Position of the popliteal artery in revision total knee arthroplasty

Background

Injury to the popliteal artery during total knee arthroplasty is a devastating complication. This topic was studied previously prior to primary total knee arthroplasty. This study aims to demonstrate the position of the popliteal artery in patients prior to revision total knee replacement.

Methods

The ultrasound scan results of the position of the popliteal artery in 23 patients were reviewed. The implant/artery distance at different levels was measured with the knee in extension and 70°–90° of flexion.

Results

There was no significant difference in the artery position at the level of the tibial metal base plate (the most critical site) on moving the knee from extension to flexion (P?=?0.26). However, the implant/artery distance was found to increase on moving from extension to flexion in relation to the femoral component at the joint line (69%), as well as 15?mm below the level of the tibial base plate representing 69.3%. There was a significant difference at 15?mm above the joint line, where the distance was found to be increased in 84.6% of cases (P?=?0.019).

Conclusion

This study has shown that in a revision knee situation, there is no reliable fall back of the popliteal artery in knee flexion; in fact, implant/artery distance may be decreased and caution must be exercised throughout the procedure. It may be worth considering either ultrasound or arteriography in selected cases.     

Anatomical evaluation of the modified posterolateral approach for posterolateral tibial plateau fracture

Objective

The study was undertaken to evaluate the efficacy and safety of a posterolateral reversed L-shaped knee joint incision for treating the posterolateral tibial plateau fracture.

Methods

Knee specimens from eight fresh, frozen adult corpses were dissected bilaterally using a posterolateral reversed L-shaped approach. During the dissection, the exposure range was observed, and important parameters of anatomical structure were measured, including the parameters of common peroneal nerve (CPN) to ameliorate the incision and the distances between bifurcation of main vessels and the tibial articular surface to clear risk awareness.

Results

The posterolateral aspect of the tibial plateau from the proximal tibiofibular joint to the tibial insertion of the posterior cruciate ligament was exposed completely. There was no additional damage to other vital structures and no evidence of fibular osteotomy or posterolateral corner complex injury. The mean length of the exposed CPN was 56.48 mm. The CPN sloped at a mean angle of 14.7° toward the axis of the fibula. It surrounded the neck of the fibula an average of 42.18 mm from the joint line. The mean distance between the opening of the interosseous membrane and the joint line was 48.78 mm. The divergence of the fibular artery from the posterior tibial artery was on average 76.46 mm from articular surface.

Conclusions

This study confirmed that posterolateral reversed L-shaped approach could meet the requirements of anatomical reduction and buttress fixation for posterolateral tibial plateau fracture. Exposure of the CPN can be minimized or even avoided by modifying the skin incision. Care is needed to dissect distally and deep through the approach as vital vascular bifurcations are concentrated in this region. Placement of a posterior buttressing plate carries a high vascular risk when the plate is implanted beneath these vessels.     

Flexions- und Extensionsosteotomien der proximalen Tibia

Background

Isolated deviations in flexion and extension of the leg axis are rare. These deviations can be corrected if necessary by osteotomy and the range of motion (ROM) of the knee joint can be optimized. In addition to correction in the frontal plane, the tibial slope (i.e. inclination of the surface of the tibial joint) can also be influenced by osteotomy and therefore osteotomy can also be utilized to optimize the biomechanical stability of the knee joint.

Method

Careful planning taking all three spatial planes and torsion into consideration is the foundation of a successful operation. A controlled surgical technique based on careful planning and some basic principles allows the alteration of the three dimensional alignment of the tibia.     

Versagen von PTA- und Stenttherapie in der popliteokruralen Region

Purpose

Percutaneous transluminal angioplasty (PTA) and stenting in the popliteal and tibial arteries is gaining widespread acceptance in spite of poor results compared to tibial and pedal bypass surgery.

Methods

Five patients with severe arterial occlusive disease having PTA and stents in the popliteal and tibial region developed arterial thrombosis and critical limb ischemia only 2–8 months after the procedure. Femorodistal bypass surgery was performed for limb salvage.

