Management of medial-sided knee injuries, part 2: posteromedial corner

Posteromedial Corner Injuries of the Knee: Imaging Findings

The posteromedial corner (PMC) of the knee is an anatomical region formed by ligamentous structures (medial collateral ligament, posterior oblique ligament, oblique popliteal ligament), the semimembranosus tendon and its expansions, the posteromedial joint capsule, and the posterior horn of the medial meniscus. Injuries to the structures of the PMC frequently occur in acute knee trauma in association with other ligamentous or meniscal tears. The correct assessment of PMC injuries is crucial because the deficiency of these supporting structures can lead to anteromedial rotation instability or the failure of cruciate ligaments grafts. This article reviews the anatomy and biomechanics of the PMC to aid radiologists in identifying injuries potentially involving PMC components.

Secondary restraints in ACL reconstruction: State-of-the-art

At-risk patients continue to experience a high likelihood of graft rupture after anterior cruciate ligament (ACL) reconstruction (ACLR). This narrative review seeks to provide the reader with an evidence-based synopsis of state-of-the-art concepts related to secondary restraint lesions, and how addressing them surgically might result in improved outcomes of ACLR.

Anatomic repair and ligament bracing as an alternative treatment option for acute combined PCL injuries involving the posteromedial or posterolateral corner-results of a multicentre study

INTRODUCTION

Combined PCL injuries involving the posteromedial/-lateral corner (PMC/PLC) usually require surgical management. Literature shows controversy regarding the standards of treatment. Suture-augmented repair leads to excellent results in acute knee dislocations but has not been investigated clinically in combined PCL injuries. The purpose of this multicentre study was to evaluate the clinical outcome of this technique in acute combined PCL injuries.

MATERIALS & METHODS

N = 33 patients with acute combined PCL injuries involving the PMC/PLC were treated by one-stage suture repair with ligament bracing of the PCL and suture repair of the accompanying PMC/PLC injuries with/without ligament bracing or primary augmentation by semitendinosus autograft. Outcome was assessed by IKDC questionnaire, Lysholm Score, Tegner Activity Scale and KOOS. Additional PCL stress-radiography was performed.

RESULTS

N = 31 patients with combined PCL injuries (female: male = 7:24; age 39.1 ± 13.8 years) with a follow-up of 16.8 ± 9.6 months were finally evaluated. 18 had PMC injuries, 13 PLC injuries. 32.2% presented with accompanying meniscal tears (70% medial meniscus). 19.4% showed cartilage injuries grade III-IV. Complications included one infection and four knee stiffnesses. Three had symptomatic postoperative instability, all affiliated to the PLC group. The IKDC was 69.8 ± 16.5, Lysholm score 85 ± 14.4 and KOOS 89.7 ± 8.1. Median loss of activity (Tegner) was 0.89 ± 1.31. Comparing PMC and PLC, all scores showed a tendency towards more favourable outcomes in the PMC group (n.s.). Stress-radiography showed an overall side-to-side difference of 3.7 ± 3.8 mm. Subgroup evaluation showed statistically significant better results (p = 0.035) of PMC (2.5 ± 1.5 mm) versus PLC (5.8 ± 5.6 mm).

CONCLUSIONS

One-stage suture repair with ligament bracing is a viable technique for acute combined PCL injuries and predominantly leads to good and excellent clinical outcomes. Patients with PLC injuries show a tendency towards inferior outcomes and higher instability rates compared to PMC injuries. These results may help in therapy planning and counselling patients with these rare injury pattern.

LEVEL OF EVIDENCE

Level II.

MR evaluation of the posteromedial corner of the knee: association of posterior horn medial meniscus tear with posterior oblique ligament and distal semi-membranosus tendon tear

OBJECTIVE

To assess if posterior oblique ligament and distal semi-membranosus tendon tears are associated with posterior horn medial meniscus tears on MRI.

METHODS

From January 1, 2018 to December 31, 2019, 56 patients who met the inclusion criteria were enrolled in this study. Of the 56 patients, 43 patients who had a posterior horn of medial meniscus tear were included in the study group. A control group of 13 individuals was formed for comparison. Two radiologists reviewed the MR images and recorded the presence and grades of posterior oblique ligament and distal semi-membranosus tendon tears. We used the independent t-test and one-way ANOVA to compare the tear grades. Interobserver agreement was analyzed using a Cohen's κ coefficient (κ value) for categorical variables.

RESULTS

The mean grades for the posterior oblique ligament and distal semi-membranosus tendon tears were significantly higher in the study group (all, p < 0.001). Interobserver agreement between the two readers was substantial in assessing the grade of posterior oblique ligament tear (κ = 0.653±0.087) and almost perfect in assessing the grade of distal semi-membranosus tendon tear (κ = 0.876±0.060).

CONCLUSION

Posterior oblique ligament and distal semi-membranosus tendon tears are significantly associated with posterior horn of medial meniscus tear and medial meniscus posterior root tears, and the peel-back mechanism could be related to this association.

ADVANCES IN KNOWLEDGE

Presenting this paper could adjust radiologist search patterns and potentially help orthopedists with management and pre-surgical planning for the posteromedial corner injury of the knee.

