was treated with one of 5 commercial antiseptics for 3 minutes. A 0.05% chlorhexidine gluconate, a surfactant-based formulation of ethanol, acetic acid, sodium acetate, benzalkonium chloride, diluted povidone-iodine (0.35%), undiluted (10%) povidone-iodine, and 1:1 combination of 10% povidone-iodine and 3% hydrogen peroxide. A 3-log reduction in CFUs compared to saline was considered clinically meaningful.

RESULTS

The CFU counts plateaued, indicating maturity, at 72 hours for both MSSA and E. coli. The scanning electron microscopy confirmed confluent biofilm formation after 72 hours. The 10% povidone-iodine was clinically effective against all MSSA biofilms and immature E. coli biofilms. The 10% povidone-iodine with hydrogen peroxide was effective in all conditions. Only 10% povidone iodine formulations produced significantly (P < .0083) reduced CFU counts against mature biofilms.

CONCLUSIONS

Bacteria rapidly form biofilm on PPE mesh. Mesh contamination can be catastrophic, and clinicians should consider utilizing an antiseptic solution at the conclusion of mesh implantation. Undiluted povidone-iodine with hydrogen peroxide should be considered when attempting to salvage infected PPE mesh.

Allograft or Synthetic Mesh Extensor Mechanism Reconstruction After TKA Carries a High Risk of Infection, Revision, and Extensor Lag

BACKGROUND

Extensor mechanism disruption is a devastating complication after TKA. Extensor mechanism reconstruction can be performed using an allograft or synthetic mesh. Recent studies have disagreed about the durability of these reconstructions. Evaluating a larger series of reconstructions that use current popular techniques and principles provides information to guide patient and surgeon expectations while bringing to light the potential fate of patients who experience an infection postoperatively.

QUESTIONS/PURPOSES

(1) What was the 5-year survival free of repeat revision surgery or persistent extensor lag of more than 30° after allograft or synthetic mesh reconstruction of extensor mechanism disruptions after TKA, and did this differ between techniques? (2) What was the 5-year survival free of infection after allograft or mesh reconstruction, and what proportion of those patients experienced a secondary severe complication (arthrodesis or amputation)?

METHODS

Between April 2008 and December 2020, 123 patients underwent extensor mechanism reconstruction after TKA at one center. Of those, 37% (45) were lost to follow-up before 2 years, had not been seen in the past 5 years, did not reach a study endpoint (repeat revision or extensor lag > 30°) before that time, or underwent primary repair and thus could not be analyzed, leaving 63% (78) for analysis here. During the study period, we considered extensor mechanism surgery when acute or chronic disruption of the patellar or quadriceps tendon was present or there was a fracture of the patella resulting in extensor lag. The decision to use either mesh or an allograft largely depended on surgeon experience and familiarity with either technique. We collected patient demographics, operative details (location of disruption and presence of a hinged prosthesis), subsequent periprosthetic joint infection (PJI), and postoperative SF-12 and Knee Injury and Osteoarthritis Outcome Score, Joint Replacement, scores. We used Kaplan-Meier survivorship analysis, with endpoints of extensor lag more than 30° or revision of the reconstruction and PJI. The mean follow-up duration was 5.3 ± 3.2 years.

RESULTS

Survivorship free from revision or recurrent extensor lag was 54% (95% CI 44% to 66%) at 5 years. There was no difference between those undergoing reconstruction with allografts and those with mesh in terms of survivorship free from those endpoints at that timepoint (52% [95% CI 40% to 68%] versus 57% [95 CI% 41 to 78%]; p = 0.99). Survivorship free from PJI was 81% (95% CI 73% to 90%) at 2 years. There was no difference between those with allografts and those with mesh in terms of survivorship free from PJI at that timepoint (79% [95% CI 69% to 92%] versus 83% [95% CI 71% to 98%]; p = 0.75). Of the 17 patients who experienced PJI, four ultimately underwent arthrodesis and three more underwent transfemoral amputation.

