Lateral Portals Research Articles

Lateral Knee Compartment Portals: A Cadaveric Study Defining a Posterolateral Viewing Safety Zone

This study attempted to define a reproducible "safe zone" based on extra- and intra-articular knee anatomy for placing one or 2 accessory portals in the lateral tibiofemoral compartment for posterolateral region viewing. Standard portals were created in 10 cadaveric knees to enable posterolateral region arthroscopic lateral tibiofemoral joint compartment viewing. After identifying the lateral knee surface tissue "soft spot," an accessory posterolateral portal (A) was created using an 18-gauge spinal needle and 4-mm cannula under direct visualization of a 70° arthroscope through the anteromedial portal. A second accessory portal (B) was then created 1cm posterior and 1cm superior to portal A. Accessory portal locations were measured relative to capsular fold and popliteus tendon locations. Distances from the peroneal nerve, lateral collateral ligament, popliteus tendon, and the biceps tendon were determined. Statistical analysis compared portal location differences from key anatomical structures (P < .05). Accessory portal A (mean ± 95% confidence interval) was located 8.8 ± 2.7mm from the popliteus tendon, 11.6 ± 2.7mm from the lateral collateral ligament (LCL), 26.8 ± 2.3mm from the peroneal nerve, and 4.9 ± 2.5mm from the biceps tendon. Accessory portal B was located 17.3 ± 2.8mm from the popliteus tendon, 20 ± 2.8mm from the LCL, 30.3 ± 3.3mm from the peroneal nerve, and 7.0 ± 4.8mm from the biceps tendon. Accessory portal B was located a greater distance from the LCL and the popliteus tendon than portal A (P < .0001). Using intra- and extra-articular anatomic landmarks, both accessory portals could be safely placed in the lateral tibiofemoral joint compartment to enable posterolateral region viewing. Accessory portals used individually or in combination may enable easier posterolateral region viewing for arthroscopic repair of lateral tibiofemoral compartment structures. Lateral tibiofemoral compartment portals can be safely created to enable improved visibility for complex arthroscopic procedures in the posterolateral viewing region.

Functional organization of cytoplasmic portals controlling access to the cystic fibrosis transmembrane conductance regulator (CFTR) chloride channel pore

The cystic fibrosis transmembrane conductance regulator (CFTR) is a Cl- channel that apparently has evolved from an ancestral active transporter. Key to the CFTR's switch from pump to channel function may have been the appearance of one or more "lateral portals." Such portals connect the cytoplasm to the transmembrane channel pore, allowing a continuous pathway for the electrodiffusional movement of Cl- ions. However, these portals remain the least well-characterized part of the Cl- transport pathway; even the number of functional portals is uncertain, and if multiple portals do exist, their relative functional contributions are unknown. Here, we used patch-clamp recording to identify the contributions of positively charged amino acid side chains located in CFTR's cytoplasmic transmembrane extensions to portal function. Mutagenesis-mediated neutralization of several charged side chains reduced single-channel Cl- conductance. However, these same mutations differentially affected channel blockade by cytoplasmic suramin and Pt(NO2)42- anions. We considered and tested several models by which the contribution of these positively charged side chains to one or more independent or non-independent portals to the pore could affect Cl- conductance and interactions with blockers. Overall, our results suggest the existence of a single portal that is lined by several positively charged side chains that interact electrostatically with both Cl- and blocking anions. We further propose that mutations at other sites indirectly alter the function of this single portal. Comparison of our functional results with recent structural information on CFTR completes our picture of the overall molecular architecture of the Cl- permeation pathway.

Arthroscopic Chondral Debridement Using Radiofrequency Ablation for Patellofemoral Compartment Pathology

The purpose of this Technical Note is to introduce a surgical technique using a fluid pressure pump, mid-lateral portal, and radiofrequency ablation for visualization, assessment, and subsequent, accurate/adequate removal of patellofemoral articular lesions for the treatment of patellofemoral compartment pathology. With the patient in the supine position, and an inflated thigh tourniquet, standard lateral and medial portals are made. The medial-femoral compartment, notch, lateral-femoral compartment, and patellofemoral compartments are assessed. If pathology is seen within the patellofemoral compartment, a mid-lateral portal is made if chondral pathology cannot be addressed thoroughly. Addressing chondral pathology to achieve chondral stability is then performed using a combination of the radiofrequency ablator and chondrotome. This technique provides greater visibility and access to accurately and thoroughly smooth chondral pathology.