Mesenchymal Stem Cells for Enhanced Healing of the Medial Collateral Ligament of the Knee Joint

Background and Objectives: The medial collateral ligament (MCL) is one of the major supporting ligaments of the knee joint, and MCL injuries are common where excessive valgus loading is applied to the knee joint. Although most MCL injuries can be treated conservatively, healing of the MCL can take several weeks to months. Furthermore, once injured, the biomechanical properties of the healed MCL differ from those of the native MCL, resulting in an increased risk of re-injury and chronic remnant symptoms. Mesenchymal stem cells (MSCs), owing to their therapeutic potential, have been investigated in various musculoskeletal injuries, and some preclinical studies regarding MSC-based approaches in MCL injuries have shown promising results. Despite satisfactory results in preclinical studies, there is still a lack of clinical studies in the orthopedic literature. This article describes the basic knowledge of the MCL, standard treatments for MCL injuries, and recent studies regarding the application of MSCs for enhanced healing of the MCL. MSC-based approaches are expected to be a potential therapeutic option for enhanced healing of the MCL in the future.

Early medial reconstruction combined with severely injured medial collateral ligaments can decrease residual medial laxity in anterior cruciate ligament reconstruction

INTRODUCTION

This study aimed to describe an anatomic medial knee reconstruction technique for combined anterior cruciate ligament (ACL) and grade III medial collateral ligament (MCL) injuries and to assess knee function and stability restoration in patients who underwent primary MCL reconstruction compared with primary repair.

METHODS

A total of 105 patients who had undergone anatomic ACL reconstruction between 2008 and 2017 were enrolled in this retrospective study and divided into two groups according to concomitant MCL ruptures. Group A included patients with isolated ACL ruptures without MCL injuries. Group B included patients with both ACL and MCL injuries, and it was subdivided into three groups according to the severity of the MCL injury and treatment modality: B-1, grade I or II MCL injury treated conservatively; B-2: grade III MCL injury treated by primary MCL repair; and B-3: grade III MCL injury treated by primary reconstruction. Knee stability was measured via Telos valgus radiography at 6-month and 2-year postoperative. The Lysholm score, Tegner activity level, Likert scales (satisfaction), and return to previous sports were evaluated at 2-year postoperative.

RESULTS

At 6-month postoperative, there was no significant difference in medial laxity between the B-2 and B-3 groups. However, at 2-year postoperative, medial laxity were significantly higher both at 30° of flexion (5.2° versus 2.2°, p = 0.020) and at full extension (3.4° versus 1.1°, p < 0.001) in patients in B-2 group compared to those in B-3 group. There were no statistically significant differences between the two groups with respect to Lysholm scores, Tegner activity levels, Likert scales (satisfaction), and returning to previous sports at the 2-year follow-up.

CONCLUSION

Primary medial reconstruction combined with severely injured MCL in ACL reconstruction may decrease residual medial laxity more than primary repair.

LEVEL OF EVIDENCE

Retrospective observational study, IV.

Medial Collateral Ligament and Posterior Oblique Ligament Reconstruction for Valgus Instability After Total Knee Arthroplasty

Medial collateral ligament (MCL) injuries are typically managed non-operatively, with high rates of clinical success. However, patients who present with medial knee laxity with valgus stress testing of a fully extended knee, anteromedial rotatory instability, associated tibial plateau fracture, or multiligament injury or those who continue to be symptomatic after non-operative treatment may benefit from surgical intervention. Patients with a history of total knee arthroplasty who suffer MCL and posterior oblique ligament (POL) injuries represent a challenging patient population and often require surgical attention. In this Technical Note, we describe the preoperative assessment, decision making, and surgical technique for anatomic reconstruction of the superficial MCL and POL with an Achilles allograft in young, active patients with medial-sided knee injuries after total knee arthroplasty.

Semimembranosus Tendon Advancement for the Anteromedial Knee Rotatory Instability Treatment

Injury to the medial compartment of the knee is the most common ligament injury to this joint. The medial approach must consider the presence of associated anteromedial instability. Untreated injury of these instabilities can result in failure of the other reconstructed ligaments. As treatment is usually associated with other ligaments, it is relevant that the technique could save grafts and synthetic material. This article aims to describe a technique for the treatment of anteromedial instabilities through semimembranosus tendon tenodesis in a more anterior and distal position, promoting the tensioning of the posteromedial structures.

Posterior oblique ligament of the knee: state of the art

The posterior oblique ligament (POL) is the predominant ligamentous structure on the posterior medial corner of the knee joint. A thorough understanding of the anatomy, biomechanics, diagnosis, treatment and rehabilitation of POL injuries will aid orthopaedic surgeons in the management of these injuries.

The resulting rotational instability, in addition to valgus laxity, may not be tolerated by athletes participating in pivoting sports. The most common mechanism of injury – accounting for 72% of cases – is related to sports activity, particularly football, basketball and skiing. Moreover, three different injury patterns have been reported: those associated with injury to the capsular arm of the semimembranosus (SM), those involving a complete peripheral meniscal detachment and those involving disruption of the SM and peripheral meniscal detachment.

