Danger to the popliteal artery in high tibial osteotomy

Avoiding Compartment Syndrome, Vascular Injury, and Neurologic Deficit in Tibial Osteotomy: An Observational Study of 108 Limbs

INTRODUCTION

Tibial deformities are common, but substantial concern may be associated with corrective osteotomy regarding major complications reported in classic literature. Such studies chiefly focused on high tibial osteotomy, with relatively little investigation of other areas and types of deformity. The primary aim of this study was to identify the rate of compartment syndrome, vascular injury, nerve injury, and other major complications after elective tibial osteotomy.

METHODS

One hundred eight tibia osteotomies performed during 2019 to 2021 were evaluated, representing all tibia osteotomies except situations of existing infection. A retrospective chart review was performed to identify patient demographics, surgical indications, anatomic location of osteotomy, fixation used, and complications prompting additional surgery.

RESULTS

The most common osteotomy locations were high tibial osteotomy (35/108 = 32%, 32/35 = 91% medial opening, and 3/35 = 9% medial closing), proximal metaphysis (30/108 = 28%), and diaphysis (32/108 = 30%). The most common fixation was plate and screw (38/108 = 35%) or dynamic frame (36/108 = 33%). Tranexamic acid was administered to 107/108 = 99% of patients and aspirin chemoprophylaxis was used for 83/108 = 86%. A total of 33/34= 97% of anterior compartment prophylactic fasciotomies were performed for diaphyseal or proximal metaphysis osteotomies. No events of compartment syndrome, vascular injury, nerve injury, or pulmonary embolism occurred. One patient required débridement to address infection. Additional surgery for delayed/nonunion occurred for nine segments (8%). Additional surgery for other reasons were performed for 10 segments (9%), none resulting in reduced limb function.

CONCLUSION

Tibial osteotomy can be safely performed for a variety of indications in a diverse range of patients, without a notable risk of the most feared complications of compartment syndrome, vascular injury, and neurologic deficit. Prophylactic fasciotomy and reducing postoperative bleeding using tranexamic acid, along with location-specific safe surgical techniques, may help prevent major complications and thereby facilitate optimized deformity care.

Patient factors impacting localization of popliteal artery before total knee arthroplasty

PURPOSE

Intraoperative injury to the popliteal artery (PA) should be avoided during total knee arthroplasty (TKA). This study was performed to clarify the preoperative localization of the PA and the patient factors that impact its localization as a preventive measure.

METHODS

Ninety-seven patients (110 knees; 18 men, 79 women) with osteoarthritis who underwent primary TKA were retrospectively reviewed. Preoperative sagittal magnetic resonance imaging was used to measure the distance between the PA and the closest point at three levels: the femoral epicondyle (DPF), the tibial articular surface (DPAS), and the posterior tibial cortex (DPT). All variables are expressed in millimeters as median (interquartile range).

RESULTS

The median distance was 10.35 (7.90-12.34) mm for DPF, 6.32 (5.12-8.57) mm for DPAS, and 3.76 (2.28-5.26) mm for DPT. Body height and weight showed weak correlations with DPF (r = 0.324, p < 0.001 and r = 0.207, p = 0.03, respectively). DPF was smaller in women [9.82 (7.64-12.23) mm] than in men [11.27 (10.26-12.75) mm] (p = 0.004). A larger flexion angle and range of motion showed a weak negative correlation with DPT (r =  - 0.282, p = 0.003 and r =  - 0.236, p = 0.016, respectively). Multiple regression analysis revealed that DPF was related to body height (β = 0.341, p < 0.001) and that DPT was related to the flexion angle (β =  - 0.264, p = 0.005).

CONCLUSIONS

Special attention should be paid to women with a small physique on the femoral side and/or patients with a large flexion angle on the tibial side as a strategy to prevent PA-related complications.

Proximal Branching of the Anterior Tibial Artery From the Popliteal Artery Increases the Risk of Vascular Injury During Total Knee Arthroplasty: A Retrospective Analysis Using Preoperative Magnetic Resonance Imaging and Intraoperative Findings

Introduction

Arterial injury following total knee arthroplasty (TKA) can be life-threatening. There are some anatomical variations in the popliteal artery (PA) and its branches. In most cases, the PA branches into the anterior tibial artery (ATA) and posterior tibial artery (PTA), which are usually distal to the height of tibial resection in TKA. However, some cases show that the PA branches into the ATA and PTA proximal to the height of tibial resection in TKA. This study aimed to assess the distance from the posterior cortex of the proximal tibia to the anterior wall of the PA or ATA at the height of the tibial cut line, during TKA in the distal and proximal branch groups.

Methods

129 patients (6 patients in the proximal branch group and 123 patients in the distal branch group) were enrolled for this study. For prediction of the distance from the posterior cortex of the proximal tibia to the anterior wall of the PA or ATA, preoperative sagittal and coronal magnetic resonance images and postoperative radiographs were evaluated.

Results

The distance between the posterior cortex of the proximal tibia and the anterior wall of the PA or ATA at the height of the tibial cut line was 1.8 ± 1.1 mm in the proximal branch group and 6.1 ± 2.6 mm in the distal branch group, which was significantly closer in the proximal group (P < .05).

Discussion

The rate of proximal branching was 4.7%. This study clarified that the proximal branching of the ATA from PA significantly decreased the distance between the posterior cortex of the proximal tibia and the anterior wall of the artery.

Conclusions

The proximal branch group has a high risk for arterial injury as the artery may be close to the saw, and appropriate retraction should be performed.

Vascular Complications in Sports Surgery: Diagnosis and Management

Orthopedic sports surgery of the knee and shoulder is generally considered to be safe and effective. Vascular complications can occur during or after arthroscopy of either joint. A thorough understanding of anatomy, particularly when placing portals in non-routine locations, is extremely important. Prompt recognition of any vascular complication is of significant importance. This review will discuss the potential vascular complications for both knee and shoulder sports surgery, review the relevant anatomy, and discuss the treatment and expected outcome of each.

Deep flexion helps to avoid popliteal artery injury during all-inside lateral meniscal repair: A cadaveric study

BACKGROUND

Arthroscopic meniscus repair rarely leads to major complications such as popliteal artery injury. The distance between the suturing device and the popliteal artery, and the risk of popliteal artery injury at different knee flexion angles during all-inside lateral meniscal repair remain unclear.