Arthroscopic Arthrodesis of the Lesser Ray Tarsometatarsal Joints: 2-Portal Technique

Tarsometatarsal (Lisfranc) destruction of the tarsometatarsal articulation of the lesser rays is most commonly due to midfoot Charcot neuroarthropathy. Tarsometatarsal arthrodesis is indicated when conservative management cannot relieve the symptoms. The purpose of this Technical Note is to describe a minimally invasive approach of arthroscopic arthrodesis of the destructed lesser ray tarsometatarsal joints. The arthroscopic procedure is performed through the lateral and P1-2 Lisfranc portals. It has the advantages of better cosmesis, less wound complication, less bone resection, and more thorough joint debridement. However, it is contraindicated if there is associated significant foot deformity or shortening of the lesser foot rays.

Modified Anterolateral Portals in Elbow Arthroscopy: A Cadaveric Study on Safety

To evaluate the proximity to the radial nerve on cadaveric specimens of 2 modified anterolateral portals used for elbow arthroscopy. Ten fresh cadaveric elbow specimens were prepared. Four-millimeter Steinman pins were inserted into 3 anterolateral portal sites in relation to the lateral epicondyle: (1) the standard distal anterolateral portal, (2) a modified direct anterolateral portal, and (3) a modified proximal anterolateral portal. These were defined as follows: direct portals 2cm directly anterior to the lateral epicondyle, and proximal portals 2cm proximal and 2cm directly anterior to the lateral epicondyle. Each elbow was then dissected to reveal the course of the radial nerve. Digital photographs were taken of each specimen, and the distance from the Steinman pin to the radial nerve was measured. The modified proximal anterolateral and direct anterolateral portals were found to be a statistically significant distance from the radial nerve compare to the distal portal site (P= .011 and P= .0011, respectively). No significant difference was found in the proximity of the radial nerve between the modified proximal and direct anterolateral portals (P= .25). Inadequate imaging was found at a single portal site for the proximal site; 9 specimens were used for analysis of this portal with 10 complete specimens for the other 2 sites. In cadaveric analysis, both the modified proximal and direct lateral portals provide adequate distance from the radial nerve and may be safe for clinical use. In this study, the distal anterolateral portal was in close proximity of the radial nerve and may result in iatrogenic injury in the clinical setting. This is a cadaveric analysis of 2 modified portal locations at the anterolateral elbow for use in elbow arthroscopy. Further clinical studies are needed prior to determining their absolute safety in comparison to previously identified portal sites.

Arthroscopic Removal of Proximal Humerus Plates in Chronic Post-traumatic Shoulder Stiffness

Proximal humerus fracture fixation may be complicated by persistent postsurgical stiffness or implant-related problems. Arthroscopic plate removal is a cosmetic and functionally beneficial procedure; however, the procedure is technically difficult in the presence of severe subdeltoid scarring. The technique described here shows an arthroscopic subdeltoid adhesiolysis and proximal humerus plate removal using systematic access to 5 regions of screw positions on the plate. After initial glenohumeral adhesiolysis, a thorough subacromial and subdeltoid bursectomy is performed. The axillary nerve and deltoid are retracted via an anterosuperolateral portal, and a posterolateral portal is used for panoramic viewing along the plate length. Lateral portals are placed above and below the axillary nerve, and these are used for screw removal. Finally, the plate is removed via a 1-inch incision along the previous surgical scar. The technique is cosmetic and minimally invasive, and early rehabilitation restores range of motion and strength. Technical tips for safe dissection in the scarred subdeltoid space and guidelines for protection of neurovascular structures are presented.