The hallmark of an injury related to POL lesions is the presence of anteromedial rotatory instability (AMRI), which is defined as ‘external rotation with anterior subluxation of the medial tibial plateau relative to the distal femur’.

In acute settings, POL lesions can be easily identified using coronal and axial magnetic resonance imaging (MRI) where the medial collateral ligament (MCL) and POL appear as separate structures. However, MRI is not sensitive in chronic cases.

Surgical treatment of the medial side leads to satisfactory clinical results in a multi-ligamentous reconstruction scenario, but it is known to be associated with secondary stiffness.

In young patients with high functional demands, return to sports is allowed no earlier than 9–12 months after they have undergone a thorough rehabilitation programme.

Cite this article: EFORT Open Rev 2021;6:364-371. DOI: 10.1302/2058-5241.6.200127

Treatment of medial-sided injuries in patients with early bicruciate ligament reconstruction for knee dislocation

PURPOSE

In knee dislocation with bicruciate ligament and medial side injury (KDIIIM), treatment method of medial side injuries is controversial. The purpose of this study was to evaluate the outcomes of non-operative treatment of proximal and midsubstance and operative treatment of distal avulsion medial collateral ligament (MCL) ruptures in patients with early bicruciate reconstruction.

METHODS

One-hundred and forty-seven patients with a knee dislocation and bicruciate ligament injury (KDII-KDV) were identified. Sixty-two patients had KDIIIM injury. Of these, 24 patients were excluded and 13 were lost to follow-up. With a minimum of 2 years of follow-up, IKDC2000 (subjective and objective), Lysholm and Tegner scores and stress radiographs were recorded.

RESULTS

Twenty-five patients were available for follow-up: 18 had a proximal or midsubstance grade-III MCL rupture (proximal MCL group) and 7 had a distal MCL avulsion (distal MCL group). In the proximal MCL and distal MCL groups, respectively, median IKDC2000 subjective scores were 80 (range 57-99) and 62 (range 39-87), and median Lysholm scores were 88 (range 57-99) and 75 (range 40-100). The median medial opening (side-to-side difference) was 2.4 mm (range 0.1-9.2) in the proximal MCL group and 2.5 mm (range 0.2-4.8) in the distal MCL group.

CONCLUSION

We found acceptable recorded outcomes in patients who underwent non-operative treatment of proximal and midsubstance grade-III MCL rupture and operative treatment of distal MCL avulsion with early bicruciate ligament reconstruction.

LEVEL OF EVIDENCE

Level IV.

The posteromedial corner of the knee: an international expert consensus statement on diagnosis, classification, treatment, and rehabilitation

PURPOSE

To establish recommendations for diagnosis, classification, treatment, and rehabilitation of posteromedial corner (PMC) knee injuries using a modified Delphi technique.

METHODS

A list of statements concerning the diagnosis, classification, treatment and rehabilitation of PMC injuries was created by a working group of four individuals. Using a modified Delphi technique, a group of 35 surgeons with expertise in PMC injuries was surveyed, on three occasions, to establish consensus on the inclusion or exclusion of each statement. Experts were encouraged to propose further suggestions or modifications following each round. Pre-defined criteria were used to refine item lists after each survey. The final document included statements reaching consensus in round three.

RESULTS

Thirty-five experts had a 100% response rate for all three rounds. A total of 53 items achieved over 75% consensus. The overall rate of consensus was 82.8%. Statements pertaining to PMC reconstruction and those regarding the treatment of combined cruciate and PMC injuries reached 100% consensus. Consensus was reached for 85.7% of the statements on anatomy of the PMC, 90% for those relating to diagnosis, 70% relating to classification, 64.3% relating to the treatment of isolated PMC injuries, and 83.3% relating to rehabilitation after PMC reconstruction.

CONCLUSION

A modified Delphi technique was applied to generate an expert consensus statement concerning the diagnosis, classification, treatment, and rehabilitation practices for PMC injuries of the knee with high levels of expert agreement. Though the majority of statements pertaining to anatomy, diagnosis, and rehabilitation reached consensus, there remains inconsistency as to the optimal approach to treating isolated PMC injuries. Additionally, there is a need for improved PMC injury classification.

LEVEL OF EVIDENCE

Level V.

Biomechanics of the posterior oblique ligament of the knee

BACKGROUND

The purpose of this systematic literature review is to analyse the isolated biomechanics of the posterior oblique ligament of the knee. In the current literature, the biomechanical aspect of the posterior oblique ligament was analysed in several articles, but this was always done in association with other capsuloligamentous structures.

METHODS

A systematic review of the existing literature was performed to identify all studies dealing with the biomechanics of the posterior oblique ligament. Two independent investigators performed the research using the MEDLINE, CINAHL, Scopus, Embase and Cochrane databases.

FINDINGS

A total of 10 articles analysed the biomechanics of the posterior oblique ligament, confirming the importance of this ligament for the stability of the knee in different positions. The posterior oblique ligament is the main stabiliser against internal rotation in early flexion angles (0°-30°) and it is an important restraint to posterior tibial translation in the posterior cruciate ligament deficient knee. Furthermore, the posterior oblique ligament bears up to 47% of the force borne by the anterior cruciate ligament in resisting the internal rotation loads when a pivot-shift maneuver is simulated.