METHODS

All-inside devices were inserted into 10 human cadaveric knees at the posterior horn of the lateral meniscus through the anterolateral portal at 60°, 90°, and 120° knee flexion; posterior segment of the lateral meniscus through the anterolateral portal at 60°, 90°, and 120°; and anteromedial portal at 90°. Distance and positional relationship between the device and popliteal artery were measured radiographically.

RESULTS

In posterior horn repair through the anterolateral portal, the median distance increased from 5.7 mm at 60° to 9.1 mm at 90° (P = 0.63) and 18.0 mm at 120° (P = 0.02). The device pushed the wire at 60° in three cases, 90° in one case, and 120° in 0 cases. In posterior segment repair through the anterolateral portal, the median distance was 12.6 mm at 60°, 10.4 mm at 90°, and 18.3 mm at 120° (P = 0.08). The median distance at 90° was 18.1 mm through the anteromedial portal, the same as that at 120° through the anterolateral portal (P = 0.43), but greater than that at 90° through the anterolateral portal (P = 0.04). The wire was not pushed in any case.

CONCLUSION

Although all-inside repair of the posterior part of the lateral meniscus through the anterolateral portal is risky, deeper knee flexion reduces the risk of popliteal artery injury.

Assessment of popliteal neurovascular safety during all-inside suturing of the posterior horn of the lateral meniscus using Upright MRIs of the knee joint

BACKGROUND

To examine the risk of injury to the popliteal neurovascular bundle (pNVB) during all-inside repair of the posterior horn of the lateral meniscus (PHLM) using Upright-MRIs.

METHODS

Upright-MRIs of 61 knees in extension (ext) and 90°-flexion (flex) were included. Distance D from the PHLM to the pNVB was compared between extended and 90°-flexed position, subgroups with/without joint-effusion and evaluated according to demographics. Portal safety was assessed simulating suturing of the PHLM via four arthroscopy portals. Distance d (shortest space from the simulated suturing-device trajectory lines to the pNVB) was compared among portals in increasing distances from the posterior cruciate ligament (PCL).

RESULTS

D is longer in flex (17.3 ± 6.0 mm) than in ext (11.3 ± 4.2 mm, p < 0.0001). MRIs with joint-effusion displayed longer values of D than scans without joint-effusion (flex: 20.4 ± 7.1 mm vs. 16.1 ± 5.2 mm, p = 0.012). Shorter distances are associated with female gender, lower body weight and lower BMI. At 0 mm from the PCL, the 1 cm-lateral portal was the safest (p < 0.0001) whereas at 3 mm/6mm/9mm/12 mm the 1 cm-medial portal showed the longest d values (p < 0.0001 each).

CONCLUSION

All-inside suturing of the PHLM is safer in 90°-flexion, in presence of intraarticular fluid and in male patients with increasing weight/BMI. Sutures of the PHLM at 0 mm from the PCL are safer from a 1 cm-lateral portal whereas for tears located ≥ 3 mm from the PCL a 1 cm-medial portal involves a lower neurovascular risk. Upright-MRI proves excellent for preoperative planning to minimize neurovascular risks.

Sawing toward the fibular head during open-wedge high tibial osteotomy carries the risk of popliteal artery injury

PURPOSE

Popliteal artery injury is a rare but devastating complication of open-wedge high tibial osteotomy (OWHTO). The objectives of this study were: to document the location of the artery in the virtual osteotomy plane (VOP), to measure the minimal distance between the popliteal artery and three virtual saw-progression lines (VSLs), and to present a safe sawing technique for OWHTO.

METHOD

In total, 45 computed tomography angiographies were reconstructed and virtual osteotomy was simulated using 3D image-processing software. The VOP was defined as an inclined plane commencing 3.5 cm below the articular plane towards the fibular head. VSLs were defined as saw-progression guidelines that lie on the VOP: "VSL-mid" runs from the midpoint of the tibial medial cortex towards the fibular head; "VSL-ant" starts from the same point as VSL-mid, but runs 10° anterior to the fibular head; and "VSL-post" runs 10° posterior to the fibular head. The distances between the popliteal artery and the three VSLs were measured, and the risk of injury was assessed.

RESULTS

The popliteal artery was located 20.7° posterior to VSL-mid and 51 mm from the starting point. The minimum distance between the popliteal artery and VSL-mid was 18 mm (99% confidence interval 9-27 mm). When the saw was moved along VSL-mid, 42% of the arteries were susceptible to injury. However, when it followed VSL-ant, there was no risk of injury.

CONCLUSIONS

Sawing toward the fibular head carries a risk of popliteal artery injury and should not be performed. When sawing in OWHTO, the recommended target should be 10° anterior to the fibular head. This technique eliminates the risk of popliteal artery injury.

Adequate protection rather than knee flexion prevents popliteal vascular injury during high tibial osteotomy: analysis of three-dimensional knee models in relation to knee flexion and osteotomy techniques

PURPOSE

(1) To analyse popliteal artery (PA) movement in a three-dimensional (3D) coordinate system in relation to knee flexion and high tibial osteotomy (HTO) techniques (lateral closed wedge HTO [LCHTO], uniplane medial open wedge HTO [UP-MOHTO], biplane medial open wedge HTO [BP-MOHTO]) and (2) to identify safe zones of the PA in each osteotomy plane.

METHODS

Sixteen knees of patients who underwent magnetic resonance imaging with extension and 90° flexion were used to develop subject-specific 3D knee flexion models. Displacement of the PA during knee flexion was measured along the X- and Y-axis, as was the distance between the posterior tibial cortex and PA parallel to the Y-axis (d-PCA). Frontal plane safety index (FPSI) and maximal axial safe angles (MASA) of osteotomy, which represented safe zones for the osteotomy from the PA injury, were analysed. All measurements were performed along virtual osteotomy planes. Differences among the three osteotomy methods were analysed for each flexion angle using a linear mixed model.

RESULTS

The average increments in d-PCA during knee flexion were 1.3 ± 2.3 mm in LCHTO (n.s.), 1.4 ± 1.2 mm in UP-MOHTO (P < 0.0001), and 1.7 ± 2.0 mm in BP-MOHTO (P = 0.015). The mean FPSIs in knee extension were 37.6 ± 5.9%, 46.4 ± 5.8%, and 45.1 ± 8.1% for LCHTO, UP-MOHTO, and BP-MOHTO, respectively. The mean MASA values in knee extension were 45.8° ± 4.4°, 37.3° ± 6.1°, and 38.9° ± 6.5° for LCHTO, UP-MOHTO, and BP-MOHTO, respectively.

