Revision Anterior Cruciate Ligament Reconstruction
DEFINITION
The anterior cruciate ligament (ACL) is the primary stabilizer preventing anterior displacement of the tibia. The ligament is composed of two functional bundles, namely the anteromedial and posterolateral bundles. These bundles are named after the position of their insertion site on the tibia.
The ACL plays a significant role in assisting capsular structures, the collateral ligaments (ie, medial collateral ligament [MCL] and lateral collateral ligament [LCL]), joint surface, and meniscal geometry to prevent rotational instability.
Failure of a primary ACL reconstruction may be due to traumatic rerupture, graft attenuation, failure of graft incorporation, failure to diagnose and treat concomitant injuries (ie, posterolateral or posteromedial corner injuries), or technical errors during primary ACL reconstruction (ie, tunnel malposition, loss of graft fixation, etc.; see Chap. 50).
ANATOMY
The anatomy of the ACL (described in previous chapters) and also that of the secondary stabilizers of the knee are critical in revision surgery. Secondary restraints to anterior translation of the tibia include the MCL,
the posterior horn of the medial meniscus, and the posterior aspect of the capsule.6
Unrecognized rotatory instability patterns play a significant role in failures of primary ACL reconstruction.
Primary ACL reconstruction can be performed using a number of different graft sources, including autograft bone-patellar tendon-bone, hamstring, and quadriceps tendon. Allograft sources include bone-patellar tendon-
bone, Achilles tendon, hamstring, anterior tibialis, and quadriceps tendon.4
Synthetic graft sources have been investigated; however, these materials have demonstrated poor clinical outcomes and high reoperation rates due to recurrent pain, synovitis, joint effusion, and ultimately, graft failure.
Graft fixation can be achieved with a number of commercially available devices. In the revision setting, it is important to understand the technique and materials used in the initial reconstruction because it is often necessary to remove existing fixation devices to obtain optimal tunnel placement and secure graft fixation during the revision procedure.
PATHOGENESIS
Poor clinical outcomes following primary ACL reconstruction can be due to a multitude of factors. Primary surgical failure can be generally classified into one of four areas, including recurrent instability, motion loss, persistent pain, or extensor mechanism dysfunction. This chapter will focus on the diagnosis and surgical management of recurrent instability.
The incidence of recurrent instability after primary ACL reconstruction is 3% to 10%.11
Graft failure has been reported as the primary cause of recurrent instability. Three different categories of graft failure have been described: (1) failure of graft incorporation, (2) suboptimal surgical technique (eg, tunnel malposition, loss of fixation), and (3) traumatic rerupture. Although recurrent instability may be due to a combination of these factors, it is important to determine the primary mode of failure in order to address this issue during revision reconstruction.
NATURAL HISTORY
The natural history of the ACL-deficient knee is not well understood.
It is commonly thought that patients who experience episodes of recurrent instability may place the knee at risk for potential damage to the articular cartilage and menisci.
Although it may be possible for some patients to avoid activities that result in instability, others may continue to participate in sports, and some patients may even experience episodes of instability with activities of daily living.
PATIENT HISTORY AND PHYSICAL FINDINGS
A detailed history of the primary mechanism of injury, associated pathology, reconstruction technique, postoperative rehabilitation, ability to return to activity, and current symptoms are helpful to determine potential reasons for failure and subsequent optimal treatment.
It is helpful to determine the time from the initial injury to the index reconstruction.
An explanation of the postoperative rehabilitation program and timing of progression through therapy should be obtained (ie, time to return to running and sport-specific activities). Any traumatic episodes after surgery should be noted.
A copy of the operative report from the primary procedure should be obtained to note graft type, tunnel placement, fixation methods and materials, and condition of the articular surfaces and menisci at the time of the procedure.
An antalgic gait may be the result of persistent pain after surgery or a recent second traumatic event.
A varus thrust during gait is highly suggestive of incompetence of the lateral or posterolateral structures and requires further evaluation with standing long-film anteroposterior radiographs to determine mechanical alignment.