INTERPRETATION

This review confirms that the posterior oblique ligament is an anatomically well-defined and distinct structure that plays a key role in stabilising the knee, especially in internal rotation. The posterior oblique ligament is frequently injured along with other anatomical structures. Future studies should develop clinical tests to evaluate the functionality and stability of the the posterior oblique ligament.

Acute primary repair of extraarticular ligaments and staged surgery in multiple ligament knee injuries

Background

The purpose of this study is to compare the outcomes of acute primary repair of extraarticular ligaments with staged surgery for acute knee dislocations (KDs) and multiligament knee injuries (MLKIs).

Materials and methods

Between January 2005 and May 2018, 61 consecutive patients diagnosed with MLKI or KD were referred to or visited our institution. Of these, 31 patients who underwent acute repair of extraarticular ligaments within 3 weeks of injury were included in this study. These patients were retrospectively classified into two groups: those who underwent only primary repair (repair group) and those who underwent staged reconstructive surgery (staged group). Follow-up examination included range of motion (ROM), knee joint stability (Lachman test, posterior drawer test, and varus and valgus stress test), Lysholm knee score, Tegner activity scale, and Knee Injury and Osteoarthritis and Outcome Score (KOOS).

Results

Twelve of the 31 patients did not need or desire further surgery and were included in the repair group. No significant difference was observed in demographic data between the repair and staged groups. Although staged surgery decreased positive posterior drawer test results, no significant difference was observed between the two groups regarding ROM, other knee joint stability tests, Lysholm scores, Tegner scale, or KOOS.

Conclusions

In this series, all patients returned to their activities of daily living and preinjury occupation levels. Acute primary repair of extraarticular ligaments provides essential knee stability without varus/valgus instability and may reduce the need for subsequent cruciate ligament reconstruction.

Level of evidence

Level IV, retrospective observational study.

[Biomechanical comparison of single-bundle and anatomical double-bundle reconstructions for grade medial collateral ligament injury]

Objective

To evaluate and compare knee joint stability of grade Ⅲ medial collateral ligament (MCL) injury treated by single-bundle and anatomical double-bundle reconstruction methods, thus providing biomechanical basis for clinical treatment.

Methods

Nine fresh cadaver specimens of normal human knee joints were randomly divided into 3 groups on average. In intact MCL group: The anterior cruciate ligament (ACL) was detached and reconstructed with single-bundle techniques, and the MCL was intact. In single-bundle and double-bundle reconstruction groups, the superficial MCL (sMCL), posterior oblique ligament (POL), and ACL were all detached to manufacturing grade Ⅲ MCL injury models. After single-bundle reconstruction of ACL, the sMCL single-bundle reconstruction and anatomical double-bundle reconstruction of sMCL and POL were performed, respectively. Biomechanical evaluation indexes included anterior tibial translation (ATT), internal rotation (IR), valgus rotation (VAL), and stresses of MCL and ACL under internal rotation and valgus torques at different ranges of motion of the knee joint.

Results

There was no significant difference in ATT at full extension and flexion of 15°, 30°, 45°, 60°, and 90° between groups ( P>0.05). At full extension and flexion of 15°, the IR and VAL were significantly higher in single-bundle reconstruction group than in double-bundle reconstruction group and intact MCL group ( P<0.05). At flexion of 30°, the VAL was significantly higher in single-bundle reconstruction group than in double-bundle reconstruction group and intact MCL group ( P<0.05). While there was no significant difference between double-bundle reconstruction group and intact MCL group ( P>0.05). There was no significant difference in the stresses of MCL and ACL between groups under the internal rotation and valgus torques at all positions ( P>0.05).

Conclusion

MCL anatomical double-bundle reconstruction can acquire better valgus and rotational stability of the knee joint compared with single-bundle reconstruction.

One-Stage Repair of Posterior Oblique Ligament Avulsion Fracture Combined with Medial Collateral Ligament Injury

Objective

To evaluate the clinical effect of the one‐stage repair of a posterior oblique ligament avulsion fracture combined with a medial collateral ligament injury.

Methods

This study was a retrospective trial. From February 2007 to May 2017, five patients with posterior oblique ligament avulsion fracture combined with medial collateral ligament injury were included in this study. The patients were aged 37–58 years old with a mean of 45.2 years. All patients underwent the primary repair of a posterior oblique ligament avulsion fracture and medial collateral ligament injury. The main observational index included Lysholm score, International Knee Documentation Committee (IKDC) score, Visual Analogue Scale (VAS) score, and range of motion (ROM).

Results

The results showed that the average time of follow‐up was 53.6 months (range, 20–86 months). When compared to preoperative scores, the preoperative Lysholm score was significantly increased (47.8 ± 5.1 vs 95.0 ± 3.7, P < 0.05), the IKDC score was significantly increased (51.2 ± 5.6 vs 88.6 ± 4.2, P < 0.05), the VAS score was significantly decreased (7.0 ± 0.7 vs 0.4 ± 0.5, P < 0.05), and the ROM was significantly increased (91.6° ± 8.4° vs 129.9° ± 4.4°, P < 0.05).

