Abstract
Introduction:
Unicompartmental knee arthroplasty (UKA) has gained renewed interest in recent years as an alternative to total knee arthroplasty (TKA) for limited degenerative disease of the knee. However, recurrence of symptoms may be seen, compromising long-term survivorship. Arthroscopy has been used to for diagnosing and treating symptoms in problematic TKA. The aim of this study was to investigate the outcome of arthroscopic procedures in symptomatic UKA. We hypothesized that arthroscopy is a viable tool in diagnosing and treating patients with recurrent symptoms after UKA and identifying patients that will benefit from revision surgery.
Methods:
A search of the institution's joint registry was conducted to identify patients who underwent arthroscopy following UKA between 2003 and 2011. Medical records were analyzed for patient demographics and comorbidities. Clinical results following arthroscopy were evaluated using the Oxford Knee Score. All patient radiograph were assessed for component alignment and loosening.
Results:
A total number of 76 arthroscopies were performed on 76 patients (45 females, 31 males) with an average age of 63.3(range 41–75) years. Patients were followed for a mean of 32 months (range, 8 to 84 months). The average duration of symptoms prior to arthroscopy was 13 months (range 1 month to 69 months) from primary UKA. Patients presented with the following symptoms: mechanical problems (instability, limited range of motion, locking and clicking) in 71%, painful prosthesis in 25%, and suspicion of periprosthetic infection in 4% of cases. Arthroscopic treatment consisted of irrigation, removal of impinging tissue or loose body as indicated. Operative diagnoses included, but were not limited to arthrofibrosis, impinging hypertrophic synovitis, chondromalacia, loose fragments, medial or lateral meniscal tear, prosthesis loosening or wear, partial anterior cruciate ligament rupture, and an infrapatellar spur. Eight patients required repeat arthroscopy and at an average follow-up of 18 months (range 1–58 months), 80% of patients had no recurrent symptoms. Fourteen patients required revision to a TKA (18%) for reasons diagnosed by arthroscopy (Table 1). One patient had an additional patellofemoral arthroplasty (1%) and another patient required revision of the femoral component (1%). At final follow-up, the mean Oxford Knee Score was 30 (range, 8–48).
Discussion and conclusion:
With the help of arthroscopy after UKA, symptoms in 80% of patients were diagnosed and treated successfully. Furthermore, arthroscopy established the need for revision TKA or other additional procedures in 20% of cases. The use of arthroscopy in patients following problematic UKA in the current study proved to be an effective method of treating and identifying the underlying cause of patient symptoms.
