Mitchell, Cecilia V

ABSTRACT Introduction/Aims Accurate needle electromyography (EMG) of the short head of the biceps femoris (SHBF) is often important to localize nerve damage when proximal to the fibular head. Techniques have been proposed for accurate SHBF EMG; however, needle placement accuracy is low and with the risk of inadvertent needle placement into the long head (LHBF) potentially resulting in false localization and inappropriate operative management. This study aimed to define the optimal window for accurate SHBF needle EMG placement through ultrasound (US) investigation of the anatomical relationships of the SHBF, LHBF, and common fibular nerve (CFN) in the distal posterolateral thigh. Methods Forty lower limbs from 20 healthy adults were evaluated using US. Distances from the popliteal crease (PC) to the SHBF and LHBF myotendinous junctions and position of the CFN in the popliteal fossa were recorded. The “SHBF window” was defined as the region where the SHBF muscle body is present in the absence of the LHBF. Results The SHBF was located anterolateral to the LHBF tendon/muscle and the CFN medial to the SHBF in all limbs. The average distances from the PC to SHBF and LHBF muscles were 0.6 and 6.4 cm, respectively. The optimal “SHBF window” was identified to be 3–4 cm (2–3 fingerbreadths) proximal to the PC, anterolateral to the LHBF tendon in the distal thigh. Discussion SHBF examination within this optimized window results in increased accuracy of needle placement, aiding in the electrodiagnostic localization of fibular nerve lesions.

ABSTRACT Snapping proximal hamstring is an uncommon phenomenon, with few case reports documenting surgical treatment. The purpose of this study is to report snapping resolution, minimum 2-year post-operative patient-reported outcome (PRO), satisfaction scores and complications from patients who underwent surgical release of the conjoint tendon from the sacrotuberous ligament with reattachment to the ischial tuberosity. Prospectively collected data from two institutional databases were retrospectively reviewed for patients who underwent hamstring repair for partial- or full-thickness tears. Patients were included if they demonstrated ‘snapping proximal hamstrings’ on preoperative physical examination, including ultrasound confirmation, and repair subsequently performed. Patients were excluded if they had reconstruction of the proximal hamstring tendon or claimed worker’s compensation. With a total of 20 patients (15 females and 5 males), successful resolution of snapping was reported in 100% of the cohort. For patients with pre- and post-surgical lower-extremity functional scores (LEFS), post-surgical LEFS were significantly higher than pre-surgical LEFS (pre-surgical: 17.0 ± 4.0, post-surgical: 73.6 ± 3.3, P < 0.001). Average post-operative PROs were as follows: International Hip Outcome Tool-12, 92.3 ± 8.3; modified Harris Hip Score, 93.2 ± 7.8; Non-arthritic Hip Score, 92.5 ± 6.8; Hip Outcome Score-Sports Specific Subscale, 94.4 ± 6.7; LEFS, 73.9 ± 3.4; and median visual analog scale of 0 with an interquartile range of 0-1. Patient satisfaction was ‘very satisfied’ in 19 (95%) patients and ‘satisfied’ in 1 (5%) patient. At a minimum 2-year follow-up, patients who underwent surgical treatment for chronic snapping of the proximal hamstrings demonstrated complete resolution of painful posterior snapping, reported high PROs and satisfaction, and had no reported post-operative complications.