Overview
ACL reconstruction treats functional anterior and rotational instability by placing a graft in an anatomic, impingement-free position and securing it while incorporation occurs. The treatment plan must also address the menisci, cartilage, alignment and associated ligament deficiencies. Restoring a single ligament without recognizing secondary instability can overload an otherwise well-placed graft (Campbell, Chapters 50 and 56).
This guide describes the anatomic single-bundle endoscopic bone–patellar tendon–bone autograft method in Campbell Technique 56.16. Hamstring, quadriceps tendon and all-inside constructs have different harvest and fixation steps; those details should not be substituted into this technique without adapting the plan.
Assessment and Indications
Consider reconstruction for symptomatic pathologic ACL laxity in a patient who wishes to maintain activities that provoke instability. The decision includes age, sport demands, recurrent giving way and associated injuries.
Nonoperative treatment remains an option for a patient willing to modify activities and undertake rehabilitation. A brace does not reliably eliminate reinjury risk during a return to demanding pivoting sport.
Document Lachman and pivot-shift findings and compare with the opposite knee. Assess collateral and posterior ligament stability, hyperextension and rotational laxity.
Review imaging for meniscal and cartilage lesions and factors that may increase graft stress, including abnormal alignment or posterior tibial slope. Reconstructive planning should account for secondary stabilizers.
Before elective reconstruction, restore motion and muscle control and reduce the acute inflammatory response. Chapter 56 describes a period of preoperative therapy, often 10–21 days in the authors' practice; readiness depends on the knee rather than a fixed calendar.
(Campbell, Chapter 50, treatment of ACL injury; Chapter 56, cruciate reconstruction.)
Graft Selection
Graft | Advantages and considerations in Campbell |
|---|---|
Bone–patellar tendon–bone autograft | Bone plugs permit interference fixation and bone-to-bone healing. Donor morbidity includes anterior knee or patellar tendon symptoms and patellar fracture risk with improper harvest. Campbell favors it for many young athletes. |
Hamstring autograft | Avoids patellar bone harvest, but involves soft-tissue incorporation and potential hamstring weakness or saphenous nerve injury. Graft size and fixation require planning. |
Quadriceps tendon autograft | Another autograft option with adequate mechanical properties; harvest morbidity and recovery of quadriceps strength remain relevant. |
Allograft | Avoids donor-site harvest but has higher failure rates in young athletic patients and slower maturation. Campbell reserves consideration for selected older or lower-demand patients. |
Graft choice is individualized. Mechanical strength measured in a laboratory does not alone establish clinical superiority; patient demands, fixation, biology and donor morbidity must be considered (Campbell, Chapters 50 and 56).
Positioning and Setup
Position supine and perform examination under anesthesia of both knees, recording anterior and rotational instability.
Apply a thigh tourniquet and padded lateral post. Confirm that the leg can reach the flexion required for independent femoral drilling before preparation and draping.
Prepare arthroscopic equipment, graft-harvest instruments, sizing blocks, guidewires, reamers and interference fixation. Have a plan for graft–tunnel mismatch or inadequate tunnel-wall support.
When diagnosis remains uncertain, or a long procedure is anticipated, Campbell describes completing the diagnostic assessment before tourniquet inflation and graft harvest.
(Campbell, Chapter 56, Technique 56.16.)
Surgical Technique
Graft Harvest and Preparation
Expose the patellar tendon through a medial parapatellar incision and open the peritenon as separate flaps for later closure.
Measure tendon width. Campbell generally harvests a 10-mm central strip or one-third of the tendon, whichever is smaller, adapting the size to the patient.
Harvest patellar and tibial bone plugs with controlled saw cuts and protect the remaining patella. Avoid excessive depth or an unnecessarily large graft, both of which increase donor-site risk.
Contour and size the bone plugs so that the complete graft passes through the corresponding trial. Prepare traction sutures and round the leading plug to facilitate passage.
Mark both bone–tendon junctions, measure the full graft and tendon lengths, and retain the graft in a protected, saline-moistened sterile location.
(Campbell, Chapter 56, Technique 56.16.)
Diagnostic Arthroscopy and Footprint Identification
Establish anterior portals without damaging the residual patellar tendon. Complete the diagnostic survey and treat relevant associated pathology.
When meniscal repair is indicated, Campbell performs it before final ACL graft fixation.
Clear enough tissue to identify the tibial and femoral ACL footprints while retaining their outlines as references. Protect the PCL during stump debridement; keep the cutting window directed away from it.
Identify the lateral intercondylar ridge, bifurcate ridge when visible, and the boundaries of the femoral footprint. View from the medial portal to assess the planned femoral position.
Perform only the notch preparation needed for visualization, graft passage and clearance. Avoid excessive medial or superior removal that could affect the patellofemoral articulation.
(Campbell, Chapter 56, Technique 56.16.)
Tibial Tunnel
Plan tunnel length from the measured graft rather than selecting an angle in isolation. Enough bone plug must remain within the tibial tunnel for fixation.
Use the native ACL footprint together with the medial tibial spine, anterior horn of the lateral meniscus and PCL as orientation landmarks.
Place and inspect the guidewire arthroscopically. The planned tunnel must avoid an excessively anterior aperture and roof impingement in extension, while preserving space from the PCL posteriorly.