CONCLUSION

Although the PA moved posteriorly during knee flexion, the small (1.7 mm) increment thereof and inconsistent movements in subjects would not be of clinical relevance to PA safety during HTO.

LEVEL OF EVIDENCE

Diagnostic study, Level II.

The Position of the Popliteal Artery and Peroneal Nerve Relative to the Menisci in Children: A Cadaveric Study

Background:

Meniscal injury in skeletally immature patients is increasingly reported. During meniscal repair, all-inside devices may protrude beyond the posterior limits of the meniscus, putting the neurovascular structures at risk.

Purpose:

The purposes of this study were (1) to examine the relationship between the popliteal artery and the posterolateral and posteromedial aspects of the menisci, (2) to examine the relationship of the peroneal nerve to the posterolateral meniscus, and (3) to develop recommendations for avoiding neurovascular injury during posterior meniscal repair in pediatric patients.

Study Design:

Descriptive laboratory study.

Methods:

A total of 26 skeletally immature knee cadaveric specimens (7 females and 19 males) were included. Specimens were divided into age groups: 2-4, 5-8, and 9-11 years. The most posterior extent of the lateral and medial menisci was identified via sagittal and axial views on computed tomography (CT) scans. The shortest distance from the most posterior aspect of the lateral and medial menisci to the popliteal artery and the shortest distance from the posterior aspect of the lateral menisci to the anterior rim of the peroneal nerve were measured, and 3-dimensional models of representative specimens were re-created through use of CT scans.

Results:

For the age groups 2-4, 5-8, and 9-11 years, the mean minimum distance from the posterolateral meniscus to the popliteal artery was 5.2, 6.7, and 8.2 mm, respectively, and the mean minimum distance from the posteromedial meniscus to the popliteal artery was 12.7, 15.4, and 20.3 mm, respectively. In all groups, the distance between the posteromedial meniscus and the popliteal artery was greater than that between the posterolateral meniscus and the popliteal artery. The mean distance from the peroneal nerve to the lateral meniscus was 13.3, 15.0, and 17.9 mm for the respective groups.

Conclusion:

Many all-inside meniscal repair devices have sharp tips that penetrate posterior to the meniscus and capsule. This study demonstrated that the distance between the posterior meniscus and popliteal artery is relatively small in pediatric patients, especially for the lateral meniscus region.

Clinical Relevance:

Because of the higher potential for meniscal healing, meniscal repair is more likely to be performed in pediatric patients. The data in this study regarding the proximity of the lateral meniscus and neurovascular structures may be used to guide safe surgical repair of posterior meniscal tears during the use of all-inside meniscal repair devices in these patients.

Surgical anatomy of medial open-wedge high tibial osteotomy: crucial steps and pitfalls

PURPOSE

To give an overview of the basic knowledge of the functional surgical anatomy of the proximal lower leg and the popliteal region relevant to medial high tibial osteotomy (HTO) as key anatomical structures in spatial relation to the popliteal region and the proximal tibiofibular joint are usually not directly visible and thus escape a direct inspection.

METHODS

The surgical anatomy of the human proximal lower leg and its relevance for HTO are illustrated with a special emphasis on the individual steps of the operation involving creation of the osteotomy planes and plate fixation.

RESULTS

The posteriorly located popliteal neurovascular bundle, but also lateral structures such as the peroneal nerve, the head of the fibula and the lateral collateral ligament must be protected from the instruments used for osteotomy. Neither positioning the knee joint in flexion, nor the posterior thin muscle layer of the popliteal muscle offers adequate protection of the popliteal neurovascular bundle when performing the osteotomy. Tactile feedback through a loss-of-resistance when the opposite cortex is perforated is only possible when sawing and drilling is performed in a pounding fashion. Kirschner wires with a proximal thread, therefore, always need to be introduced under fluoroscopic control. Due to anatomy of the tibial head, the tibial slope may increase inadvertently.

CONCLUSIONS

Enhanced surgical knowledge of anatomical structures that are at a potential risk during the different steps of osteotomy or plate fixation will help to avoid possible injuries.

LEVEL OF EVIDENCE

Expert opinion, Level V.

Risk of vascular injury when screw drilling for tibial tuberosity transfer

PURPOSE

During tibial tubercle transfer, popliteal vessels are at risk from drills and screws. The risk is around 0.11%, as described in the literature. We reviewed knee injected CT scan for analysis of the location of arteries, identified landmarks allowing minimizing risks, and defined a safe zone.

MATERIAL AND METHOD

Distances between the posterior cortex and arteries were measured on CT scans from 30 adults (60 knees) at three levels (proximal part of the tibial tuberosity, 20 mm and 40 mm distally). Data were used to create a "risk map" with different angular sectors where the frequency of the presence of arteries was analyzed in each area. We also analyzed the position of 68 screws of 47 patients who underwent a medial tibial tuberosity transfer.

RESULTS

The nearest distance between artery and the posterior tibial cortex was found at the level corresponding to the top of the tuberosity with less than 1 mm, while the largest distance was found at the distal level. We were able to define a safe zone for drilling through the posterior tibial cortex which allows a safe fixation for the screws. This zone corresponds to the medial third of the posterior cortex. When the safe zone is not respected, screws that overtake the posterior cortex may be close to arteries as observed for 37 of the 68 screws analyzed.

CONCLUSION

We described new landmarks and recommendations to avoid this complication during tibial tuberosity transfer.

[Extensor mechanism complications in revision total knee arthroplasty : Joint exposure and prevention of extensor mechanism complications]

BACKGROUND

Revision total knee arthroplasty is complex surgery that has to be well planned from its indication to the actual surgical procedure.

OBJECTIVES

To review surgical techniques that allow a secure exposure of the joint in revision total knee arthroplasty.

MATERIALS AND METHODS

The authors summarize a review of the literature and present their own experience in knee joint exposure aiming to minimize extensor mechanism complications in revision TKA.

