Popliteal Neurovascular Bundle Research Articles

An in-vitro three-dimensional surgical simulation technique to predict tibial tunnel length in transtibial posterior cruciate ligament reconstruction

BackgroundDuring the transtibial posterior cruciate ligament (PCL) reconstruction, drilling depth excessively longer than the tibial tunnel length (TTL) is an important reason to cause popliteal neurovascular bundle injury when preparing the tibial tunnel. This study aims to develop an in-vitro three-dimensional surgical simulation technique to determine the TTL in anteromedial (AM) and anterolateral (AL) approaches.MethodsA total of 63 knees’ 3-dimensional (3D) computed tomography models were included in this study. The SuperImage system was used to reconstruct the 3D knee model and locate the tibial PCL site. The established 3D knee model and the coordinates of the tibial PCL site were imported into Rhinoceros 3D modeling software to simulate AM and AL tibial tunnel approaches with different tibial tunnel angles (TTA). The TTL and the tibial tunnel height (TTH) were measured in this study.ResultsIn AM and AL tibial tunnel approaches, the TTL showed a strong correlation with the TTA (for AM: r = 0.758, p < 0.001; for AL: r = 0.727, p < 0.001). The best fit equation to calculate the TTL based on the TTA was Y = 1.04X + 14.96 for males in AM approach, Y = 0.93X + 17.76 for males in AL approach, Y = 0.92X + 14.4 for females in AM approach, and Y = 0.94X + 10.5 for females in AL approach.ConclusionMarking the TTL on the guide pin or reamer could help to avoid the drill bit over-penetrated into the popliteal space to damage the neurovascular structure.

Modified Oblique Lobenhoffer (MOL) approach for posterolateral and posteromedial column access in tibial plateau fractures: a detailed cadaveric anatomical study

BackgroundTibial plateau fractures involving posteromedial (PM) and posterolateral (PL) columns are complex injuries that require an appropriate approach. The management of the PL column in these cases can be controversial, and limitations using deep posteromedial interval approaches have been referenced. In this paper, a modification of the Lobenhoffer approach, designed to optimize the access to the PL column, is described in detail. The aim of this study was to assess the feasibility of this approach in a cadaveric anatomical study.Materials and methodsIn total, five fresh-frozen cadaveric specimens were used for detailed anatomical study surrounding the approach. Relationships with cutaneous and deep neurovascular structures were evaluated. The exposure area of the PL and PM columns using this approach was assessed.ResultsThe cadaveric study showed safe and adequate exposure. Oblique skin and fascia incision just medial to the posterior midline was safe to protect the medial sural cutaneous nerve and the small saphenous vein. Elevation of the popliteus and tibialis posterior muscles offered safe protection of the anterior tibial artery and popliteal neurovascular bundle during retractor placement. Adequate full proximal exposure of the PM and PL columns, including the posterolateral lateral (PLL) and posterolateral central (PLC) segments, was obtained in all specimens.ConclusionsThe Modified Oblique Lobenhoffer (MOL) approach can be a feasible option to access PL and PM columns in tibial plateau fractures.Level of evidenceIV.

Intraoperative radiographic analysis and adjustment of the optimal position of plate in high tibial osteotomy.

When high tibial osteotomy is performed for genu varus deformity, it is not easy to determine the accurate placement of the plate. To determine a simple way to assess the position of the plate, to provide more effective mechanical support and to reduce the risk of implant rupture and vascular injury. Two human anatomical marks, the patellar ligament and semimembranosus, were connected and divided into four parts to identify points Ⅰ, Ⅱ, and Ⅲ. These points determined the areas for Tomofix placement: anterior, anterolateral, and lateral. Simulated internal fixation placed hole B of Tomofix at points Ⅰ (anterior), Ⅱ (anterolateral), and Ⅲ (lateral). We analyzed the pointing direction of the locking screws in Tomofix holes on MRI to assess potential injury risk to the popliteal neurovascular bundle. In the X-ray: holes B and C appeared as the plate in the anterior, only hole C appeared as the plate in the anterolateral, and none of the holes appeared as the plate in the lateral. In the general view of the sawbones, the screw pointed towards the popliteal neurovascular bundle when the plate was in the anterior. If a small number of holes on the plate is visible under fluoroscopy, then several lateral positions of the plate can be obtained; the direction of the screw tunnel tends to deviate from the popliteal neurovascular bundle with the posterior position of the plate.

