Infrapatellar Branch Research Articles

The Efficacy of Cryoneurolysis on Chronic Pain in Patients with Knee Osteoarthritis; A Double-blinded Randomized Controlled Sham Trial.

The objective was to investigate if cryoneurolysis were superior to sham in reducing pain intensity in patients with chronic knee osteoarthritis. We hypothesized that cryoneurolysis was an effective and safe therapy to reduce chronic pain in patients with knee osteoarthritis. The study was a randomized, double-blind, sham-controlled. Eighty-seven patients with chronic knee osteoarthritis were randomized to either cryoneurolysis or a sham procedure, followed by an exercise program. The target nerves, anterior femoral cutaneous nerve and infrapatellar branch of the saphenous nerve were identified using transcutaneous electrical nerve stimulation and cryoneurolysis was performed ultrasound-guided. The primary outcome was the difference in average pain at 14d post intervention between the cryoneurolysis and sham group. For the intention to treat analysis, no difference was observed for the primary outcome (0.49, 95% CI [-0.3 ; 1.2], p=0.198). Both groups showed a significant reduction in pain scores 14d post intervention (Cryoneurolysis: -1.9, 95% CI [-2.4 ; -1.3], Sham: -1.4, 95% CI [-1.9 ; -0.8]). At 6 months follow-up, a significant reduction in pain was observed in the cryoneurolysis group compared to sham group (1.1, 95% CI [0.3 ; 1.9], p=0.009). Cryoneurolysis was well-tolerated, with minor, transient adverse effects. This study did not show a clinically relevant reduction in pain after intervention comparing cryoneurolysis and sham. Further studies are needed.

Donor Site Morbidity is Higher When Comparing Bone-Tendon-Bone vs 4-Strand Semitendinosus/Gracilis & All-inside 4-Strand Semitendinosus for Anterior Cruciate Ligament Reconstruction.

To study pain and sensory alterations of 75 (three cohorts of 25 patients) patients that underwent different anterior cruciate ligament reconstruction (ACLR) techniques. The cohorts were divided in the bone-patellar tendon-bone (BTB) autograft, the quadruple strand semitendinosus and gracilis (4ST/G) autograft and the all-inside quadruple strand semitendinosus autograft cohort. We conducted a retrospective study to evaluate pain and sensory alterations after surgery. All these patients followed a similar rehabilitation protocol, being 2 years the minimal follow-up time. Pain was characterized by duration and anatomical location and sensory deficits were evaluated concerning duration and affected area. Patients also scored on 3 different subjective tests: Knee Walking Test (KWT); Lysholm Knee Scoring Scale (LKSS) and International Knee Documentation Committee Subjective Knee Form (IKDC-SKF) and were divided according to its Tegner Activity Level Scale (TALS). The mean anterior knee pain (AKP) duration amongst the 3 cohorts was 1.8 ± 4.5 months and was smaller in the 4ST/G cohort. The majority of patients of the BTB cohort located pain on the patellar tendon while patients in the 4ST/G and all-inside cohorts referred that it was diffuse. At 15 days' post-surgery, hypoesthesia was reported by 56% patients and was higher on the BTB cohort and lower in the all-inside cohort. At 2-year follow-up, the all-inside cohort had no patients with hypoesthesia. In the BTB cohort, the sensitive alterations were only located on the area innervated by the infra-patellar branch of the saphenous nerve (IPBSN). The 4ST/G cohort located the hypoesthesia in the area innervated by the IPBSN and in the area of the lateral sural cutaneous nerve (LSCN). The all-inside group located the sensitive alterations mostly in the LSCN. The KWT was painful in BTB and 4ST/G patients and reported 0% for the all-inside cohort. No statistic significant relevance was found for the IKDC-SKF and LKSS. All cohorts referred pain and sensitive alterations. Using BTB autograft for ACLR seems to condition a higher number of anterior knee pain and hypoesthesia on medium post-operative follow-up and KWT was more often reported. The 4ST/G group had the smallest duration of AKP. The all-inside cohort showed, globally, a lower number of complaints and a shorter time of symptom persistence, namely in terms of sensory deficits. III.