In four patients, limb salvage was achieved by appropriate distal bypass surgery. In one patient, after stent related thrombosis of the last pedal artery, arterialization of the foot veins was performed but failed to improve the ischemia. This patient sustained a below knee amputation.

Conclusion

The good results of endovascular tools for the appropriate functioning in coronary arteries are not transferable to the peripheral vasculature despite a similar size of the tibial arteries. Some patients with limited occlusive arterial disease and focal lesions will be suitable for endovascular treatment, but the majority of patients will require meticulous tibial bypass surgery for limb salvage.     

Shank vessel injuries: the forgotten vascular injuries

Introduction

Vascular injuries in branch vessels of the popliteal artery, such as the tibioperoneal trunk, and shank vessels, such as anterior, posterior tibial, and peroneal vessels, occur in both blunt and penetrating trauma. Their management has evolved significantly in the past few decades. While their incidence is variable, limb loss and morbidity remain significant.

Material and methods

Physical examination, along with measuring an Ankle–Brachial Index (ABI), is still sometimes all that is required for diagnosis and can expeditiously triage those that require urgent operation. Despite our technological advancements and newer algorithms for lower extremity vascular trauma, operative intervention and exposure still remain difficult and pose a great challenge for surgeons that normally do not operate on this area.

Conclusions

Shank vessel injuries still comprise a significant proportion of combat and civilian vascular injuries, and modern advances have led to a dramatic decrease in amputation rates.     

Injury Risk to Extraosseous Knee Vasculature During Osteotomies: A Cadaveric Study With CT and Dissection Analysis

Background

Realignment osteotomies about the knee may be performed as distal femoral or proximal tibial osteotomies; both may be performed either on the medial or lateral sides of the knee, in closing- or opening-wedge fashion. Although rare, injury to neurovascular structures may occur, and the proximity of the vascular structures to the osteotomy saw cuts has been incompletely characterized.

Questions/purposes

We performed a cadaver study to assess the risk of vascular injury in patients undergoing realignment osteotomies by (1) quantifying the distances between osteotomy saw cuts and blood vessels using three-dimensional CT reconstruction after distal femoral and proximal tibial osteotomies; and (2) qualitatively describing the small- and medium-sized vasculature around the knee, to provide the link between the CT analysis and wedge incision measures, and better show the potential extraosseous supply to the regions investigated.

Methods

Twelve human cadaveric knees were injected with a latex and barium sulfate suspension into the superficial femoral artery. Each specimen underwent CT to evaluate vascular perfusion and was randomized to either a lateral opening-wedge distal femoral osteotomy and medial opening-wedge proximal tibial osteotomy group, or a medial closing-wedge distal femoral osteotomy and lateral closing-wedge proximal tibial osteotomy group. Postoperatively, knees underwent CT in extension to measure the shortest distance between the osteotomies and the popliteal artery, anterior and posterior tibial arteries, and genicular arteries. Vessels between 5 mm and 10 mm from the osteotomy cut were considered in a zone of moderate risk for damage, while vessels less than 5 mm from the cut were considered in a zone of high risk for damage. Vessels more than 10 mm from the cut were not considered to be at risk. Subsequently, knees underwent dissection and chemical débridement to qualitatively describe the smaller vessels. This part of the study added visual information and gave a comprehensive overview of the vessels at risk.