Effectiveness of arthroscopic debridement and release for post-traumatic arthritis of subtalar joint

To evaluate the effectiveness of arthroscopic debridement and release for post-traumatic arthritis of subtalar joint. Between January 2011 and December 2014, 14 cases of post-traumatic arthritis of the subtalar joint underwent arthroscopic debridement and release, and the clinical data were retrospectively analyzed. All patients were male, aged 42 years on average (range, 32-62 years). Calcaneus fracture was caused by falling from height; 8 cases received conservative treatment and the other 6 cases received open reduction and internal fixation. The mean interval from injury to operation was 3.4 years (range, 2-7 years). The arthroscopic debridement and release were performed through lateral portals. The injury degree of articular cartilage was classified as grade 3 in 4 cases and grade 4 in 10 cases based on Outerbridge rating. The degree of pain was assessed by visual analogue scale (VAS) and the function of joint was assessed by the American Orthopaedic Foot & Ankle Society (AOFAS) Ankle Hindfoot Scale. All incisions healed by first intention and no complication occurred. The follow-up time was 18 months. Pain was relieved obviously; VAS was significantly decreased to postoperative 3.8±0.9 at 18 months from preoperative 7.7±1.2 ( t=9.728, P=0.000), and AOFAS Ankle Hindfoot Scale was significantly increased to postoperative 59.1±8.8 from preoperative 37.6±8.2 ( t=6.688, P=0.000). During follow-up, no patient was given arthrodesis and no worsened sign was found on the postoperative CT and MRI. Arthroscopic debridement and release for post-traumatic arthritis of the subtalar joint can relieve clinical symptoms and delay subtalar arthrodesis.

Retropatellar Accessory Portals for Improved Access to the Patella: Anatomic Description and Evaluation of Safety.

Background:Standard knee arthroscopy portals are frequently used to address retropatellar chondral pathology. Alternative portals may offer a safe and simple substitute, particularly when reaching the base of deep lesions is required.Purpose:To describe and assess the safety of accessory retropatellar portals.Study Design:Descriptive laboratory study.Methods:An anatomic study was performed on 10 fresh-frozen cadaveric knees. Medial and lateral retropatellar portals were created, and the distance to adjacent neurovascular structures (common peroneal nerve [CPN] and infrapatellar branch of the saphenous nerve [IPBSN]) and bony landmarks (medial and lateral epicondyles and margins of the midpatella) was recorded. A clinical account of portal use is provided through a retrospective chart review.Results:The medial and lateral retropatellar portals were a mean 15.8 ± 15.5 mm and 53.8 ± 7.2 mm from the IPBSN and CPN, respectively. No nerves were contacted in any specimens. Clinically, the portals have been used in 109 cases over a 7-year period without complication.Conclusion:The high level of IPBSN variability poses some risk to medial portal use; however, there is little to no risk laterally. Clinical experience with portals suggests that they can be used safely. We recommend careful blunt dissection to minimize chance of iatrogenic nerve injury.Clinical Relevance:Retropatellar portals may offer improved access to chondral lesions of the patella, thereby safely allowing one to maintain an arthroscopic approach.

Arthroscopic subtalar arthrodesis

Arthroscopic subtalar arthrodesis is gaining in popularity based on evidence of bone fusion in over 90% of cases, with a shorter time to healing, a simpler postoperative course, and fewer complication compared to open surgery. Two arthroscopic techniques have been reported: one with the patient in lateral decubitus and lateral portals and the other with the patient prone and posterior portals. The objective of this technical note is to describe these two techniques, with emphasis on the specific characteristics of each.

Arthroscopic “Panorama” View of the Subacromial Space via Deltoid Fascia Release

Proper visualization is of paramount importance during arthroscopic rotator cuff repair. We propose a technique that significantly improves the visualization of the rotator cuff when viewing from the anterolateral or lateral portals. This “panorama” view is obtained by a release of the deep layer of the deltoid fascia, which in turn increases the space between the humerus and the deltoid muscle. This release increases the volume of the subdeltoid bursa, secondarily increasing the field of view of the subacromial space with the camera viewing from the anterolateral or lateral portals. This technical note describes a new technique useful in obtaining an excellent view of the subacromial space proving very useful in both the diagnosis and treatment of rotator cuff pathology.

