Tunnel widening in anterior cruciate ligament reconstruction: a prospective evaluation of hamstring and patella tendon grafts

• Published in: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA Vol. 7; no. 3; pp. 138 - 145
• Main Authors: Clatworthy, M G, Annear, P, Bulow, J U, Bartlett, R J
• Format: Journal Article
• Language: English
• Published: Germany Springer Nature B.V 01.05.1999
• Subjects: Adult; Anterior Cruciate Ligament - surgery; Anterior Cruciate Ligament Injuries; Arthroscopy; Clinical significance; Endoscopy; Female; Follow-Up Studies; Humans; Knee; Knee Injuries - diagnostic imaging; Knee Injuries - surgery; Knee Joint - diagnostic imaging; Knees; Ligaments; Magnetic Resonance Imaging; Male; Measurement; Muscle strength; Muscle, Skeletal - transplantation; Muscles; Patella; Patients; Postoperative Complications - diagnostic imaging; Prospective Studies; Radiography; scoring; Skin & tissue grafts; Strength; Surgery; Tendons; Tendons - transplantation; X-rays; Australia; Melbourne Victoria Australia
• ISSN: 0942-2056; 1433-7347
• DOI: 10.1007/s001670050138

We report a prospective series evaluating the incidence and degree of tunnel widening in a well-matched series of patients receiving a hamstring or patella tendon graft for anterior cruciate ligament (ACL) deficiency. We correlated tunnel widening with clinical factors, knee scores, KT-1000 and isokinetic muscle strength to determine the clinical significance of this finding. Seventy-three patients at least 12 months post-ACL reconstruction were evaluated. Thirty-eight patients had received a doubled semitendinous and gracilis graft and 35 a bone-patella tendon-bone graft. All patients underwent a similar endoscopic procedure and accelerated postoperative rehabilitation. Tunnel widening was determined using standardized anteroposterior (AP) and lateral X-rays adjusted for magnification. A limited series of MRIs was performed to validate these measurements. There was a significant difference in the degree of tunnel widening between the two groups. The mean increase in femoral tunnel area in the hamstring group was 100.4% compared with a decrease of 25% in the patella tendon group (P = < 0.0001). In the tibial tunnel the mean increase in the hamstring group was 73.9% compared with a decrease of 2.1% in the patella tendon group (P = < 0.0001). The MRIs validated the plain film measurements. Tunnel widening did not correlate with the clinical findings, knee scores, KT-1000 or isokinetic muscle strength. Tunnel widening is marked in the hamstring group. Tunnel widening does not correlate with instability or a poor clinical outcome in the short term. The long-term implications of this finding are still to be determined.