RESULTS

The choice of adequate skin incision, detailed scar removal and a systematic soft tissue release are inevitable prerequisites for an optimal joint exposure and the minimization of extensor mechanism complications. In most patients, a medial parapatellar arthrotomy is sufficient to expose the knee joint and, if necessary, allows a proximal extension using a quadriceps snip or VY-quadricepsplasty, or a distal extension via a tibial tubercle osteotomy. Whether the quick and easy quadriceps snip or a tibial tubercle osteotomy has to be performed depends in each case on the extent of scar formation, the extensor mechanism contracture and the preoperative position of the patella. In general, a parapatellar and lateral release has to be executed; therefore, a partial lateral facetectomy ensures a secure eversion of the patella. Alternative approaches to access the joint do not reveal significant advantages and play a minor role in revision total knee arthroplasty.

CONCLUSION

Revision total knee arthroplasty is a challenging surgical procedure. In addition to the regular soft tissue release techniques and joint approaches, the surgeon has to be aware of proximal and distal extension procedures to securely expose the joint and minimize the risk of extensor mechanism complications.

Knee MRI: Vascular Pathology

OBJECTIVE

Patients who undergo knee MRI for presumed musculoskeletal disease can have unexpected vascular findings or pathology in the imaged field. Some vascular processes are limb threatening and affect treatment planning and patient outcome.

CONCLUSION

Unexpected vascular findings on knee MRI can range from incidental to symptomatic and can include such processes as variant anatomy, aneurysm, traumatic injury, and neoplasm. The assessment for vascular pathology should be a key component of every radiologist's search pattern when evaluating knee MRI.

Magnetic resonance study on the anatomical relationship between the posterior proximal region of the tibia and the popliteal artery

Objective

To analyze and describe the distance from the popliteal artery to three specific areas of the proximal region of the tibia, with the knee extended, by means of magnetic resonance.

Methods

Images of 100 knees of patients who underwent magnetic resonance examinations were analyzed. The location of the popliteal artery was measured in three different areas of the posterior proximal region of the tibia. The first measurement was made at the level of the knee joint (tibial plateau). The second was 9 mm distally to the tibial plateau. The third was at the level of the anterior tuberosity of the tibia (ATT).

Results

The distances between the popliteal artery and the tibial plateau and ATT region were significantly greater in males than in females. The distances between the popliteal artery and the regions 9 mm distally to the tibial plateau and the ATT were significantly greater in the age group over 36 years than in the group ≤36 years.

Conclusion

Knowledge of the anatomical position of the popliteal artery, as demonstrated through magnetic resonance studies, is of great relevance in planning surgical procedures that involve the knee joint. In this manner, devastating iatrogenic injuries can be avoided, particularly in regions that are proximal to the tibial plateau and in young patients.

Vascular safety during arthroscopic all-inside meniscus suture

PURPOSE

The purpose of the study is to assess the orientation and distance of the popliteal artery (PA) from both the anteromedial and anterolateral portals.

METHODS

The records of 97 patients (100 knees) who underwent knee arthroscopy were reviewed. The shortest distance from the posterior tibial cortex to the PA on the lines from both the medial and lateral borders of the patellar tendon to the PA was evaluated by magnetic resonance imaging at full knee extension. The figure-of-four position was compared between patients with intact and deficient anterior cruciate ligaments (ACLs). The shortest distances from the posterior cruciate ligament (PCL) to the lines running from the medial and lateral borders of the patellar tendon to the PA were also measured.

RESULTS

The shortest distances from the posterior tibial cortex to the PA were significantly longer in the figure-of-four position than at full knee extension and during extension in the ACL-deficient than intact group. Distances did not significantly differ in the figure-of-four position. The PA was hidden from the anteromedial portal by the PCL, but remained vulnerable from the anterolateral portal.

CONCLUSIONS

All-inside meniscus suturing of the posterior horn of the lateral meniscus inserted through the anteromedial portal is safer when the knee is in the figure-of-four position than fully extended. Meniscus repairs should be completed before ACL reconstruction due to vascular positions and the ease of approach.

LEVEL OF EVIDENCE

Prospective correlation study, Level IV.

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.

Iatrogenic popliteal artery injury in non arthroplasty knee surgery

We have investigated iatrogenic popliteal artery injuries (PAI) during non arthroplasty knee surgery regarding mechanism of injury, treatment and outcomes, and to identify successful strategies when injury occurs.

In all, 21 iatrogenic popliteal artery injuries in 21 patients during knee surgery other than knee arthroplasty were identified from the Swedish Vascular Registry (Swedvasc) between 1987 and 2011. Prospective registry data were supplemented with case-records, including long-term follow-up. In total, 13 patients suffered PAI during elective surgery and eight during urgent surgery such as fracture fixation or tumour resection. Nine injuries were detected intra-operatively, five within 12 to 48 hours and seven > 48 hours post-operatively (two days to 23 years).

There were 19 open vascular and two endovascular surgical repairs. Two patients died within six months of surgery. One patient required amputation. Only six patients had a complete recovery of whom had the vascular injury detected at time of injury and repaired by a vascular surgeon. Patients sustaining vascular injury during elective procedures are more likely to litigate (p = 0.029).

We conclude that outcomes are poorer when there is a delay of diagnosis and treatment, and that orthopaedic surgeons should develop strategies to detect PAI early and ensure rapid access to vascular surgical support.

Cite this article: Bone Joint J 2015;97-B:192–6.

Vascular injuries during closing-wedge high tibial osteotomy: A cadaveric angiographic study

INTRODUCTION

Closing-wedge high tibial osteotomy is a surgical option for patients with isolated medial compartment osteoarthritis and varus knee alignment. Vascular complications are rare, but incriminate the use of oscillating saw or osteotome. It is important to know the steps of this surgery that involve risk of vascular injury and what to do to decrease that risk.

HYPOTHESIS

Performing the distal osteotomy cut using an oscillating saw is a step with high risk of vascular injury. A protective device behind the tibia may decrease this risk.

MATERIALS AND METHODS

In this descriptive angiographic cadaver study, closing-wedge high tibial osteotomy was performed on 6 cadaveric knees in 90° knee flexion, and the distance between the surgical instrument and the popliteal artery was measured on fluoroscopy with artery opacification at the various steps of surgery.

RESULTS

Tibial osteotomy with oscillating saw involves high vascular risk: the mean distance between the saw-blade and the popliteal artery is 10.6mm in 90° knee flexion. Using a specific device placed behind the tibia protects the vascular structures.