Rotator Cuff Tear Shape Characterization

Objectives:Proper surgical planning requires accurate and reliable pre-operative patient information. The more comprehensive the data, the more the surgeon can tailor a general surgical technique to an individual patient’s unique anatomy. A previous retrospective study demonstrated that three-dimensional magnetic resonance imaging more accurately characterized rotator cuff tears compared to two-dimensional images when checked against intra-operative pictures. The purpose of this study was to determine if three-dimensional MRI imaging would continue to be more accurate than two-dimensional imaging in a prospective study.Methods:Patients were prospectively included if they had a full-thickness primary rotator cuff tear on pre-operative MRI. Intra-op videos were taken from the posterior and lateral portals, with a grasper fully mobilizing the torn tendon in each view. 7 surgeons then reviewed the videos and independently characterized the shape of the tears into crescent, U-shaped tears, L-shaped tears, or massive tears. This was considered the gold-standard. Two musculoskeletal radiologists reviewed the corresponding MRI studies independently and blind to the arthroscopic findings and characterized the shape on the basis of the tear’s retraction and size 2D MRI. The 3D reconstructions of each cuff tear were reviewed by each radiologist to characterize the shape. Statistical analysis included 95% confidence intervals and fleiss’s kappa.Results:37 patients were enrolled in the study. Among the 7 surgeons, agreement on cuff tear was 93% ( =.87). The accuracy for differentiating between crescent-shaped, longitudinal, and massive tears using measurements on 2D MRI was 73.4% for reader 1 and 71.2% for reader 2. The accuracy for tear shape characterization into crescent and longitudinal U- or L-shaped using 3D MRI was 92% for reader 1 and 94% for reader 2. When further characterizing the longitudinal tears as massive or not using 3D MRI, both readers had an accuracy of 83%. The overall accuracy of 3D MRI was 91%, significantly different (P=.07) from 2D MRI accuracy (70.4).Conclusion:Our study has demonstrated that 3D MR reconstructions of the rotator cuff improve the accuracy of characterizing rotator cuff tear shapes compared with current 2D MRI-based techniques.

Portal placement in elbow arthroscopy by novice surgeons: cadaver study.

In this anatomical cadaver study, the distance between major nerves and ligaments at risk for injury and portal sites created by trainees was measured. Trainees, inexperienced in elbow arthroscopy, have received a didactic lecture and cadaver instruction prior to portal placement. The incidence of iatrogenic injury from novice portal placement was also determined. Anterolateral, direct lateral, and anteromedial arthroscopic portals were created in ten cadavers by ten inexperienced trainees in elbow arthroscopy. After creating each portal, the trajectory of the portal was marked with a guide pin. Subsequently, the cadavers were dissected and the distances between the guide pin in the anterolateral, direct lateral, and anteromedial portals and important ligaments and nerves were measured. The difference between the distance of the direct lateral portal and the posterior antebrachial cutaneous nerve (PABCN) (22mm, p<0.001), the lateral antebrachial cutaneous nerve (4.0mm, p<0.001), and the radial nerve (25mm, p<0.001) was different from the average reported distances in the literature. A difference was found between the distance of the anterolateral portal and the PABCN (32mm, p<0.001) compared to previous studies. Three major iatrogenic complications were observed, including: laceration of the posterior bundle of the medial ulnar collateral ligament, lateral ulnar collateral ligament midsubstance laceration, and median nerve partial laceration. Surgeons increasingly consider arthroscopic treatment as an option for elbow pathology. In the present study a surgical complication rate of 30% was found with novice portal placement during elbow arthroscopy. Furthermore, as the results from this study have indicated, accurate, precise, and safe portal placement in elbow arthroscopy is not easily achieved by didactic lecture and cadaver instruction session alone. Level of evidence V.

Neurovascular Structures at Risk During Anterolateral and Medial Arthroscopic Approaches of the Hip

To describe the safety areas for placement of 5 anterolateral portals (anterior, anterior lateral, posterior lateral, proximal anterior medial and distal anterior medial portals) and 3 recently described medial portals (anterior medial, posterior medial and distal posterior medial portals) to provide topographical description of the safety of each. A descriptive, observational and crosssectional study in which femoral triangle dissection was performed in 12 hips. 5 lateral portals and the 3 medial portals were placed. Clinically relevant neurovascular structures associated with each portal, were identified measured and documented. The lateral portal with the highest risk of injury to a nearby neurovascular structure was the anterior portal, the most adjacent to the femoral cutaneous nerve, 1.42 cm (±0.85) lateral to the portal. In the medial portals, the anterior medial portal has the narrowest margin in relation to the femoral artery, 2.14 cm (±0.35) lateral to the portal and medial to the obturator nerve by 0.87 cm (±0.62). The lateral portals have a higher safety margin; the portal with the most proximity to a neurovascular structure is the anterior portal, associated laterally with the femoral cutaneous nerve, presenting a higher risk of injury. Medial portals have a higher risk of injuring the femoral neurovascular bundle as well as the obturator nerve.

