The causes of a stiff elbow are numerous including: post-traumatic elbow, burns, head injury, osteoarthritis, inflammatory joint disease and congenital.
Types of stiffness include: loss of elbow flexion, loss of elbow extension and loss of forearm rotation. All three have different prognoses in terms of the timing of surgery and the likelihood of restoration of function.
Contractures can be classified into extrinsic and intrinsic (all intrinsic develop some extrinsic component). Functional impairment can be assessed medicolegally; however, in clinical practice the patient puts an individual value on the arc of motion. Objectively most functions can be undertaken with an arc of 30 to 130 degrees.
The commonest cause of a Post-traumatic Stiff elbow is a radial head fracture or a complex fracture dislocation. Risk factors for stiffness include length of immobilisation, associated fracture with dislocation, intra-articular derangement, delayed surgical treatment, associated head injury, heterotopic ossification. Early restoration of bony columns and joint stability to allow early mobilisation reduces incidence of joint stiffness. Heterotopic ossification (HO) is common in fracture dislocation of the elbow. Neural Axis trauma alone causes HO in elbows in 5%. However, combined neural trauma and elbow trauma the incidence is 89%. Stiffness due to thermal injury is usually related to the degree rather than the site. The majority of patients have greater than 20% total body area involved.
Extrinsic contractures are usually managed with a sequential release of soft tissues commencing with a capsular excision (retaining LCL/MCL), posterior bundle of the MCL +/− ulna nerve decompression (if there is loss of flexion to 100 degrees). This reliably achieved via a posterior incision, a lateral column exposure +/− ulna nerve mobilisation. A medial column exposure is a viable alternative. Arthroscopic capsular release although associated with a quicker easier rehabilitation is associated with increased neural injury. Timing of release is specific to the type of contracture, i.e. flexion contractures after approx. six months, extension contractures ASAP but after four months, loss of forearm rotation less 6 to 24 months.
The use of Hinged Elbow Fixators is increasing. The indications include reconstructions that require protection whilst allowing early movement, persistent instability or recurrent/late instability or interposition arthroplasty.
Post-operative rehabilitation requires good analgesia, joint stability and early movement. The role of CPM is often helpful but still being evaluated.