Advanced three-dimensional anatomical mapping of saphenous and inferior medial genicular nerve branching: enhancing precision in knee joint denervation.

Radiofrequency ablation is a common non-opioid treatment to manage chronic knee pain. The inferior medial genicular nerve is conventionally targeted. It has been suggested that the infrapatellar branch (saphenous nerve) should also be targeted. There is controversy regarding the contribution of the infrapatellar branch to the innervation of the knee joint capsule. (1) Identify the frequency of the branching pattern(s) of the infrapatellar branch in three-dimensional (3D); (2) Assess spatial relationships of branches of infrapatellar branch to the inferior medial genicular nerve; (3) Determine if capturing infrapatellar branch could result in additional benefit to the existing protocol. Anatomical study. The infrapatellar branch and inferior medial genicular nerve were serially dissected, digitized, and modelled in 3D in 7 specimens (mean age 91.3 ± 6.5; 2F/5M) and their relationship documented. The spatial relationship of the nerves was used to assess the anatomical efficacy of including the infrapatellar branch in the protocol. The infrapatellar branch is most frequently a cutaneous nerve. This nerve was variable and found to be unbranched or have 2-3 branches and in all specimens was located superficial to the branches of inferior medial genicular nerve. When the infrapatellar branch (1) coursed more distally, the strip lesion would not capture the infrapatellar branch but would capture inferior medial genicular nerve consistently; (2) overlapped with the inferior medial genicular nerve, the strip lesion would capture both nerves. Proposed protocol targeting the infrapatellar branch is likely to capture the inferior medial genicular consistently regardless of the anatomical variation of the infrapatellar branch.

The prognosis of iatrogenic saphenous nerve injuries during hamstring tendon harvesting in anterior cruciate ligament reconstruction

PurposeThis study aims to evaluate the long-term outcomes of saphenous nerve (SN) injuries from hamstring tendon harvesting during ACL reconstruction, focusing on clinical results and patient satisfaction after at least two years. Additionally, it investigates the incidence, recovery patterns, and impact of these injuries on functional outcomes, daily activities, and ACL re-rupture rates immediately post-surgery and at final follow-up.Materials and methodsA retrospective review was conducted on patients who had undergone ACL reconstruction with hamstring tendon grafts at a single institution between January 2015 and January 2020. The incidence of SN injuries was assessed immediately after surgery and at final follow-up. Additionally, the recovery rate and time were evaluated, and the impact of these injuries on functional outcomes was measured using the Lysholm Knee Score (LKS) and patient-reported effects on daily activities.ResultsOf the 159 patients analyzed, iatrogenic SN injuries were initially observed in 87 (54.7%) patients post-ACLR. By the final follow-up, paresthesia had resolved in 36 (22.6%) patients within an average of 11.1 months. Persistent SN injuries were recorded in 51 (32.1%) patients, affecting various extents of the infrapatellar branch (IPBSN) and the sartorial branch (SBSN) of the saphenous nerve. Patients with persistent SN injuries experienced a significant impact on daily activities and had lower LKS scores compared to those without injuries or with recovered injuries. Furthermore, a higher re-rupture rate was associated with persistent SN injuries.ConclusionsThe study finds that SN injuries during hamstring graft harvesting for ACL reconstruction are common, with a significant portion of patients experiencing persistent sensory deficits for at least two years postoperatively. These injuries are observed to adversely affect patient satisfaction and functional outcomes and to increase the re-rupture rate.

Eczematous dermatitis of knees after bilateral total knee replacement: a rare cause.

