Table 2.

Anatomical and clinical distinctions for guiding regional block selection

Feature	Intracapsular fractures	Extracapsular fractures
Clinical diagnoses	Primarily femoral neck fractures	Intertrochanteric and subtrochanteric fractures
Nociceptive source	Pain originates from the anterior capsule, synovium, and intra-articular ligaments	Pain involves the greater trochanter, lateral femoral wall, and periosteum
Surgical dissection	Trauma is confined to the deep joint space with minimal lateral soft tissue disruption	Extensive incision involves the fascia lata, tensor fasciae latae, and vastus lateralis
Target innervation	Restricted to high articular branches of the FN, ON, and AON	Includes articular branches plus the LFCN and lateral afferents
PENG block	Provides site-specific capsular analgesia while preserving motor function	Leaves an “incisional gap” due to failure to block the LFCN and lateral skin
S-FICB	Offers inconsistent obturator nerve coverage with unnecessary motor block	Relies on volume-dependent spread to effectively cover the LFCN and surgical site

Abbreviations: AON accessory obturator nerve, FN femoral nerve, LFCN lateral femoral cutaneous nerve, ON obturator nerve, PENG pericapsular nerve group, S-FICB supra-inguinal fascia iliaca compartment block