Accuracy of Needle Placement into the Intra-Articular Space of the Knee in Osteoarthritis Patients for Viscosupplementation.

Knee osteoarthritis is characterized by inflammation in the intra-articular space or synovial membrane, breakdown of articular cartilage, and sclerosis of the subchondral bone. Intra-articular injections of Sodium hyaluronate which have viscoelastic and protective effect on articular cartilage and restores normal articular homeostasis. The efficacy of these injections is diminished when they are placed inadvertently outside the joint. For the maximum benefit, injection of hyaluronic acid derivatives needs to be placed accurately into the knee joint. The study was performed to know the correct placement of needle inside the knee joint prior to Viscosupplementation by fluoroscopy using a contrast material. The accurate placement of needle was evaluated in a prospective series of 94 consecutive injections in patients without clinical knee effusion. All the injections were performed by single orthopaedic surgeon using a 5 cm 21-gauge needle through anterolateral, and lateral midpatellar portals. The needle placement in the knee joint was confirmed with fluoroscopy using the contrast material. The accuracy rates through Lateral midpatellar and Anterolateral portals were lower than expected rate (100%). A total of 43 out of 47 injections were intra-articular, indicating accuracy of 91.5% through lateral midpatellar portal, 41 out of 47 injections were intra-articular through anterolateral portal with accuracy of 87.4%. Study showed that the accuracy of needle placement was higher through Lateral midpatellar than the Anterolateral portal.

Variation in the shape of the tibial insertion site of the anterior cruciate ligament: classification is required.

To propose a classification system for the shape of the tibial insertion site (TIS) of the anterior cruciate ligament (ACL) and to demonstrate the intra- and inter-rater agreement of this system. Due to variation in shape and size, different surgical approaches may be feasible to improve reconstruction of the TIS. One hundred patients with a mean age of 26±11years were included. The ACL was cut arthroscopically at the base of the tibial insertion site. Arthroscopic images were taken from the lateral and medial portal. Images were de-identified and duplicated. Two blinded observers classified the tibial insertion site according to a classification system. The tibial insertion site was classified as type I (elliptical) in 51 knees (51%), type II (triangular) in 33 knees (33%) and type III (C-shaped) in 16 knees (16%). There was good agreement between raters when viewing the insertion site from the lateral portal (κ=0.65) as well as from the medial portal (κ=0.66). Intra-rater reliability was good to excellent. Agreement in the description of the insertion site between the medial and lateral portals was good for rater 1 and good for rater 2 (κ=0.74 and 0.77, respectively). There is variation in the shape of the ACL TIS. The classification system is a repeatable and reliable tool to summarize the shape of the TIS using three common patterns. For clinical relevance, different shapes may require different types of reconstruction to ensure proper footprint restoration. Consideration of the individual TIS shape is required to prevent iatrogenic damage of adjacent structures like the menisci. III.

Anatomic Feasibility Study of Posterior Arthroscopic Tibiotalar Arthrodesis.

Operative indications for an anterior arthroscopic tibiotalar arthrodesis are well defined. A posterior approach with the patient in a prone position may be indicated when the anterior approach is precluded by the soft tissue condition or for a 1-step procedure associated with posterior approach subtalar fusion. An anatomic study assessed the feasibility of posterior arthroscopic tibiotalar fusion and sought to determine arthroscopy entry points, mortise cartilage freshening quality, and the risk of osseous, tendinous, vascular, and neural complications. Twenty-two zones of the fibular tibiotalar mortise were mapped from 10 specimens. Medial and lateral para-Achilles arthroscopic portals were used with a 4 mm 30-degree arthroscope. Chondral resection was performed with a motorized burr, curette, and osteotome. The entire plafond of the tibia could be debrided in all cases, whereas the talar dome was debrided in its entirety in 20% of cases; in 80%, only the posterior two-thirds could be treated with the anterior portion approaching the neck of the talus being poorly accessible. More than 50% of the area of the malleolar grooves was debrided. There was 1 medial malleolar fracture and 1 peroneal artery lesion. The technique was shown to be feasible if there was no frontal hindfoot deformity or tibiotalar equinus preventing satisfactory resection of the posterior and anterior talar cartilage. This study demonstrated that a posterior approach arthroscopic ankle fusion would lead to adequate joint preparation. This procedure reduces the risk of nerve damage.