DISCUSSION

High tibial osteotomy is indicated in medial compartment osteoarthritis of the knee and can be performed by closing or opening-wedge. Vascular injuries in closing-wedge osteotomy exist and it is recommended to perform this surgery at 90° knee flexion, although some studies report that this does not move the artery out of the way. A risk of vascular lesion should be kept in mind. The oscillation of the saw and the direction of the osteotomy should also be taken into consideration when performing a closing-wedge high tibial osteotomy in order to protect the popliteal artery.

STUDY DESIGN

Descriptive cadaver study. Level IV.

Location of the popliteal artery and its relationship with the vascular risk in the suture of the posterior horn of the lateral meniscus

INTRODUCTION

The proximity of the posterior horn of the lateral meniscus to the popliteal artery determines a risk of vascular injury in its suture. The aim of this study is to determine the location of the popliteal artery, and to establish the minimal distance from the posterior wall of the lateral meniscus to the artery, the common peroneal nerve (CPN), and its correlation to other variables.

MATERIAL AND METHODS

A total of 102 magnetic resonance studies were retrospectively reviewed from patients undergoing surgery at our institution. The axial section where the lateral meniscus could be clearly defined was selected, and the measurements were performed.

RESULTS

The artery lay laterally to the midline in 94% of the cases. The minimal mean distance from the posterior wall of the lateral meniscus to the popliteal artery was 1.01cm. (0.32-1.74, SD: 0.304). The minimal mean distance to the CPN was 1.74cm. (0.75-2.87, SD: 0.374). No association was found between the minimal mean distance from the posterior wall to the popliteal artery with the height, weight, BMI, the lateral meniscus diameter, or the tibial plateau diameter. An association was found between the distance from the posterior wall to the CPN with the weight and the BMI.

CONCLUSIONS

The proximity of the posterior horn to the popliteal artery should be considered when performing sutures. This distance is within the recommended depth for all-inside meniscus repair devices. This distance is not related to height, weight, BMI, lateral meniscus nor tibial plateau diameters.

Sagittal and coronal plane location of the popliteal artery in the open-wedge high tibial osteotomy

PURPOSE

The objectives of this study were (1) to evaluate the sagittal and coronal plane location of the popliteal artery during the advancement of open-wedge high tibial osteotomy and (2) to confirm the effect of osteoarthritis if it changes the relationship between the popliteal artery and posterior cortex.

METHODS

Two hundred consecutive patients were enrolled, and we divided patients into two subgroups according to age and cartilage status in the radiologic report of magnetic resonance imaging (group I: 100 non-arthritic knees; group II: 100 arthritic knees). For prediction of the location of the popliteal artery during the operation, sagittal and coronal plane location along the osteotomy plane was evaluated.

RESULTS

The distance between the posterior cortex of the osteotomy and popliteal artery was 13-14 mm on the sagittal plane, and the popliteal artery was located at an approximately 35 ± 5.5 mm portion from the starting point of the osteotomy on the coronal plane. The distance at the starting point of osteotomy was larger than at the end portion and prominent area. In comparison between groups I and II, group II showed a larger distance on the sagittal planes [osteotomy-vascular: 13.6 vs 14.4 (p = 0.01), fibula-vascular: 4.88 vs 6.5 (p < 0.01), and prominence-vascular: 4.3 vs 5.3 (p < 0.01)] compared to the group I.

CONCLUSIONS

Special caution and some protection should be given until the approximately 35 mm portion from the starting point of the posteromedial cortex with consideration for the approximity on the sagittal plane. In comparison between the non-arthritic and arthritic knee, differences were observed on the sagittal plane. However, the value was minimal, and the clinical relevance was questionable.

LEVEL OF EVIDENCE

Case series, Level IV.

Complications of osteotomies about the knee

High tibial osteotomy and distal femoral osteotomy are 2 popular techniques for the treatment of monocompartmental osteoarthritis of the knee joint in young patients. Injury to the popliteal neurovascular bundle is still considered to be the most severe complication during an osteotomy procedure even if the rate of occurrence is very low. Loss of correction and hardware failures are more frequent, but not as devastating. Patella baja and modification of tibial slope are associated with high tibial osteotomy. In contrast, complications most commonly associated with distal femoral osteotomy include nonunion and failure of the internal fixation. In general with evolution of techniques and fixation devices, complication rates seem to be reduced. A summary and literature review of complications associated with knee osteotomies will be discussed in this paper.

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 relationship between the proximal tibia and posterior neurovascular structures: a safe zone for surgeries involving the proximal tibia

The purpose of this study was to provide a quantitative description of the anatomical relationship between the proximal tibia and posterior neurovascular structures to delineate a safe zone for tibial surgery. We measured the distance between the tibial cortex and neurovascular structures, and the width of the medial/lateral part of the tibia without neurovascular structures, using magnetic resonance imaging data of 50 knees. The average distance was <10 mm. Neurovascular structures passed just lateral to the posterior middle line of the tibia, with major branches passing laterally at 5.5 to 6 cm below the joint line. There was a safe zone posterior to the medial half of the tibia for penetration of the posterior cortex.

Evaluation of popliteal artery injury risk with locked lateral plating of the tibial plateau

OBJECTIVES

This study was undertaken to determine if there is increased likelihood of popliteal artery injury as one places a fixed-angle lateral proximal tibia locking plate with posterior plate lift off and or anterior plate translation from the ideal position.

METHODS

A Synthes (Synthes USA, West Chester, PA) 3.5-mm and 4.5-mm lateral proximal tibia locking plate was placed consecutively on each of six specimens in the straight lateral (SL) position. Screw position with respect to the medial cortex was recorded as well as the distance of the posterior most screw tip to the popliteal artery. Next a 3-mm shim was placed under the posterior edge of the same plate to mimic posterior plate lift off (LO) followed by placement of a 6-mm shim. The same experiment was repeated with the plate translated 5 mm anteriorly (AT).

RESULTS

The popliteal artery was injured in zero of six specimens using the 3.5-mm plate. The popliteal artery was injured in six of six specimens using the 4.5-mm plate in the 5-mm AT 6-mm LO position, five of six with 5-mm AT and 3-mm LO, two of six with only 5-mm AT, four of six with SL and 6-mm LO, two of six with SL and 3-mm LO, and zero of six with SL.

