Gregory S. DiFelice

Primary repair of the anterior cruciate ligament: A paradigm shift

Over the last century, many surgical treatments have been developed in the orthopedic field, including treatments of anterior cruciate ligament (ACL) injuries. These treatments ideally evolve in a process of trial and error with prospective comparison of new treatments to the current treatment standard. However, these evolutions are sometimes not linear and periodically undergo paradigm shifts. In this article, we review the evolution of ACL treatment and explain how it underwent a paradigm shift. Open primary ACL repair was the most common treatment in the 1970s and 1980s, but because multiple studies noted deterioration of outcomes at mid-term follow-up, in addition to several randomized clinical trials (RCTs) that noted better outcomes following ACL reconstruction, the open primary repair technique was abandoned. At the end of the primary repair era, however, several studies showed that outcomes of open primary repair were good to excellent and did not deteriorate when this technique was selectively performed in patients with proximal ACL tears, whereas primary repair led to disappointing and unpredictable results in patients with mid-substance tears. Unfortunately, enrollment of patients in the aforementioned RCTs was already finished, ultimately leading to abandoning of open primary repair, despite the advantages of ligament preservation. In this review, we discuss (I) why the evolution of ACL treatment underwent a paradigm shift, (II) which factors may have played a role in this and (III) what the future role of arthroscopic primary ACL repair is in the evolution of ACL treatments.

Preoperative magnetic resonance imaging predicts eligibility for arthroscopic primary anterior cruciate ligament repair

PurposeTo assess the role of preoperative magnetic resonance imaging (MRI) on the eligibility for arthroscopic primary anterior cruciate ligament (ACL) repair.MethodsAll patients undergoing ACL surgery between 2008 and 2017 were included. Patients underwent arthroscopic primary repair if sufficient tissue length and quality were present, or they underwent single-bundle ACL reconstruction. Preoperative MRI tear locations were graded with the modified Sherman classification: type I (>90% distal remnant length), type II (75–90%), or type III (25–75%). MRI tissue quality was graded as good, fair, or poor. Arthroscopy videos were reviewed for tissue length and quality, and final treatment.ResultsSixty-three repair patients and 67 reconstruction patients were included. Repair patients had more often type I tears (41 vs. 4%, pxa0<xa00.001) and good tissue quality (89 vs. 12%, pxa0<xa00.001). Preoperative MRI tear location and tissue quality predicted eligibility for primary repair: 90% of all type I tears and 88% of type II tears with good tissue quality were repaired, while only 23% of type II tears with fair tissue quality, 0% of type II tears with poor tissue quality, and 14% of all type III tears could be repaired.ConclusionsThis study showed that tear location and tissue quality on preoperative MRI can predict eligibility for arthroscopic primary ACL repair. These findings may guide the orthopaedic surgeon on the preoperative assessment for arthroscopic primary repair of proximal ACL tears.Level of evidenceLevel IV.

Gap formation following primary repair of the anterior cruciate ligament: A biomechanical evaluation

BACKGROUNDnHistorically, inconsistent and unpredictable results of open primary anterior cruciate ligament (ACL) repair were reported. Recently, however, good results of arthroscopic primary ACL repair of proximal tears have been reported. Purpose of this study was to assess the direct postoperative gap formation and maximum failure load following simulated knee motion after primary ACL repair.nnnMETHODSnSix matched-paired human cadaveric knees (mean age: 52years, range: 48 to 56years) were used. After primary proximal ACL repair with either suture button fixation or suture anchor fixation, knees were cycled five, 50 and 100 times with a simulated active quadriceps force. Gap formation between the femoral wall and ligament was measured using a digital caliper and maximum failure load was tested.nnnRESULTSnGap formation after five, 50 and 100cycles of the knee were 0.30mm (±0.23), 0.75mm (±0.55) and 0.97mm (±0.70), respectively, with no significant differences between both fixation techniques. The overall maximum failure load was 243N (±143) with no difference between both techniques. Most common failure mode was slipping of suture from the fixation.nnnCONCLUSIONnFollowing proximal ACL repair, gap formation of approximately one millimeter was measured after repetitious knee cycling with mean maximum failure load of 243N. These findings are likely to be sufficient for careful early active range of motion (ROM) when extrapolating from other available studies. Future studies with second-look arthroscopy are necessary to assess the gap formation and healing in patients treated with primary repair.