Results

All variations of the osteotomies put at least one artery at risk. The popliteal artery was found in a risk zone for injury in two specimens during closing-wedge distal femoral osteotomy (median distance, 11.6 mm; range, 5.2–14.6 mm). The superior lateral genicular artery was in a risk zone in all the specimens during opening-wedge distal femoral osteotomy (median distance, 3.0 mm; range, 0.7–6.5 mm), and in five specimens during closing-wedge distal femoral osteotomy (median distance, 4.5 mm; range, 1.3–11.2 mm). A concomitant risk for superior medial genicular artery injury was observed in five specimens during opening-wedge distal femoral osteotomy (median distance, 8.7 mm; range, 0.8–13.9 mm) and in four specimens during closing-wedge distal femoral osteotomy (median distance, 4.1; range, 0.5–41.7 mm). The popliteal artery was in a risk zone in four specimens during opening-wedge proximal tibial osteotomy (median distance, 9.6 mm; range, 6.6–12.9 mm), and in three specimens during closing wedge proximal tibial osteotomy (median distance, 9.6 mm; range, 4.4–11 mm). The inferior medial genicular artery could be classified at risk in five specimens during opening-wedge proximal tibial osteotomy (median distance, 2.1 mm; range, 0.3–32 mm) and in five specimens during closing-wedge proximal tibial osteotomy (median distance, 5.8 mm; range, 1.4–13 mm). Furthermore, the inferior lateral genicular artery was found in a risk zone in two specimens of closing-wedge proximal tibial osteotomies (median distance, 17.4 mm; range, 8–23.3 mm). There were no differences between opening-wedge and closing-wedge distal femoral osteotomies and proximal tibial osteotomies in the vessels at risk during the procedure. After chemical débridement, knees showed abundant vascularization of the distal femur and lateral tibia, whereas the medial tibia contained few arteries.

Conclusions

With the numbers available, we found that none of the osteotomy techniques performed was safer than any other in terms of the proximity of the major arterial structures and some vessels appear to be at relatively high risk during these procedures.

Clinical Relevance

This study clarifies that the genicular arteries on the opposite side of the surgical field, which cannot be seen and protected during the procedure, can be at risk of injury, particularly when the cortical hinge is compromised. Additional studies are necessary to address the potential risk of the dissection needed for plate placement and injuries related to drilling and screw placement during osteotomies around the knee.     

Arterielle Gef??variationen am Unterschenkel und Fu?

Backround

Patients with diabetic foot syndrome belong to a high risk group for amputation. To preserve the lower limbs, crural and pedal bypasses are performed between the main arteries. We studied the variations of arteries in relationship to surgical intervention and outcome.

Material and methods

The popliteal, tibial and fibular arteries and the foot arteries of alcohol-fixed lower legs (n=12) were dissected and marked with colours for photographic documentation. Thiel-fixed lower legs (n=10) were tested by digital substraction angiography (DSA).

Results

The following variations occurred: trifurcation, anterior tibial artery originating from the fibular artery, dominant fibular artery, plantar arch running through the second interosseus space, dominant deep plantar artery, deep branch of the medial plantar artery and prominent arcuate artery. The arteries for the plantar arch varied manifold. DSA can be done with Thiel-fixed material.

Conclusion

Surgeons should examine the prominent arteries and dorso-plantar anastomoses with the plantar arch for successful crural and pedal bypasses in diabetic patients with respect to individual variations.     

Ein modifizierter posterolateraler Zugang für die operative Versorgung von Tibiakopffrakturen

Objective

Open reduction and internal fixation of posterolateral tibial plateau fractures.

Indications

Tibial plateau fractures involving the posterolateral quadrant.

Contraindications

Critical soft-tissue conditions. Tibial plateau fractures which do not involve the posterolateral quadrant.

Surgical Technique

90° side positioning on the contralateral side, skin incision along the fibular head, exposure of the peroneal nerve, lateral arthrotomy and exposure of the joint, dissection of the popliteal cavity between the lateral head of the gastrocnemius muscle and soleus muscle. Blunt preparation between popliteus muscle and soleus muscle under preservation of the popliteal artery and vein. Sharp dissection of the soleus muscle from the dorsal parts of fibula and tibia until the peroneal nerve at the fibular neck enters into the muscle. Exposure of the posterolateral tibial head. The dorsal joint capsule and the popliteal corner are prevented from any soft-tissue damage. Visual control of fracture reduction by viewing in the joint gap through lateral arthrotomy. Reduction of the fracture from dorsal with pointed reduction forceps. A conventional or locking radius T-plate can be pinched off with lateral cutters and anatomically bent for fracture fixation and is dorsally fixed at the tibial plateau.

