The Anatomical Study And Clinical Application Of The Anteromedial Neurovascular Interval Approach Of The Elbow

Part One Anatomical study of the anteromedial neurovascular interval approach of the elbowObjective: The purpose of this study was to explore the anatomy of anteromedial neurovascular and related structures of the elbow joint,providing references for relevant surgical approaches and presenting practical surgical options for elbow fractures in clinical setting.Methods: We seleccted 24 upper extremities of 12(6 males and 6females)formalin-fixed adult cadavers perfused with red latex in artery.The latex was solidified one week before observation of anatomic structure of upper extremeties.According to anatomical layers and measurement methods,the incision was initiated at space between brachioradialis and pronator teres.Dissection was subsequently performed at the neurovascular space among median nerve,brachial artery and ulnar artery,exposing joint capsule of the anterior elbow,coronoid fossa of the humerus,the articular surface of the distal humeral trochlea,the humeral head,humeroulnar joint and ulnar coronoid.We observed and measured the lateral branches of the brachial and radial artery,the medial branches of the brachial and ulnar artery,the distance from these branches to radial and ulnar artery bifurcation as well as vessel diameter of these branches.We also observed and documented distribution of the median nerve and its branches apart from their anotomical structures,and the length of blood vessels and concomitant nerves without branches across them.Results:By means of anteromedial neurovascular interval approach of elbow,nerves and blood vessels were well protected,with excellent exposure of the anterior structures of the elbow,including the ulna coronoid process,humeroulnar joint and trochlea of humerus.The length of blood vessels andconcomitant nerves without branches across them was(5.79±1.64)cm.Specifically,no significant branches were observed between them and lateral retraction was effortless,thereby providing good exposure to the corresponding parts of the elbow.Brachial artery and radial artery give off more and thick lateral branches close to the ulna coronoid,whereas brachial artery and ulnar artery give off fewer thin medial branches,thereby allowing easy lateral retraction.The muscle branches of median nerve were given off laterally from the trunk at a minimal acute angle,almost parallel to the trunk,thus allowing easy medial retraction and excellent visualization for surgery.Conclusions: Anteromedial neurovascular interval approach to the elbow provided excellent exposure to anteromedial anatomical structure of the elbow joint,including the trochlea of the humerus,coronoid process of the ulna and the anterior elbow capsule.As an optimal surgical technique for elbow joints,this approach possesses a series of benefits,such as simple anatomical layer,good operation field under excellent visualization,minimal soft tissue dissection,minimal complications and shorter recovery time.Part Two An anteromedial neurovascular interval approach to the elbow for fixation of fracture of the coronoid process of the ulnaObjective: To introduce a novel anteromeidal approach to the elbow for fracture of coronoid process of the ulna with minimal damage,excellent exposure and good visualization for reduction and internal fixation.Methods: From February 2011 to April 2015,a total of 12 patients(8male and 4 females;range 14-62 years;mean age 31 years)underwent surgical fixation through anterior approach to the elbow for fracture of coronoid process of ulna.According to the classification proposed by Adams et al.,we included 5 patients with type ?,3 with type III,3 with type ?(AM)and 1 with type ?(AL).They all had closed fractures caused by traffic injuries(n=4),falls(n=7),crush-related injuries(n=1)and fracture complicated with osteofascial compartment syndrome(OCS;n=1).The fractures were managed initially by dissection to reduce tension.Surgical procedures were as followed.The “S” type skin incision was made proximalto elbow flexion crease.Careful blunt subcutaneous dissection was performed to expose the deep fascia,the biceps and bicipital aponeurosis.Transverse split of bicipital aponeurosis allowed excellent exposure of the brachial artery and vein as well as the median nerve.Incision was made at the space between the brachial artery,ulnar artery and median nerve.Brachial artery and ulnar artery were retracted laterally,whereas the median nerve was retracted medially,giving the best exposure of the brachial muscle.Blunt or sharp dissection of brachial muscle as well as medial/lateral retraction accomplished good visualization of the anterior