SKINTED (Surgery of the knee, injury to the infrapatellar branch of the saphenous nerve, traumatic eczematous dermatitis) is a form of denervation dermatitis that occurs after total knee replacement (TKR). It is characterised by a delayed onset, localisation lateral to the surgical scar and associated hypoaesthesia. It is important to distinguish SKINTED from hypersensitivity to the implant which can also cause delayed eczematous reactions near the implant site. SKINTED has a good prognosis with resolution in a few months, while hypersensitivity to implant material has been associated with persistent eczema, systemic contact dermatitis and implant failure.

Infrapatellar branch of the saphenous nerve lesion following tibial nailing: it is possible to avoid it?

Iatrogenic injury to the infrapatellar branches of saphenous nerve is a common complication following tibial nailing. This lesion seems to be directly related to the surgical approach adopted for nail insertion. The aim of the present study was to systematically review the current literature in order to assess the eventual superiority of one surgical approach for tibial nailing over the others in limiting the neurological impairment related to infrapatellar branch injury. The available literature was systematically screened searching papers dealing with iatrogenic injury to the infrapatellar branch of saphenous nerve after intramedullary tibial nailing. The terms "Saphenous" and "Infrapatellar branch" were used in combination with "intramedullary nailing" and "tibial fractures", supplying no limits regarding the publication year. Only publications in English were considered. Case reports, technical notes, instructional course, literature reviews, biomechanical and/ or in vitro studies were all excluded. Coleman methodological score was performed in all the retained articles. Four articles matched the inclusion criteria. There were one original article and three retrospective study. Hypoesthesia and a larger extension of the area of sensory-loss were more frequently observed after vertical incision approach in three out of four articles. A trend towards a lower rate of iatrogenic nerve damage using a transverse incision was found in the remaining one, without any statistical significance. In order to avoid infrapatellar nerve lesion, horizontal or oblique incisions or percutaneous approaches should be favored, although in some cases a longitudinal incision is required. Limited-extension incisions could minimize the risk and the incidence of this complication.

Moving a skin incision to lateral side of tibial tubercle reduces the risk of persistent skin numbness compared with a regular midline one: A randomized paired study in bilateral total knee arthroplasty

The midline incision during total knee arthroplasty (TKA) is known to damage the infrapatellar branch of the saphenous nerve (IPBSN), leading to lateral flap numbness. The aim was to evaluate the rate of persistent skin numbness (RSN) and area of skin numbness (AON) after a lateral-based skin incision compared with the standard midline incision in bilateral TKA patients. Thirty-six patients undergoing bilateral TKA were included and randomly assigned to receive the lateral skin incision (lateral side of the tibial tubercle) on one knee and the standard midline incision on the contralateral. All other surgical steps were identical. Primary outcomes were the RSN at 1year and the AON at 6weeks, 3, 6, and 12months postoperatively. Kneeling ability test (KAT), operative time, and length of incision were also recorded. The lateral incision had half the RSN at 12months compared to the midline incision (25% vs 53%; p=0.01). The median AON at 1-year after surgery was 0 [0-0.5] cm2 in lateral incision vs 4 [0-7.5] cm2 in midline group (p<0.001). KAT was minimally better in the lateral group at 110° of kneeling between 6-month to 1-year. Operative time and length of incision were similar between both groups. The lateral skin incision reduced RSN by approximately 50% compared with the midline incision. The AON in lateral incision was 4cm2 smaller than midline at 1-year after surgery. Moving a skin incision more lateral may be considered to minimize the numbness after TKA.