CONCLUSION

Allograft and synthetic mesh reconstructions commonly left patients with persistent limb dysfunction, while several patients had PJI and some underwent salvage procedures. Although improvements have been made with regard to treating extensor mechanism disruptions, patients and surgeons should be well aware of the potential adverse outcomes when determining management and use these findings to conduct risk-benefit analyses. There is a need for future studies to identify protocols that improve the durability of reconstructions and to determine whether interventions such as prolonged prophylactic antibiotic therapy have a role in minimizing the risk of PJI.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Extensor Mechanism Disruption Remains a Challenging Problem

BACKGROUND

Extensor mechanism disruption (EMD) following total knee arthroplasty (TKA) is a devastating problem commonly treated with allograft or synthetic reconstruction. Understanding of reconstruction success rates and patient recorded outcomes is lacking.

METHODS

Patients who have an EMD after TKA undergoing mesh or whole-extensor allograft reconstruction between 2011 and 2019, with minimum 2-year follow-up were reviewed at two tertiary care centers. Functional failure was defined as extensor lag >30 degrees, amputation, or fusion, as well as revision extensor mechanism reconstruction (EMR). Survivorship was assessed using Kaplan-Meier curves, and factors for success were determined with logistic regressions.

RESULTS

Of fifty-six EMRs (49 patients), 50.0% (28/56) were functionally successful at 3.2 years of mean follow-up (range, 0.2 to 7.4). In situ survivorship of the reconstructions at 36 months was 75.0% (42 of 58). There were 50.0% (14 of 28) of functionally failed EMRs that retained their reconstruction at last follow-up. Mean extensor lag among successes and failures was 5.4 and 71.0° (P = .01), respectively. Mean Knee Injury and Osteoarthritis Outcome Score, Joint Replacement scores were 67.1 and 48.8 among successes and failures (P = .01). There were 64.0% (16 of 25) of successes and 1 of 19 failures that obtained a Knee Injury and Osteoarthritis Outcome Score, Joint Replacement score above the minimum patient-acceptable symptom state for TKA. Survivorship and success rates were similar between reconstruction methods (P = .86; P = .76). All-cause mortality was 8.2% (4 of 49), each with EMR failure prior to death. All-cause reoperation rate was 42.9% (24 of 56), with a 14.3% (8 of 56) rate of revision EMR and 10.7% (6 of 56) rate of above-knee-amputation or modular fusion.

CONCLUSIONS

This multicenter investigation of mesh or allograft EMR demonstrated modest functional success at 3.2 years. Complication and reoperation rates were high, regardless of EMR technique. Therefore, EMD after TKA remains problematic.

Satisfactory outcomes of patellar tendon reconstruction using achilles' tendon allograft with bone block after infected total knee arthroplasty

PURPOSE

Extensor mechanism disruption is an uncommon and devastating complication after total knee arthroplasty. It negatively affects patients' quality of life and leads to significant functional limitations and the inability to stand and walk. The purpose of the present study was to evaluate the outcomes of the extensor mechanism reconstruction using Achilles' tendon allograft after infected total knee arthroplasty. It was hypothesized that it is a safe procedure and that patients will present good clinical and functional results.

METHODS

Ten patients treated for infra-patellar extensor mechanism disruption after infected total knee arthroplasty were prospectively followed for two years. The mean age of patients was 70.8 (range 55-85), with a median BMI of 28.72 ± 2.2 kg/m². All patients underwent reconstruction using a fresh frozen Achilles tendon allograft. Preoperative and postoperative evaluation included knee-related clinical and functional assessment based on objective and subjective scores, including the knee flexion, the extension lag, the Knee Society Score (KSS) clinical and functional, and the visual analog scale (VAS) for pain at 12 and 24 months. Radiological evaluation was also performed using the Caton-Deschamps index. Reported complications were also recorded.

RESULTS

Clinical and functional outcomes recorded significant improvements (p < 0.05) at the final follow-up compared with baseline as follows: Knee flexion was improved from 66° ± 4.8 to 99.7° ± 3.9, and the extension lag was decreased from 28.3° ± 4.4 to 9° ± 2.7. The mean KSS clinical and functional were also improved from 22.6 ± 7.9 to 73.4 ± 3.9 and from 10 ± 13.8 to 55 ± 13.8, respectively. The VAS for pain was decreased from 8.1 ± 1.2 to 1.9 ± 1.2. The Caton-Deschamps index demonstrated a tendency to patella Alta. Two treatment failures were recorded, one patellar dislocation and one re-rupture revised to arthrodesis.

CONCLUSIONS

Extensor mechanism reconstruction using Achilles' tendon allograft after infected total knee arthroplasty is an efficient and safe procedure for infra-patellar disruption. The present study's findings demonstrate that most of the patients (80%) presented significant clinical and functional improvement at two-year follow-up.

