OBJECTIVETo investigate the relationship of the greater tuberosity and the lateral fin of the prosthesis by using cadaveric research.

METHODSNine pairs of fresh-frozen upper extremity specimens (n = 18) were collected. Two-part anatomical neck fracture models were created by osteotomy along the anatomical neck. A standardized humeral head replacement procedure was carried out. The prosthesis was implanted in 20 degrees and 40 degrees of retroversion respectively, and the distance between the bicipital groove and lateral fin of the prosthesis was measured.

RESULTSThe lateral fins of prostheses in all specimens were located behind the bicipital groove. The average distances were 7.3 mm in 20 degrees retroversion and 4.0 mm in 40 degrees retroversion.

CONCLUSIONIt is better to fix the greater tuberosity over the lateral fin during humeral head replacement.

Arthroplasty, Replacement ; methods ; Humans ; Humerus ; anatomy & histology ; surgery ; Shoulder Fractures ; surgery ; Shoulder Joint ; anatomy & histology ; surgery

Injection of the neurolytic agents into motor points of the biceps brachii or brachialis muscles is an effective treatment of spasticity of the elbow flexors in many stroke survivors. Accurate localization of the motor points of each muscle is necessary for enhancing the efficacy of motor point blocks. To identify the precise locations of the motor points (terminal nerve endings) of the biceps brachii and brachialis muscles in relation to anatomic surface landmarks for motor point blocks, we dissected 23 limbs from 12 cadavers. A reference line was defined as a line connecting the coracoid process with the lateral epicondyle of the humerus. The location of the motor points of the biceps brachii and brachialis muscles was identified in reference to the reference line. The motor point of the biceps brachii muscle was found to be approximately half of the reference line. In the brachialis muscle, the location of the motor point was 70% of the reference line from the coracoid process and 2 cm medial to the line. The results are expected to facilitate effective localization of the motor point block of these muscles in selective motor nerve block.
Adult ; Aged ; Aged, 80 and over ; Cadaver ; Female ; Humans ; Humerus/anatomy & histology ; Male ; Middle Aged ; Motor Neurons/*drug effects ; Muscle, Skeletal/*anatomy & histology ; Muscles ; Nerve Block ; Shoulder ; Skin/*drug effects