Do broken cross-pins compromise stability after anterior cruciate ligament reconstructions with hamstring tendons?
OBJECTIVE
The purpose of this prospective study was to define the relation between the integrity of cross-pin femoral fixation and stability after anterior cruciate ligament (ACL) reconstructions.


METHODS
Thirty-one consecutive ACL reconstructions were performed with hamstring tendons fixed with bioabsorbable cross-pin femoral fixation. All patients underwent magnetic resonance imaging at 6 months postoperatively to assess the status of the cross-pin fixation. Clinical evaluations were performed via the Lachman and pivot-shift tests. The side-to-side differences were measured by KT-1000 testing (MEDmetric, San Diego, CA) at 2 years postoperatively. The patients were divided into 2 groups according to the status of the cross-pin. Group I consisted of those in whom the cross-pins were intact, and group II had broken cross-pins.


RESULTS
There were 19 patients in group I and 12 (38.7%) in group II. Among the 24 cross-pins used in the 12 patients in group II, 18 were broken. Among the patients in group I, the tip of the cross-pin was inside the posterior cortex of the distal femur in 7 (36.8%) and outside in 12 (63.2%). In group II the tip of the cross-pin was outside the posterior cortex of the distal femur in all patients. This number was significantly higher than that in group I (P = .017). Group I had significantly lower KT-1000 measurements than group II (P = .003). The mean KT-1000 side-to-side difference was 0.47 mm in group I and 3.0 mm in group II. The Lachman and pivot-shift test data revealed no significant differences between the 2 groups (P = .467 and P = .796, respectively).


CONCLUSIONS
This study showed that breakage of bioabsorbable cross-pins is a relatively common phenomenon. Broken cross-pins were a factor relating to laxity after ACL reconstructions with hamstring grafts. Posterior direction of the cross-pin may be a cause of pin breakage.


METHODS
Level IV, therapeutic case series.
Choi
Nam-Hong
NH
Department of Orthopaedic Surgery, Eulji Medical Center, Seoul, South Korea. cnh2406@yahoo.com
Lee
Jung-Hoon
JH
Victoroff
Brian N
BN
D000293:Adolescent; D000328:Adult; D016118:Anterior Cruciate Ligament / Q000601:surgery; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D001858:Bone Nails; D001863:Bone Screws; D005260:Female; D005269:Femur / Q000601:surgery; D005500:Follow-Up Studies; D006801:Humans; D007593:Joint Instability / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery; D007718:Knee Injuries / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D019637:Orthopedic Procedures / Q000295:instrumentation; D011475:Prosthesis Failure; D016059:Range of Motion, Articular / Q000502:physiology*; D019651:Plastic Surgery Procedures / Q000379:methods*; D012189:Retrospective Studies; D013536:Suture Techniques / Q000295:instrumentation; D013710:Tendons / Q000637:transplantation*