Arthroscopic Trans-septal Portal of the Knee With Direct Visualization and No Need for Posterolateral Portal Creation

Arthroscopic visualization and access of the posterior knee are limited when using standard anterior and posterior portals. The creation of a trans-septal portal allows for complete access to the posterior compartment as arthroscopic instruments are able to be passed back and forth between the posteromedial and posterolateral compartments. Due to the close proximity of the popliteal artery and its branches, precise portal placement and safe orientation of arthroscopic instruments are critical to avoid iatrogenic injury. The conventional technique of trans-septal portal creation, involving a posterolateral portal, can be difficult in some cases. To overcome these obstacles, a posteromedial technique of trans-septal portal creation is presented. By using the medial parapatellar portal as the viewing portal, our technique allows for direct visualization of the posterior septum on each step of creation of the trans-septal portal, eliminating the need for “blind” maneuvers. What is more, no posterolateral portal is needed, decreasing the risk of potential complications. Using the posterior cruciate ligament fibers as a main landmark for trans-septal portal placement, preservation of the posterior part of the septum is achieved. This ensures optimal safe-margin distance away from the popliteal neurovascular bundle and making the technique safe and reproducible.

Single-incision bone bridge lateral meniscus allograft transplantation: preserving neurovascular safety with promising results for posterior horn distortion and graft maturation.

This study aimed to investigate the graft maturation and safety of single-incision bone bridge lateral meniscus allograft transplantation (LMAT). This study involved 35 patients who underwent LMAT between 2019 and 2020. All patients completed at least 2years of follow-up (median 34months; range 24-43) and underwent preoperative magnetic resonance imaging (MRI) to assess the trajectory safety of the leading suture passer and all-inside suture instrument (Fast-Fix). Graft status was evaluated according to the Stoller classification. Based on preoperative MRI measurements, the expected trajectory of the leading suture passer did not transect the common peroneal nerve (CPN), with the closest distance between the expected trajectory and CPN being 1.4mm and the average distance being 6.8 ± 3.2mm. The average distance from the lateral meniscal posterior horn (LMPH) to the popliteal neurovascular bundle (PNVB) was 7.4 ± 2.6mm and the nearest was 4.8mm. The expected trajectory of the all-inside suturing instrument did not transect the PNVB when the distance was at least 12mm, from the most lateral margin of the posterior cruciate ligament (PCL). Grade 3 signal intensity in the posterior third of the allograft on MRI was observed in 6 of 35 (17.1%) patients. Amongst the grade 3 signal intensities in the posterior one-third of the allografts, 3 of the 35 (8.5%) LMATs had a distorted contour. The single-incision bone bridge LMAT technique introduced in this study is a convenient approach that preserves neurovascular safety and provides good results for the distortion of the posterior horn of the allograft and graft maturation. The safety zone for the penetrating devices during the procedure extended from 12mm laterally to the most lateral margin of the PCL to the medial margin of the popliteal hiatus. IV.

Anatomic Posterolateral Corner Reconstruction With Single Graft Tibial Socket Fixation

Introduction: The posterolateral corner (PLC) is comprised of the fibular collateral ligament, popliteus tendon, and popliteofibular ligament. Injuries to the PLC are associated with significant morbidity and functional limitation, most frequently manifested through a varus thrust gait. In the previous 2 decades, advances have been made in understanding the importance of the PLC and as a result, many techniques have been developed to address its reconstruction. Material and Methods: The Laprade technique is a previously described anatomic reconstruction of the PLC. We propose some modifications to this technique, which involve dissection of the posterolateral tibia to allow direct protection of the popliteal neurovascular bundle while establishing tibial fixation. A single hamstring graft is utilized for the reconstruction, is routed through the fibular tunnel and subsequently secured with the use of a dual-expanding tenodesis anchor, placed in a tibial socket removing the need for a tibial tunnel. Conclusion: The present study describes a novel anatomic technique that allows for improved protection of neurovascular structures, better control of graft tensioning and tunnel management, and the judicious use of a single tendon autograft while maintaining the described benefits of the anatomic Laprade technique.