Range of motion and complications following primary repair versus reconstruction of the anterior cruciate ligament

INTRODUCTIONnRecently, there has been a resurgence of interest in primary anterior cruciate ligament (ACL) repair. The procedure is less invasive than ACL reconstruction, yet studies assessing early postoperative course are lacking. Goal therefore was to assess postoperative range of motion (ROM), complications and operative times following primary repair and compare this to the gold standard of reconstruction.nnnMETHODSnA retrospective study was performed for which 52 repair and 90 reconstruction patients could be included. Patients were examined at one week and one, three and six months. Rehabilitation protocol consisted of early ROM and was equal for both groups. Outcomes were compared using independent t-tests and chi-square tests, and reported in mean±standard deviation.nnnRESULTSnRepair had more ROM than reconstruction patients at one week (89°±18 vs. 61°±21, p<0.01) and one month (125°±14 vs. 116°±18, p < 0.01) postoperatively. Fewer repair patients had 90° ROM at one week (23% vs. 84%, p<0.01), and more repair patients had full ROM at one month (57% vs. 30%, p<0.01). Treatment of meniscal lesions, but not chondral lesions, influenced ROM. Trends towards fewer complications (2% vs. 9%, p=0.19) and infections (0% vs. 6%, p=0.20) were noted following primary repair, and the procedure was significantly shorter.nnnCONCLUSIONSnFollowing primary repair, patients had better ROM, and trends towards fewer complications than reconstruction. Primary repair is a safe, brief procedure with early ROM and low complication rates.

Role of tear location on outcomes of open primary repair of the anterior cruciate ligament: A systematic review of historical studies

BACKGROUNDnThe general opinion is that outcomes of open primary repair of the anterior cruciate ligament (ACL) in the historical literature were disappointing. Since good outcomes of primary repair of proximal tears have recently been reported, we aimed to assess the role of tear location on open primary repair outcomes in the historical literature.nnnMETHODSnAll studies reporting outcomes of open primary ACL repair published between the inception of PubMed, Embase and Cochrane and 2000 were identified. Studies were included if tear location was reported. Outcome scores, return to sports, stability examinations, failures and patient satisfaction were collected and reviewed in the total study cohort and in a subgroup of studies treating only proximal tears. Spearman correlation analysis was performed between the percentage of proximal tears in the studies and all outcomes.nnnRESULTSnTwenty-nine studies were included reporting outcomes of open primary in 1457 patients of which 72% had proximal and 23% midsubstance tears. Mean age was 30years, 65% were males, and mean follow-up was 3.6years. Good outcomes were noted in the total cohort, and excellent outcomes were noted following repair of proximal tears. Positive correlation was found between the percentage proximal tears in the studies and percentage satisfied patients (p=0.010).nnnCONCLUSIONnTear location seems to have played a role on the outcomes of open primary ACL repair. Outcomes of open primary repair in patients with proximal tears were excellent, which confirms there may be a potential role for primary repair as treatment for proximal ACL tears.

Primary Repair of the Medial Collateral Ligament With Internal Bracing

The medial collateral ligament (MCL) is commonly injured in the setting of anterior cruciate ligament (ACL) injuries. Because the MCL has better healing capacity than the ACL, the general perception is that MCL injuries can be treated conservatively. Treating these injuries conservatively, however, can lead to residual valgus laxity. Furthermore, it delays time to surgery, which prevents acute treatment of concomitant ACL injuries using primary repair or acute reconstruction. Several treatment methods for MCL injuries have been proposed, including primary repair, augmented repair with autograft tissue, or primary reconstruction. In this surgical technique article, we present the technique of acute primary MCL repair with internal bracing with 2 limited incisions. With this technique, early surgical intervention is possible, and early rehabilitation is safe because of the internal bracing. Advantages include fast recovery, avoidance of muscle atrophy because of early mobilization, prevention of residual valgus instability, and maintenance of proprioception.

Arthroscopic Primary Posterior Cruciate Ligament Repair With Suture Augmentation

Isolated posterior cruciate ligament (PCL) injuries are relatively rare and PCL injuries most commonly occur in the setting of multiligamentous knee injuries. PCL injuries can be treated with primary repair, which has the advantages of preserving the native tissue, maintaining proprioception, and minimal invasive surgery when compared with reconstruction surgery. Historically, primary repair of PCL injuries was performed in all tear types using an open approach, and, although the subjective outcomes were relatively good, patients often had residual laxity. Modern advances and increasing knowledge could improve the outcomes of PCL repair. With magnetic resonance imaging patients with proximal tears and sufficient tissue quality can be selected, and with arthroscopy and suture anchors minimal invasive surgery with direct fixation can be performed. Furthermore, with suture augmentation the healing of the repaired PCL can be protected and the residual laxity can be prevented. In this Technical Note, we describe the surgical technique of arthroscopic primary repair of proximal PCL tears with suture anchors and suture augmentation. The goal of arthroscopic primary repair is the preservation of the native PCL using a minimally invasive method and subsequent protection of this repair using suture augmentation.