Conclusion

Our study found that with the combination of the one‐stage repair of a posterior oblique ligament (POL) avulsion fracture and medial collateral ligament injury, the patient's postoperative function recovered well, their pain was relieved, and their knee joint stability was reliable.

Medial side knee injuries: simplifying the controversies: current concepts

Injuries to the medial side of the knee (MSK) are the most common knee ligament lesions. Historically, these injuries have been treated conservatively; however, a better understanding of the anatomy and biomechanics of the different structures of the MSK have resulted in diverse and controversial opinions about the ideal management of these lesions. A cautious analysis should be done in nomenclature because the same surgical technique principles have been differently named in the literature. The diagnostic process of MSK injuries must involve a critical thinking process to precise those lesions that imply an imminent risk of healing failure. This review article provides an evidence and clinical-based clarification of the controversies regarding injuries to the MSK and proposes an evidence-based algorithm for their management.

Management of multiligament knee injuries

Up to 18% of multiligament knee injuries (MLKI) have an associated vascular injury.All MLKI should be assessed using the ankle brachial pressure index (ABPI) with selective arteriography if ABPI is < 0.9.An ischaemic limb following knee dislocation must be taken to the operating theatre immediately for stabilization and re-vascularization.Partial common peroneal nerve (CPN) injury following MLKI has better recovery than complete palsy.Posterior tibial tendon transfer is offered to patients with complete CPN palsy if there is no recovery at six months.Operative treatment with acute or staged reconstructions provides the best outcome in MLKI.Effective repair can only be performed within three weeks of injury.There is no difference between repair and reconstruction of medial collateral ligament and posteromedial corner.Posterolateral corner reconstruction has a lower failure rate than repair.Early mobilization following MLKI surgery results in fewer range-of-motion deficits. Cite this article: EFORT Open Rev 2020;5:145-155. DOI: 10.1302/2058-5241.5.190012.

Diagnosis and treatment of rotatory knee instability

BACKGROUND

Rotatory knee instability is an abnormal, complex three-dimensional motion that can involve pathology of the anteromedial, anterolateral, posteromedial, and posterolateral ligaments, bony alignment, and menisci. To understand the abnormal joint kinematics in rotatory knee instability, a review of the anatomical structures and their graded role in maintaining rotational stability, the importance of concomitant pathologies, as well as the different components of the knee rotation motion will be presented.

MAIN BODY

The most common instability pattern, anterolateral rotatory knee instability in an anterior cruciate ligament (ACL)-deficient patient, will be discussed in detail. Although intra-articular ACL reconstruction is the gold standard treatment for ACL injury in physically active patients, in some cases current techniques may fail to restore native knee rotatory stability. The wide range of diagnostic options for rotatory knee instability including manual testing, different imaging modalities, static and dynamic measurement, and navigation is outlined. As numerous techniques of extra-articular tenodesis procedures have been described, performed in conjunction with ACL reconstruction, to restore anterolateral knee rotatory stability, a few of these techniques will be described in detail, and discuss the literature concerning their outcome.

CONCLUSION

In summary, the essence of reducing anterolateral rotatory knee instability begins and ends with a well-done, anatomic ACL reconstruction, which may be performed with consideration of extra-articular tenodesis in a select group of patients.

[Posteromedial corner of the knee]

The posteromedial corner of the knee is increasingly being recognized in orthopedic surgery, traumatology and musculoskeletal radiology. The medial collateral ligament consists of a superficial part and a deep part. The posteromedial corner consists of the posterior oblique ligament (POL), the oblique popliteal ligament (OPL), the semimembranosus tendon and its arms, the posteromedial joint capsule and the posterior horn of the medial meniscus. The structures provide stability to the knee joint with respect to valgus stress, rotational stability as well as with respect to anterior and posterior translation. Injuries are frequently associated with other severe injuries of the knee. This underlines the importance of recognizing the structures and their injuries on magnetic resonance imaging (MRI), in order to enable adequate therapy.

[Effect of posterior oblique ligament repair on rotational stability of knee joint]

Objective

To investigate effect of posterior oblique ligament (POL) repair on the rotational stability of the knee joint for the medial collateral ligament (MCL) combined with anterior cruciate ligament (ACL) ruptures.

Methods

The clinical data of 50 patients (50 knees) with grade-3 MCL-ACL combined injuries who met the selection criteria between January 2013 and December 2015 were retrospectively analyzed. All ACLs were reconstructed with autogenous tendon and the superficial and deep layers of MCLs were sutured; then, POLs were also sutured in 25 patients of repair group and only received conservation treatment postoperatively in 25 patients of conservation group. There was no significant difference in gender, age, disease duration, and preoperative KT-1000 measuring, medial joint space opening, International Knee Documentation Committee (IKDC) score, visual analogue scale (VAS) score, and knee range of motion between the two groups ( P>0.05).