Extensor Mechanism Reconstruction After Total Knee Arthroplasty with Allograft Versus Synthetic Mesh: A Multicenter Retrospective Cohort

INTRODUCTION

Patellar and quadriceps tendon ruptures after total knee arthroplasty (TKA) have historically poor outcomes. To date, there is no consensus for optimal treatment. The purpose of this study is to directly compare clinical outcomes and survivorship between allograft versus synthetic mesh for reconstruction of native extensor mechanism (EM) rupture after TKA.

METHODS

A multicenter, retrospective review identifying consecutive TKA patients operated between December 2009 to November 2019 was conducted. Patients aged ≥ 45 years old with native EM disruption treated with either allograft or synthetic mesh with minimum 2 year follow-up were included. Demographic information, injury mechanism, range of motion, surgical time, revision surgeries, and postoperative Knee Injury and Osteoarthritis Outcome Scores (KOOS Jr.) were collected. Student t-tests and Fisher exact tests were used to compare the demographic data between groups. The Kaplan-Meier survival curve method was used to determine the survivorship as treatment failure was defined as postoperative EM lag >30° or revision surgery. Survival curves were compared using the log-rank test. Univariate Cox proportional hazard regression identified risk factors associated with treatment failure.

RESULTS

Twenty patients underwent EM reconstruction using allograft versus 35 with synthetic mesh. Both groups had similar demographics and an average follow-up time of 3.5 years (P = 0.98). Patients treated with allograft had significantly greater postoperative flexion than patients treated with mesh (99.4 ± 9.5 allograft versus 92.6 ± 13.6 synthetic mesh, P = 0.04). Otherwise, there was no difference in postoperative outcomes between the two groups in average KOOS Jr. (P = 0.29), extensor lag (P = 0.15), graft failure (P = 0.71), revision surgery rates (P = 0.81), surgical time (P = 0.42), or ambulatory status (P = 0.34) at the most recent follow-up. Survival curve comparison also yielded no difference at up to 5-year follow-up (P = 0.48).

DISCUSSION AND CONCLUSION

Our findings suggest that reconstruction with allograft or synthetic mesh leads to similar clinical outcomes with good survivorship. Future studies, including larger randomized control trials, are required to determine the superior reconstruction method for this injury.

LEVEL OF EVIDENCE

III.

Early patellar tendon rupture after total knee arthroplasty: A direct repair method

BACKGROUND

Patellar tendon rupture after total knee arthroplasty (TKA) is a catastrophic complication. Although the occurrence of this injury is rare, it can lead to significant dysfunction for the patient and is very tricky to deal with. There has been no standard treatment for early patella tendon rupture after TKA, and long-term follow-up data are lacking.

AIM

To introduce a direct repair method for early patella tendon rupture following TKA and determine the clinical outcomes and complications of this method.

METHODS

During the period of 2008 to 2021, 3265 consecutive TKAs were retrospectively reviewed. Twelve patients developed early patellar tendon rupture postoperatively and were treated by a direct repair method. Mean follow-up was 5.7 years. Demographic, operative, and clinical data were collected. The clinical outcomes were assessed using the Western Ontario and McMaster Universities (WOMAC) score, the Hospital for Special Surgery (HSS) score, knee range of motion, extensor lag, and surgical complications. Descriptive statistics and paired t test were employed to analyze the data.

RESULTS

For all 12 patients who underwent direct repair for early patellar tendon rupture, 3 patients failed: One (8.3%) for infection and two (17.6%) for re-fracture. The two patients with re-fracture both underwent reoperation to reconstruct the extensor mechanism and the patient with infection underwent revision surgery. The range of motion was 109.2° ± 10.6° preoperatively to 87.9° ± 11° postoperatively, mean extensor lag was 21° at follow-up, and mean WOMAC and HSS scores were 65.8 ± 30.9 and 60.3 ± 21.7 points, respectively.

CONCLUSION

This direct repair method of early patellar tendon rupture is not an ideal therapy. It is actually ineffective for the recovery of knee joint function in patients, and is still associated with severe knee extension lag and high complication rates. Compared with the outcomes of other repair methods mentioned in the literature, this direct repair method shows poor clinical outcomes.

