The structure of elbow joint is tight, and the adhesion between joint capsule and its surrounding tissue is likely to occur after trauma or inflammation. Thus, the incidence of elbowstiffness is high. Meanwhile, as the hand function depends on the flexion and extension of elbow joint and the rotation of forearm, the elbow joint dysfunction impairs the function of elbow joint as well as hand. The main causes of elbow stiffness derive from the inside and outside of elbow joint. Morrey, et al. divided elbowstiffness into three subtypes based onetiology and injured structure: intra-articular stiffness, extra-articular stiffness and mixed stiffness. The factors of intra-articular stiffness include articular cartilage defect, loose body, osteophyte impingement, arthritis, synovitis, joint capsule scar adhesion, contracture, etc. The factors of extra-articular stiffness include muscle tissue spasm caused by pain, soft tissue scar contracture and adhesion, collateral ligament contracture, heterotopic ossification, etc. The factors of mixed stiffness include both of the above.With the in-depth study of elbow joint biomechanics , the improvement of surgical instrument and surgical methodand the postoperative standardized rehabilitation training, arthrolysis has become a preferred choice for the elbow stiffness that does not respond to conservative treatment. However, intraoperative neurovascular injury and poor postoperative result are still problems for surgeon. The elbow arthrolysis can be performed by incision or arthroscopy.The former one is a routine surgical method for the treatment of elbow stiffness, which needs to extensively dissect the surrounding soft tissue for adequate exposure and has large damage, massive hemorrhage and long recovery time.Consequently, the formations of hematoma, fibrous scar hyperplasia and heterotopic ossification are easily resulted.The latter one is performed through various approaches to accurately assess the location and extent of elbow joint lesion, which can be safely and intraarticularly performed with less damage, less bleedingand faster recovery.Due to the anatomical featureof elbow joint, the application range of arthroscopic arthrolysis is narrow, and the nerves around arthroscopic approach are densely distributed. The risk of nerve damage is greater during surgery, and the most vulnerable one is radial nerve.The arthroscopic arthrolysis of elbow was improved by O'Driscoll, et al. to minimize the risk of nerve damage, and a four-step method was proposed: (1) entrance of elbow joint and establishment of field; (2) further exposure to create working space; (3) removal of osteophyte and avoidance of impingement; (4) joint capsule resection.Objective To evaluate the efficacy of O’Driscoll four-step arthroscopic elbow arthrolysis for the treatment of elbow stiffness.

From June 2016 to June 2018,25 patients (20 males and 5 females) with elbowstiffnesswere treatedwith O’Driscoll four-step arthroscopic elbow arthrolysisin the department of bone and joint surgery of Changhai hospital in Shanghai. The age ranged from 17 to 67 years with an average of (42.8±18.1) years. 9 cases had the left side affected, and 16 cases had the right side affected . Physical examination, X-ray film, CT three-dimensional reconstruction and MRI scan were performed preoperatively and well recorded.The elbow range of motion (ROM) , Visual analogue scale (VAS) score and Mayo elbow performance score (MEPS) were compared and observed for analysis. The data were analyzed by t-test using SPSS 17.0 software.

The twenty-five patients were followed up for 6-12 monthswith an average of (8.7±0.8) months. Twenty-three patients were followed up effectively. The wounds healed in the first stage without complication of nerve damage, infection, vascular injury, joint instability, myositis ossificans, etc.The average maximum elbow flexionswere (86.5±22.1) ° before operation and (126.5±16.5) ° after operation. The average maximum elbow extensions were (34.8±12.6) ° before operation and (11.3±13.1) ° after operation. The total mean ROM were (51.7±21.0) ° before operation and (115.2±9.2) ° after operation.The therapeutic efficacy was evaluated based on MEPS, and the preoperative and postoperative scoreswere (60.5±13.4) points and (88.7±6.3) points, respectively.The postoperative score increased with statistical difference (P<0.05) .

The O’Driscoll four-step arthroscopic arthrolysis for the treatment of elbow stiffnesscan expand the application range of arthroscopy with low incidence of nerve damage, effectively improve the elbow ROM and reduce pain. The early onset of postoperative systematic rehabilitation training is also critical.