Buckling of the knee, especially in the initial phase of gait, may suggest quadriceps weakness and may give the patient the subjective sensation of knee instability.
Sensory status and palpation of pulses must be noted in all cases. Any decrease in pulses may suggest an initial
P.477
dislocation of the knee and require appropriate workup to rule out a vascular injury.
Common examinations to determine instability patterns of the knee include the following:
Anterior drawer test: When compared to the contralateral knee, increased anterior laxity may indicate an ACL-deficient knee.
Posterior drawer test: When compared to the contralateral knee, increased posterior laxity may be indicative
of a posterior cruciate ligament (PCL)-deficient knee.
Lachman test: This is a sensitive test for ACL deficiency, especially when the contralateral knee has an intact native ACL.
Varus/valgus stress testing: Increased joint space widening at 30 degrees of flexion is consistent with injury to the collateral ligaments. If joint space opening occurs in both 0 and 30 degrees, severe injury to collateral ligaments and other ligamentous structures, such as the cruciate ligaments or capsule, is suggested.
Pivot shift: This is a highly sensitive test for ACL deficiency.1 It is a complex, multiplanar maneuver that includes coupled translation (the anterior subluxation of the lateral tibia followed by its reduction) and rotation (rotation of the tibia relative to the femur). It is often difficult for the patient to relax in the setting of a painful knee, however.
Posterolateral drawer test: Increased posterolateral translation compared with the intact, contralateral knee may suggest posterolateral rotatory instability.
Dial test: A difference of more than 10 degrees at 30 degrees of flexion is consistent with injury to the posterolateral corner (PLC). A difference of more than 10 degrees at 90 degrees of flexion is consistent with a combined injury to both the PLC and PCL.
 |
 |
FIG 1 • A,B. Left knee ACL reconstruction performed with an EndoButton (Smith & Nephew, Andover, MA) on the femur and staple fixation of the graft on the tibia. C,D. Anterior placement of the femoral tunnel in this right knee primary ACL reconstruction performed with a two-incision technique.
The varus recurvatum test reveals varus angulation, hyperextension, and external rotation of the tibia. A positive test suggests posterolateral rotatory instability of the knee.
Testing for intra-articular injuries should be performed to detect concomitant meniscal, articular cartilage, or patellofemoral injuries.
Large effusions are common in the setting of a native ACL tear. In the revision setting, graft disruption may not result in a large hemarthrosis given the decreased vascularity of the graft material compared to the native ACL. Effusions in the setting of a failed ACL reconstruction may be small or even nonexistent.
IMAGING AND OTHER DIAGNOSTIC STUDIES
Routine radiographs, including weight-bearing anteroposterior and lateral views as well as patellar views,
should be performed. In the revision setting, these images facilitate critical assessment of previous tunnel placement and evaluation of any bone loss at previous tunnel sites, which may require further evaluation and treatment.
Metallic graft fixation devices make previous tunnel placement easy to identify, but bioabsorbable screws and other types of fixation can also be evaluated to determine tunnel placement on these images (FIG 1). These images also facilitate evaluation for possible evidence of osteoarthritis.
P.478
If concern regarding a significant amount of bone loss is present after initial radiographic evaluation, three-dimensional imaging with computed tomography (CT) scan or magnetic resonance imaging (MRI) can facilitate precise quantification of tunnel enlargement (FIG 2). MRI may also aid in the evaluation of tunnel size, graft continuity, and the status of other intra-articular structures (eg, articular cartilage, menisci). Metallic graft fixation devices may create significant artifact on both of these imaging techniques, thus limiting their use in some cases.
For varus alignment, or chronic posterolateral rotatory instability, radiographs that facilitate evaluation of mechanical alignment may be necessary. These will help the surgeon to determine whether there is a significant varus deformity of the knee.
In ACL-deficient knees with varus malalignment, any ligament reconstruction may be predisposed to gradual attenuation and eventual failure if the alignment is not first addressed with an osteotomy procedure.
 |
 |
FIG 2 • A,B. Anteroposterior and lateral radiographs of a 25-year-old patient that underwent primary and subsequent revision double-bundle ACL reconstruction using suspensory fixation on the femur. C,D. A CT scan was obtained to evaluate the amount of tunnel widening in both the femur and tibia.