Easy Arthroscopic Transseptal Approach of the Knee

Background: The arthroscopic approach to the posterior compartment of the knee is always challenging. This easy arthroscopic transseptal approach allows safe access to the posterior compartment of the knee, avoiding any potential neurovascular injury. Indications: Indications include arthroscopic posterior cruciate ligament (PCL) reconstruction, fixation of avulsion fractures of the tibial attachment of the PCL, arthroscopic posterolateral corner reconstruction, removal of loose bodies from the posterior compartment, PCL cyst removal, ramp repair, and arthroscopic arthrolysis of the posterior compartment. Technique Description: Using a posteromedial portal, a shaver is introduced with the tip in direct contact with the medial side of the septum facing anteriorly, away from the popliteal neurovascular bundle. The scope is then inserted into the posterolateral compartment to visualize the lateral side of the septum while the shaver remains in the posteromedial compartment. The septum is then released until the tip of the shaver is visible. The shaver is then removed and the scope can now be inserted from the posteromedial portal to the posterolateral compartment through the released septum. Results: The transseptal approach can be performed without any additional risk if the shaver remains centrally on the inferior aspect of the septum. Therefore, the risk of iatrogenic injury of the middle genicular artery is minimized. Likewise, with the knee flexed to 90°, there is no risk of damaging the popliteal neurovascular bundle. Having a precise knowledge of the anatomy of the posterior compartment of the knee minimizes any risks of the transseptal approach, avoiding any additional surgical time whilst facilitating the indicated operation. Conclusion: This easy arthroscopic transseptal approach allows safe access to the posterior compartment of the knee, avoiding any potential neurovascular 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

BackgroundTo 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. MethodsUpright-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). ResultsD 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). ConclusionAll-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.

Avoiding Injury to the Popliteal Neurovascular Bundle in All-Inside Suturing of the Posterior Horn of the Lateral Meniscus: A Magnetic Resonance Imaging Assessment of Portal Selection and Safety

We assessed the risk of injury to the popliteal neurovascular bundle (PNVB) while suturing the posterior horn of the lateral meniscus (PHLM). We simulated all-inside suturing of the PHLM using magnetic resonance imaging of 60 knees. Lines were drawn from the medial and the lateral edges of the patellar tendon to the PHLM at increasing distances from the posterior cruciate ligament (PCL) to simulate suturing device trajectory. Distance from each line to the PNVB was measured (d). A similar analysis was performed using lines drawn from 1cm medial and 1cm lateral to the patellar tendon. We compared the average "d" at increasing distances from the PCL, between the different simulated portal entry points. We have also analyzed the association between different demographic characteristics and the shortest distance from the PVNB to the PHLM. Of 1200 measurements performed, the simulated suturing trajectory transected the PNVB 343 times (28.6%). At 0mm from the PCL, the safest portal was the 1-cm lateral portal (P < .001), with an average "d" of 2.7mm. At 3mm, 6mm, 9mm, and 12mm from the PCL, the safest portal was the 1-cm medial portal (P < .001), with average "d" of 3.8mm, 6.9mm, 10.1mm, and 13.5mm, respectively. Average distance between the PHLM and the PNVB was 7.8mm. Shorter distance between the PHLM and the PNVB was associated with younger age and female sex (P= .014 and .001, respectively). All-inside suturing of the PHLM at 0mm from the PCL is safer with a more lateral portal. Beyond 3mm from the PCL, a more medial portal carries a lower risk to the PNVB. Young and female patients have a shorter distance between the PHLM and the PNVB, suggesting a greater risk for injury to the PNVB. Careful preoperative magnetic resonance imaging assessment may assist in safer portal selection when planning repair of the PHLM. This study describes a magnetic resonance imaging-based risk assessment for injury of the PVNB while suturing the PHLM. It allows the orthopaedic surgeon a better understanding of the anatomic relationship between the popliteal neurovascular bundle and the lateral meniscus and can assist in portal selection and safety.

Mid-term results of multi-ligament posterior and anterior cruciate ligament reconstruction using a modified method of bone tunnels drilling