Anatomical Variation of Infrapatellar Innervation Determines Clinical Risk of Infrapatellar Neuropathy

BACKGROUND: Infrapatellar neuropathy arises from traumatic, iatrogenic, or compression injury to the infrapatellar branch (IB) of the saphenous nerve. The risk of infrapatellar neuropathy has been shown to depend on the IB’s anatomical course. The infrapatellar branch of the saphenous nerve (ISBN) has been discovered to take varying courses, and the IB can emerge directly from the femoral nerve. The variety of the IBSN’s courses and the prevalence of cases involving the infrapatellar branch of the femoral nerve (IBFN) call the uniform IB course described in textbooks into question. OBJECTIVES: In this study, we aim to identify sites of IB emergence and their anatomical relations and evaluate them for their risk of neuropathy. STUDY DESIGN: The study is an anatomical prospective pilot study. SETTING: The setting is a single-center cadaveric study performed at the anatomical institute of the Medical University of Vienna. METHODS: Twenty-two anatomical specimens were evaluated for the relationship of their IBs to anatomical risk sites. The subsartorial course, distal sartorial penetration, and the crossing of the medial femoral epicondyle were assessed. The measurements and relations of the IB were determined with callipers and assessed by computational modelling. RESULTS: Nine IBs originated from the saphenous nerve, 11 originated from the femoral nerve, and 2 originated from both. The subsartorial course was most frequent in IBs of saphenous origin. Penetrating and profound distal sartorial relations correlated moderately with emergence type and were highest in the saphenous group. The crossing of the medial femoral epicondyle was the most common relation of IBs that emerged femorally. LIMITATIONS: The study’s limitations were the low number of cadavers to examine and the confining of the exploration of knee extension to anatomical specimens that restricted an inferential analysis. CONCLUSION: Infrapatellar innervation can emerge from the saphenous nerve, the femoral nerve, or a combination of both, and the origin of the innervation determines the clinical risk for infrapatellar neuropathy. While innervation from the IBSN may lead to compression at the subsartorial course, distal sartorial penetration, and the crossing of the medial femoral epicondyle, innervation from the IBFN carries reduced anatomical risk for infrapatellar neuropathy. KEY WORDS: Infrapatellar neuropathy, anatomical variation, infrapatellar innervation, anterior knee pain syndrome, compression syndromes

Rare nerve compression neuropathies

In regard to the complex anatomical relationship of peripheral nerves and muscles, tendons, fasciae as well as their long course within those anatomical structures and additional close contact to bony structures, they are prone to suffer from local compression syndromes. Hence creating a vast majority of entrapment syndromes - well described in literature for almost every single nerve. The purpose of this article is to give an overview of symptoms, signs, diagnostic studies and treatment options, addressing especially the less known syndromes. Compression syndromes of the upper arm and shoulder region include the suprascapular nerve syndrome the compression of the axillary nerve within the spatium quadrilaterale and the compression of the long thoracic nerve at the chest wall. The upper extremity offers a variety of infrequent entrapment syndromes, as the pronator teres syndrome and anterior interosseus syndrome, both resulting from pressure to the median nerve in the forearm. Compression neuropathy in the course of the radial nerve in the distal upper extremity is also known as supinator syndrome. Guyon's canal syndrome is the ulnar side equivalent to the well-known carpal tunnel syndrome. In the case of a Cheiralgia paresthetica, a compression of a sensory branch of the superficial radial nerve can be seen. In the lower extremities, a variety of nerves especially in the groin and thigh area can be compressed as they pass through the narrow spaces between the abdominal muscles or underneath the inguinal ligament. Compression of the lateral femoral cutaneous nerve is the most common syndrome. Compression syndromes of the femoral and obturator nerves are most often iatrogenic. Pain around the knee, especially the lateral part and following orthopedic procedures of the knee, can arise from a compression or a lesion of a small infrapatellar branch of the saphenous nerve. Another probably underdiagnosed syndrome is piriformis syndrome, resulting from an entrapment of the sciatic nerve as it passes through certain muscular structures. In the distal lower extremity, the peroneal and tibial nerves can be compressed at multple sites, clinically known as peroneal nerve paralysis resulting from nerve compression around the fibular head, the anterior and posterior tarsal tunnel syndrome, and Morton's metatarsalgia.

Infrapatellar Branch of the Saphenous Nerve: Therapeutic Approaches to Chronic Knee Pain.