Bone scan and serologic tests, including complete blood count, erythrocyte sedimentation rate, C-reactive protein, and bacterial cultures of knee aspirates, should be performed in any case that is suspicious for infection, including those cases with significant osteolysis of previous tunnels.
DIFFERENTIAL DIAGNOSIS
Meniscal injury Osteochondral injury
Subjective weakness or anterior knee pain secondary to quadriceps weakness Patella subluxation or dislocation
Multiligamentous injury (eg, PCL, PLC, MCL, LCL)
NONOPERATIVE MANAGEMENT
Patients with complaints of knee pain in the setting of a nonfunctioning ACL graft must understand that revision ACL reconstruction will not alleviate their pain and that
nonoperative management may be a better approach to address their symptoms.
P.479
The basis of any nonoperative treatment approach for an ACL-deficient knee is to avoid those activities that put the knee at risk, such as cutting and pivoting sports.
Strengthening the dynamic stabilizers of the knee such as the hamstrings (an antagonist to anterior translation of the tibia) may increase stability of the knee for routine activities.
Functional bracing is a nonoperative treatment alternative to provide kinematic restraint, reduce functional deficits, and prevent subsequent injury. However, it has variable success in controlling instability.
SURGICAL MANAGEMENT
Revision ACL reconstruction is primarily indicated in any patient with a chief complaint of symptomatic knee instability during physical activity. It is important to review the following expectations of revision surgery with the patient:
Revision ACL reconstruction does not address pain that may be experienced with physical activity. In these patients, contributing intra-articular pathology should be investigated as the cause of subjective pain.
Revision ACL reconstruction may prevent the progression of intra-articular pathology but will not, in itself, treat other lesions that may be present.
In general, the subjective outcomes following revision ACL reconstruction are inferior to primary ACL reconstruction.
Preoperative Planning
A common cause of failure related to surgical technique is anterior placement of a femoral tunnel, which can
be detected on the lateral radiograph (FIG 1D).6 This may lead to excessive tightening of the graft with knee flexion, thus leading to graft attenuation and subsequent failure.
A preoperative plan should take all of the preoperative findings, including patient history, examination, and imaging for other intra-articular pathology, into consideration. The surgeon should be prepared to address these comorbidities at the time of revision surgery.
Even if the surgeon does not expect to discover additional pathology at the time of revision surgery, it is important to be prepared to address any concomitant findings. All treatment options must be covered in detail during preoperative discussions with the patient.
In the setting of possible posterolateral rotational instability, varus malalignment, or significant bone loss requiring bone grafting, the patient must be aware of the potential decision to perform a staged procedure, and the details of alterations in the postoperative course should be discussed preoperatively.
The possibility of hardware removal requires knowledge of any previous implants used and extraction tools, such as a commercially available ACL revision tray, should be available in the operating room at the time of surgery.
Once anesthesia has been induced, a thorough examination of the knee relative to the contralateral extremity is critical. Concerns regarding posterolateral or varus instability will not be answered during arthroscopic
evaluation and are best assessed prior to prepping and draping.
Positioning
We prefer to position the patient supine on the operating room (OR) table and use a lateral post throughout the case.
The lateral post should be placed proximal enough to ensure the surgeon has unobstructed access to tibial tunnel drilling when the patient's knee is flexed over the edge of the table (FIG 3).
Approach
The standard anteromedial, anterolateral, and superolateral outflow portals are used for diagnostic arthroscopy.
If the previous incisions were adequately positioned, they may be used, but the placement of portal incisions should not be compromised for the sole purpose of reusing the previous incisions.
A complete diagnostic arthroscopic evaluation of the knee should be performed.
Treatment of other comorbid conditions should be performed before the ACL reconstruction is performed. These include repair or débridement of meniscal tears, removal of loose bodies, débridement with possible microfracture of osteochondral lesions, and hardware removal, if necessary.
 |
 |
FIG 3 • The lateral post is placed high against the lateral femur to allow adequate room on the medial aspect of the tibia to drill a tibial tunnel without interference from the operative table.