capsule of the elbow,ulnar coronoid fracture fragment and the base of coronoid process.The dissection and reduction of coronoid process fracture were performed under direct visualization followed by internal fixation with cannulated screws or miniature plate.Of all patients,one showed significant joint instability.Therefore,another incision was performed to repair collateral ligament injury,followed by subsequent fixation with hinged external fixator.Functional exercise was initiated 3 weeks after surgery.Others received external fixation with plast splint,followed by functional exercise at 2 weeks.Follow-up was made on union of fracture and postoperative functional recovery for evaluation of therapeutic effects.Results: The mean follow-up period for all 12 patients eligible was 21months(range,13 to 36 months).In addition,we provided guidance of functional exercise and collected information on union of fracture and functional recovery.None of the patients showed incision infection,deep infection,nonunion of fracture,elbow dislocation,subluxation,traumatic arthritis and poor joint activities as well as intraoperative and postoperative neurovascular complications with this approach.Mild heterotopic ossification was found in one case,whoever,nevertheless,had a good elbow function.The arc of elbow flextion and extension were(137.08±9.88)°,whereas forearm pronation/supination were restored to(164.17±8.48)°.When compared with the normal side,there was no significant difference in functional outcome(P ?0.05).Based on Mayo Elbow Performance Score(MEPS),results were categorized as excellent in ten patients and good in one,with satisfaction rate of 100%.Conclusions: In terms of fracture of ulnar coronoid process,anterior approach itself possesses the benefits of simplicity,good safety,minimal invasion,excellent exposure,and strong operability.Used alone or in combination with other surgical approaches,it is optimal for open reduction and internal fixation of fracture of ulnar coroniod process.Part Three An anteromedial neurovascular interval approach of the elbow in the treatment of coronal shear fractures of the distal humerusObjective:This paper aims to exlore the therapeutic effect of an anteromedial neurovascular interval approach of the elbow on coronal shear fractures of the distal humerus.Methods:A prospective study was conducted in our department.There were a total of 9 patients,including 5 males and 4 females(aged 16-64 years;mean age 33 years).According to the classification system proposed by Dubberley et.al,we enrolled one patient with type I fracture,3 with type II,and 5 with type III.All patients had closed fractures attributed to falling off the bicycle(n=6),traffic injuries(n=2)and fall injuries(n=1).The mean time interval between injury and surgery was 2 days(range,1-3 days).None of the patients reported signs of neurovascular injury or OCS in the forearm.Of all patients,one had fracture complicated with fracture of ulna coronoid process and one complicated with fracture of lateral epicondyle of the humerus.Those patients eligible were treated with open reduction and internal fixation by anteromedial neurovascular interval approach.As for one patient with the ulna coronoid process fracture,reduction and internal fixation of coronoid fracture were performed through the same approach.With respect to another patient with fracture of lateral epicondyle of the humerus,another incision was made for reduction and internal fixation,followed by plast splint,which was then removed to initiate functional exercise of the elbow.Results:None of the patients reported neurovascular complications and infection intraoperatively and postoperatively.All patients had excellentfracture reunion.At the 12-month follow-up,all of the patients resumed their work and normal life without pain or complications,such as heterotopic ossification,traumatic arthritis and poor joint activity.The arc of elbow flexion and extension were(141.11±4.86)° and forearm pronation/supination were restored to(168.33±5.00)°.When compared with the normal side,there were no significant differences in the functional outcome(all P ? 0.05).Based on MEPS,the mean score was 98.9,with excellence in ten patients and satisfaction rate of 100%.Conclusion: An anteromedial neurovascular interval approach of the elbow in the treatment of shear fracture of articular surface of the distal humerus,particularly the trochlea of the humerus,contributed to minimal soft tissue dissection,excellent exposure,direct visualization for reduction and fixation of the fracture,thus reducing the incidence of complications.Used alone or in combination with other suigical approaches,this will achieve satisfactory therapeutic effects.