The infrapatellar branch of the saphenous nerve (IPS) is an under-investigated nerve that can be a source of chronic knee pain. This literature review aims to deliver an up-to-date review of chronic pain transmitted via the IPS along with therapeutic approaches available for pain refractory to conservative measures. Knee pain transmitted via the IPS can arise from several etiologies. Damage to the IPS is often iatrogenic and develops following total knee arthroplasty, anterior cruciate ligament reconstruction, and other knee surgical procedures. Other causes of IPS-derived pain include entrapment of the nerve, neuromas, Schwannomas, and pain from knee osteoarthritis transmitted through the IPS.This article investigated therapeutic approaches to pain derived from the IPS. Common approaches included radiofrequency ablation, neuroma excisions, Schwannoma excision, nerve blocks, surgical exploration, surgical release of an entrapped nerve, cryoablation, and peripheral nerve stimulation. Pain scores, duration of pain relief, adverse events, and secondary outcomes were all included in this review. A subset of the patient population experiences chronic pain deriving from the IPS that is refractory to conservative treatment measures. This review aims to evaluate the etiologies and therapeutic approaches for chronic pain arising from the IPS refractory to conservative treatments.

CAN SENSORY DISTURBANCES DUE TO INJURY TO THE INFRAPATELLAR BRANCH OF THE SAPHENOUS NERVE BE PREVENTED BY AN OBLIQUE INCISION?

To evaluate the incidence of injuries to the infrapatellar branch of the saphenous nerve (IPBSN) after anterior cruciate ligament reconstruction (ACLR) with an oblique incision for hamstring graft harvesting. In total, 59 knees (from 57 patients) were evaluated in the follow-up of ACLR for six months. We drew a horizontal line parallel to the ground, passing through the most medial portion of the surgical incision and another, perpendicular to the first, starting at the tibial tuberosity (TT). We measured the length and angle of the cut, the distances from its most medial point to the perpendicular line, and from the TT to the horizontal line. Skin sensitivity was tested with a brush and the altered sensitivity area was measured. Patients were asked about difficulties in activities daily of living (ADL). A total of 27 knees (45.7%) had sensory disorders, which persisted until the sixth postoperative month in 92.6% of them. The ADL were compromised in one knee (3.7%). No significant differences were found between the groups with and without changes in sensitivity regarding age, affected side, incision angle, or measured distances. The incision size was larger in the group without alteration in sensitivity. An oblique incision did not avoid IPBSN injuries. This condition rarely compromised the ADL. Level of Evidence II, Lesser Quality Prospective Study.

Ultrasound assessment of medial crural cutaneous nerve and infrapatellar branch and of the saphenous nerve: establishing a safety zone for preventing nerve injury in knee surgery and injections.

Our study aimed to illustrate the positional relationship of the two branches of the saphenous nerve: the infrapatellar branch of the saphenous nerve (IPBSN) and medial crural cutaneous nerve (MCCN), as well as the anatomical landmarks using high-resolution ultrasound (HRUS) to help prevent iatrogenic nerve injury. We used HRUS to explore the positional relationships among the anatomical landmarks, IPBSN, and MCCN in 40 knees of 20 participants. The distances from these branches to key reference points were recorded. Using the ultrasound caliper mode, we measured the depth from the skin surface to the nerves at four distinct points. The average distances between IPBSN and medial border of patella (MBP) and IPBSN and medial border of patellar ligament (MBPL) were 47 ± 7mm and 42 ± 9mm, respectively. MCCN showed mean distances of 94 ± 9mm and 96 ± 9mm to MBP and MBPL, respectively. The mean distance from the upper edge of pes anserine to IPBSN at the patellar apex (PA) level was 24 ± 10mm and to MCCN was 34 ± 9mm. We used high-resolution ultrasound to evaluate IPBSN and MCCN and their positions relative to anatomical landmarks. The study results offer valuable insights into the course of these nerves, which can help establish a safety zone to prevent accidental nerve injuries during knee surgeries and injections.