Results

All incisions of the two groups healed by first intention, no surgical related complications occurred. All patients were followed up, with follow-up time of 28-56 months (mean, 38.1 months) in repair group and 26-55 months (mean, 29.1 months) in conservation group. At last follow-up, the IKDC score, VAS score, KT-1000 measuring, medial joint space opening, and knee range of motion significantly improved in the two groups when compared with preoperative ones ( P<0.05); but there was no significant difference between the two groups ( P>0.05). The Slocum test showed that there was no instability of the anterior medial rotation in the two groups.

Conclusion

The POL repair can't obtain more medial stability after ACL reconstruction and MCL repair (superficial and deep layers) for patients who have MCL-ACL combined injuries.

Operative Treatment for a Painful Nonunion Avulsion Fracture of the Femoral Attachment of the Medial Collateral Ligament in a Teenager: A Case Report

CASE

A 13-year-old female gymnast presented with medial knee pain despite several months of nonoperative management for a valgus hyperextension injury resulting in a bony avulsion fracture of the medial collateral ligament (MCL) origin at the medial femoral condyle. The MCL was repaired via open reduction and internal fixation (ORIF) with a single 4.0 mm cannulated screw and washer.

CONCLUSIONS

ORIF is a successful treatment option for extra-articular bony MCL origin avulsion fractures that fail conservative treatment. Following surgical intervention and structured physical therapy, our patient had full return to sports at 10 months.

Combined Anterior Cruciate Ligament, Medial Collateral Ligament, and Posterior Oblique Ligament Reconstruction Through Single Tibial Tunnel Using Hamstring Tendon Autografts

Combined anterior cruciate ligament (ACL) and medial collateral ligament (MCL) injuries are the most common type of combined ligamentous injury of the knee. The optimal treatment for these combined injuries is controversial. Combined ACL and MCL-posterior oblique ligament (POL) reconstruction avoids late anteromedial rotatory instability and chronic valgus instability of the knee and decreases the increased stress on the ACL graft. Graft choice (hamstring tendon autograft, quadriceps bone-patellar tendon-bone autograft, or Achilles tendon allograft) and anatomic restoration of the medial and posteromedial corner of the knee are challenges of this combined reconstruction. This article describes a technique that allows combined ACL and MCL-POL reconstruction. The hamstring tendons from the contralateral limb are tripled and used as the ACL graft. The gracilis tendon from the ipsilateral limb is doubled and used as the MCL-POL graft. The semitendinosus tendon of the ipsilateral limb is preserved. After ACL reconstruction, the MCL-POL graft is suspended on the ACL graft at the distal end of the tibial tunnel and the graft limbs are used for open reconstruction of the MCL and POL. Three interference screws (Arthrex, Naples, FL) and 1 metal staple are used for graft fixation of this combined reconstruction.

The Biomechanics of Multiligament Knee Injuries: From Trauma to Treatment

The multiple ligament injured knee is a complex biomechanical environment. When primary stabilizers fail, secondary stabilizers have an increased role. In addition, loss of primary restraints puts undue stress on the remaining intact structures of the knee. Treatment of these injuries requires accurate diagnosis of all injured structures, and careful consideration of repairs and reconstructions that restore the synergistic stability of all ligaments in the knee.

Short- to mid-term outcomes of anatomic MCL reconstruction with Achilles tendon allograft after multiligament knee injury

PURPOSE

Multiple techniques have been described in the literature for reconstruction of the medial collateral ligament. The purpose of this study is to describe functional outcome, range of motion, and knee stability following anatomic MCL reconstruction utilizing an Achilles tendon bone allograft after multiligament knee injury.

METHODS

A comprehensive search of a single-hospital multiligament knee injury (MLKI) procedural database was conducted to identify all patients that underwent reconstruction of the MCL utilizing an Achilles tendon bone allograft and with 2-year clinical follow-up. Medical charts were retrospectively reviewed to determine each patient's knee dislocation (KD) grade, final range of motion, stability on clinical examination, and the incidence of complications and reoperations. KOOS, IKDC, and Marx scores were also collected.

RESULTS

Thirty-two knees in 32 patients (21 males and 11 females) with a mean age of 30 years (range 15-51) were followed for an average of 40 months (range 28-87 months) following MCL reconstruction with Achilles tendon bone allograft. For patients with multiligament knee injuries, there were 14 KD-I (11 ACL/MCL; 3 MCL/PCL; 1 MCL/ACL/LCL; 1 MCL/PCL/LCL), 12 KD 3-M, and 3 KD-IV. One patient underwent isolated revision MCL reconstruction. At final follow-up, clinically significant valgus laxity was observed in only 1 patient (3%). All patients were able to achieve full extension of the knee and the average flexion was 121.1 ± 19.6. The average IKDC score was 67.6 ± 19.9 (range 27.7-98.9), the average KOOS score 77.1 ± 16.8 (range 31-100). The average Marx score was 4.9 (range 0-16, SD 5.2). Thirty-one of 32 (96%) patients reported being satisfied with results of the surgery. Knee dislocation grades were significantly correlated with post-operative outcome measures.

