The treatment of recurrent posterolateral elbow joint instability
Authors: B.S. Olsen
References: SECEC 2005, Rome
Posterolateral elbow joint instability, prior described by more authors, was experimentally shown to be caused by insufficiency of the Lateral Collateral Ligament Complex. The condition is seen following an elbow dislocation, or a simple distortion, furthermore the instability was reported following surgery involving the lateral ligaments as radial head excision or lateral epicondylitis. Among patients with a prior joint dislocation we observed signs of posterolateral elbow joint instability in up to 30% of the cases, with recurrent dislocations only in a minority of the patients. For the diagnosis a relevant anamnesis is required, furthermore the patients should be tested for joint stability, especially the pivot shift test, prior described by O’Driscoll as a combined valgus and external rotatory stress, during extension and flexion movement. Positive test result is either apprehension or posterior subluxation/dislocation of the radial head.
The patient is placed in the lateral decubitus position with a tourniquet. A straight posterior approach is used with a radial tricepssplit for harvesting the graft (12 cm long and 1 cm wide). The radiohumeral joint is opened through release of the anconeus muscle and the posterolateral capsule. The insertion of the LCL at the radial epicondyle is prepared with drill holes using a 4 mm drill, in order to tunnelate the midportion of the triceps tendon graft in the epicondyle. The undersurface of the radial epicondyle is prepared with a Mitek© anchor placed in the centre of rotation of the joint, and used for fixation of the graft and for reinsertion of the remaint of the LCL. The proximal part of the suppinator crest on the ulna is prepared for graft insertion, following testing for isometrics with a suture. A fresh bleeding osseous well is created using a high speed bur. In the centre of this through two Mitek© anchors are inserted, for distal graft fixation. The graft reconstruction is performed with the elbow in 90° of elbow joint flexion, since prior kinematic studies showed a maximal joint laxity following ligament injury in this position. Finally the triceps tendon is closed using non-absorbable sutures, and conventional wound closure is performed.
18 patients were clinically followed up at a mean of 44 months postoperative (Range 14-88 month). The elbows were evaluated for Range of Motion (ROM), pain, subjective and objective stability to valgus/varus stress, stressed supination and pronation and finally with the pivot shift stress test as described by O’Driscoll and co-authors. All patients evaluated their activity level before injury, posttraumatic and following surgery, using an upper extremity activity score. Furthermore all elbows were evaluated using a functional elbow score, and since all cases of PLI are unilateral, the contralateral elbow was used as a reference. Included in the elbow joint score is an evaluation of power in elbow extension and flexion using an isobex apparatus. This allows an evaluation of possible loss of triceps muscle strength due to the triceps split and the triceps tendon graft. Finally all complications were registered.
Fourteen patients or 78% achieved an objectively stable elbow joint following the surgery. None of the patients demonstrated any redislocations, but in 4 cases or 22% we observed persistent apprehension to the pivot shift stress test. Only one of the patients had subjective sensation of joint instability or laxity.
Fourteen patients or 78% had no deficits in ROM, despite the long postoperative immobilisation. 2 patients had extension deficits of 15° respectively, further 2 patients had flexion deficits less than 15°. Therefore all patients achieved a functional ROM as defined by Morrey and An.
Fifteen patients or 83% had no or occasional slight pain in the elbow at follow up, 3 patients had moderate pain and none developed severe pain following surgery. In no cases did the surgery increase the reported elbow pain.
Weakness of the triceps muscle was observed following surgery, since the extension stress measurements obtained with the isobex showed a decrease of elbow extension force of mean 2.3 kg (Range -1, 1-10). The elbow score showed a mean difference between operated and non-operated elbow of 7 (Range -1-23). P<0.01 (Paired t-test). Fifteen patients or 83% had returned to their pretraumatic activity level. None of the patients developed infections or neurological deficits.
Seventeen patients or 95% were satisfied with the operative outcome.
The present technique is recommended as treatment of choice in case or recurrent posterolateral elbow instability following a traumatic elbow joint dislocation, since it is safe, gives reliable results, and allows the use of only one incision. Contrary to the technique used by Nestor and co-authors, were a secondary incision is needed to harvest the palmaris longus tendon.
1. Nester BJ, O’Driscoll SW & Morrey BF. Ligamentous reconstruction for posterolateral rotatory instability of the elbow. J Bone Joint Surg (Am) 1992; 74-A:1235-41
2. O’Driscoll SW, Morrey BF, Kporinek S & An KN. Elbow subluxation and dislocation. A spectrum of instability. Clin Orthop 1992; 280:186-97
3. Olsen BS & Soejbjerg JO. The treatment of recurrent posterolateral instability of the elbow. J Bone Joint Surg (Br) 2003; 85-B:342-6
4. Olsen BS, Soejbjerg JO, Nielsen KK et al. Posterolateral elbow joint instability: the basic kinematics. J Shoulder Elbow Surg 1998;7:19-29
5. Osborne G & Cotteril P. Recurrent dislocation of the elbow. J Bone Joint Surg. (Br) 1966;102:554-71