P.480
TECHNIQUES
-
Arthroscopy and Notchplasty
The diagnosis of an ACL-deficient knee is confirmed at the time of examination under anesthesia.
After completion of the diagnostic arthroscopy and treatment of any concomitant intra-articular pathology, the tourniquet is inflated.
The knee is flexed 90 degrees over a bump under the distal thigh with the popliteal space left free to allow the neurovascular structures to fall posterior to the posterior capsule.
The previous graft is removed with a 5.5-mm shaver down to the footprint of the native ACL.
The shaver can also be used to remove any areas of the fat pad that may be obstructing the surgical field, periosteum off the lateral wall of the notch, and any scar tissue present in the intercondylar notch.
 |
 |
 |
TECH FIG 1 • A. Significant overgrowth of the notch noted at the time of revision right knee ACL reconstruction. B. A thin layer of periosteum is easily visualized at the posterior wall of the notch. C. Note the anterior placement of the femoral tunnel interference screw used during the primary ACL reconstruction. The femoral tunnel for the revision can be placed at the appropriate location without removing the interference screw used in the primary procedure. D. The new femoral tunnel and interference screw are placed in the appropriate location without compromise from the screw used in the index procedure. E. View of femoral notch after placement of femoral tunnel and interference screw via anteromedial portal. This allows divergence of the old and new femoral tunnel. F. A divergent drilling technique can facilitate safe tunnel reaming and help avoid tunnel compromise. Using a slightly altered angle for femoral tunnel reaming creates a new tunnel with sufficient bone to obtain adequate fixation. (continued)
In revision ACL reconstruction, the intercondylar notch is often overgrown and narrow, likely as a result of the previous ACL reconstruction (TECH FIG 1A).
A notchplasty is completed with a 5.5-mm burr, starting at the anterior opening of the notch if necessary.
The location of the previous femoral tunnel is identified.
Notchplasty is carried back to the posterior wall as needed. A small, curved curette may be used to inspect the back of the notch. A thin white strip of periosteum usually identifies the posterior wall (TECH FIG 1B). Careful attention to localizing the posterior wall is critical, especially because the lateral side and the roof of the notch are often irregular with altered anatomy due to the previous surgery.
Anterior placement of the femoral tunnel is a common cause of recurrent laxity following primary ACL reconstruction; so in many cases, there is enough room to place a second femoral tunnel
P.481
in the appropriate position without interference or compromise from the previous tunnel. If this is the case, the previous interference screw can be left in place or removed (TECH FIG 1C-E).
 |
 |
TECH FIG 1 • (continued) G. This patient underwent transtibial ACL reconstruction. Note the vertical position of the tunnel after the graft material was débrided (black arrow). H. Using an anteromedial portal for femoral tunnel reaming, a divergent tunnel was safely created without encroaching on the previously drilled tunnel (black arrow). I. Final ACL reconstruction. Note the previous tunnel direction denoted by the black arrow. J. A flexible reamer introduced through the anteromedial portal. K. A flexible reaming system used to drill the femoral tunnel through an anteromedial portal.
A curved curette is used to remove a small area of bone to localize the desired position of the new femoral tunnel.
A properly placed femoral tunnel can be extremely challenging to revise following graft failure. In this case, it can be difficult to create a new tunnel that does not overlap with the old tunnel.
We have found that femoral tunnels drilled in a transtibial fashion can often be revised by drilling the revision tunnel through an anteromedial portal. Using this technique, the tunnels diverge, with only the intra-articular outlets overlapping (TECH FIG 1F-I). Flexible reaming systems are particularly helpful to achieve a divergent tunnel (TECH FIG 1J,K).
Conversely, if an appropriately placed femoral tunnel was previously drilled via an anteromedial portal, it can often be revised by drilling in a transtibial fashion to achieve diverging tunnels.