CONCLUSION

In a series utilizing a modified Marx Achilles tendon, MCL reconstruction in the setting of MLKI demonstrated satisfactory clinical and functional outcomes, as well as patient satisfaction at short- to mid-term follow-up. Furthermore, knee dislocation grades were demonstrated to correlate with post-operative IKDC, KOOS, and Marx scores.

LEVEL OF EVIDENCE

Type IV.

Reefing of the Posteromedial Capsule in Anteromedial Rotatory Instability

The posterior oblique ligament (POL) is the main component of the posteromedial corner (PMC) of the knee and plays a crucial role in acting as a secondary restraint against translation, rotation, and valgus forces. Injuries to the PMC often occur in association with acute or chronic deficiency of the anterior cruciate ligament and may result in anteromedial rotatory instability. A surgical technique for treatment of acute and chronic injuries of the posteromedial structures was first established by Hughston in 1973. This procedure involves an advancement and reefing of the POL and adherent posterior capsule to the stout tissue of the intact medial collateral ligament, potentially using suture anchors if the POL tissue is detached from bone. Additionally, in cases of residual laxity, the semimembranosus tendon may be advanced anteriorly to improve dynamic stabilization. This procedure appears to be useful in cases of moderate posteromedial insufficiency and avoids retrieval of a medial tendon graft from the region of the medially stabilizing hamstrings or from the healthy contralateral side.

The Effect of Hamstring Tendon Autograft Harvest on the Restoration of Knee Stability in the Setting of Concurrent Anterior Cruciate Ligament and Medial Collateral Ligament Injuries

BACKGROUND

A hamstring autograft is commonly used in anterior cruciate ligament (ACL) reconstruction (ACLR); however, there is evidence to suggest that the tendons harvested may contribute to medial knee instability.

HYPOTHESIS

We tested the hypothesis that the gracilis (G) and semitendinosus (ST) tendons significantly contribute to sagittal, coronal, and/or rotational knee stability in the setting of ACLR with a concurrent partial medial collateral ligament (MCL) injury.

STUDY DESIGN

Controlled laboratory study.

METHODS

Twelve human cadaveric knees were subject to static forces applied to the tibia including an anterior-directed force as well as varus, valgus, and internal and external rotation moments to quantify laxity at 0°, 30°, 60°, and 90° of flexion. The following ligament conditions were tested on each specimen: (1) ACL intact/MCL intact, (2) ACL deficient/MCL intact, (3) ACL deficient/partial MCL injury, and (4) ACLR/partial MCL injury. To quantify the effect of muscle loads, the quadriceps, semimembranosus, biceps femoris, sartorius (SR), ST, and G muscles were subjected to static loads. The loads on the G, ST, and SR could be added or removed during various test conditions. For each ligament condition, the responses to loading and unloading the G/ST and SR were determined. Three-dimensional positional data of the tibia relative to the femur were recorded to determine tibiofemoral rotations and translations.

RESULTS

ACLR restored anterior stability regardless of whether static muscle loads were applied. There was no significant increase in valgus motion after ACL transection. However, when a partial MCL tear was added to the ACL injury, there was a 30% increase in valgus rotation ( P < .05). ACLR restored valgus stability toward that of the intact state when the G/ST muscles were loaded. A load on the SR muscle without a load on the G/ST muscles restored 19% of valgus rotation; however, it was still significantly less stable than the intact state.

CONCLUSION

After ACLR in knees with a concurrent partial MCL injury, the absence of loading on the G/ST did not significantly alter anterior stability. Simulated G/ST harvest did lead to increased valgus motion. These results may have important clinical implications and warrant further investigation to better outline the role of the medial hamstrings, particularly among patients with a concomitant ACL and MCL injury.

CLINICAL RELEVANCE

A concurrent ACL and MCL injury is a commonly encountered clinical problem. Knowledge regarding the implications of hamstring autograft harvest techniques on joint kinematics may help guide management decisions.

The Posteromedial Corner of the Knee: Anatomy, Pathology, and Management Strategies

The posteromedial corner of the knee encompasses five medial structures posterior to the medial collateral ligament. With modern MRI systems, these structures are readily identified and can be appreciated in the context of multiligamentous knee injuries. It is recognized that anteromedial rotatory instability results from an injury that involves both the medial collateral ligament and the posterior oblique ligament. Like posterolateral corner injuries, untreated or concurrent posteromedial corner injuries resulting in rotatory instability place additional strain on anterior and posterior cruciate ligament reconstructions, which can ultimately contribute to graft failure and poor clinical outcomes. Various options exist for posteromedial corner reconstruction, with early results indicating that anatomic reconstruction can restore valgus stability and improve patient function. A thorough understanding of the anatomy, physical examination findings, and imaging characteristics will aid the physician in the management of these injuries.

An anatomical-like triangular-vector ligament reconstruction for the medial collateral ligament and the posterior oblique ligament injury with single femoral tunnel: a retrospective study

Background

The purpose of this study was to evaluate the clinical outcomes of anatomical-like triangular-vector ligament reconstruction (TLR) in treating the combined injury of medial collateral ligament (MCL) and posterior oblique ligament (POL).