The problem of diagnosis and treatment of chronic anterior-posterior instability of the knee joint in multi-ligamentous injuries remains relevant, both medically and socially. Conservative treatment of patients with this pathology is ineffective due to severe instability and gross violation of the biomechanics of the knee joint. Currently, there is no consensus on the tactics of surgical treatment of this disease, and on the method of plastic replacement of the lost ligamentous apparatus.&#x0D; Objective. To evaluate the clinical results of the modified technique of arthroscopic plastic surgery of both cruciate ligaments of the knee joint.&#x0D; Patients and methods. Based on previous anatomical studies, the authors formulated the basic principles of safe formation of bone tunnels in simultaneous arthroscopic plastic surgery of the anterior (PKS) and posterior (ZKS) cruciate ligaments. An original method of surgery aimed at minimizing the risk of injury to the popliteal artery during the formation of the tibial bone tunnel is proposed. In the period from 2010 to 2017, the Department of endoscopic surgery treated 20 patients with damage to the SCS and SCS using this technique. The results were evaluated 6 and 12 months after surgery. Clinical examination, IKDC and Lisholm-Gillqist questionnaires and the visual analog pain assessment scale (VAS) were used to evaluate clinical results.&#x0D; Results. The average score on the IKDC questionnaire was 34.1613.31 points before surgery, and 34.8918.37 points on the lisholm Gillqist questionnaire. 6 months after surgery 58.756.38 and 69.7814.10 points according to IKDC and LisholmGillqist, respectively, which is statistically significant (p0,05) higher than before surgery. A year after the operation, the positive dynamics was observed even more clearly (p0.01): 76.839.26 and 82.006.38 points, respectively. The final result of the evaluation according to the IKDC Protocol: 11(55.0%) patients were assigned to group A (good result),6 (30.0%) to group В (close to good result),2 (10.0%) to group C (satisfactory result) and 1 (5.0%) patient to group D (unsatisfactory result). Conclusion. The obtained clinical results allow to evaluate the proposed method as effective. In this case, the method of forming bone tunnels has a number of advantages compared to the classical technique, including minimizing the risk of intraoperative damage to the structures of the popliteal neurovascular bundle.

Avoiding Damage to the Popliteal Neurovascular Bundle in All-Inside Suturing of the Posterior Horn of the Lateral Meniscus: An MRI Assessment of Portal Selection and Safety

All-Inside suturing of the posterior horn of the lateral meniscus (PHLM) carries a risk for a rare, however, possibly devastating injury to the popliteal neurovascular bundle (NVB). The purpose of this study is to assess the risk of damage to the PNVB while suturing the PHLM.

The Safe Distance to the Popliteal Neurovascular Bundle in Pediatric Knee Arthroscopic Surgery: An Age-Based Magnetic Resonance Imaging Anatomic Study.

Background:The close proximity of the popliteal neurovascular bundle to the posterior horn of the lateral meniscus puts it at risk of compromise during lateral meniscal repair. This is particularly important in smaller pediatric patients, who are commonly treated for lateral meniscal abnormalities in isolation (discoid meniscus) or concomitantly with anterior cruciate ligament reconstruction.Purpose:To quantify the distance between the posterior horn of the lateral meniscus and the popliteal neurovascular bundle along the path of meniscal repair and to investigate for associations with age, sex, height, weight, body mass index (BMI), and skeletal maturity.Study Design:Cross-sectional study; Level of evidence, 3.Methods:A total of 144 magnetic resonance imaging scans were evaluated in a cohort of patients aged 10 to 18 years without meniscal or ligament abnormalities. Measurements were made along a line from the anterolateral portal between the popliteal neurovascular bundle and the free edge, midpoint, and meniscocapsular junctions of the posterior horn of the lateral meniscus. In addition to descriptive statistics of these distances by age and sex, analyses of variance and linear regression analyses were performed to investigate for associations with age, sex, height, weight, BMI, and skeletal maturity.Results:Male participants had a significantly larger mean free edge distance (14.4 ± 2.5 vs 13.1 ± 2.5 mm, respectively; P = .005) and midpoint distance (9.6 ± 2.2 vs 8.9 ± 1.8 mm, respectively; P = .011) than female participants but not a significantly larger meniscocapsular distance (5.2 ± 1.6 vs 4.6 ± 1.4 mm, respectively; P = .096). Linear regression analyses revealed significant associations between these distances and age, height, weight, and BMI (P < .001 for all). There were statistically significant pairwise differences for free edge and midpoint distances to the neurovascular bundle between patients with open and closed physes.Conclusion:The distance between the posterior horn of the lateral meniscus and the popliteal vasculature along a trajectory from the standard anterolateral arthroscopic portal increases linearly throughout development between the ages of 10 and 18 years. There were also significant associations between height, weight, BMI, and skeletal maturity and these anatomic distances. Knowing the safe distance to the popliteal vasculature will increase the safety of arthroscopic lateral meniscal repair in children, especially with all-inside devices that require setting the penetration depth for the advancement of a sharp delivery device beyond the posterior capsule.