CONCLUSION

The Synthes 4.5-mm plate can put the popliteal artery at risk with as little as 3-mm posterior liftoff in the intended straight lateral position or with 5-mm anterior plate translation with no posterior liftoff. Therefore, placement of the 4.5-mm plate in the proper position and confirmation of its position with a true lateral radiograph is paramount to avoid injury to the popliteal artery.

Popliteal artery-tibial plateau relationship before and after total knee replacement: a prospective ultrasound study

It seems to be a general belief that knee flexion releases the tension on the popliteal artery (PA) and displaces it posteriorly. Furthermore, there are opinions suggesting that previous surgery may result in fibrosis and rigidity of the vessels in the posterior knee region, which can lead to tethering of the PA, bringing it closer to the posterior tibia and making it more vulnerable during revision knee surgery. The aim of this study was to assess the distance between the PA and the tibial plateau in extension and flexion of the knee before and after surgery with total knee replacement (TKR). We studied 40 consecutive patients who were about to undergo TKR. The distance between the PA and tibial plateau was measured by ultrasound bilaterally in full knee extension without quadriceps contraction and in 90 degrees knee flexion, both preoperatively and 15 weeks postoperatively. The mean preoperative distances in flexion and in extension were 7 mm (3-12) and 8 mm (4-13), respectively (p < 0.05). Postoperatively, the distances were significantly increased both in flexion, 9 mm (4-14) (p < 0.001) and in extension 9 mm (3-15) (p < 0.01). Assessment of the contralateral legs where 14 previously had been operated with TKR showed no significant difference either between flexion and extension or between pre- and postoperative measurements. In conclusions, knee flexion does not increase the distance between the artery and the proximal tibia in this osteoarthritis patient group. At 15 weeks post-TKR, there was an increased distance from the PA to the posterior tibia and assessment of the contralateral knee where previous TKR had been performed showed equal distance to the ipsi-lateral preoperative knee, suggesting that the postoperative changes at 15 weeks were due to capsular swelling.

Vascular safety during high tibial osteotomy: a cadaveric angiographic study

BACKGROUND

High tibial osteotomy is technically demanding. Risks include injury to the popliteal neurovascular bundle. The present goal was to further define this risk.

HYPOTHESIS

The distance from the posterior tibia to the popliteal artery increases with increasing knee flexion. A saw angle perpendicular to the coronal plane can injure the popliteal artery.

STUDY DESIGN

Descriptive laboratory study.

METHODS

Seven fresh-frozen cadaveric lower extremities were used. Lateral radiographs at knee flexion angles of 90 degrees , 60 degrees , 45 degrees , 30 degrees , and 0 degrees were taken to measure the distance from the anterior border of the popliteal artery to the posterior cortex of the tibia 5.0 mm and 2.0 cm below the joint line. After an opening wedge high tibial osteotomy was made, qualitative assessments were made of the depth of a saw blade inserted into the kerf and the relative encroachment of the saw blade on the popliteal artery. The interval through which the space anterior to the popliteus can be accessed was identified by gross dissection in all specimens.

RESULTS

The distance from the posterior tibia to the popliteal artery increased with knee flexion. At 5.0 mm and 2.0 cm below the joint line, the mean distance at 90 degrees was significantly greater than at all other angles. The popliteal artery could be injured by the oscillating saw at angles greater than 30 degrees to the coronal plane. A protective device inserted anterior to the popliteus protects the neurovascular structures.

CONCLUSION

The popliteal artery is farthest from the posterior tibia at 90 degrees of knee flexion. Saw angles greater than 30 degrees from the coronal plane put the popliteal neurovasculature at risk of injury.

CLINICAL RELEVANCE

To perform a safe osteotomy, the knee should be positioned in 90 degrees of flexion with the saw angled less than 30 degrees from the coronal plane. A protective device deep to the popliteus may protect against popliteal injury.

False aneurysm at the origin of the anterior tibial artery after opening wedge osteotomy

We report the case of a false aneurysm at the origin of the anterior tibial artery complicating upper tibial osteotomy. The proximally located lesion compressed the posterior tibial nerve, and despite successful decompression, the patient suffers from probably irreversible neurologic after-effects. Even though it is rare, this complication must be considered when faced with leg pain consecutive to upper tibial osteotomy without deep venous thrombosis.

Closing wedge osteotomy of the tibia and the femur in the treatment of gonarthrosis

New developments in osteotomy techniques and methods of fixation have caused a renewed interest in closing wedge osteotomies of the tibia and femur in the treatment of gonarthrosis. The rationale, definition and techniques of closing wedge tibial and femoral osteotomies in the treatment of gonarthrosis are discussed. The principal indications include unicompartmental medial and much less so, varus knee gonarthrosis and unicompartmental lateral or valgus knee gonarthrosis with a well-maintained range of motion in patients who are physiologically young. Newer techniques have provided more rigid fixation and improved accuracy of correction.

Complications of closing wedge high tibial osteotomy

Closing wedge high tibial osteotomy is a common, effective and well-established procedure to treat unicompartment osteoarthrosis of the knee. It is, however, not without its complications. This article will discuss some of these complications and present an overview of the current literature. It will examine current thoughts on aetiology, techniques to try to avoid, and methods of treatment of these complications.

Pseudoaneurysm of the popliteal artery complicating medial opening wedge high tibial osteotomy

The popliteal artery is vulnerable to injury during surgeries performed around the knee joint. Pseudoaneurysm of the popliteal artery following a high tibial osteotomy is rare. Few case reports describe the development of this complication after a lateral closing wedge high tibial osteotomy. Our patient underwent an uneventful medial opening wedge high tibial osteotomy and autogenous bone grafting fixed with dual plating for medial osteoarthritis of the knee. The procedure was performed under tourniquet control, which was released only once after the wound closure. Postoperatively, the dressing was soaked, and a large volume of hemorrhagic collection was present in the suction drain. The patient experienced decreased sensation over the sole, which was successfully treated conservatively with medication. Other clinical parameters like motor function and distal pulses were normal. The patient was discharged after 2 weeks. Two days later, the patient presented with pain and numbness over the entire lower limb and a pulsatile swelling in the popliteal fossa. A femoral angiogram revealed a pseudoaneurysm arising from the popliteal artery just below the osteotomy site. Open vascular surgery with resection of the pseudoaneurysm and end-to-end anastomosis using contralateral saphenous vein interposition graft was performed. During the vascular surgery, a pinhead-sized tear was clearly identified on the anterior wall of the popliteal artery, which may have occurred while using the oscillating saw during opening wedge high tibial osteotomy. Careful placement of retractors around the osteotomy site during sawing and flexing the knee to displace the popliteal artery away are recommended to prevent this complication. To our knowledge, this is the first report of a popliteal artery pseudoaneurysm occurring after a medial opening wedge high tibial osteotomy.

