Comparison of the Effects of Femoral Nerve Block and Adductor Canal Block on Postoperative Analgesia in Patients to Undergo Unilateral Knee Arthroplasty

Comparison of the Effects of Femoral Nerve Block and Adductor Canal Block on Postoperative Analgesia in Patients to Undergo Unilateral Knee Arthroplasty [Kafkas J Med Sci]

Kafkas J Med Sci. 2025; 15(1): 64-70 | DOI: 10.5505/kjms.2025.06787

Comparison of the Effects of Femoral Nerve Block and Adductor Canal Block on Postoperative Analgesia in Patients to Undergo Unilateral Knee Arthroplasty

Soner Kına¹, Ayşe Surhan Çınar², Kerim Şahin³, Onur Demircioğlu²
¹Department of Cardiology, Kafkas University School of Medicine, Kars, Türkiye
²Hamidiye Etfal Health Training and Research Hospital, Istanbul, Türkiye
³Alanya Alaaddin Keykubat Training and Research Hospital, Antalya, Türkiye

Aim: Total knee arthroplasty (TKA) is a major orthopedic procedure often associated with significant postoperative pain. Effective pain management is critical for early mobilization, rehabilitation, and reducing complications such as chronic pain. With the increasing use of ultrasound in regional anesthesia, the frequency of femoral nerve block (FNB) and adductor canal block (ACB) for analgesia after TKA is rising. This study aimed to compare the effects of femoral nerve block and adductor canal block on postoperative analgesia in patients undergoing unilateral knee arthroplasty.
Material and Methods: The study was conducted with the approval of the ethics committee, and written consent was obtained from the patients. It was carried out on 70 patients aged 18–70, with an American Society of Anesthesiologists (ASA) score of I-II, who planned to undergo elective TKA surgery. The study was designed as a prospective, randomized, and single-blind trial. Demographic data of the patients were recorded, and routine monitoring and general anesthesia induction were performed. Patients were divided into two groups: those who received FNB (Group F) and those who received ACB (Group A). Both groups were administered 20 mL of 0.375% bupivacaine. Heart rate (HR) and mean arterial pressure (MAP) were recorded intraoperatively before and after induction and every 30 minutes. In the postoperative period, patient-controlled analgesia (PCA) with intravenous tramadol was applied. Total tramadol usage and the number of times analgesia was needed were recorded. HR, MAP, and visual analog scale (VAS) scores were recorded at postoperative 30 minutes, 1, 2, 4, 6, 12, and 24 hours. Complications (nausea/vomiting, hypotension, bradycardia, itching) were recorded for 24 hours.
Results: Mean VAS scores were significantly lower in the FNB group at postoperative 0, 1, 2, and 6 hours (p<0.05). Total tramadol consumption and bolus requests were higher in the ACB group (p<0.001). Both techniques achieved VAS scores below 4, with no significant differences in additional analgesic use or complications. Nausea and vomiting rates were 5% (FNB) and 10% (ACB). No significant differences were observed in perioperative and postoperative MAP or HR between the groups.
Conclusions: Femoral nerve block and ACB provide effective analgesia after TKA, with VAS scores below 3 and high patient satisfaction. However, FNB demonstrated superior early postoperative pain control and lower opioid consumption. ACB, as a sensory block, is advantageous for minimizing quadriceps weakness and should be considered part of multimodal analgesia strategies. It was concluded that femoral nerve block is more effective in providing postoperative analgesia for patients undergoing unilateral knee arthroplasty.

Keywords: total knee arthroplasty, femoral nerve block, adductor canal block, multimodal analgesia; postoperative analgesia

Tek Taraflı Diz Artroplastisi Geçirecek Hastalarda Femoral Sinir Bloğu ile Adduktor Kanal Bloğunun Postoperatif Analjezi Üzerine Etkilerinin Karşılaştırılması

Amaç: Total diz artroplastisi (TDA) sonrası ağrı şiddetlidir ve tedavi edilmediğinde kronikleşebilir. Ultrasonografinin rejyonel anestezide kullanımında artmasıyla beraber TDA sonrası analjezi amacıyla femoral sinir bloğu (FSB) ve adduktor kanal bloğu (AKB) uygulama sıklığı artmaktadır. Çalışmamızda tek taraflı diz artroplastisi geçirecek hastalarda femoral sinir bloğu ve adduktor kanal bloğunun postoperatif analjezi üzerine etkilerinin karşılaştırılmayı amaçladık.
Gereç ve Yöntem: Çalışma, etik kurulu onayı, hastalardan yazılı izin alınarak, elektif TDA cerrahisi uygulanacak American Society of Anesthesiologists (ASA) skoru I-II olan 18–70 yaş grubu 70 hastada gerçekleştirildi. Çalışma prospektif, randomize ve tek kör olarak planlandı. Hastaların demografik verileri kaydedilerek rutin monitörizasyon ve genel anestezi indüksiyonu uygulandı. Hastalar FSB (Grup F) ve AKB (Grup A) yapılan grup olarak ikiye ayrıldı. Her iki gruba 20 mL %0,375 bupivakain uygulandı. Tüm hastaların kalp atım hızı (KAH) ve ortalama arter basıncı (OAB) indüksiyon öncesi, indüksiyon sonrası ve intraoperatif her 30 dakikada bir kaydedildi. Postoperatif dönemde intravenöz tramadol ile hasta kontrollü analjezi (HKA) uygulandı. Toplam kullanılan tramadol miktarı ve kaç defa analjezi ihtiyacı olduğu kaydedildi. KAH, OAB ve vizüel analog skala (VAS) skoru postoperatif 30 dk, 1, 2, 4, 6, 12 ve 24. saatlerde kaydedildi. Komplikasyonlar 24 saat boyunca (bulantı/ kusma, hipotansiyon, bradikardi, kaşıntı) kaydedildi.
Bulgular: Demografik verilerde, intraoperatif ve postoperatif hemodinamik verilerde, ek analjezik ihtiyacı ve komplikasyonlar her iki grupta istatistiksel olarak anlamlı fark bulunmadı (p>0,05). Postoperatif VAS skorları, kullanılan toplam tramadol miktarı istatiksel olarak Grup F’de anlamlı düşük bulundu.
Sonuç: Tek tek taraflı diz artroplastisi geçirecek hastalarda femoral sinir bloğunun postoperatif analjezi üzerine daha etkin olduğunu sonucuna ulaşıldı.

Anahtar Kelimeler: total diz artroplastisi, femoral sinir bloğu, adduktor kanal bloğu, multimodal analjezi; postoperatif analjezi

Soner Kına, Ayşe Surhan Çınar, Kerim Şahin, Onur Demircioğlu. Comparison of the Effects of Femoral Nerve Block and Adductor Canal Block on Postoperative Analgesia in Patients to Undergo Unilateral Knee Arthroplasty. Kafkas J Med Sci. 2025; 15(1): 64-70

Corresponding Author: Soner Kına, Türkiye

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