Postoperative Management

10 kg partial weight bearing for 6–8 weeks. Limited range of motion 0-0-90° for 6 weeks.

Results

In a period of 2 years, seven patients with posterolateral tibial plateau fractures received open reduction and internal fixation by using the modified posterolateral approach. The patients were examined at follow-up between 12 and 24 months after surgery. Six patients were free of pain with full range of motion and stable knee joints. Radiologically, a good fracture reduction was achieved in six cases. In one patient with a posterolateral comminuted dislocation fracture, a small fracture step and a gap could be observed. No approach-related complications were found.     

Stellenwert der knienahen Osteotomie bei medialer Gonarthrose

Background

Frontal plane deformities result in significant overload of the (ipsilateral) affected compartment of the knee and in rapid progression of osteoarthritis. The indication for osteotomy around the knee is related mainly to the constitutional metaphyseal deformity in the frontal plane.

Methods

Exact analysis and planning based on a long-leg standing radiograph is mandatory. Valgus high tibial osteotomy can be performed safely and atraumatically by biplanar open-wedge osteotomy from medial using a specific plate-fixator. A new technique of closed wedge biplanar distal femur osteotomy with fixation by a new plate fixator is also presented.

Results

Our multicenter follow-up study with 533 patients revealed good functional outcome scores with a small complication rate. The subjective ratings were better than in comparable groups with unicondylar knee replacement and with total knee arthroplasty. Metaanalysis from the literature have proven good long-term results of osteotomy around the knee.

Conclusion

Osteotomy around the knee results in good middle-term and long-term results if the indication criteria are respected and a specific surgical technique is used.     

Comparisons of tunnel-graft angle and tunnel length and position between transtibial and transportal techniques in anterior cruciate ligament reconstruction

Purpose

Our aim was to evaluate tunnel-graft angle, tunnel length and position and change in graft length between transtibial (30 patients) and anteromedial (30 patients) portal techniques using 3D knee models after anterior cruciate ligament (ACL) reconstruction.

Methods

The 3D angle between femoral or tibial tunnels and graft at 0° and 90° flexion were compared between groups. We measured tunnel lengths and positions and evaluated the change in graft length from 0° to 90° flexion.

Results

The 3D angle at the femoral tunnel with graft showed a significant difference between groups at 0° flexion (p?=?0.01) but not at 90° flexion (p?=?0.12). The 3D angle of the tibial tunnel showed no significant differences between groups. Femoral tunnel length in the transtibial group was significantly longer than in the transportal group (40.7 vs 34.7 mm,), but tibial tunnel length was not. The relative height of the lateral femoral condyle was significantly lower in the transportal than the transtibial group (24.1 % vs 34.4 %). No significant differences were found between groups in terms of tibial tunnel position. The change in graft length also showed no significant difference between groups.

Conclusion

Even though the transportal technique in ACL reconstruction can place the femoral tunnel in a better anatomical position than the transtibial technique, it has risks of a short femoral tunnel and acute angle at the femoral tunnel. Moreover, there was also no difference in the change of the graft length between groups.     

Kinematic factors affecting postoperative knee flexion after cruciate-retaining total knee arthroplasty

Purpose

The purpose of this study was to investigate kinematic factors affecting postoperative knee flexion after cruciate-retaining (CR) total knee arthroplasty (TKA) by analysing pre- and postoperative knee kinematics.

Methods

We retrospectively analysed 58 patients with osteoarthritis who received the same implant series. Pre- and postoperative kinematics were measured intraoperatively using a navigation system. As a clinical outcome, we measured the knee flexion angle before and one year after surgery. Correlations among pre- and postoperative kinematics and postoperative flexion were analysed using simple linear regression analyses.

Results

Preoperative knee kinematics, including tibial internal rotation and anterior translation (R?=?0.87, P?<?0.001; R?=?0.53, P?<?0.001, respectively), were significantly correlated with postoperative kinematics. Preoperative varus–valgus movements improved significantly postoperatively; however, tibial internal rotation remained unchanged. Furthermore, postoperative knee flexion angle was significantly correlated with postoperative tibial internal rotation (R?=?0.45, P?<?0.001).