A Muscle-Preserving Short Transverse Incision for Unicompartmental Knee Arthroplasty: A Technical Note.

We describe the use of a short transverse incision technique with muscle retention for unicompartmental knee arthroplasty (UKA). The incision is made transversely just above the joint line, followed by a detachment of subcutaneous soft tissue from the underlying capsule and fascia to create a mobile window. The fascia is incised along the medial border of the vastus medialis and the capsule of the suprapatellar pouch is incised laterally, preserving vastus medialis muscle. All procedures are performed within the mobile window while controlling the knee flexion angle. Following implantation, the capsule and fascia are anatomically repaired. This approach was used in 30 consecutive patients who underwent Oxford UKA, including one bi-unicompartmental knee arthroplasty without complications. Importantly, no patients had any disturbances of the infrapatellar branch of the saphenous nerve disturbancessuch as numbness, hyperesthesia, hypoesthesia, or neuroma pain. The transverse approach is thought to be a safe and feasible method for UKA.

Injury of the Infrapatellar Branch of Saphenous Nerve Between Vertical and Oblique Skin Incision in Medial Opening Wedge High Tibial Osteotomy.

The infrapatellar branch of saphenous nerve (IPBSN) has anatomic variations and prone to injury during surgery around the medial side of the knee. High tibial osteotomy is one of the procedures that may be risky to the IPBSN. This research was aimed to establish which skin incision (vertical vs oblique) is less likely to damage to the IPBSN and also to study the anatomy of the IPBSN, with the institutional review board reference (No. LH611054, date 10/1/2020). The primary outcomes are aimed to establish which skin incision (vertical vs oblique) is less damaging to the IPBSN. The secondary outcome is to study about the anatomy of the IPBSN. Twenty-two fresh cadavers (forty-four knees) were dissected by randomisation under the block of four technique, and two different incisions were performed for each knee. Exploration was performed from the skin incision to the IPBSN around the incision zone. If the discontinuity of the nerve was found, it was classified as IPBSN injury. The anatomic measurement was performed. The IPBSN injury between two groups were analysed with the chi-square test. The risk of IPBSN injury in the oblique group was 2 from 22 knees (9.1%), and 12 knees from 22 knees (54.5%) in the vertical group (P=0.001). Most common number of branch(es) found, is one branch, the horizontal distance ranged from 2.6cm to 8.5cm (average 5.7±1.6), the vertical distance ranged from 4.4cm to 12.6cm (average 7.6±1.9) and the declination angle ranged from 6° to 87° (average 34.7±24.3). The risk of the IPBSN injury in oblique skin incision may be less than the vertical incision in the medial opening wedge HTO.

ID: 202084 An Atypical Presentation of Infrapatellar Saphenous Neuralgia: A Case Report

Persistent anteromedial knee pain due to injury to the infrapatellar branch of the saphenous nerve is not uncommon after knee surgeries and trauma. However, it is unusual for a patient to develop lateral knee pain and numbness from infrapatellar saphenous neuralgia as the saphenous nerve’s sensory distribution is more medial. We discuss a case where a 28-year-old man presented with three months of burning left lateral knee pain and numbness after an unknown mechanism of injury to his knee while playing basketball. Prior to presentation, the patient completed physical therapy and underwent a pes anserine bursa injection with minimal relief of pain. On exam, palpation of a small, localized area of tenderness over the anteromedial left knee elicited lateral infrapatellar knee pain. The patient had full strength and intact sensation to light touch except for a small area of numbness at the lateral infrapatellar left leg.