Peroneus Longus Tendoscopy at the Sole: A Cadaveric Study

The aim of this study was to investigate the safety of tendoscopy of the peroneus longus (PL) at the sole in a cadaveric model. Twelve fresh-frozen foot and ankle specimens were used. The locations of the plantar medial and plantar lateral portals were studied. The relationships of the medial and lateral plantar nerves to the tendon sheath of the PL at the sole were also studied. The plantar lateral portal was located on average 11 mm (6 to 16 mm) proximal and 9 mm (6 to 15 mm) plantar to the fifth metatarsal styloid. The plantar medial portal was located on average 1 mm (12 mm proximal to the joint to 7 mm distal to the joint) proximal to the first tarsometatarsal joint. The lateral plantar nerve touched the PLT sheath in 8 specimens. The nerve was separated from the tendon sheath by a thin layer of muscle in 4 specimens. The medial plantar nerve was separated from the tendon sheath of the PL by the flexor digitorum longus and flexor hallucis longus tendons in all specimens. Tendoscopy of the PL at the sole of the foot is described; however, the lateral plantar nerve can be at risk and the tendoscopy should be performed with caution. This cadaveric study provides the anatomic basis of the PL tendoscopy of the sole.

Arthroscopic Treatment of Suprascapular Neuropathy from a Suprascapular Notch Cyst Using a Lateral Subacromial Approach

We describe a safe surgical technique for arthroscopic decompression of a suprascapular notch cyst in the setting of compressive suprascapular neuropathy. Position the patient in the standard beach-chair position. Palpate and mark the subcutaneous landmarks of the shoulder in preparation for later arthroscopy. Create standard anterior and posterior portals for glenohumeral visualization. Establish accessory superior and lateral portals and transition to a lateral viewing portal to perform suprascapular notch decompression. Establish a G Portal and release the transverse scapular ligament using arthroscopic scissors. Perform arthroscopic lavage of the subacromial space and glenohumeral joint and close arthroscopic portals. As suprascapular nerve entrapment is a relatively rare entity, with only a limited number of studies from which to draw conclusions regarding the outcomes of arthroscopic suprascapular nerve release, Shah et al. recently reported on their results in twenty-four patients using this surgical technique.IndicationsContraindicationsPitfalls & Challenges.

X-ray structure of the mouse serotonin 5-HT3 receptor.

Neurotransmitter-gated ion channels of the Cys-loop receptor family mediate fast neurotransmission throughout the nervous system. The molecular processes of neurotransmitter binding, subsequent opening of the ion channel and ion permeation remain poorly understood. Here we present the X-ray structure of a mammalian Cys-loop receptor, the mouse serotonin 5-HT3 receptor, at 3.5Å resolution. The structure of the proteolysed receptor, made up of two fragments and comprising part of the intracellular domain, was determined in complex with stabilizing nanobodies. The extracellular domain reveals the detailed anatomy of the neurotransmitter binding site capped by a nanobody. The membrane domain delimits an aqueous pore with a 4.6 Å constriction. In the intracellular domain, a bundle of five intracellular helices creates a closed vestibule where lateral portals are obstructed by loops. This 5-HT3 receptor structure, revealing part of the intracellular domain, expands the structural basis for understanding the operating mechanism of mammalian Cys-loop receptors.

Arthroscopic triple fusion joint preparation using two lateral portals: a cadaveric study to evaluate efficacy and safety.

Arthroscopic triple fusion has several advantages over open techniques, but its use has yet to become widespread. Preliminary published techniques use five portals with neurovascular risk. Our aim was to assess the safety and efficacy of an alternative lateral two portal technique. Four cadaveric hindfeet were arthroscopically prepared for a triple fusion using two lateral portals. The distance to relevant subcutaneous nerves was measured as well as the prepared joint surface percentage. Mean distance from mid-lateral portal to the nearest sural nerve branch was 22.3mm (range 20-24mm) and from the dorsolateral portal to the intermediate branch of the superficial peroneal nerve was 7.8mm (range 4-11mm). Mean percentages of joint preparation were 63% (talar head), 62% (navicular), 75% (calcaneum) and 74% (cuboid). Two lateral arthroscopic portals allow adequate joint preparation for triple fusion procedures. The proximity of subcutaneous nerves is important to appreciate when using these portals.