Proximity of the Neurovascular Bundle During Posterior-Lateral Meniscal Repair: A Comparison of the Transpatellar, Anteromedial, and Anterolateral Portals

To compare the neurovascular proximity of the transpatellar portal with that of the medial and lateral portals and to determine the safe penetration depth for an all-inside device for use on the posterior horn lateral meniscus. Dissection of the popliteal fossa was performed in 10 cadaveric knees to identify all structures. Arthroscopy was performed using penetration depths of 10, 12, 14, and 16mm with the all-inside system through the anteromedial, anterolateral, and transpatellar portals. Penetrations were made 5 and 10mm lateral to the posterior horn root at the meniscocapsular junction. Needle-tip distances were measured from the popliteal artery and vein, tibial nerve, and common peroneal nerve. Among 240 trials, the average distance to the popliteal neurovascular bundle using the medial, transpatellar, and lateral approaches was 6.9mm, 6.5mm, and 3.1mm, respectively. The transpatellar-portal needle had a larger distance from the neurovascular bundle than the lateral portal (P= .001), with no statistical difference compared with the medial portal (P= .58). Compared with the position at a 10-mm distance from the root, the position at a 5-mm distance from the root was closer to the neurovascular bundle in all approaches (P= .001). The transpatellar approach set to 14mm had a 5% rate of capsular underpenetration and 10% rate of gastrocnemius penetration. The transpatellar and medial portals had no neurovascular penetrations, whereas the lateral approach had a 14% rate of penetration (P < .05). The transpatellar portal and anteromedial portal are in less proximity to the neurovascular bundle compared with the anterolateral portal for all-inside meniscal repair of the posterior horn lateral meniscus. Low rates of neurovascular penetration, gastrocnemius muscle penetration, and capsular underpenetration occurred with a depth setting of 14mm. This study shows the utility of medial and transpatellar portals when using all-inside devices to repair posterior horn lateral meniscal tears and neurovascular proximity based on penetration depth.

DEFINING A SAFE ZONE FOR ALL INSIDE LATERAL MENISCUS REPAIRS IN PEDIATRIC PATIENTS: A MAGNETIC RESONANCE IMAGING STUDY

Purpose All-inside posterior horn lateral meniscal (PHLM) repair puts the popliteal neurovascular bundle (PVNB) at risk of injury by meniscal repair devices. The purpose of this study was to establish a safe zone of all-inside meniscal fixation in pediatric patients using MRI measurements between the popliteus tendon (PT) and popliteal neurovascular bundle (PNVB). We hypothesize that males and older age groups will have a larger distance between PT and PNVB. Methods Axial MRIs of 250 pediatric (5-16 yrs.) patients were retrospectively reviewed. Patients were grouped by age: group I (5-7yrs.): 61; II (8-10yrs.): 59; III (11-13yrs.): 60; IV (14-16yrs.): 70. At the level of the lateral meniscus, two lines starting at the lateral patella tendon border ending at the medial edge of the PT (D1) and the lateral edge of the PNVB (D2) were made on an axial knee MRI. D3 connected D1 to D2 at the meniscocapsular junction of the PHLM. D4 was derived geometrically, parallel and 8 mm anterior to D3 simulating the anterior edge of the PHLM. Results Analysis showed significant correlation between age and sex for D3 (p&lt;0.0001). For D3, there were significant differences among all age groups, except between groups III and IV. Average (STD) D3 for age groups was: 14.1mm(3.1), 15.8(2.5), 17.0(3.3), 17.2(3.1). For D4, the average (STD) was: 11.9 mm(2.9); 13.9(2.5); 15.4(3.0); 15.2(2.9). There was significant difference in D3 and D4 in males versus females (17.6 vs 15.7 mm; p &lt;0.001; 14.9 vs 13.2; p &lt;0.001), particularly in III and IV (17.0 vs 13.8 and 16.8 vs 13.9). Conclusions This study provides normative data of the distance between popliteal neurovascular bundle and popliteus tendon at the meniscocapsular junction (D3) and anterior edge of the posterior horn lateral meniscus (D4) with the knee in full extension. Combined with previous studies showing the addition of knee flexion increases the distance between the meniscus and the neurovascular bundle, surgeons can use this data to improve safety of posterior horn lateral meniscus repair in pediatric patients.