-
Graft Preparation
We usually prepare the graft after the tunnels have been drilled. With this approach, the bone plugs on the graft can be oversized in the unlikely event that the new tunnel and old tunnel substantially overlap and create a bony defect that is considerably larger than the standard tunnel size.
The graft of choice can be used.
We do not attempt to reharvest previously harvested tendons. Graft options include both autogenous and allogenic sources. We commonly use bone-patellar tendon-bone allograft.
Both bone plugs are cut to a length of 25 mm, with a height and width of 10 mm using a micro-oscillating saw.
A small rongeur is used to contour the bone plugs to fit through a 10-mm tunnel.
A 2-mm drill is used to drill one hole between the proximal twothirds and the distal one-third of the bone plug from the patella.
Two similar holes are drilled at a 90-degree angle to each other in the tibial bone plug. These holes are located at points approximately one- and two-thirds along the length of the bone plug.
No. 5 braided polyester sutures loaded on Keith needles are passed through each hole.
The graft is passed through a 10-mm sizer. The graft should slide easily with enough contact to ensure a tight fit when passed through the drilled tunnels.
The length of the tendinous part of the graft is measured from one end of the bone plug to the other end of the opposite bone plug.
The graft is wrapped in saline-soaked gauze and protected on the back table.
-
Tunnel Placement
P.482
Neither tibial nor femoral tunnel placement should be compromised based on the location of the previous tunnels.
The tibial tunnel guidewire is inserted in the same fashion as a primary ACL reconstruction procedure using a commercially available tibial guide.
We set the tibial guide at n + 7, with n being the length of the graft between the two bone plugs (n + 7 rule).9
The tip of the guide is placed in the posteromedial aspect of the native ACL footprint. The difficulty in revision cases is that the native ACL footprint is no longer visible. Therefore, we place the guidewire so that it penetrates the joint 6 to 7 mm anterior to the PCL and in a line that intersects the posterior aspect of the anterior horn insertion of the lateral meniscus (TECH FIG 2A).
If a metallic tibial interference screw was used in the previous reconstruction, it is usually in a location that necessitates removal.
At this point, the leg is brought back onto the table, and the interference screw is localized.
All overgrown soft tissue and bone is carefully removed, and then the appropriate driver (based on the operative note from the previous procedure) is used to remove the screw.
Next, the guide is rechecked and the sliding bullet is placed flush on the tibia. The measurement on the bullet should be slightly longer than the tendinous portion of the graft (n + 2 rule).12
The guidewire is then advanced, and if correctly placed, the tibial tunnel is drilled with a 10-mm reamer.
Soft tissue and bone debris are removed with the use of a 5.5-mm shaver, and the tunnel is inspected with the arthroscope for wall compromise from the previous tunnel. This can be performed by placing the arthroscope up the tibial tunnel.
![]()
![]()
TECH FIG 2 • A. Placement of the tibial tunnel guidewire just anterior to the native PCL in a left knee. B. After reaming the femoral tunnel to a depth of 10 mm, the tunnel is inspected to ensure the posterior wall is intact.
If there is concern regarding fixation strength with the interference screw, the tibial bone plug can be reinforced by tying the suture previously placed through the bone plug over a post just distal to the tibial tunnel.
Attention is then directed to the femoral notch.
A point is marked with a curette along the femoral notch 6 mm (for a 10-mm graft) anterior to the posterior wall in the 1:30 position (left knee) or the 10:30 position (right knee).
A Beath pin is advanced across the joint to the previously marked site on the femur. This usually can be achieved using a transtibial technique.
In some cases, it is not possible to get the pin to the desired location. In such a case, the knee is flexed to 120 degrees and the Beath pin is passed through the anteromedial portal.
As previously mentioned, this technique can also be used when the previous femoral tunnel was placed in an acceptable position using a transtibial technique.
This facilitates divergence of the new tunnel with respect to the old without compromising the entry point into the femoral notch (see TECH FIG 1F).
A 10-mm acorn reamer is then advanced by hand through the joint, using care not to damage the PCL. The reamer is advanced to a depth of 10 mm.
It is then brought back into the notch so that the back wall can be inspected (TECH FIG 2B).
