Tibial tubercle osteotomy with screw fixation for total knee arthroplasty

Contemporary outcomes of tibial tubercle osteotomy for revision total knee arthroplasty

Aims

Tibial tubercle osteotomy (TTO) facilitates surgical exposure and protects the extensor mechanism during revision total knee arthroplasty (rTKA). The purpose of this study was to determine the rates of bony union, complications, and reoperations following TTO during rTKA, to assess the functional outcomes of rTKA with TTO at two years' minimum follow-up, and to identify the risk factors of failure.

Methods

Between January 2010 and September 2020, 695 rTKAs were performed and data were entered into a prospective database. Inclusion criteria were rTKAs with concomitant TTO, without extensor mechanism allograft, and a minimum of two years' follow-up. A total of 135 rTKAs were included, with a mean age of 65 years (SD 9.0) and a mean BMI of 29.8 kg/m2 (SD 5.7). The most frequent indications for revision were infection (50%; 68/135), aseptic loosening (25%; 34/135), and stiffness (13%; 18/135). Patients had standardized follow-up at six weeks, three months, six months, and annually thereafter. Complications and revisions were evaluated at the last follow-up. Functional outcomes were assessed using the Knee Society Score (KSS) and range of motion.

Results

The mean follow-up was 51 months (SD 26; 24 to 121). Bony union was confirmed in 95% of patients (128/135) at a mean of 3.4 months (SD 2.7). The complication rate was 15% (20/135), consisting of nine tibial tubercle fracture displacements (6.7%), seven nonunions (5%), two delayed unions, one tibial fracture, and one wound dehiscence. Seven patients (5%) required eight revision procedures (6%): three bone grafts, three osteosyntheses, one extensor mechanism allograft, and one wound revision. The functional scores and flexion were significantly improved after surgery: mean KSS knee, 48.8 (SD 17) vs 79.6 (SD 20; p < 0.001); mean KSS function, 37.6 (SD 21) vs 70.2 (SD 30; p < 0.001); mean flexion, 81.5° (SD 33°) vs 93° (SD 29°; p = 0.004). Overall, 98% of patients (n = 132) had no extension deficit. The use of hinge implants was a significant risk factor for tibial tubercle fracture (p = 0.011).

Conclusion

TTO during rTKA was an efficient procedure to improve knee exposure with a high union rate, but had significant specific complications. Functional outcomes were improved at mid term.

Finite element study of the effects of fragment shape and screw configuration on the mechanical behavior of tibial tubercle osteotomy

PURPOSE

Tibial tubercle osteotomy (TTO) is a surgical technique used in the management of severe fractures of the knee joint and revision total knee arthroplasty. Limited research discusses the performance of the osteotomy and fixation of the TTO with screws. Therefore, this study investigated the effects of fragment shape and screw configuration on the mechanical behavior in the fixation of the TTO using the finite element (FE) method.

METHODS

FE TTO models with three fragment shapes and three screw configurations were developed. The three fragment shapes were a step cut, bevel cut, and straight cut. The screw configurations were two parallel horizontal and downward screws and two trapezoidal screws. A 1654-N upward tension force was applied on the tibia tubercle, and the distal end of the tibia was completely fixed.

RESULTS

The results indicated that the step cut resulted in higher stability than the bevel and straight cut, but the stress was higher as well. Among the screw configurations, two parallel downward screws resulted in the highest stability, given the same fragment shape. In the horizontal configuration, the step cut tibia developed the largest contact force to achieve stability of the bone fragment under loading.

CONCLUSION

The fragment shape with a step cut and fixation with two parallel horizontal or downward screws are suggested for TTO, while the trapezoidal screw configuration is not suggested. Furthermore, the downward screw configuration is a suitable strategy to reduce bone stress.

Gap between the fragment and the tibia affects the stability of tibial tubercle osteotomy: A finite element study