Defining a Safe Zone for All-Inside Lateral Meniscal Repairs in Pediatric Patients: A Magnetic Resonance Imaging Study

To establish a safe zone for all-inside meniscal fixation in pediatric patients by use of magnetic resonance imaging (MRI) measurements between the popliteal tendon (PT) and popliteal neurovascular bundle (PNVB). Patients aged 5 to 16years with normal or nearly normal knee MRI scans were included. They were grouped by age: group I, 5 to 7years (n= 61); group II, 8 to 10years (n= 59); group III, 11 to 13years (n= 60); and group IV, 14 to 16years (n= 70). At the level of the lateral meniscus, 2 lines starting at the lateral patellar tendon border and ending at the medial edge of the PT (D1) and the lateral edge of the PNVB (D2) were made on an axial knee MRI scan. A third line (D3) connected D1 to D2 at the meniscocapsular junction of the posterior horn of the lateral meniscus (PHLM). A fourth line (D4), derived geometrically, was parallel and 8mm anterior to D3, simulating the anterior edge of the PHLM. Axial MRI scans of 250 pediatric patients (aged 5-16years) were retrospectively reviewed. Analysis showed significant correlation between age and sex for D3 (P < .0001). For D3, there were significant differences among all age groups, except between groups III and IV. The average D3 by age group was 14.1mm (standard deviation [SD], 3.1mm) for group I, 15.8mm (SD, 2.5mm) for group II, 17.0mm (SD, 3.3mm) for group III, and 17.2mm (SD, 3.1mm) for group IV. The average D4 was 11.39mm (SD, 2.6mm), 13.24mm (SD, 2.24mm), 14.59mm (SD, 2.89mm), and 14.80mm (SD, 2.79mm), respectively. There were significant differences in D3 and D4 in male versus female patients (17.6mm vs 15.7mm, P < .001, and 14.9mm vs 13.2mm, P < .001, respectively), particularly in groups III and IV (17.0mm vs 13.8mm and 16.8mm vs 13.9mm, respectively). This study provides normative data of the distance between the PNVB and PT at the meniscocapsular junction (D3) and anterior edge of the PHLM (D4) with the knee in full extension. Combined with previous studies showing that the addition of knee flexion increases the distance between the meniscus and the neurovascular bundle, these data can be used by surgeons to improve the safety of PHLM repair in pediatric patients. Level III, diagnostic study of nonconsecutive patients.

Evaluating the risk of popliteal artery injury in the all-inside meniscus repair based on the location of posterior meniscal lesions.

The 'all-inside' meniscus repair is extremely useful technique in addressing tears at the far posterior horn of meniscus. However, this procedure may place the popliteal neurovascular bundle at risk of injury. The purpose of this study was to evaluate the risk of popliteal artery injury by the trajectory of anchor delivery instruments inserted through standard knee arthroscopic portals for the repair of the far posterior horn of meniscus tears. Standard arthroscopic portals were marked on five human cadaveric knees which were subsequently disarticulated. Axial photographs were taken after marking the 5 10, and 15 mm points from the meniscal root on the posterior horns of the menisci. The unsafe zones for meniscus repair at each of these points were identified on the photographs of knees by first drawing two lines from the edges of the popliteal artery and crossing at the respective points at the posterior horns. The points at which these lines meet a circular protractor applied to the center of each meniscus in the knee photograph were recorded as a range. The range signifies the unsafe zone for each respective point on the posterior horn of meniscus. The anterolateral arthroscopic portal fell within the unsafe zone of the 5 mm point on the posterior horn of lateral meniscus in three of the five knees and within the unsafe zone of the 10 mm point on the posterior horn of lateral meniscus in another two knees. A cautious approach should be practiced during the repair of tears located at these two points. None of the other points' unsafe zones (lateral 15 mm, medial 5 mm, 10 mm and 15 mm points) coincided with the ipsilateral portal sites. Level of evidence 5 (Human cadaveric study).

Posterior Approaches to the Tibial Plateau

Modern concepts regarding the fixation of tibial plateau fractures increasingly recognized the importance of reduction and stable fixation of posterior fragments. As such, there have been a multitude of approaches described to access the posterior cortical surface. Due to the proximity of the popliteal neurovascular bundle and common peroneal nerve, all approaches balance dissection of neurovascular structures with achievable surgical exposure, and thus when selecting an approach, the surgeon must assess the risk of the desired exposure with the potential benefit. Although there are many variations in position and incision placement, five anatomical intervals are used for treatment of posterior tibial plateau fractures:

Popliteal neurovascular bundle is safe during inside-out repair of medial meniscus without a safety incision.

