Knee replacement surgery is one of the most common surgical procedures performed worldwide. Unfortunately, knee prostheses can become painful over time, necessitating appropriate analgesic treatment. Bisphosphonates such as clodronate (CLO) may play an important role in the treatment of painful knee prostheses by virtue of its analgesic and anti-inflammatory properties.
In this prospective open label pilot study, eighteen consecutive patients aged 73.2±8.9 years affected by knee painful prosthesis and osteoarthritis were treated with a rehabilitation cycle in addition to i.v. or i.m. CLO. Induction dose was 2.0-2.1g, followed by a weekly dose of 200 mg (i.m.) for 6 months. Visual analogue scale (VAS) pain score and Tegner Lysholm Score (TLS) were used to assess improvement following CLO treatment.
Thirteen out of 18 patients completed the 6-month follow-up. VAS pain score decreased from 8.1±1.8 at baseline to 5.6±2.6 (P<0.05) and TLS increased from 40.4±20.3 at baseline to 62.7±24.1 at 6 months (P<0.05). Univariate regression revealed that among a range of variables, BMI was positively correlated with VAS (r=0.73, P=0.004) and lower TLS after 1 month (r= -0.62, P=0.006).
CLO in association with rehabilitation exercises can reduce pain and ameliorate the functionality of painful knee prostheses. Administration of a high dose (induction dose) of CLO every 3 months appears to be the most effective regimen compared to a weekly maintenance dose.