Tibial tubercle osteotomy (TTO) is commonly performed in cases of complicated juxta-articular trauma or revision total knee arthroplasty. However, strategies for firmly fixing the resulting osteotomy bone fragment are not sufficiently understood. This study aims to investigate the effect of the location of the gap between the fragment and the tibia and with various fixed screw configurations on TTO stability, contact force on the fragment, and bone stress by using the finite element method. A TTO model with a 1-mm gap, either above or below the fragment, was developed. Furthermore, five screw configurations, including two parallel horizontal screws placed at 20- and 30-mm intervals, two parallel downward screws, two trapezoid screws, and two divergent screws, were used. A vertically upward 1600-N force was applied on the tibial tubercle to mimic a worst-case condition. Placing the fragment close to the superior cutting plane (above the gap) yielded greater stability and less stress on the bone than did placing it close to the inferior cutting plane. The superior cutting plane of the tibia generated the largest contact force on the superior plane of the fragment for static balance under loading. Additionally, among all screw configurations, the configuration involving two parallel downward screws resulted in the highest stability but also the greatest stress on the cortical bone. The fragment obtains a solid barrier and support from the tibia immediately after surgery to against the patellar tension force when the fragment is close to the superior cutting plane of the tibia.

Biomechanical investigation of tibial tubercle osteotomy fixed with various screw configurations

INTRODUCTION

To date, the effects of various screw configurations on the stability of tibial tubercle osteotomy (TTO) are not completely understood. Hence, the first aim of this study is to evaluate the stability of TTO under various screw configurations. The second aim is to evaluate the internal stresses in the bone and the contact forces on the bone fragment that are developed by the tibia and screws in response to the applied load after the equilibrant is revealed.

METHODS

To calculate the biomechanical responses of the bone and screw under loading, finite element (FE) method was used in this study. Six types of screw configurations were studied in the simulation: two parallel horizontal screws placed at a 20 mm interval, two parallel horizontal screws placed at a 30 mm interval, two parallel upward screws, two parallel downward screws, two trapezoid screws, and two divergent screws. The displacement of the bone fragment, contact forces on the fragment, and the internal stress in the bone were used as indices for comparison.

RESULTS

Among all configurations, the configuration of two parallel downward screws yielded the highest stability with the lowest fragment displacement and gap opening. Although the maximum displacement of the TTO with the configuration of two parallel horizontal screws was slightly higher than that of the downward configuration, the difference was only 0.2 mm. The configuration of two upward screws resulted in the highest fragment displacement and gap deformation between the fragment and tibia. The stress of the osteotomized bone fragment was highest with the configuration of two upward screws.

CONCLUSION

Based on the present model, the current configuration of two parallel horizontal screws is recommended for TTO. If this is inappropriate in a specific clinical scenario, then the downward screw configuration may be used as an alternative. By contrast, the configuration of two parallel upward screws is least suggested for the fixation of TTO.

Tibial tubercle osteotomy (TTO) in total knee arthroplasty, is it worth it? A review of the literature

INTRODUCTION

Tibial tubercle osteotomy (TTO) is a well-established extensile approach to improve joint visualization and implant removal. Despite this, TTO is a challenging technique with a long learning curve and potential pitfalls. Complications are not infrequent, even if performing the correct surgical steps. Aim of this paper is to review the current literature about TTO, its safeness and reliability, and finally the complications rate.

MATERIALS AND METHODS

We performed a systematic review of the available English literature, considering the outcomes and the complications of TTO. The combinations of keyword were "tibial tubercle osteotomy", "total knee arthroplasty", "total knee revision", "outcomes", "complication" and "surgical approach".

RESULTS

From the starting 322 papers available, 26 manuscripts were finally included. Most of the papers show significant improvements in clinical outcomes, both in primary and in revision procedures. Radiographic fragment healing is close to 100%. Related complications can range from 3.8-20%.

CONCLUSION

TTO may be necessary to correct pathological tuberosity position or patella tracking. However, TTO is a challenging technique to improve the surgical approach during total knee arthroplasty. A strict surgical technique can lead to better results and to minimize complications. However, it is not clear if the improved outcome can outweigh the longer surgery and the higher risk of pitfalls.

Proximalisation of the tibial tubercle gives a good outcome in patients undergoing revision total knee arthroplasty who have pseudo patella baja

AIMS

The aim of this study was to compare the outcome of revision total knee arthroplasty (TKA) with and without proximalisation of the tibial tubercle in patients with a failed primary TKA who have pseudo patella baja.

PATIENTS AND METHODS

All revision TKAs, performed between January 2008 and November 2013 at a tertiary referral University Orthopaedic Department were retrospectively reviewed. Pseudo patella baja was defined using the modified Insall-Salvati and the Blackburne-Peel ratios. A proximalisation of the tibial tubercle was performed in 13 patients with pseudo patella baja who were matched with a control group of 13 patients for gender, age, height, weight, body mass index, length of surgery and Blackburne-Peel ratio. Outcome was assessed two years post-operatively using the Knee Society Score (KSS).