At this time, the tunnel is inspected to ensure that the previous femoral tunnel does not compromise the new tunnel.
If there is compromise, one of the other techniques mentioned in the following sections is performed. If the back wall is intact, the reamer is advanced to a depth of 30 mm.
-
Graft Passage and Tensioning
Once appropriate tunnels have been drilled, the single suture from the bone plug from one end of the graft is passed through the Beath pin and then advanced into place.
The bone plug is advanced into the femoral tunnel under careful visualization to ensure the graft does not rotate and the bone plug is in the anterior aspect of the tunnel.
The knee is flexed to 120 degrees, and the interference screw is placed while gentle tension is maintained on the graft.
Again, careful visualization is used to ensure the graft is not cut by the threads of the advancing screw. The screw is advanced so that it is recessed 1 to 2 mm from the tunnel opening.
After checking for appropriate isometry of the graft by palpating the tibial bone plug through an arc of motion, the graft is manually tensioned.
While maintaining tension, the knee is flexed to about 10 to 20 degrees, and the tibial interference screw is placed.
A final range-of-motion (ROM) check is performed, and a gentle Lachman test is used to ensure that stability has been restored.
-
Two-Incision Technique
P.483
For cases in which the previous femoral tunnel was placed in a location that would have been preferred for the revision procedure, or significant osteolysis around the previous tunnel makes placement of the new tunnel difficult, the two-incision technique may be used to create the femoral tunnel.
This technique uses the same tunnel aperture but at a different angle.
This facilitates fixation of the femoral bone plug at the lateral cortex of the distal femur, a location typically not affected by previous ACL reconstruction.
For cases in which the primary ACL reconstruction was performed with a two-incision technique, our standard arthroscopic technique typically works without difficulty to ensure proper placement of the femoral tunnel.
For femoral tunnel reaming using a two-incision technique, a commercially available, rear-entry drill guide is used.
![]()
![]()
TECH FIG 3 • A. The femoral interference screw is placed into the femoral tunnel of a right knee through the lateral cortex. B. A retrograde drill with a manually retractable cutting blade can aid in creating a divergent tunnel. Here, the reverse cutting blade is used to create a blind femoral socket away from a vertically oriented tunnel in a left knee.
A lateral incision is performed over the distal metaphyseal region.
The tip of the guide is placed at the posterior aspect of the lateral wall of the notch in the 1:30 position (left knee) or 10:30 position (right knee).
The sliding bullet is advanced to the bone, and the guidewire is advanced.
While protecting the PCL with a large curette, the femoral tunnel is created with a 10-mm reamer.
After graft passage, an interference screw is placed at the lateral cortex and advanced until it is adjacent with the bone plug (TECH FIG 3A).
Newer commercially available drilling systems facilitate retrograde femoral tunnel drilling without the need for a large incision over the lateral aspect of the knee. Preservation of the lateral femoral cortex with these systems also allows suspensory fixation to be used for graft fixation (TECH FIG 3B).
The remainder of the procedure is performed as previously described.
-
Bone Grafting of Tibial Tunnels
If significant bone loss has occurred around the previous femoral or tibial tunnels, bone grafting may be necessary, followed by staged revision ACL reconstruction. This is common with synthetic grafts and bioabsorbable fixation devices, which can cause an immune reaction from the synthetic material. Tunnel osteolysis has also been proposed to occur more frequently with hamstring grafts due to the theoretical
“windshield wiper” effect of the graft with fixation at the distal end of the tunnel.2,7,13 Lastly, revision cases following primary ACL reconstruction using a double-bundle technique can also result in significant bone loss. In some cases, bone grafting of the femoral tunnels (TECH FIG 4) may be necessary, although we have found the need for this to be infrequent.
After removal of the fixation devices, the previous tunnels are fully débrided of soft tissue using a shaver, curette, and rasp.
If sclerotic bone is encountered, a 2-mm drill can be used to drill the walls of the tunnel.
The old tunnels and regions of bony deficiency can be filled with autograft bone (taken in dowels from
the iliac crest13) or allograft dowels (commonly available from tissue banks2).
