Anatomic repair or reconstruction of the superficial MCL and posterior oblique ligament for valgus and anteromedial rotatory instability | advanced
Surgical Imaging
Location: The infrapatellar branch of the saphenous nerve crosses the anteromedial knee 2-4 cm distal to the joint line in a highly variable transverse course.
Risk: Transection during skin incision or subcutaneous dissection causes painful neuroma, numbness over the anteromedial knee, and chronic neuropathic pain — the most common iatrogenic complication of the medial approach.
Protection: Use a longitudinal incision placed posterior to the nerve trajectory when possible, or identify the nerve under loupe magnification and protect with a vessel loop before deeper dissection.
Pathology: In distal tibial avulsion the sMCL stump flips superficial to the pes anserinus and lies in the subcutaneous plane — the pes acts as a barrier preventing anatomic reattachment.
Recognition: Palpate a discrete tender cord or mass superficial to the pes anserinus insertion on the anteromedial tibia in acute valgus injuries; MRI shows the flipped stump.
Management: Requires surgical repair or reconstruction — non-operative treatment will fail because the ligament cannot heal in its displaced position.
Anatomy: The POL arises from the posteromedial tibia and blends with the semimembranosus tendon and the posterior capsule — it is the primary restraint to anteromedial rotatory instability.
Risk: Isolated sMCL reconstruction without addressing a torn POL leaves residual anteromedial rotatory laxity and recurrent giving-way.
Fix: Always assess POL integrity intraoperatively with the dial test at 30 and 90 degrees; include POL reconstruction when anteromedial rotation is increased.
Anatomy: The deep MCL (meniscofemoral and meniscotibial ligaments) attaches to the medial meniscus — disruption allows meniscal extrusion and loss of hoop stresses.
Risk: Aggressive retraction or failure to repair the meniscotibial ligament leaves the meniscus unstable and accelerates medial compartment degeneration.
Protection: Identify and repair the meniscotibial ligament attachment during deep dissection; use suture anchors or transosseous sutures to reattach the meniscus periphery.
Pattern: The most common multiligament pattern — the ACL fails first, followed by the MCL under continued valgus load.
Timing: Acute simultaneous reconstruction of both ligaments is safe and preferred; staged MCL healing followed by delayed ACL reconstruction increases stiffness risk.
Technique: Reconstruct the ACL first, then tension the MCL graft with the knee in slight valgus and 20 degrees flexion to avoid over-constraining the medial compartment.
Assessment: Long-standing valgus laxity greater than 5 mm often coexists with femoral or tibial valgus malalignment — soft-tissue reconstruction alone will stretch out.
Evaluation: Full-length standing radiographs to measure mechanical axis; if valgus greater than 5 degrees, consider corrective osteotomy before or with ligament reconstruction.
Consequence: Ignoring alignment is the most common cause of reconstruction failure and recurrent laxity.
M.C.L.-P.O.L.MCL — Anatomy and Restraints
S.U.R.G.E.R.Y.SURGERY — Indications and Decision Making
A.P.P.R.O.A.C.H.APPROACH — Medial Knee Exposure
Surgical Indications
Absolute Indications
- Stener-like distal sMCL avulsion with the tibial stump flipped superficial to the pes anserinus
- Multiligament knee injury involving the MCL (ACL-MCL, MCL-PCL, or KD-III medial pattern)
- Bony avulsion of the femoral or tibial MCL footprint with greater than 5 mm displacement
- Acute valgus instability greater than 10 mm with absent endpoint in a high-demand athlete requiring early return to sport
Relative Indications
- Chronic symptomatic valgus laxity greater than 5 mm side-to-side difference with functional giving-way after 3 months of conservative care
- Combined ACL-MCL injury in a young athlete where staged procedures would delay return to sport
- Anteromedial rotatory instability with POL disruption confirmed on dial test at 90 degrees
- Valgus malalignment greater than 5 degrees with symptomatic medial laxity requiring corrective osteotomy plus ligament reconstruction
Contraindications
Absolute:
- Isolated grade I-II MCL injury with firm endpoint — greater than 90 percent heal with bracing
- Active infection or open knee injury requiring staged soft-tissue coverage
- Severe medical comorbidities precluding major reconstruction
Relative:
- Low-demand elderly patient with minimal functional impairment
- Valgus malalignment greater than 8 degrees without planned corrective osteotomy
- Previous failed MCL surgery with significant stiffness — consider arthroscopic release first
Evidence for Non-Operative Treatment
Isolated MCL Tears
- Grade I and II injuries heal reliably with 4-6 weeks of hinged bracing and protected weight bearing — return to sport rates exceed 95 percent
- Grade III isolated tears also heal in greater than 90 percent of cases when the POL and deep MCL remain intact; residual laxity of 3-5 mm is common but rarely symptomatic
- A prospective series (Indelicato 1983) demonstrated that 95 percent of grade III isolated MCL injuries treated non-operatively achieved good to excellent results at 2 years with minimal residual laxity
Timing of ACL Reconstruction in Combined Injuries
- Early simultaneous ACL-MCL reconstruction (within 2 weeks) yields equivalent stability and lower stiffness rates than staged procedures
- Delayed ACL reconstruction after MCL healing increases the risk of arthrofibrosis and requires more aggressive postoperative mobilisation
Evidence for Surgery
Primary Repair versus Reconstruction
- Acute repair with suture anchors is appropriate for bony avulsions and clean mid-substance tears with good tissue quality
- Chronic or mid-substance tears with poor tissue quality require anatomic reconstruction using autograft or allograft
- Anatomic double-bundle reconstruction (sMCL and POL) restores valgus and rotational stability more reliably than single-bundle techniques
Repair versus Anatomic Reconstruction — Decision Framework
Key Evidence
Non-operative treatment of complete tears of the medial collateral ligament of the knee
The anatomy of the medial part of the knee
Surgical technique: development of an anatomic medial knee reconstruction
Accuracy and reliability of determining the isometric point of the knee for multiligament knee reconstruction
Clinical Decision Scenarios
Practise clinical reasoning and management decisions out loud
“A 28-year-old professional footballer sustains a valgus injury to the right knee during a tackle. MRI shows a complete distal sMCL avulsion with the tibial stump flipped superficial to the pes anserinus, an intact ACL, and a torn POL. How do you manage this injury?”
“A 35-year-old recreational skier presents 8 months after a valgus injury with persistent medial knee pain and giving-way on pivoting. Examination shows 7 mm side-to-side valgus laxity at 30 degrees with a soft endpoint and increased external rotation at 90 degrees. MRI shows chronic mid-substance sMCL and POL attenuation. How do you proceed?”
“During a combined ACL-MCL reconstruction, you have fixed the ACL graft and are now tensioning the MCL reconstruction. The knee is in full extension and you notice the medial compartment is over-constrained with limited flexion. How do you correct this?”