CPT 27429: Reconstruction of Intra- and Extra-Articular Knee Ligaments - OpenPayer

Summary & Overview

CPT 27429: Reconstruction of Intra- and Extra-Articular Knee Ligaments

CPT code 27429 represents a complex knee ligament reconstruction that addresses both intra–articular and extra–articular ligament structures and may include graft reinforcement. Nationally, this code is used to bill surgical repair and reconstruction of multiple knee ligaments following traumatic injury or chronic instability, and it captures procedures that cross the joint capsule boundary. The code matters because it denotes a higher-complexity operative service with implications for surgical resource use, perioperative care, and payer coverage policies.

Key payers covered in this analysis include Aetna, Blue Cross Blue Shield, Cigna Health, UnitedHealthcare, and Medicare. Readers will find a concise overview of clinical context for the procedure, expected settings of care (hospital operating room and ambulatory surgical center), and typical considerations that influence billing and claims adjudication. The publication summarizes common modifiers encountered in practice and notes where input data is missing.

This resource helps clinicians, coders, and policy analysts understand the intent of CPT code 27429, the clinical scenarios in which it is applied, and the payer landscape relevant to national billing practice. Data not available in the input includes associated taxonomies, specific ICD-10 diagnoses, related codes, and detailed payer-specific reimbursement benchmarks.

AetnaBlue Cross Blue ShieldCigna HealthUnitedHealthcareMedicare27429CPTknee surgeryligament reconstructionorthopedic surgeryambulatory surgical centeroperating roomsurgical graft

Billing Code Overview

CPT code 27429 describes a surgical procedure to reconstruct both intra–articular and extra–articular ligaments of the knee, with the option to reinforce the repair using a graft. Service type: Ligament reconstruction of the knee involving both internal (intra–articular) and external (extra–articular) ligamentous structures. Typical site of service: Hospital operating room or ambulatory surgical center, as the procedure is operative and requires surgical facilities and anesthesia.

Clinical & Coding Specifications

Clinical Context

A typical patient is a 22-year-old recreational soccer player who sustains an acute knee injury with instability after a pivoting mechanism. Clinical evaluation and MRI demonstrate combined intra-articular anterior cruciate ligament (ACL) rupture and injury to extra-articular structures such as the anterolateral ligament or lateral collateral ligament. The patient presents for operative reconstruction under general anesthesia. The clinical workflow includes preoperative evaluation (history, physical exam, imaging review), informed consent, graft selection (autograft or allograft), arthroscopic assessment and intra-articular ligament reconstruction, open or arthroscopic reconstruction/reinforcement of extra-articular stabilizers as indicated, intraoperative graft fixation, hemostasis, wound closure, immediate postoperative recovery and discharge planning with rehabilitation instructions. Typical site of service is an ambulatory surgery center or hospital operating room. Procedure duration varies with complexity and may require concurrent procedures (e.g., meniscal repair).

Coding Specifications

Modifier	Description	When to Use
`22`	Increased procedural services	Use when the work, time, or technical difficulty substantially exceeds the typical effort for `27429`.

CPT 27390: Open Tenotomy of Single Hamstring Tendon

cpt-27438-patellar-prosthesis-replacement

CPT 27438: Patellar Prosthesis Replacement

cpt-27466-femur-lengthening-osteodistraction

CPT 27466: Femur Lengthening by Osteodistraction

cpt-27479-epiphyseal-implant-growth-arrest-near-knee

CPT 27479: Epiphyseal Implant for Growth Arrest Near Knee

cpt-27407-knee-cruciate-ligament-repair

CPT 27407: Knee Cruciate Ligament and Capsule Repair

cpt-27412-knee-autologous-cartilage-transplantation

CPT 27412: Knee Autologous Cartilage Transplantation

cpt-27424-patellectomy-surgical-removal-of-patella

CPT 27424: Patellectomy for Dislocating Patella

cpt-27465-femoral-shortening-surgery-leg-length-discrepancy

CPT 27465: Femoral Shortening Surgery for Leg Length Discrepancy

cpt-27430-quadriceps-release-knee-flexion-improvement

CPT 27430: Quadriceps Femoris Release to Improve Knee Flexion

cpt-27435-knee-posterior-capsulotomy-flexion-contracture-release

CPT 27435: Knee Posterior Capsulotomy for Flexion Contracture

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Taxonomy Code	Specialty	Notes
2080S0008X	Orthopaedic Surgery	Primary specialty performing knee ligament reconstructions, including intra- and extra-articular repairs.
208VP0000X	Sports Medicine (Physician)	Focus on athletes and complex ligamentous knee injuries and return-to-sport planning.
207L00000X	Physical Medicine & Rehabilitation	Often involved in postoperative rehabilitation planning, capably documents functional goals.
207K00000X	Physical Therapy	Provides postoperative rehab but uses non-physician taxonomy; included for workflow coordination.

Related Diagnoses

ICD-10 Code	Description	Clinical Relevance
`S83.511A`	Sprain of anterior cruciate ligament of right knee, initial encounter	ACL rupture is a primary indication for intra-articular reconstruction covered by `27429`.
`S83.512A`	Sprain of anterior cruciate ligament of left knee, initial encounter	Same relevance for left-sided ACL injuries requiring reconstruction.
`M23.5`	Chronic instability of knee	Indicates persistent instability where combined intra- and extra-articular reconstruction may be indicated.
`M23.50`	Internal derangement of knee, unspecified	Used when specific derangement (e.g., meniscal or ligamentous injury) is identified intraoperatively and addressed during reconstruction.
`S83.41XA`	Sprain of lateral collateral ligament of knee, initial encounter	LCL injury is an example of extra-articular ligament pathology addressed during combined reconstructions.
`S83.42XA`	Sprain of medial collateral ligament of knee, initial encounter	MCL injury may be addressed as part of multi-ligament reconstruction strategies.
`S83.501A`	Other tear of meniscus, current injury, right knee, initial encounter	Concomitant meniscal tears commonly coexist and are often repaired during the same operative session.

Related CPT Codes

CPT Code	Description	Relationship to This Procedure
`29888`	Arthroscopically aided anterior cruciate ligament reconstruction, including arthroscopy and may include graft harvesting	Commonly performed as the arthroscopic intra-articular component when reconstructing the ACL prior to or as part of combined reconstructions reported with `27429` when extra-articular work is distinct.
`27427`	Ligamentous reconstruction (augmentation of knee joint) with extra-articular augmentation, open procedure	May be used for extra-articular ligament reconstruction; when both intra- and extra-articular reconstructions are performed, `27429` describes combined intra- and extra-articular reconstruction so code selection depends on the exact procedures performed.
`29866`	Arthroscopically aided meniscal repair using suture	Performed frequently at the same operative session if meniscal tears are identified during arthroscopy performed with ligament reconstruction.
`20930`	Allograft, musculoskeletal tissue, extensive processing (e.g., for graft material)	Report graft procurement or implanted allograft material when billed separately according to payer policy.
`20610`	Arthrocentesis, aspiration and/or injection; major joint or bursa (e.g., knee)	May be performed preoperatively for diagnostic/therapeutic reasons or postoperatively for drainage or injections; not typically billed on same day as major reconstruction without modifier.

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