Allograft dowels, when used, should be about 1 mm larger than the diameter of the tunnel and placed using a press-fit technique.
Reconstruction must be staged to allow time for incorporation of the bone graft.
Incorporation of the bone graft can be monitored on CT imaging and usually takes 4 to 6 months.13
P.484
![]()
![]()
![]()
![]()
TECH FIG 4 • Failed right knee double-bundle reconstruction with tunnel enlargement. In this case, femoral tunnel reaming would have resulted in a large femoral bone defect so allograft bone dowels were inserted using a press-fit technique.
PEARLS AND PITFALLS
Indications
-
It is critical to determine whether the patient's chief complaint is instability or pain.
-
For patients 25 years of age and younger, a good reason is needed not to perform revision reconstruction of an ACL-deficient knee.
-
For patients 45 years of age and older, a good reason is needed to consider revision reconstruction in an ACL-deficient knee.
-
Subjective and objective findings of instability should be present to support consideration for revision surgery. Some patients with objective instability are able to participate at a high level of competition in cutting sports without symptomatic instability.
-
Interference screws
-
In our experience, metallic screws allow easy identification of tunnel placement. We currently do not use “bioabsorbable” screws because we have found that they commonly do not absorb, can be difficult to drill across, and difficult to remove during revision surgery.
Synthetic grafts
-
Careful débridement of all synthetic material must be performed to prevent further immune reaction around the new graft.
-
POSTOPERATIVE CARE
In the operating room, the knee is placed in a hinged knee brace locked in extension and the patient is permitted to bear weight as tolerated within the brace.
At all other times, the brace can be removed and immediate postoperative ROM is initiated.
Once adequate quadriceps control has been regained, the hinged knee brace is discontinued. This usually occurs within 1 week postoperatively.
A cold therapy device, compression stockings, and elevation are used to control edema.
The first postoperative appointment is on day 2. A wound check is performed, and Steri-Strips (3M, St. Paul, MN) are changed as needed.
The initial physical therapy appointment is scheduled for 3 to 5 days postoperatively and focuses on immediate ROM.
The patient is educated regarding use of the knee brace, ROM therapy, and operative findings.
At the second postoperative visit, on day 8 or 10, sutures are removed, a ROM examination is done, and appropriate ROM exercises are explained with a specific focus on regaining full extension. In addition, the knee brace is discontinued at this time.
The general postoperative rehabilitation schedule is as follows:
Months 1 to 3: Focus on ROM and quadriceps strengthening.
Months 3 to 4: Progress to eccentric quadriceps strengthening and running. Months 4 to 7: Continue strengthening.
Months 7 to 8: Begin agility drills. Months 8 to 9: Begin sport-specific drills.
No contact sports are permitted until 9 to 12 months postoperatively.
OUTCOMES
The critical factor in successful revision ACL reconstruction is appropriate diagnosis and treatment of the primary mode of graft failure. The ultimate clinical outcome is likely based
P.485
on a multitude of factors, including graft laxity, chondral injury, and meniscal status.
Recent large, multicenter studies have provided more insight into the primary cause of primary ACL graft failure as well as clinical outcomes. A cross-sectional study by the Multicenter ACL Revision Study (MARS) group noted the mode of failure in 460 patients was traumatic injury in the majority of cases (32%). The remaining causes were technical (24%), biologic (7%), combination (37%), and infection (<1%). At the time of revision ACL reconstruction, meniscus and/or chondral damage was found in 90%
of patients.8
Further data collected from the MARS cohort (total of 1200 patients) revealed patients with multiple revision ACL reconstructions demonstrated lower activity levels, as measured by the Marx activity score (primary revision ACL group [9.77 score] vs. multiple revision procedures [6.74]). Chondral injuries were more common in the multiple revision group and were more commonly observed in the medial and
patellofemoral compartments.3
Grossman et al,5 in a study that focused on failure of revision ACL reconstruction based on pathologic laxity, found fairly similar outcomes for subjective and objective measures when compared with primary ACL reconstruction studies.