Arthroscopic Primary Cruciate Repair in the Multiligament Injured Knee

Multiligamentous injuries of the knee (MLIK) are rare and devastating injuries. The literature regarding the optimal management of MLIK is both inconsistent and confusing, thus creating numerous controversies regarding the best treatment strategies for the MLIK. One of the most controversial topics is the role of acute repair versus reconstruction of the damaged ligaments. While allograft reconstructive techniques are the most widely used for the majority of patients, repair techniques can be very effective in selected situations. Despite the many benefits of primary repair, recent trends are moving in favor of reconstruction for all injuries. Our experience with arthroscopic primary repair of the cruciate ligaments has been very promising in strictly indicated patients. Patients with avulsion injuries of the ACL or PCL from the femoral or tibial footprint are the most likely to benefit from acute primary arthroscopic repair. It is not advisable to utilize repair for cruciate ligaments with midsubstance injuries. The described technique can and should be used as one tool in the surgical armamentarium used to treat the MLIK. Patient outcomes will be dependent on the prudent management of associated bony, articular, soft tissue, and collateral ligament injuries. The surgeon must apply appropriate surgical indications, demonstrate the technical ability to perform this challenging surgery, and communicate closely with the patient and physical therapist postoperatively to optimize results.

Reply to the letter to the editor regarding our article “Preoperative magnetic resonance imaging predicts eligibility for arthroscopic primary anterior cruciate ligament repair”

The first surgical treatment of anterior cruciate ligament (ACL) injuries consisted of open primary repair [22–25, 27, 35]. The initial short-term outcomes in the 1970s and 1980s were promising [8, 9, 16], but Feagin and Curl were the first to note a deterioration of these results at midterm follow-up [10]. Despite many improvements, such as using non-absorbable sutures [18, 19], the results remained unpredictable at mid-term follow-up [13], and the technique was ultimately abandoned [35]. At the end of the primary repair era, in 1991, Sherman et al. [28] attempted to find an explanation for the deterioration of their results at mid-term follow-up by performing an extensive subgroup analysis. They categorized ACL tears by tear location and tissue quality and noted that better outcomes were associated with proximal (type I) tears and good tissue quality compared to mid-substance tears and poor tissue quality. Subsequently, several authors reported excellent outcomes of open primary repair when selectively treating patients with proximal tears and good tissue quality [4, 11, 37]. Despite these results, reconstructive surgery had become the standard operative treatment for all ACL injuries [35]. More recently, there has been a renewed interest in primary ACL repair using arthroscopy. DiFelice et al. were the first to report excellent outcomes of arthroscopic primary repair in patients with proximal (type I) tears and Abstract Purpose To assess the role of preoperative magnetic resonance imaging (MRI) on the eligibility for arthroscopic primary anterior cruciate ligament (ACL) repair. Methods All patients undergoing ACL surgery between 2008 and 2017 were included. Patients underwent arthroscopic primary repair if sufficient tissue length and quality were present, or they underwent single-bundle ACL reconstruction. Preoperative MRI tear locations were graded with the modified Sherman classification: type I (>90% distal remnant length), type II (75–90%), or type III (25– 75%). MRI tissue quality was graded as good, fair, or poor. Arthroscopy videos were reviewed for tissue length and quality, and final treatment. Results Sixty-three repair patients and 67 reconstruction patients were included. Repair patients had more often type I tears (41 vs. 4%, p < 0.001) and good tissue quality (89 vs. 12%, p < 0.001). Preoperative MRI tear location and tissue quality predicted eligibility for primary repair: 90% of all type I tears and 88% of type II tears with good tissue quality were repaired, while only 23% of type II tears with fair tissue quality, 0% of type II tears with poor tissue quality, and 14% of all type III tears could be repaired. Conclusions This study showed that tear location and tissue quality on preoperative MRI can predict eligibility for arthroscopic primary ACL repair. These findings may guide the orthopaedic surgeon on the preoperative assessment for arthroscopic primary repair of proximal ACL tears.

Multiligament Repair With Suture Augmentation in a Knee Dislocation With Medial-Sided Injury

Knee dislocations often result in a severe multiligament injured knee (MLIK) with complex instability. Multiligament reconstruction can successfully restore knee stability and is commonly recommended, although surgical morbidity is induced by graft harvesting and tunnel drilling, and convergence of multiple tunnels can complicate the surgery. Therefore, as an alternative, primary repair of knee ligaments is currently reconsidered. The main advantages of primary repair consist of tissue preservation and decrease of surgical morbidity, which might improve knee functionality. Techniques in which avulsed ligaments are reapproximated to their anatomic origin have resulted in good clinical outcomes in selected patients over the past decade. More recently, repaired ligaments have been augmented with suture tape, to protect them from excessive stretch, which can improve healing and allows early rehabilitation. The surgical technique of primary repair in the multiligament injured knee has not yet been described. The purpose of this Technical Note is to explain suture augmented primary repair in KDIII-M injury, including the anterior cruciate ligament, posterior cruciate ligament, and medial collateral ligament.