The location of the popliteal artery in extension and 90 degree knee flexion measured on MRI

We measured the location of the popliteal artery (PA) in extension and 90 degree of knee flexion by magnetic resonance images (MRI) to provide practical information to avoid PA injury. The MRIs of 30 knees of Korean male subject whose mean age was 20.7 were acquired in knee extension and 90 degree flexion. The distance from the posterior aspect of knee joint to the PA was measured at three levels on the axial images and one sagittal image. At the joint line level, the PA was located lateral to the PCL 2.4 mm in extension and 3.2 mm in flexion (p=0.247), and 3.9 mm in extension and 7.6 mm in flexion from the posterior capsule (p<0.001). At 1 cm distal to the joint line, it is 2.7 mm in extension and 7.2 mm in flexion (p<0.001), and at 2 cm distal to the joint line, 4.9 mm in extension and 9.7 mm in flexion from the posterior tibial cortex (p<0.001). In sagittal plane, the nearest distance between PA and posterior tibial cortex was 1.8 mm in extension, and 6.2 mm in flexion (p<0.001). The PA was located around 3 mm lateral to the PCL, and within 5 mm in extension and 10 mm in 90 degree flexion of the knee behind knee joint. It moves farther posteriorly in 90 degree flexion than in extension of the knee. The conventional wisdom of flexing the knee to prevent the PA injury was supported by this study.

The aberrant anterior tibial artery: magnetic resonance appearance, prevalence, and surgical implications

BACKGROUND

Injury of a popliteal fossa artery during orthopaedic knee surgery is very rare but has serious consequences. The risk of vascular trauma during orthopaedic procedures may be increased when there is abnormal branching of the popliteal artery with an aberrant anterior tibial artery originating above the popliteus muscle and coursing between the posterior tibial cortex and ventral margin of the popliteus muscle. Preoperative identification of this anatomical variant may help avoid these injuries.

HYPOTHESIS

The aberrant anterior tibial artery is present in a substantial portion of the population and can be visualized by magnetic resonance imaging.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Retrospective review of 1116 consecutive knee magnetic resonance imaging studies was performed to evaluate the prevalence of an aberrant anterior tibial artery. Images were reviewed by 3 musculoskeletal radiologists.

RESULTS

The aberrant anterior tibial artery was present in 23 of 1116 extremities for a prevalence of 2.1%. The aberrant artery was most easily identified on axial and sagittal magnetic resonance imaging scans.

CONCLUSION

The aberrant anterior tibial artery is a relatively common normal variant, and magnetic resonance is an excellent modality for detection of the artery close to the posterior joint capsule and tibial cortex.

CLINICAL RELEVANCE

The anatomy suggests the aberrant anterior tibial artery may be at greater risk of injury in orthopaedic procedures such as high tibial osteotomy, revision total knee arthroplasty, lateral meniscal repair, posterior cruciate ligament reconstruction, and screw fixation for tibial tubercle osteotomy. Careful inspection of preoperative magnetic resonance imaging studies may alert the surgeon to the presence of this anatomical variant.

Transepicondylar distal femoral pin placement in computer assisted surgical navigation

The use of optical tracking systems in computer assisted surgical navigation requires the rigid fixation of a dynamic reference base to the target bone to be navigated. This report presents the results of a new approach to optical tracker fixation in the distal femur. Four embalmed cadavers were evaluated for pin placement. It was found that placement of pins from medial to lateral parallel to the transepicondylar axis placed the pins well posterior to the center of the intramedullary canal and away from neurovascular structures. Eighty-six consecutive patients underwent total knee arthroplasty using this new technique. All procedures were successful for performing a navigation-assisted total knee replacement. Obesity was not a factor, nor was there any loosening of the pin array during the procedure. There were no wound-healing problems in any patient. At one year follow-up, no patient could identify subjective symptoms related to either the medial epicondylar area or the stab wound portals. No direct neurovascular injuries were noted and no patient developed a fracture of the femur related to the pin sites.

CONCLUSION

A new technique is described that facilitates pin placement for minimally invasive approaches while eliminating complications. Sagittal plane optical array orientation simplifies the surgical technique.

Osteotomy for the Early Varus Arthritic Knee

High tibial osteotomy is a well-established procedure for the management of medial compartment arthritis that is currently experiencing a resurgence in popularity. A number of techniques have been described, with the ultimate goal of obtaining appropriate alignment to provide pain relief and functional improvement over a long-term period. Appropriate patient selection and careful surgical technique is necessary to achieve these goals with a minimal risk of complication. Newer technology such as computer navigation promises to improve the overall accuracy of the procedure. The need for alignment correction in combination with ligament reconstruction and chondral resurfacing surgery will increase the indications for this procedure. This article discusses the techniques available for high tibial osteotomy, the results and relative advantages of each, and the appropriate surgical technique to achieve optimal results while minimizing complications.

Safe femoral pin placement in knee navigation surgery: a cadaver study

A number of navigation systems used for total knee replacement surgery currently require the insertion of a distal femoral reference sensor pin, which is placed anterior to posterior just superior to the level of the knee joint. There is potential for the posterior neurovascular bundle to be damaged during the insertion of this sensor device. The aim of this cadaveric study was to identify the structures at risk during insertion of the distal femoral sensor, and determine whether a safe zone for insertion could be identified. Sixteen cadaveric lower limbs (8 pairs) were studied. In each knee Steinman pins were passed from anterior to posterior, 5 cm proximal to the level of the femoral articular cartilage, directly AP and angled at 30 degrees passing medially or laterally. All pins that were passed directly from anterior to posterior and from lateral to medial passed within 5 mm of a major neurovascular structure, while 62.5% of pins passing from medial to lateral passed within 5 mm of a major neurovascular structure. The popliteal vessels and the sciatic nerve are at risk of injury from a navigation pin or drill placed in the distal femur during knee navigation. Caution should be exercised in passing these pins and alternate methods of fixing femoral sensors should be considered.