Ream initially below the intended final diameter, inspect the trajectory and range of motion, and make necessary adjustments before final sizing.
Complete the tunnel to match the graft and smooth its margins. Remove tissue that could obstruct graft passage or extension.
(Campbell, Chapter 56, Technique 56.16.)
Femoral Tunnel
Use a high medial viewing portal and localize the low medial working portal with a spinal needle to reach the intended anatomic footprint.
Protect the articular surface during instrument passage. In the technique described, the knee is flexed to about 120 degrees for femoral drilling.
Maintain adequate posterior wall support. Campbell describes a roughly 2-mm posterior wall and a position approximately 5 mm from the femoral articular surface for the specified construct.
Start the reamer just enough to confirm the aperture location. Recheck before completing the socket; the source aims for approximately 30 mm of depth when feasible.
Withdraw the reamer carefully to avoid posterior-wall damage and smooth the aperture. Verify that the tunnel can support the planned fixation.
(Campbell, Chapter 56, Technique 56.16.)
Graft Passage and Fixation
Pass a shuttle through the femoral tunnel and use it to draw the graft through the tibial tunnel into the femoral socket. Guide the plug under arthroscopic vision.
Confirm graft orientation and adequate bone-plug engagement in both tunnels before fixation. Address length mismatch while there is still an opportunity to adjust seating and fixation.
Insert femoral interference fixation in line with the tunnel and plug, using protection to avoid graft injury. Minimize divergence and ensure that the implant does not protrude into the joint.
Apply distal tension and cycle the knee. Inspect for impingement, abnormal graft excursion or loss of extension. Correct a mechanical problem before final tibial fixation.
Allow stress relaxation during cycling. Avoid overtensioning that captures the joint or compromises graft behavior.
Fix the tibial side with the knee in full extension as described for this BPTB construct, then recheck the full arc of motion.
(Campbell, Chapter 56, Technique 56.16.)
Final Checks and Closure
The knee reaches full extension without roof or PCL impingement and flexes without abnormal graft tightening or pistoning.
The graft is stable to probing and no bone plug or screw protrudes into the joint.
Repeat Lachman and pivot-shift assessment and compare with the examination under anesthesia.
Confirm meniscal treatment and any planned stabilization of secondary ligament deficiencies.
Approximate the tendon without undue tension, graft the patellar harvest defect with available bone as described, and close the peritenon and wounds.
(Campbell, Chapter 56, Technique 56.16.)
Postoperative Rehabilitation
Rehabilitation balances restoration of motion and strength with protection of the healing graft. Concurrent meniscal repair or cartilage surgery can change the permitted loading and range of motion (Campbell, Chapters 50 and 56).
Phase | Priorities described by Campbell |
|---|---|
Early recovery | Restore full extension, control swelling and recover quadriceps activation. Allow controlled flexion and protected loading according to the operative findings. |
Progressive recovery | Regain flexion and a normal gait, then progress strengthening and neuromuscular training while avoiding excessive strain on the graft. |
Running and agility | Require a quiet, stable knee with adequate motion, strength and control before progression. Chapter 56 provides a staged protocol rather than immediate unrestricted activity. |
Return to sport | Assess objective strength, motion and sport-specific function in addition to elapsed time. Chapter 50 cautions that many patients are not ready at 6 months; Box 56.12 places formal agility testing at approximately 36 weeks. |
The thresholds and stages in the book are source-specific protocols. Chapter 50 notes that return-to-play criteria are evolving, graft maturation continues beyond 6 months, and early return to high-level sport increases failure risk.
Complications and Pitfalls
Technical failure: nonanatomic tunnels, posterior wall loss, graft–tunnel mismatch, weak fixation, graft damage during screw insertion or impingement.
Persistent instability: missed secondary ligament injury, meniscal deficiency, abnormal alignment or excessive tibial slope may continue to stress the graft.
Motion loss: arthrofibrosis or mechanical obstruction may compromise extension and function.
Harvest morbidity: anterior knee pain, patellar tendinopathy, patellar fracture or sensory nerve symptoms.
General complications: infection, hemarthrosis, venous thromboembolism and recurrent graft rupture.
(Campbell, Chapters 50 and 56.)
Outcomes and Evidence
Reconstruction can restore stability, but a stable knee is not synonymous with return to the previous sporting level. Campbell also emphasizes that ACL reconstruction has not been shown to prevent subsequent osteoarthritis. Meniscal and cartilage preservation, correction of associated instability and appropriate rehabilitation remain central to long-term function (Campbell, Chapter 50).
References
Bernholt DL, Azar FM. Knee injuries. In: Azar FM, Sawyer JR, Throckmorton TW, eds. Campbell's Operative Orthopaedics. 15th ed. Elsevier; 2026. Chapter 50, ACL treatment and reconstruction, pp. 2067–2069; rehabilitation, outcomes and complications, pp. 2089–2091.
Bernholt DL, Mihalko MJ. Arthroscopy of the lower extremity. In: Azar FM, Sawyer JR, Throckmorton TW, eds. Campbell's Operative Orthopaedics. 15th ed. Elsevier; 2026. Chapter 56, pp. 2366–2374; Technique 56.16 and Box 56.12.