There is a theoretical risk of injury to neurovascular structures during inside-out meniscal repair without a safety incision, although there are limited studies assessing this risk. This simulation study on archival MRI films was performed to assess the risk for the popliteal neurovascular bundle and the peroneal nerve during passage of needles for inside-out meniscus repair without a "safety incision", thereby defining a "safe zone" of the menisci that can be safely repaired using this technique. Archival MRI scans (n = 50) were retrieved and axial sections through the menisci were used for simulation. The needle passage was simulated for different points on the posterior horn and body of lateral and medial menisci at "half-hour" intervals using clock method (15° intervals) with three different portals and two different needle cannulas, resulting in six different scenarios of needle passage for each point on the meniscus. The distance of the needle in each scenario was measured from popliteal vessels (n = 50) and peroneal nerve (n = 10). The value "mean-3SD" was calculated for positive means and "Mean + 3SD" was calculated if the mean was negative. An additional 2mm was defined as "safe distance". Thus, simulation models in which the mean - 3SD was less than 2mm (or mean + 3SD was greater than - 2mm for negative means) were labelled as "unsafe". Needle passage through medial meniscus at and medial to 1 o'clock position for a right knee (or 11 o'clock position for a left knee) was safe, irrespective of the portal and needle type. For the lateral meniscus, only the equatorial region was found to be safe with this method. The popliteal neurovascular bundle is safe during the inside-out medial meniscal repair without a safety incision. For the terminal-most part of the posterior horn, the AM portal and the straight cannula should be avoided. However, this method without safety incision cannot be recommended for lateral meniscus because of the risk to the popliteal vessels and the peroneal nerve. Instead, the inside-out method with a safety incision, or an all-inside method should be used for lateral meniscus. III.

Bakers Cyst Occurrence Following Arthroscopic Medial Meniscal Debridement in a Recreational Athlete: Some Potential Indications for Ultrasound Guided Needle Aspiration

Objectives: Though identification of underlying anatomical causation and surgical management of is the mainstay of treatment, needle aspiration with or without injection of corticosteroid is a common conservative management for enlarged and painful Baker's cysts (BC). This report explores some of the circumstances in which ultra-sound guided BC aspiration may be a first-line option. Methods: A 46 year-old recreational athlete developed marked posterior knee pain and swelling several years after arthroscopic medial meniscal debridement. Needle aspiration of a large & symptomatic BC was performed under ultrasound guidance, and the patient commenced rehabilitation. Results: Posterior knee pain completely abated post procedure. Increased knee joint flexion, and squatting was sustained, without cyst recurrence on 6 month follow-up. Conclusion: Ultrasound-guided aspiration of painful or enlarged Bakers cyst may have sustained benefits after knee arthroscopy in the older athlete, particularly in cases when no further surgery is indicated or planned. Diagnostic ultrasound differentiates BC from other types of masses, provides real-time dynamic visualization of the popliteal neurovascular bundle, guides needle placement, and helps to insure complete BC aspiration, accurate injection, and fenustration. BC aspiration, may also be indicated in cases of operative delay, comorbidities contraindicating surgery, to facilitate rehabilitation, or when the underlying causation of BC is indeterminate. Large cysts causing neurovascular compression may require more emergent aspiration. As this case report illustrates, symptomatic relief and functional improvements may be sustained for several months.

Ultrasound in diagnosis of nontraumatic lower extremity pain syndromes: Case report

Introduction. Musculoskeletal impairment is the most prevalent impairment in people over 65. The spine involvement is the most frequently reported. However, common regional pain syndromes usually arise from undefined mechanical, musculoskeletal or soft tissue disturbances. Use of imaging methods is becoming a mandatory tool in the clinical practice in order to achieve the prompt and accurate disease definition. Case report. The Caucasian 79-year-old-male patient attended with the history of an acute, piercing pain along the postero-medial side of the right Achilles tendon and the medial side of the right sole. According to the spine magnetic resonance imaging, X-rays and electrodiagnostic studies, diagnoses of the radicular, neurogenic pain and plantar fasciitis was suspected. However, the popliteal groove ultrasound assessment revealed the presence of hypertrophied semimembranosus- gastrocnemius bursa, compressing the popliteal neurovascular bundle. Conclusion. In patients with a symptomatology of peripheral neuropathy, use of imaging techniques such as ultrasound may be essential for accomplishing patients’ diagnostic approach.