Therapy of chronic extensor mechanism deficiency after total knee arthroplasty using a monofilament polypropylene mesh

Introduction

Lesions of the quadriceps or patellar tendon after total knee arthroplasty (TKA) are a rare but serious complication which, if left untreated, can lead to loss of function of the knee joint. While acute and subacute extensor mechanism disruptions may have several causes, chronic deficiencies are often related to multiple prior revision surgeries for joint infection or aseptic TKA failure. Up to date, biological allograft reconstruction showed unsatisfying results. The use of a monofilament polypropylene mesh is a promising approach for this pathological condition. The aim of the present study was to evaluate clinical, functional and patient reported outcomes of this procedure in patients with chronic extensor mechanism deficiency.

Materials and Methods

Twenty-eight patients with chronic extensor mechanism deficiency (quadriceps tendon rupture n = 9, patellar tendon rupture n = 19) after TKA were included in this retrospective study. None of the patients were lost to follow-up. Surgical reconstruction was performed at one institution between 2014 and 2020 with a monofilament polypropylene mesh (Marlex Mesh, Bard, Murray Hill, USA). The mean age at the time of surgery was 69 years. Patients presented with a mean BMI of 33 kg/m². The mean follow-up period was 23 months.

Results

The 2-year survivorship free of mesh revision was 89% [95% confidence interval (CI): 75% to 100%]. Three patients (11%) had to undergo revision because of mechanical mesh failure and received another polypropylene mesh. No further revisions were performed thereafter. Flexion was 87° (range, 30–120°) on average. The majority of patients (75%, 21/28) had a full active extension. The mean active extension lag after surgery was 4 degrees (range, 0–30°).

Discussion

We observed a substantial improvement of extensor mechanism function. The majority of patients had full extension and showed good clinical results. A failure rate of over 50% has been published for alternative procedures. Thus, the use of the described augmentation technique represents a reasonable treatment option for chronic extensor mechanism disruptions of the patellar tendon as well as the quadriceps tendon after total knee arthroplasty. However, there might be a potentially higher risk for infection persistence in periprosthetic joint infection cases due to the presence of a foreign material.

Techniques for extensor mechanism reconstruction after total knee arthroplasty: Is there a clear winner?

Extensor mechanism (EM) disruption after total knee arthroplasty (TKA) is rare, but can result in devastating outcomes for patients including inability to ambulate. Disruption can occur at the quadriceps tendon, patella, or patellar tendon. This complication can be traumatic, but is often atraumatic from an iatrogenic or degenerative etiology. Primary repair for treatment of EM disruption has led to poor results with high failure rates and has mostly been abandoned. Most commonly accepted techniques center around Achilles tendon allograft reconstruction, synthetic mesh reconstruction, or other smaller options. However, to date, there is still no consensus for the optimal EM reconstructive technique due to the heterogeneity and small sample sizes of published studies. The need to identify a consistent and effective surgical technique is paramount to restore quality of life to patients who suffer from EM disruption after TKA. The purpose of this review is to describe the osteology, vasculature, and EM of the knee, identify risk factors associated with EM disruption after TKA, outline the considerations for surgical management, as well as compare and analyze the latest contributions to the literature, in particular allograft versus synthetic mesh, in the reconstruction of the EM after TKA.

Extensor mechanism ruptures

Native patellar tendon injuries are seen in younger patients compared to quadriceps tendon ruptures.

Up to a third of the patients may have local (antecedent tendinopathy and cortisone injections) or systemic risk factors (obesity, diabetes, hyperparathyroidism, chronic renal failure, fluoroquinolone or statin use) of injury, these are more frequent in bilateral disruptions.

Complete extensor mechanism disruptions should be repaired surgically. Although isolated primary repair has been reported to have good outcomes in younger patients with acute tears and good tendon quality, augmentation of the repair with autograft, allograft or synthetic material should be considered in patients with poor tendon quality, chronic tears or tendon defects.

High rates of return to work/sports have been reported in native patellar and quadriceps tendon tears, with re-rupture rates <5%.

Extensor mechanism disruptions in patients with a total knee arthroplasty are challenging due to older age, systemic co-morbidities and poor local conditions, resulting in inferior outcomes compared to native extensor mechanism injuries. Some form of augmentation with autograft, allograft or synthetics is advisable in all cases. Salvage procedures such as whole extensor mechanism allografts provide acceptable outcomes in multiply operated knees with extensive bone and soft tissue deficits.