Thermal modification of partial tears of the anterior cruciate ligament.

PURPOSE

Partial tears of the anterior cruciate ligament (ACL) are common, representing 10% to 28% of all ACL tears. Untreated partial tears of the ACL may go on to complete rupture in up to 42% of cases, and as few as 30% of patients return to their preinjury activity level. The purpose of this study was to evaluate the effectiveness of thermal modification for the treatment of partial tears of the ACL.

TYPE OF STUDY

A prospective, nonrandomized consecutive case series.

METHODS

Thirteen patients with a partial tear of a native ACL were treated with thermal modification of the ACL. All patients had a preoperative office examination significant for an end-point to Lachman examination and pivot-glide. All patients had bilateral preoperative KT-1000 measurements. All tears were confirmed by arthroscopy to constitute a 50% or less loss of structural integrity of the ligament. The ACL underwent thermal modification using the Oratec thermal probe (Oratec Interventions, Menlo Park, CA), and was examined by intraoperative KT-1000 testing. Patients were evaluated postoperatively at 6 weeks, and at 3, 6, 12, and 24 months by office examination and functional outcome scoring.

RESULTS

KT-1000 arthrometer testing revealed a mean side-to-side difference of 4.35 mm preoperatively (SD = 1.1 mm). At the most recent follow-up, averaging 23 months (range, 18 to 28 months), 10 patients had a negative Lachman examination and no pivot-shift. Two patients had persistent grade II Lachman and complaints of giving way 3 months postoperative. Both patients underwent ACL reconstruction. One patient was lost to follow-up. Of the remaining 10 patients, all patients achieved full extension, and the average flexion range of motion was 131 degrees (SD = 5.6). Compared with the preoperative KT-1000 arthrometer testing, the most recent evaluation revealed a decrease in mean side-to-side difference to 1.9 mm (SD = 1.5 mm). At most recent follow-up, the mean Lysholm score was 96.3 (SD = 4.4), the mean Tegner score was 6.1 (SD = 1.2), and the mean Cincinnati score was 94 (SD = 3.0).

CONCLUSIONS

With cautious application, thermal modification may be a viable treatment option for partial tears of the ACL in a select subset of patients. Further investigation is necessary to determine the long-term effectiveness of this procedure.

LEVEL OF EVIDENCE

Level IV, Therapeutic Case Series Study (no or historical control group).