Short-Term Outcomes of Anterior Cruciate Ligament Reconstruction with Hamstring Tendon Graft: A Randomized Trial Comparing Risk of Injury to the Infrapatellar Branch of Saphenous Nerve in Terms of Knee Hypoesthesia Among Different Oblique Incision Angles

Purpose: To study the short-term outcomes of anterior cruciate ligament reconstruction (ACLR) with hamstring grafts by comparing the risk of injury to the infrapatellar branch of the saphenous nerve (IPBSN) in terms of the incidence of knee hypoesthesia using 30°, 45°, and 60° oblique incisions. Methods: We conducted a randomized controlled trial among patients who underwent ACLR with hamstring grafts in Buriram Hospital between December 1, 2020 and December 31, 2021. We randomly allocated 111 patients to three groups of 37 patients each, and each group underwent either a 30°, 45°, or 60° oblique incision for hamstring graft harvesting. When incisions were being performed, the age, sex, body mass index, diagnosis, incision length, and operating time were recorded. The incidence and area of knee hypoesthesia were evaluated at 1-, 3-, and 6- month follow-ups. Results: Demographic and surgical data were similar in all three groups. The incidence of knee hypoesthesia was significantly lower in the 45°-incision group than that in other groups at 1-, 3-, and 6-month follow-ups. At the 6-month follow-up, the incidence was 8.1% in the 45° group, 45.9% in the 30° group, and 35.1% in the 60° group. The area of sensory loss in the 45° group was significantly smaller than that in the other two groups at 3- and 6-month follow-ups. Conclusions: Performing a 45° oblique incision reduced the risk of the IPBSN injury after ACLR with a hamstring graft more significantly than a 30° or 60° incision. This technique is safe, uncomplicated, and efficacious.

Ultrasound-guided Genicular Nerve Radiofrequency Treatment-Three- versus Five-Nerve Protocol: Prospective Randomized Comparative Trial.

Genicular nerve radiofrequency (RF) procedure is increasingly being performed to treat chronic pain due to knee osteoarthritis (OA). Targeting additional sensory nerves and improving target identification by using ultrasound (US) guidance may improve treatment success. The aim of this study was to compare the effectiveness of traditional genicular nerves versus two additional sensory nerves to traditional genicular nerves for US-guided genicular nerve RF procedures in patients with chronic knee OA. A total of 80 patients were randomized into two groups. Patients in the three-nerve targeted (TNT) group received a genicular RF with traditional genicular nerves; superior lateral, superior medial, and inferior medial nerves, and the five-nerve targeted (FNT) group received a genicular RF with recurrent fibular and infrapatellar branch of the saphenous nerve in addition to the traditional genicular nerves. Numerical Rating Scale (NRS), Short Form-36 (SF-36), Western Ontario and McMaster Universities Arthritis Index (WOMAC), Quantitative analgesic questionnaire (QAQ) and patient satisfaction were evaluated at pretreatment, at week 1, months 1,3,6. Both techniques provided significant pain reduction and functional improvement up to six months post-procedure (p < 0.05). The FNT group showed significant improvement with respect to the NRS, WOMAC total and SF-36 score compared to the TNT group at each follow-up point. No differences in QAQ or patient satisfaction scores were observed between both groups. The US-guided five-nerve targeted technique is a safe method, and a more effective therapeutic procedure than the traditional three-nerve targeted technique for chronic knee OA. US National Library of Medicine https://clinicaltrials.gov/ct2/show/NCT05073887?term=Selin+Guven+kose&draw=4&rank=5.

The Origin and Course of the Infrapatellar Branch of the Saphenous Nerve: An Anatomical Study