Conclusions

Preoperative knee kinematics were unchanged even after CR-TKA. Postoperative tibial internal rotation is one of the most important factors affecting postoperative knee flexion.     

Tuberositasosteotomie in der Knieendoprothetik

Objective

Tibial tubercle osteotomy facilitates access to the knee joint without excessive tension of the extensor apparatus with the lateral parapatellar approach and the medial parapatellar approach in case of contracture or revision arthroplasty.

Indications

Inadequate exposure of the knee joint with the lateral parapatellar approach and inadequate exposure of the knee joint with the medial parapatellar approach in case of contracture and revision arthroplasty.

Contraindications

Severe periarticular osteoporosis or bone atrophy after knee arthroplasty and damage to the patella tendon insertion due to previous operations.

Surgical technique

A bone block 8?C10?cm long is excised with the tibial tubercle using an oscillating saw. A step cut inferior to the tibial plateau is created with a chisel. Refixation is performed with two cortical screws. Alternatively, in case of poor bone quality, refixation is accomplished with two cerclage wires.

Postoperative management

In case of stable refixation, full weight bearing is allowed with an extension brace for 2?C4?weeks and passive flexion is increased as tolerated. In case of poor bone quality, it is recommended that full weight bearing be postponed for 6?weeks, whereby full flexion is regained in 30° steps at 2, 4, and 6?weeks postoperatively.

Results

From 2001?C2004, 67 osteotomies of the tibial tubercle were performed for revision arthroplasty. During follow-up in 2010, no pseudarthrosis or dislocation was noticed. Postoperatively, two hematoma and one skin necrosis had to be revised. The risk of hematoma and pseudarthrosis or dislocation of the fragment can be minimized by using the correct operative technique.     

Is There a Gold Standard for TKA Tibial Component Rotational Alignment?

Background

Joint function and durability after TKA depends on many factors, but component alignment is particularly important. Although the transepicondylar axis is regarded as the gold standard for rotationally aligning the femoral component, various techniques exist for tibial component rotational alignment. The impact of this variability on joint kinematics and stability is unknown.

Questions/purposes

We determined how rotationally aligning the tibial component to four different axes changes knee stability and passive tibiofemoral kinematics in a knee after TKA.

Methods

Using a custom surgical navigation system and stability device to measure stability and passive tibiofemoral motion, we tested 10 cadaveric knees from five hemicorpses before TKA and then with the tibial component aligned to four axes using a modified tibial tray.

Results

No changes in knee stability or passive kinematics occurred as a result of the four techniques of tibial rotational alignment. TKA produces a ‘looser’ knee over the native condition by increasing mean laxity by 5.2°, decreasing mean maximum stiffness by 4.5 N·m/°, increasing mean anterior femoral translation during passive flexion by 5.4 mm, and increasing mean internal-external tibial rotation during passive flexion by 4.8°. However, no statistically or clinically important differences occurred between the four TKA conditions.

Conclusions

For all tibial rotations, TKA increased laxity, decreased stiffness, and increased tibiofemoral motion during passive flexion but showed little change based on the tibial alignment.

Clinical Relevance

Our observations suggest surgeons who align the tibial component to any of the axes we examined are expected to have results consistent with those who may use a different axis.     

Pathoanatomy and incidence of the posterolateral fractures in bicondylar tibial plateau fractures: a clinical computed tomography-based measurement and the associated biomechanical model simulation

Objectives

The aim of our study is to evaluate the incidence and pathoanatomy of posterolateral fragments and analyze the associated fracture mechanism in bicondylar tibial plateau fractures.

Methods

From 1.1.2008 to 3.15.2012, all patients suffering bicondylar tibial plateau fractures were identified, scanned and analyzed at the Shanghai Clinical Trauma Center. Furthermore cadaver knees were selected into three groups of 30/60/90 knee flexion to simulate the posterolateral tibial plateau fracture by an impact device.

