Can preoperative imaging predict the outcomes after arthroscopic release for elbow arthritis?

INTRODUCTION: The primary symptoms of elbow osteoarthritis are the progressive development of stiffness along with pain at the end range of motion due to osteophyte impingement. Surgical treatment involves resecting these "bone stops". In the literature, these osteophytic lesions are more common than cartilage lesions, which suggests they may occur beforehand. The aim of our study was to confirm osteophytes are more common than cartilage lesions, and also to establish a link between these lesions and the functional outcomes. METHODS: This was a prospective multicenter (8 hospitals) study conducted in the context of a symposium of the Francophone Arthroscopy Society (SFA). Eighty-seven patients with elbow osteoarthritis treated by arthroscopic release were included. The clinical outcomes (range of motion in flexion, extension and pronation-supination; strength; pain at rest and during activity; satisfaction; Andrews and Carson score; QuickDASH, Patient-Rated Elbow Evaluation (PREE), Mayo Elbow Performance Score (MEPS), Self-Evaluation Elbow (SEE) were determined before the procedure and at the 6-month follow-up visit. A standard radiographic assessment was done before the surgery and at the last follow-up visit. A CT arthrogram was done before the procedure. The presence of joint narrowing, osteophytes, filling of fossa along with secondary osteochondroma was evaluated in terms of their location, severity, size and/or number. The presence of radial head subluxation was recorded. The Bröberg & Morrey and Rettig & Hastings classification systems were applied. All the postoperative clinical data along with their change (difference between preoperative and postoperative values) were compared to the imaging findings. RESULTS: Osteophytes were found in 95% of our patients. They were located at the olecranon in 85% of cases and at the coronoid process in 81%. Filled fossae found in 94% of cases. The olecranon, coronoid and radial fossa were filled in 83%, 80% and 60% of elbows, respectively. On the initial X-rays, joint narrowing was found in 68% of elbows. CT arthrogram identified narrowing in 70% of cases. Narrowing was present in the humeroradial joint in 60% of cases and in the humeroulnar joint in 23% of cases. The presence of joint narrowing on CT arthrogram was a negative prognostic factor for pain during activity (p<0.05) along with the Quick DASH (p<0.01) and PREE (p<0.05). Involvement of the humeroradial joint impacted pain at rest (p<0.01). Narrowing of the humeroulnar joint was associated with worse outcomes in terms of pain at rest (p<0.05) and during activity (p<0.05), QuickDASH (p<0.005), MEPS (p<0.05), PREE (p<0.05) and the SEE (p<0.05). The presence of loose bodies before the procedure was associated with better outcomes in terms of pain at rest (p<0.05), QuickDASH (p<0.001), MEPS (p<0.001), Andrews & Carson score (p<0.05) and PREE (p<0.005). The osteoarthritis stage in the Bröberg & Morrey or the Rettig & Hastings classification systems did not impact the various clinical parameters or functional outcome scores. DISCUSSION/CONCLUSION: In the imaging work-up, signs of impingement (osteophytes and filling of fossa) are more common than signs of joint narrowing. The presence of humeroulnar and/or humeroradial impingement when there are no cartilage lesions visible may correspond to a pre-arthritic stage. The outcomes of arthroscopic release are better in elbows with isolated impingement than in those with cartilage lesions, especially at the humeroulnar joint. Excision of secondary osteochondromas is also an excellent surgical indication. Current classification systems cannot be used to determine the prognosis before arthroscopic release of elbow osteoarthritis cases. LEVEL OF EVIDENCE: III, Prospective multicenter observational cohort study.