Introduction: Nerve injury of the saphenous nerve or infrapatellar branch seems to be a frequent complication following knee surgery or trauma. Denervation results vary and in some cases no pain relief is achieved. This might be due to anatomic variation. The purpose of this anatomical study is to identify variation in the course of the infrapatellar branch and saphenous nerve. Materials and Methods: We dissected 18 cadavers from adult donors. Medial to the knee, the saphenous nerve and infrapatellar branch were identified and followed proximally to the point where the infrapatellar branch branched from the saphenous nerve. The location where the infrapatellar branch came off from the saphenous nerve relative to the knee joint and where the branch and nerve passed the knee joint were measured. Results: A total of 23 infrapatellar branches were found. We identified 10 branches that came off the saphenous nerve between 0-10 cm proximal to the knee joint, 3 branches at 10-20 cm, and 9 branches at >20 cm. Between the patella and semitendinosus tendon, the knee joint was crossed by 5 branches in the anterior, 15 in the middle, and 2 in the posterior one-third. 13 of the 18 saphenous nerves crossed the knee joint in the posterior one-third and 5 in the middle one-third of the line. Conclusion: The origin of the infrapatellar branch and the location at which it passes the knee are highly variable. This, in addition to people having multiple branches, might explain why denervation is frequently unsuccessful. Based on the anatomical findings, we propose a more proximal diagnostic nerve block to help differentiate between a distal-middle, or proximal origin of the infrapatellar branch. Appropriate placement of the nerve block might help identify people who benefit from denervation.

The anterior branch of the medial femoral cutaneous nerve innervates the anterior knee: a randomized volunteer trial.

The midline skin incision for total knee arthroplasty may be an important generator of chronic neuropathic pain. The incision is innervated by the medial femoral cutaneous nerve (MFCN), the intermediate femoral cutaneous nerves (IFCN) and the infrapatellar branch from the saphenous nerve. The MFCN divides into an anterior (MFCN-A) and a posterior branch (MFCN-P). The primary aim was to compare the areas anesthesized by MFCN-A versus MFCN-P block for coverage of the incision. Nineteen healthy volunteers had IFCN and saphenous nerve blocks. The subgroup of volunteers with a non-anesthetized gap between the areas anesthetized by the saphenous and the IFCN blocks was defined as the study group for the primary outcome. Subsequently selective MFCN-A block and MFCN block (MFCN-A + MFCN-P) were performed to investigate the contributions from MFCN-A and MFCN-P to the innervation of the midline incision. All assessments were performed blinded. Ten out of 19 volunteers had a non-anesthetized gap. Nine out of these 10 volunteers had coverage of the non-anesthetized gap after selective anesthesia of the MFCN-A, whereas anesthesia of the MFCN-P did not contribute to coverage of the gap in any of the 10 volunteers. In half of the cases, a gap of non-anesthetized skin was present on the surgical midline incision after anesthesia of the saphenous nerve and the IFCN. This gap was covered by selective anesthesia of the MFCN-A without contribution from MFCN-P. The selective MFCN-A block may be relevant for diagnosis and interventional management of neuropathic pain due to injury of MFCN-A.

Neuropathy Dermatitis: An Underdocumented Complication Following Total Knee Arthroplasty.

Midline surgical incision used in Total Knee Arthroplasty (TKA) is associated with iatrogenic injury to the infrapatellar branch of the saphenous nerve, which leads to neuropathic dermatitis around the healed surgical scar. There are very few studies with a limited number of cases that have reported this complication. We evaluated the incidence of neuropathic dermatitis and its implication for the functional outcome in TKA patients. Patients who underwent primary TKA between 1 January 2010 and 31 August 2019 and presented in follow-up with sensory disturbances and skin lesions adjacent to the surgical incision were evaluated in this study. A total of 3318 patients with 4282TKAswere included, of which 188 patients presented with the clinical picture of neuropathic dermatitis. There were 136 females and 52 males with a mean age of 67.13years (range 37-92years). The mean duration from surgery to the appearance of skin lesions was 4.4months (range 2-6months), and they resolved at a mean duration of 7.67 (range 6-12) weeks. In our study, we found an incidence of 5.52%. All these patients had a stable and well-functioning knee at the time of presentation of the lesion with a mean Knee Society Score (KSS) of 92 (range 84-96). In our study, we found the incidence of neuropathic dermatitis to be 5.52%, without any long-term implication on the functional outcome of operated knees. For aself-limiting complication of midline knee incision ofTKA, it either resolves on its own or requires a short duration of topical steroid application.