Results

One hundred and sixty-four (44.32 %) bicondylar tibial plateau fractures finally satisfied our requirements. Fifty-three and ninety-four cases were measured eventually in the groups of posterolateral split and depression. The posterolateral articular fragment proportion was 15.43 %. The posterolateral articular fragment angle showed an average of 12.94°. The posterolateral fragment cortical height was on average 2.96 cm. The posterolateral sagittal fragment angle averaged at 72.06°. Ninety-four cases were measured in the posterolateral depression group. The average posterolateral articular depression proportion was 16.74 %. The average posterolateral articular depression height was 2.47 cm. In the biomechanical modeling of such kinds of fracture patterns, posterolateral split fractures in 30° and 60° flexion are significantly more than those in 90° flexion. Posterolateral splits combined with anterolateral depression fractures in 30° flexion are significantly more than those in 90° flexion.

Conclusion

The incidence of posterolateral fractures is 44.32 % in bicondylar tibial plateau fractures. The morphology of posterolateral area can be referenced for the surgeon in the future clinical work. The information is also helpful for the design of locking plate and fracture modeling in biomechanical test. In addition, that posterolateral split and posterolateral depression might be caused by different injury mechanisms. Different angles of knee flexion under the axial impact loading are possibly the interpretations for these two fracture patterns.     

Kniegelenknahe Osteotomietechniken

Background

Bone geometry following osteotomy around the knee suggests that biplanar rather than uniplanar open wedge techniques simultaneously create smaller wedge volumes and larger bone surface areas. However, precise data on the bone surface area and wedge volume resulting from both open and closed wedge high tibial osteotomy (HTO) and distal femoral osteotomy (DFO) techniques remain unknown.

Objectives

It was hypothesized that biplanar rather than uniplanar osteotomy techniques better reflect the ideal geometrical requirements for bone healing, representing a large cancellous bone surface combined with a small wedge volume.

Methods

Tibial and femoral artificial bones were assigned to four different groups of valgisation and varisation osteotomy consisting of open wedge and closed wedge techniques in a uniplanar and biplanar fashion. Bone surface areas of all osteotomy planes were quantified. Wedge volumes were determined using a prism-based algorithm and applying standardized wedge heights of 5 mm, 10 mm and 15 mm.

Results

Both femoral and tibial biplanar osteotomy techniques created larger contact areas and smaller wedge volumes compared to the uniplanar open wedge techniques.

Conclusion

Although this idealized geometrical view of bony geometry excludes all biological factors that might influence bone healing, the current data suggest a general rule for the standard osteotomy techniques applied and all surgical modifications: reducing the amount of slow gap healing and simultaneously increasing the area of faster contact healing may be beneficial for osteotomy healing. Thus, biplanar rather than uniplanar osteotomy should be performed for osteotomy around the knee.     

Arthroscopic anatomic study of posteromedial joint capsule in knee joint associated with popliteal cyst

Purpose

The purpose of this study was to examine the arthroscopic anatomy of posteromedial capsule and magnetic resonance imaging (MRI) findings in internal derangement of the knee joint and to analyze the relationship between popliteal cysts and the posteromedial capsule.

Methods

From 2011 to 2012, a prospective study included 194 knees of consecutive arthroscopic surgeries for assorted knee problems. The anatomy of the posteromedial joint capsule was evaluated arthroscopically and divided into three types by the presence of capsular fold and opening: no capsular fold and no opening (type I), capsular fold without opening (type II), capsular fold with opening (type III). The presence and size of popliteal cyst were documented by MRI.

Results

Type I was observed in 160 knees (82.5 %), type II in 10 (5.1 %) and type III in 24 (12.4 %). Popliteal cysts were found in 25 knees (12.9 %) by MRI. Of these cases, symptomatic popliteal cysts were identified in 12 knees (6.9 %). On 160 knees demonstrated to be type I, only 3 knees (1.9 %) had popliteal cysts in MRI, 6 knees (60 %) in 10 knees of type II and 16 knees (66.7 %) in 24 knees of type III. Therefore, there was a statistically significant relationship between the type of anatomy in the posteromedial capsule and the popliteal cyst (p < 0.001).