RESULTS

The increase in KSS was significantly higher in the osteotomy group compared with the control group. The outcome was statistically better in patients in whom proximalisation of > 1 cm had been achieved compared with those in whom the proximalisation was < 1 cm.

CONCLUSION

In this retrospective case-control study, a proximal transfer of the tibial tubercle at revision TKA in patients with pseudo patella baja gives good outcomes without major complications. Cite this article: Bone Joint J 2017;99-B:912-16.

Tibial Tubercle Osteotomy in Revision Knee Arthroplasty

BACKGROUND

Obtaining adequate exposure while maintaining the integrity of the extensor mechanism is crucial to the success of revision knee arthroplasty. This is particularly important in infected cases where staged procedures are necessary. While the use of a long, tibial tubercle osteotomy (TTO) is an established method to improve exposure, controversy still exists concerning complication rates and sequential use.

METHODS

Forty-two TTOs were performed in revision knee arthroplasties between 2009 and 2015. Follow-up period ranged from 3 to 24 months. Twenty-four TTOs were performed for single-stage revisions, and 18 TTOs were performed for 2-stage infected revisions. In infected cases, the initial osteotomy was left unfixed between stages. Screws were used to fix the osteotomy flap in all cases.

RESULTS

All osteotomies united with no fractures, and there were no extensor lags. Minor proximal migration was noted in 1 case, and refixation was required in another. Greater range of motion (ROM) and improved Oxford Knee Scores were achieved in the single-stage revision group. In the infected 2-stage group, sequential use did not decrease union rates, and infection was eradicated in 14 of the 16 knees (88%).

CONCLUSION

We conclude that TTO is a safe and reproducible procedure when exposure needs improving in revision knee arthroplasty. In 2-stage revisions, sequential osteotomies do not decrease union rates, and leaving the osteotomy unfixed after the first stage does not cause any adverse issues.

Tibial Tubercle Osteotomy to Aid Exposure for Revision Total Knee Arthroplasty

Introduction

A tibial tubercle osteotomy can provide reliable and safe exposure during revision total knee arthroplasty with a high union rate, low complication rate, and predictable outcomes.

Indications & Contraindications

Step 1 Preoperative Planning Figs 1-A through 2-B

Determine the need for an extensile approach on the basis of the preoperative knee range of motion; position of the patella; bone quality; medical comorbidities; and cement mantle, tibial keel or stem, and thickness of the anterior tibial cortex.

Step 2 Incision and Arthrotomy

Create full-thickness subcutaneous flaps and perform a medial parapatellar arthrotomy with complete synovectomy and careful excision of scar tissue from the medial and lateral gutters.

Step 3 Incision Extension and Preparation for Tibial Tubercle Osteotomy Figs 3 and 4 Videos 1 2 and 3

Extend the skin and subcutaneous dissection distal to the tibial tubercle and mark the chevron osteotomy using electrocautery.

Step 4 Tibial Tubercle Osteotomy Fig 5 Videos 4 and 5

Perform the osseous cut for the tibial tubercle osteotomy with a thin saw blade in a medial-to-lateral direction, such that the fragment hinges on the lateral soft tissue and musculature.

Step 5 Revision Total Knee Arthroplasty Videos 6 and 7

With the knee maximally flexed and lateral subluxation of the extensor mechanism, for full visualization of the femoral and tibial components, remove the components and perform the knee revision.

Step 6 Preparation for Insertion of Tibial Component

The final tibial component should have a diaphyseal stem long enough to bypass the distal extent of the tibial tubercle osteotomy by at least 2 cortical diameters.

Step 7 Trialing and Insertion of Final Tibial Component Figs 6 and 7 Videos 8 9 and 10

When cementing the final tibial component, take care to remove cement anterior to the tibial stem that would otherwise impede complete reduction of the osteotomy fragment and interfere with osseous union at the osteotomy site.

Step 8 Reduction of Tibial Tubercle Osteotomy Fragment Figs 8 and 9 Videos 11 12 and 13

Manually position the osteotomized bone fragment over the tibia and obtain an anatomic reduction either freehand or using bone clamps, depending on the soft-tissue tension.

Step 9 Fixation of Tibial Tubercle Osteotomy Fragment Video 14

Obtain rigid fixation with a 6.5-mm screw proximally and 2 sets of doubled-over 18-gauge wires distally.

