Anatomical MCL reconstruction following TKA

Combined Medial Collateral Ligament Reconstruction and Polyethylene Exchange for Valgus Instability Following Total Knee Arthroplasty

Valgus instability can occur after total knee arthroplasty (TKA) due to traumatic medial collateral ligament (MCL) injury, component malpositioning, or progressive ligamentous laxity. Although revision TKA with exchange of the polyethylene to a varus-valgus-constrained liner can reduce laxity due to MCL insufficiency, isolated liner exchange in the setting of collateral ligament insufficiency may lead to greater strain at the cement-bone or implant-cement interface and possibly a greater rate of aseptic loosening. Anatomic MCL reconstruction can be performed in conjunction with liner exchange to restore stability and reduce strain compared with liner exchange alone. The purpose of this Technical Note is to describe a technique for MCL reconstruction and liner exchange for treatment of valgus instability after TKA.

Medial Collateral Ligament Reconstruction With Autograft Versus Allograft: A Systematic Review

BACKGROUND

Medial collateral ligament (MCL) reconstruction (MCLR) is performed after failed nonoperative treatment or high-grade MCL injury with associated valgus instability.

PURPOSE

To evaluate clinical outcomes after MCLR with autograft versus allograft.

STUDY DESIGN

Systematic review, Level of evidence, 4.

METHODS

A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The authors conducted a search of the PubMed, CINAHL, EMBASE, and Cochrane databases to identify studies comparing outcomes of MCLR with autograft versus allograft. Studies were included if they evaluated clinical outcomes after MCLR using autograft and/or allograft. Any study that included concomitant knee ligament injury other than the anterior cruciate ligament injury was excluded. A quality assessment was performed using the modified Coleman Methodology Score.

RESULTS

The initial search identified 746 studies, 17 of which met the inclusion criteria and were included in this review. The studies included 307 patients: 151 (49.2%) patients received autografts, and 156 (50.8%) received allografts. The most used autograft was the semitendinosus tendon (136 grafts; 90.1% of specified allografts), and the only allograft used was the Achilles tendon (110 grafts; 100% of specified autografts). The mean follow-up of the studies was 25.6 months. Postoperative pain (Lysholm scores) ranged from 82.9 to 94.8 in patients receiving autografts and 87.5 to 93 in patients receiving allografts. Postoperative range of motion was full in 8 of 15 (53.3%) patients receiving autografts compared with 82 of 93 (88.2%) patients receiving allografts. Five of the 151 (3.3%) patients who had MCLR with autografts had complications such as infection, instability, and prominent screws. Two of the 156 (1.3%) MCLRs with allografts developed complications of prominent screws and nonhealing incisions.

CONCLUSION

MCLR with either autografts or allografts leads to improved patient-reported, radiographic, and clinical outcomes. Patient-reported postoperative pain was similar in patients receiving either graft type. Other outcomes were difficult to compare between graft types because of nonstandardized reporting and a lack of pre- and postoperative measurements. Therefore, there is no evidence of significantly improved outcomes in the use of either autograft or allograft with MCLR.

Medial Collateral Ligament and Posterior Oblique Ligament Reconstruction for Valgus Instability After Total Knee Arthroplasty

Medial collateral ligament (MCL) injuries are typically managed non-operatively, with high rates of clinical success. However, patients who present with medial knee laxity with valgus stress testing of a fully extended knee, anteromedial rotatory instability, associated tibial plateau fracture, or multiligament injury or those who continue to be symptomatic after non-operative treatment may benefit from surgical intervention. Patients with a history of total knee arthroplasty who suffer MCL and posterior oblique ligament (POL) injuries represent a challenging patient population and often require surgical attention. In this Technical Note, we describe the preoperative assessment, decision making, and surgical technique for anatomic reconstruction of the superficial MCL and POL with an Achilles allograft in young, active patients with medial-sided knee injuries after total knee arthroplasty.

Medial Collateral Ligament Reconstruction for Valgus Instability After Total Knee Arthroplasty: A Case Report

CASE

Medial collateral ligament (MCL) injuries after total knee arthroplasty (TKA) are a rare occurrence. Traditional treatment options include repair and revision to a constrained prosthesis. We present a case of an 80-year-old man who opted for MCL reconstruction in the setting of previous TKA due to late MCL injury from a skiing accident. The presentation, operative techniques, and outcomes of this treatment option are presented.

CONCLUSIONS

MCL reconstruction in the setting of TKA can lead to a successful and satisfactory outcome without the need for revision TKA.

[Prevention and treatment of iatrogenic medial collateral ligament injuries in total knee arthroplasty]

Objective

To summarize the prevention and treatment of iatrogenic medial collateral ligament (MCL) injuries in total knee arthroplasty (TKA).

Methods

The relevant literature about iatrogenic MCL injuries in TKA was summarized, and the symptoms, causes, preventions, and treatments were analyzed.

Results

Preventions on the iatrogenic MCL injuries in TKA is significantly promoted. With the occurrence of MCL injuries, the femoral avulsion can be fixed with the screw and washer or the suture anchors; the tibial avulsion can be treated with the suture anchors fixation, bone staples fixation, or conservative treatment; the mid-substance laceration can be repaired directly; the autologous quadriceps tendon, semitendinosus tendon, or artificial ligament can be used for the patients with poor tissue conditions or obvious residual gap between the ligament ends; the use of implant with greater constraint can be the last alternative method.

Conclusion

No consensus has been reached to the management of iatrogenic MCL injuries in TKA. Different solutions and strategies can be integrated and adopted flexibly by surgeons according to the specific situation.

Increased valgus laxity in flexion with greater tibial resection depth following total knee arthroplasty

PURPOSE

Soft tissue balancing is of central importance to outcome following total knee arthroplasty (TKA). However, there are lack of data analysing the effect of tibial bone cut thickness on valgus laxity. A cadaveric study was undertaken to assess the biomechanical consequences of tibial resection depth on through range knee joint valgus stability. We aimed to establish a maximum tibial resection depth, beyond which medial collateral ligament balancing becomes challenging, and a constrained implant should be considered.

METHODS

Eleven cadaveric specimens were included for analysis. The biomechanical effects of increasing tibial resection were studied, with bone cuts made at 6, 10, 14, 18 and 24 mm from the lateral tibial articular surface. A computer navigation system was used to perform the tibial resection and to measure the valgus laxity resulting from a torque of 10 Nm. Measurements were taken in four knee positions: 0° or extension, 30°, 60° and 90° of flexion. Intra-observer reliability was assessed. A minimum sample size of eight cadavers was necessary. Statistical analysis was performed using a nonparametric Spearman's ranking correlation matrix at the different stages: in extension, at 30°, 60° and 90° of knee flexion. Significance was set at p < 0.05.

RESULTS

There was no macroscopic injury to the dMCL or sMCL in any of the specimens during tibial resection. There was no significant correlation found between the degree of valgus laxity and the thickness of the tibial cut with the knee in extension. There was a statistically significant correlation between valgus laxity and the thickness of the tibial cut in all other knee flexion positions: 30° (p < 0.0001), 60° (p < 0.001) and 90° (p < 0.0001). We identified greater than 5° of valgus laxity, at 90° of knee flexion, after a tibial resection of 14 mm.

CONCLUSION

Increased tibial resection depth is associated with significantly greater valgus laxity when tested in positions from 30° to 90° of flexion, despite stability in extension. Greater than 5° of laxity was identified with a tibial resection of 14 mm. When a tibial bone cut of 14 mm or greater is necessary, as may occur with severe preoperative coronal plane deformity, it is recommended to consider the use of a constrained knee prosthesis.