However, only 68% of these patients were able to return to their preoperative level of activity; a rate significantly lower than the commonly reported 75% to 85% return rate to preinjury level sports following primary ACL reconstruction.
A prospective study by Noyes and Barber-Westin11 investigating revision ACL reconstruction using autogenous bone-patellar tendon-bone grafts resulted in subjective improvement in 88% of patients; however, only 62% of these patients were able to return to athletics without symptoms.
The authors did report an overall graft failure rate of 24%, a threefold increase compared to a previous study10 by the same authors investigating results following primary ACL reconstruction.
In both of the studies by Noyes and Barber-Westin,10,11 the condition of the articular cartilage had a significant effect on subjective scores.
In their later study, Noyes and Barber-Westin11 reported that 93% of patients had additional pathology such as articular cartilage damage, meniscal pathology, loss of secondary ligament restraints, and varus malalignment.
Although reconstruction of the ACL may provide stability to the knee, these compounding problems likely play a significant role in patient satisfaction and the ability to return to preinjury activities.3
COMPLICATIONS
Loss of motion
Graft failure
Anterior knee pain secondary to patellofemoral cartilage degeneration, extension deficit (loss of ROM), or quadriceps weakness
Unrealistic expectations in those patients with articular cartilage damage regarding their ability to return to strenuous sports
Complex regional pain syndrome
REFERENCES
-
Bach BR Jr, Warren RF, Wickiewicz TL. The pivot shift phenomenon: results and a description of a modified clinical test for anterior cruciate ligament insufficiency. Am J Sports Med 1988;16:571-576.
-
Battaglia TC, Miller MD. Management of bony deficiency in revision anterior cruciate ligament reconstruction using allograft bone dowels: surgical technique. Arthroscopy 2005;21:767.
-
Chen JL, Allen CR, Stephens TE, et al. Differences in mechanisms of failure, intraoperative findings, and surgical characteristics between single- and multiple-revision ACL reconstructions: a MARS cohort study. Am J Sports Med 2013;41(7):1571-1578.
-
Fox JA, Pierce M, Bochuk J, et al. Revision anterior cruciate ligament reconstruction with nonirradiated fresh-frozen patellar tendon allograft. Arthroscopy 2004;20:784-794.
-
Grossman MG, ElAttrache NS, Shields CL, et al. Revision anterior cruciate ligament reconstruction: three-to nine-year follow-up. Arthroscopy 2005;21:418-423.
-
Harner CD, Giffin JR, Dunteman RC, et al. Evaluation and treatment of recurrent instability after anterior cruciate ligament reconstruction. Instr Course Lect 2001;50:463-474.
-
Maak TG, Voos JE, Wickiewicz TL, et al. Tunnel widening in revision anterior cruciate ligament reconstruction. J Am Acad Orthop Surg 2010;18(11):695-706.
-
MARS Group; Wright RW, Huston LJ, Spindler KP, et al. Descriptive epidemiology of the Multicenter ACL Revision Study (MARS) cohort. Am J Sports Med 2010;38(10):1979-1986.
-
Miller MD, Hinkin DT. The “N+7 rule” for tibial tunnel placement during endoscopic anterior cruciate ligament reconstruction. Arthroscopy 1996;12:124-126.
-
Noyes FR, Barber-Westin SD. A comparison of results in acute and chronic anterior cruciate ligament ruptures of arthroscopically assisted autogenous patellar tendon reconstruction. Am J Sports Med 1997;25:460-471.
-
Noyes FR, Barber-Westin SD. Revision anterior cruciate surgery with use of bone-patellar tendon-bone autogenous grafts. J Bone Joint Surg Am 2001;83-A:1131-1143.
-
Olszewski AD, Miller MD, Ritchie JR. Ideal tibial tunnel length for endoscopic anterior cruciate ligament injuries. Arthroscopy 1998; 14:9-14.
-
Thomas NP, Kankate R, Wandless F, et al. Revision anterior cruciate ligament reconstruction using a 2-stage technique with bone grafting of the tibial tunnel. Am J Sports Med 2005;33:1701-1709.