Step 10 Stressing the Osteotomy Site and Wound Closure Figs 10 11 and 12 Videos 15 and 16

Stress the osteotomy site by flexing the knee 90°, deflate the tourniquet, place a drain if needed, and close.

Step 11 Postoperative Restrictions and Protocol Figs 13-A and 13-B

Allow weight-bearing as tolerated and a 0° to 90° range of motion in a hinged knee brace.

Results

Tibial tubercle osteotomy to aid in exposure during revision total knee arthroplasty has been reported to yield favorable outcomes in the orthopaedic literature^7-18.

Pitfalls & Challenges

Complex Primary Total Knee Replacement (TKR) Using Prophylactic Gastrocnemius Flap and Rotating-Hinge Knee in Post-traumatic, Infective Arthritis of the Knee - A Case Report

INTRODUCTION

Prophylactic gastrocnemius flap with primary rotating hinge knee is technically demanding in a case of neglected post-traumatic, infective arthritis of the knee, with challenges of compromised skin and soft tissues, articular bone defect, limb mal-alignment, gross instability, retained hardware and a contracted extensor mechanism with the patella fixed in the lateral gutter all in combination, is rarely reported. We report such a complex case in this study.

CASE REPORT

We report a 48 year male patient with a history of fracture lateral femoral condyle of right knee due to road traffic accident 10 years back, for which he got operated with open reduction and internal fixation with cancellous screws, which subsequently got infected. Primary procedure undertaken was removal of implants, debridement, placement of antibiotic-cement spacer followed by prophylactic medial gastrocnemius flap and a temporary joint spanning external fixator. Definitive procedure undertaken, after clearance of infection in 12 weeks was conversion to a rotating hinge TKR using a lateral para-patellar arthrotomy & tibial tubercle osteotomy to address the challenges of fixed patella in the lateral gutter and contracted ligamentum patellae. At one year follow up, the knee was painless, stable, with satisfactory range of motion and improved function without any infection or aseptic lysis.

CONCLUSION

Prophylactic Gastrocnemius flap cover along with rotating hinge knee arthroplasty using a lateral para-patellar approach and tibial tubercle osteotomy in a case of neglected post-traumatic, infective arthritis of knee with the complexities of limb mal-alignment, compromised skin and soft tissue, articular bone loss and ligamentous instability is a satisfactory bail out option in such a highly complex joint scenario.

Tibial tubercle osteotomy for patello-femoral joint disorders

Tibial tubercle osteotomy has a long history in the management of patella instability and patello-femoral arthritis. This review aims to provide a comprehensive review of the literature describing the biomechanics of the patello-femoral joint and the rationale behind the use of the tibial tubercle osteotomy in modern day practice. Several different tibial tubercle osteotomies are available and we aim to detail the concepts behind their use and the subsequent clinical results. With continued developments of chondrocyte implantation techniques, the potential to fill defects on the chondral surface of either the patella or trochlea in conjunction with a tibial tubercle osteotomy may well become more commonplace in a group that is commonly young and difficult to manage. Level of evidence III.

Tibial tubercle osteotomy in septic revision total knee arthroplasty

PURPOSE

The incidence of revision knee arthroplasty for infection is increasing and the required surgical approach for the revision is a challenge for surgeons. Extensile approaches are frequently used when it is impossible to evert the extensor mechanism. The aim of this paper is to report our experience with tibial tubercle osteotomy (TTO) and the functional results in patients who underwent a two-stage revision due to prosthesis infection.

METHODS

Twenty-six patients underwent a TTO as a surgical approach in the second stage of revision for infection. The patients were clinically assessed by means of functional scales (the Knee Society Score and WOMAC) and X-rays.

RESULTS

The TTO healed without complications in 22 patients (84.6%) and the average length of follow-up was 3.4 years. Non-union was observed in two patients. One patient presented an extension lag of 5°. A total of 23 patients (88.4%) were free from infection. Twenty-five patients (96.1%) had better scores on the Knee Society Score and WOMAC after the procedure.

CONCLUSIONS

In patients undergoing the second stage of revision total knee arthroplasty for infection, the TTO approach provides a large operating field. This enables surgeons to withdraw spacers and position new implants without damaging the extensor mechanism of the knee or altering the postoperative rehabilitation process. The complications that have been reported as a result of this procedure could be reduced by performing a meticulous surgical technique.

LEVEL OF EVIDENCE

Retrospective case series, Level IV.