Anatomical And Clinical Study Of The Lateral Epicondyle Osteotomy Approach And The Olecranon Osteotomy Approach

PurposeThe first purpose of this study is to compare the exposure of the distal humerus articular surface between the lateral epicondyle osteotomy approach and the olecranon osteotomy approach and evaluate the safety of the lateral epicondyle osteotomy approach.To provide an anatomical reference for the surgical approach of the treatment of coronal shear fractures of the distal humerus and using quantified anatomical data to guide the clinical work.The second purpose is to demonstrate the lateral epicondyle osteotomy approach in open reduction and internal fixation is effective and safe for coronal shear fractures of the distal humerus.Methods(1)16 fresh frozen upper limb specimens of adult cadavers were randomly divided into the lateral epicondyle osteotomy group(L group)and the olecranon osteotomy group(O group).After each upper limb specimen was dissected according to the corresponding surgical approach,a 0.5 mm Kirschner wire was inserted along the edge to mark the articular surface visualization area.The radial nerve and posterior interosseous nerve were dissected for each upper limb specimen,and the distances of their specific points to the highest point of the lateral epicondyle were measured.We also measured the size of the footprint area of the lateral collateral ligament complex of 8 upper limb specimens in the olecranon approach osteotomy group.Finally,we removed each elbow's soft tissue of and used the surface scanning system to create a three-dimensional digital model.Each surgical approach's visible joint surface area was mapped and quantified using markers created by Kirschner wires.(2)The 3 cases of coronal shear fractures of the distal humerus admitted to our department were treated with open reduction and internal fixation by the lateral epicondyle osteotomy approach,and we evaluated the effectiveness and safety the lateral epicondyle osteotomy approach by the elbow joint range of motion,the mayo elbow performance score(MEPS)and the disability of the arm,shoulder,and hand(DASH)score and complications.Results(1.1)Articular surface exposure:The lateral epicondyle osteotomy approach of the humerus and the olecranon osteotomy approach can expose 75.49±3.57%and 56.73±3.50%(t=9.933,P<0.001)of the distal humeral articular surface respectively,100±0%and 31.50±5.78%(t=31.370,P<0.001)of the capitellum,58.93±1.20%and 74.03±3.06%(t=12.160,P<0.001)of the trochlea,64.54±3.55%and 47.78±6.06%(t=6.319,P<0.001)of the anterior trochlea,and 53.10±3.36%and 100±0%(t=36.950,P<0.001)of the posterior trochlea.(1.2)Radial nerve and posterior interosseous nerve:The distances from the highest point of the lateral epicondyle to the points at which the radial nerve crosses over the anterior,lateral,and posterior aspect of the humeral shaft(lateral view)are 7.59±0.93 cm,9.32±0.84 cm,and 11.15±0.81 cm,respectively.The distances from the highest point of the lateral epicondyle to the points at which the posterior interosseous nerve crosses over the anterior,lateral,and posterior aspect of the radial shaft(lateral view)are were 5.20±0.49 cm,6.27±0.53 cm,and 7.33±0.56 cm,respectively.(1.3)The size of the footprint area of the lateral collateral ligament complex:the longitudinal diameter is 1.79±0.11 cm,and the lateral diameter is 1.26±0.15 cm.(2)The three patients had excellent functional results according to the MEPS.The average range of motion was 118°in flexion/extension and 172°in pronation/supination.Only case 2 had one complication,which was implant prolapse.ConclusionBased on the anatomical study of 16 fresh frozen upper limb specimens,this study proved that the lateral epicondyle osteotomy approach is better than the olecranon osteotomy approach for exposing the the distal humerus articular surface,capitellum,and the anterior trochlea,but the latter is better for the posterior trochlear.At the same time,this study also proved that the safe length of the skin incision for the lateral epicondyle osteotomy approach is approximately 8 cm,and the longitudinal and lateral diameters of the lateral epicondyle osteotomy block should not be shorter than 2 cm and 1.6 cm,to avoid damage to the lateral collateral ligament complex.Our experience regarding the management of these three cases initially proved the effectiveness and safety of the lateral epicondyle osteotomy approach.