Conclusion

An association between popliteal cyst and arthroscopic anatomy of posteromedial capsule was demonstrated. Comprehensive understanding and knowledge of the arthroscopic anatomy of posteromedial capsule would contribute to the arthroscopic approach in understanding the pathogenesis of popliteal cyst.

Study design

Development of diagnostic criteria on basis of consecutive patients.

Level of evidence

2.     

Treatment of fixed knee flexion deformity and crouch gait using distal femur extension osteotomy in cerebral palsy

Purpose

The purpose of this study was to evaluate the results of distal femur extension osteotomy and medial hamstring lengthening in the treatment of fixed knee flexion deformity in patients with spastic diparetic cerebral palsy.

Methods

A retrospective study was done in a group of 12 diparetic cerebral palsy patients. A distal femur extension osteotomy was performed as part of multilevel surgery on lower limbs. The fixed knee flexion deformity was measured during physical examination, whereas hip and knee flexion in the stance phase and anterior pelvic tilt were both analyzed at kinematics. The pre- and post-surgery results were compared and analyzed statistically. A medical record review was done in order to identify the complications. The mean follow-up was 28 months.

Results

A significant reduction of fixed knee flexion deformity at physical examination and knee flexion in the stance phase at kinematics was observed, but with no decrease in hip flexion. As a non-desired effect, there was an increase in anterior pelvic tilt after surgical procedures. With regard to complications, a single patient had skin breakdown at a calcaneous area on one side and the recurrence of deformity was seen in 27% of cases.

Conclusions

In this study, in which fixed knee flexion deformity did not exceed 40° before surgery, the distal femur extension osteotomy was effective in increasing knee extension in the stance phase. However, an increase in anterior pelvic tilt, deformity recurrence and necessity for walking aids are possible complications of this procedure.     

Kombination von VKB-Ersatzplastik und hoher tibialer Umstellungsosteotomie

Objective

Replacement of the anterior cruciate ligament (ACL) with an autologous tendon together with a high tibial osteotomy (HTO) in one operation.

Indication

Simultaneous symptomatic ACL insufficiency and symptomatic varus osteoarthritis.

Contraindications

Risk of a higher complication rate for a one-stage procedure, e.g., in loss of motion due to soft tissue contracture, loss of motion due to insufficiency of a existent ACL replacement with tunnel malplacement, tunnel widening of an existent ACL replacement with the risk of tunnel confluence, infection in a former operation. Varus osteoarthritis with a hollow posteromedial tibial plateau (knee abuser). Exclusion criteria include PLC insufficiency, lateral or posterolateral instability, lateral arthritis.

Surgical technique

Osteotomy: placement of the two K-wires from the medial tibia about 4–5 cm below the medial tibial plateau towards the lateral hinge about 2 cm below the lateral tibial plateau. Mobilization of the long fibers of the medial collateral ligament distal of the osteotomy, mobilization of the pes anserinus tendons. Frontal and axial osteotomy with an oscillating saw. Completion and opening of the osteotomy with chisels. Opening of the osteotomy with a spreader according to the new leg axis of the preoperative planning. Fixation of the osteotomy with an angle stable plate (PPP Arthrex, Tomofix Synthes). In case of a distal osteotomy of the hiberosity fixation with 2 screws. Arthroscopy: positioning of a 2.4 mm K-wire in the center of the remnant femoral ACL insertion, cannulated drilling according to the graft diameter. Positioning of a 2.4 mm K-wire in the center of the remnant tibial ACL insertion, cannulated drilling. In the case of interference of the tibial tunnel with one of the osteotomy screws, removal of the screw and finishing of the tunnel preparation. Measurement of the length and insertion of the respective osteotomy screw. Insertion of the graft and fixation with a button-wire construct at the femur and with a bioabsorbable interference screw and a lag screw at the tibia.

Postoperative management

Postoperative management relating to weight bearing rehabilitation follows osteotomy rules, while range of motion rehabilitation follows the ACL protocol.