High tibial osteotomy for medial compartment osteoarthritis

Unicompartmental osteoarthritis of the knee is often a difficult management problem in the younger age group. A high tibial osteotomy has been found to be quite an effective procedure for this condition in the past. A better understanding of the principles of this technique and innovations in the instrumentation has renewed interest in this procedure. This article provides an overview of the principles, biology, indications, contraindications, planning and execution, postoperative care, results and complications of high tibial osteotomy. An attempt has been made to incorporate important technical considerations, recent developments and other treatment options in this condition.

A safe zone for the passage of screws through the posterior tibial cortex in tibial tubercle transfer

In tibial tubercle transfer, surgery drills and screws can put the popliteal vessels at risk if the posterior cortex is breached. This complication can be devastating. We have looked at arteriograms of 50 knees and identified a safe zone through which an instrument can be passed with more confidence. In our study we found no vessels directly posterior to the supero-medial aspect of the proximal metaphysis in any knee. Whilst care must still be taken, this area will allow surgeons greater confidence to obtain a stronger bicortical hold with any fixation device.

Stiffness after total knee arthroplasty

Limitation of motion after knee arthroplasty can be the result of a multiplicity of factors. Among these are malpositioning of the components, especially in the sagittal plane; oversizing at the patellofemoral or tibiofemoral joint spaces; retaining posterior osteophytes; and persisting with a tight posterior cruciate ligament. Postoperatively, problems with physical therapy likewise can cause limitation of both extension and flexion. Specific patient factors also may affect the range of motion after surgery. Although most patients achieve a postoperative flexion that is highly correlated to that which was present preoperatively, factors such as pain, obesity, and deformities of adjacent joints may limit such motion.

Posterior "back and forth" approach in arthroscopic surgery on the posterior knee compartments

We report the feasibility, indications, and usefulness of an arthroscopic approach to the posterior knee compartments. We developed an arthroscopic approach to the posterior knee compartment involving use of a posteromedial portal and a posterolateral portal opposite each other. Each posterior portal is used in alternation for the arthroscope and instruments. The posterior portals are established using an original "back and forth" technique. The feasibility of the technique was evaluated on a cadaver. It allowed us to define safety rules to protect the vessels and nerves that course through the popliteal fossa. The approach provided a broader field of view compared with classical techniques. After removal of the septum dividing the posterior compartment, the synovial fold enclosing the posterior cruciate ligament and lining the upper and posterior parts of the posterior capsule was readily accessed, suggesting that this approach may be particularly valuable for total synovectomy. This was confirmed in 6 patients with villonodular synovitis, in whom the new approach was used in combination with arthroscopic anterior synovectomy. This technique allows removal of parts of the synovium that are difficult to access through conventional arthroscopic approaches. For total synovectomy, it can be used as an alternative to open posterior synovectomy, in combination with arthroscopic anterior synovectomy.

Flexion of the knee increases the distance between the popliteal artery and the proximal tibia: MRI measurements in 15 volunteers

We determined which angle of flexion best prevents popliteal artery injury during knee surgery. We took MRIs of the knee in the lateral position with the knee in 0 degrees, 45 degrees, 90 degrees, and 120 degrees of flexion in 15 volunteers. The shortest distance between the posterior cortex of the tibia and the popliteal artery was measured at various levels from the knee joint to 60 mm distally. At the level of the joint and 15 mm distally, the distance between the tibia and artery increased with increasing knee flexion. More distally, no significant difference was noted with increasing flexion. Flexion of the knee may minimize injury to the popliteal artery in procedures between the level of the joint and 15 mm distal to the joint.

Proximity of the posterior cruciate ligament insertion to the popliteal artery as a function of the knee flexion angle: implications for posterior cruciate ligament reconstruction

PURPOSE

The purpose of this study was to determine if an optimal knee flexion angle existed that would minimize the risk of neurovascular injury from the passage of transtibial hardware during posterior cruciate ligament (PCL) reconstruction.

TYPE OF STUDY

Cadaveric.

MATERIALS AND METHODS

Fourteen fresh-frozen cadaveric knees were mounted in a Plexiglas apparatus that could be set at 5 different knee flexion angles (0 degrees, 45 degrees, 60 degrees, 90 degrees, and 100 degrees ) while joint distention was maintained. Each knee underwent magnetic resonance imaging in the axial and sagittal planes at each of the 5 flexion angles to determine the distance between the PCL tibial insertion and popliteal artery.

RESULTS

The mean distance, over all 5 flexion angles, between the PCL insertion and the popliteal artery in the axial plane was 7.6 mm, whereas the mean distance in the sagittal plane was 7.2 mm. There was a significant increase in distance with progressive flexion in both planes. Maximum mean distances were noted at 100 degrees of flexion in both the axial (9.9 mm) and sagittal (9.3 mm) planes. An artificial line mimicking the path of a transtibial drill passed through the popliteal artery in 10 of 10 cases at the 0 degrees, 45 degrees, 60 degrees, and 90 degrees angles, and in 6 of 10 cases at the 100 degrees angle.

CONCLUSIONS

The results of this study suggest that increasing knee flexion reduces, but does not completely eliminate, the risk of arterial injury during arthroscopic PCL reconstruction.

Osteotomia valgizante de tíbia com placa "calço" de Puddu: apresentação de técnica

O objetivo do presente trabalho é apresentar os resultados iniciais, obtidos com a osteotomia valgizante de adição de tíbia, fixada com placa calço descrita por Puddu. Foram operados 29 joelhos em 27 pacientes para correção de geno-varo, sendo que, em apenas um paciente o procedimento bilateral teve objetivo profilático. O seguimento foi de 3 a 28 meses com média de 14 meses. A osteotomia proximal de tíbia foi feita de forma oblíqua iniciando na inserção distal do ligamento colateral medial em direção ao tubérculo de Gerdy. A osteotomia foi aberta e fixada com uma placa calço de Puddu. O espaço aberto da osteotomia foi preenchido por enxerto autólogo de ilíaco. A carga total era dada com 45 dias de pós-operatório. Os resultados obtidos mostraram que entre 4 a 6 meses os pacientes tiveram uma significativa melhora na sintomatologia indutora do procedimento cirúrgico. A avaliação final mostrou 27 resultados satisfatórios e apenas 2 regulares. Como conclusão essa técnica tornou a osteotomia de tíbia um procedimento reprodutível com resultados previsíveis com excelente manutenção no pós-operatorio da correção obtida no trans-operatório.