The role of arthroscopic debridement after anterior cruciate ligament reconstruction

Additional surgery after anterior cruciate ligament reconstruction: can we improve technical aspects of the initial procedure?

PURPOSE

To determine factors that cause reoperation after anterior cruciate ligament (ACL) reconstruction and determine which cause of reoperation can be addressed to help to improve technical aspects of the initial procedure.

METHODS

Between 1988 and 1998, 436 patients underwent an ACL reconstruction by a single surgeon. We analyzed all 207 patients who had a bone-patellar tendon-bone reconstruction (BPTB). The same technique was used in all operations, which consisted of the 1-incision endoscopic approach with autologous central third patellar-tendon graft. Of these patients, 196 were available for full evaluation. Evaluation included: a detailed history, physical examination, functional knee ligament testing, KT-1000 arthrometer testing, One-leg-hop testing, Lysholm score, Tegner score, and the International Knee Documentation Committee standard evaluation form. All technical surgical aspects concerning the index operation and the reoperations were collected and evaluated in detail to detect predictors for failure or improvement. Position of the graft was measured radiographically using the Amis circle and Taylor score.

RESULTS

The average age of the 196 patients at the time of the operation was 34 years, and the mean duration of follow-up was 7.4 years. Seventy-seven reoperations were performed in 54 (27.6%) patients during a period of 83 months postsurgery. Reoperations were done between day 22 and 83 months post-ACL reconstruction. Indications for reoperations were: pain caused by fixation material (n = 25); meniscal lesions (n = 24); cyclops lesion (n = 16); donor site morbidity (n = 5); re-rupture of the ACL (n = 5); posterior cruciate ligament rupture (n = 1); and a medial collateral ligament lesion (n = 1). A more ventral position of the graft on the femur (Amis <60%) was correlated with a higher frequency of meniscal lesions and cyclops lesions (P < .01). Patients who had a meniscal lesion after an ACL reconstruction had significantly lower Lysholm (P < .05) and Tegner scores (P < .01).

CONCLUSIONS

A large percentage of the patients (27.6%) required additional surgical procedures after patellar tendon autograft ACL reconstruction. A poor position of the graft resulted in cyclops and meniscal lesions. Analyzing the reasons for reoperations gives information about how to improve our surgical technique.

LEVEL OF EVIDENCE

Level IV, therapeutic case series.

Loss of extension after reconstruction of the anterior cruciate ligament

The most common complication of anterior cruciate ligament (ACL) reconstruction is loss of extension, which is often functionally worse for patients than their preoperative instability. Many preventable surgical and nonsurgical etiologic factors have been identified. Accurate placement of the tibial tunnel, adequate notchplasty, and the routing of the femoral side of the graft are all critical factors. Several studies report that early range-of-motion therapy emphasizing immediate postoperative "hyperextension" and avoiding immobilization in flexion reduces the rate of loss of extension. Initial studies investigating the effect of acute versus chronic ACL reconstruction suggested that acute reconstruction is associated with a higher rate of loss of extension. However, the authors of two recent studies in which modern techniques were used have disputed this conclusion. It is likely that the loss of extension historically seen with acute ACL reconstructions was related to tibial tunnel placement and postoperative immobilization. It is possible that the timing of acute ACL reconstruction has less of an effect than originally postulated. On the basis of the results of several biomechanical studies, it appears that ACL reconstruction may be performed with the knee in full extension during graft placement with excellent results and a very low rate of loss of extension. Use of the descriptive term "loss of extension" is preferred to the often misleading terms "arthrofibrosis" and "flexion contracture."

Cyclops lesion

Postoperative impingement of the knee following ACL reconstruction does occur. MRI can be useful in the diagnosis of the patient who is not recovering as quickly as expected following surgical reconstruction. MRI allows the assessment of 1) tunnel position and alignment, 2) graft integrity, 3) the menisci for possible re-tear or extension of previous tears, and 4) joint for scar tissue and cartilaginous bodies either loose or fixed.

Knee extension and its relationship to the slope of the intercondylar roof. Implications for positioning the tibial tunnel in anterior cruciate ligament reconstructions

This study determined that knee extension (range, -30 degrees to 2 degrees) and the slope of the intercondylar roof (range, 26 degrees to 46 degrees) vary widely between knees in both men and women. We found a weak relationship between knee extension and the slope of the intercondylar roof (r2 = 0.207); therefore, roof angle cannot be predicted by clinically measuring knee extension. CLINICAL RELEVANCE; A knee with a given degree of extension can have a variety of different slopes to the intercondylar roof. Knees with the combination of hyperextension and a vertically oriented slope to the intercondylar roof are "unforgiving" because they require a more posterior position for the tibial tunnel to avoid roof impingement and an extensive roofplasty. If the surgical objective is to minimize the extent of the roofplasty and avoid roof impingement, then consideration should be given to customizing the placement of the tibial tunnel to account for variability in knee extension and roof angle when reconstructing the anterior cruciate ligament. Studies have shown that isometric graft placement can be achieved with this surgical approach.

Problems in regaining full extension of the knee after anterior cruciate ligament reconstruction: does arthrofibrosis exist?

A total of 194 patients was reviewed after ACL reconstruction using a patellar tendon graft or Leeds-Keio prosthesis supplemented with a MacIntosh lateral substitution. There were five groups of patients: patellar tendon with cast immobilisation in flexion (n = 34); restricted extension but no cast (n = 40); immediate full extension (n = 40); 40); immediate full extension with notch widening (n = 40); Leeds-Keio ligament prosthesis (n = 40). The incidence of a click or a block to extension requiring operation ranged from 59% following cast immobilisation to 2.5% with the Leeds-Keio ligament. The incidence was significantly less when a Leeds-Keio prosthesis was used, and these problems may be associated with biological materials only. Restricting extension after operation significantly increased the loss of extension, confirming the work of others. Loss of extension was due to a mechanical block in all cases examined arthroscopically. All were relieved by arthroscopic surgery, and no case of flexion contracture or arthrofibrosis was encountered. A simple mechanical block to extension caused by a Cyclops lesion should be clearly distinguished from flexion contracture and arthrofibrosis, conditions which are probably extremely rare and overdiagnosed.