Methods

During July 2013 to May 2014, 26 patients who received anatomical-like TLR were included into this study. All patients received clinical physical examination, imaging examination, and knee joint function score both preoperative and follow-up. The stability of the medial structure of the knee joint was examined by physical examination and imaging evaluation, including excessive knee medial opening (EKMO) and tibial external rotation angle (TERA). The function of the knee was evaluated by the subjective questionnaire, including Lysholm, Tegner, and IKDC score. SPSS software was used for statistics analysis.

Results

The mean follow-up time exceeds 24 months. Two patients occurred with serious heterotopic ossification, and one patient received revision because of screw breakage. EKMO over the contralateral state at 0° decreased from 9.76 ± 2.76 mm to 2.79 ± 1.02 mm with statistical significance (P < .001) and 10.32 ± 2.75 mm decreased to 3.13 ± 0.85 mm at 30° (P < .001). Meanwhile, TERA significantly decreased from 53.38 ± 6.71° to 27.15 ± 4.92° (P < .001). The postoperative Lysholm, Tegner, and IKDC score were superior to preoperative with statistical significance (P < .001).

Conclusions

Anatomical-like TLR can reconstruct the graft to cover the insertions which can regain anatomic form and function with a cramped space. Not only the valgus stability and rotational stability can be restored obviously at follow-up but also the usage of implantation can be reduced, decreasing the incidence rate of allergy and saving costs.

Clinical outcome of primary medial collateral ligament-posteromedial corner repair with or without staged anterior cruciate ligament reconstruction

INTRODUCTION

Medial collateral ligament (MCL) is a prime valgus stabilizer of the knee, and MCL tears are currently managed conservatively. However, posteromedial corner (PMC) injury along with MCL tear is not same as isolated MCL tear and the former is more serious injury and requires operative attention. However, literature is scarce about the management and outcome of PMC-MCL tear alongside anterior cruciate ligament (ACL) tear. The purpose of this study is to report the clinical outcome of primary repair of MCL and PMC with or without staged ACL reconstruction.

METHODS

A retrospective evaluation was performed on patients with MCL-PMC complex injury with ACL tear who underwent primary repair of MCL-PMC tear followed by rehabilitation. Further, several of them chose to undergo ACL reconstruction whereas rest opted conservative treatment for the ACL tear. A total of 35 patients of two groups [Group 1 (n=15): MCL-PMC repaired and ACL conserved; Group 2 (n=20): MCL-PMC repaired and ACL reconstructed] met the inclusion criteria with a minimum follow-up of two years. Clinical outcome measures included grade of valgus medial opening (0° extension and 30° flexion), Lysholm and International knee documentation committee (IKDC) scores, KT-1000 measurement, subjective feeling of instability, range of motion (ROM) assessment and complications.

RESULTS

While comparing group 2 versus group 1, mean Lysholm (94.6 vs. 91.06; p=0.017) and IKDC scores (86.3 vs. 77.6; p=0.011) of group 2 were significantly higher than group 1. 60% patients of group 1 complained of instability against none in the group 2 (p<0.0001). All the knees of both the groups were valgus stable with none requiring late reconstruction. The mean loss of flexion ROM in group 1 and 2 was 12° and 9° respectively which was not statistically different (p=0.41). However while considering the loss of motion, two groups did not show any significant difference in clinical scores.

CONCLUSIONS

Primary MCL-PMC repair renders the knee stable in coronal plane in both the groups and further ACL reconstruction adds on to the stability of the knee providing a superior clinical outcome. Minor knee stiffness remains a concern after primary MCL-PMC repair but without any unfavorable clinical effect.

[Classification, diagnosis, and treatment system of posteromedial structure and posterolateral corner injury in knee dislocation]

Objective

To review the research progress of diagnosis and treatment system for knee dislocation (KD) based on the stage and classification of posteromedial structure and posterolateral corner injury, so as to provide guidance for clinical work.

Methods

The relevant literature on the classification, diagnosis and treatment was extensively reviewed.

Results

At present, the criterion of the stage and classification of KD mainly include classification based on the size of the injury energy, Kennedy classification, and the improved Schenck classification, but they are not perfect because of no stage and classification of multiple ligament injury and no standardized treatment of different injuries. Hua Xi Knee Dislocation and Multiple Ligament Injury (HX-KDMLI) has optimum plan for injury treatment of posteromedial structure and posterolateral corner injury in KD based on stage and classification.

Conclusion

At present, there is no unified opinion on stages and classifications of the posteromedial structure and posterolateral corner injury in KD as well as on diagnosis and treatment. HX-KDMLI has certain feasibility for the stage and classification of the posteromedial structure and posterolateral corner injury in KD, to a certain extent, it can be used as reference for the diagnosis and treatment of KD.

Loading of the medial meniscus in the ACL deficient knee: A multibody computational study

The menisci of the knee reduce tibiofemoral contact pressures and aid in knee lubrication and nourishment. Meniscal injury occurs in half of knees sustaining anterior cruciate ligament injury and the vast majority of tears in the medial meniscus transpire in the posterior horn region. In this study, computational multibody models of the knee were derived from medical images and passive leg motion for two female subjects. The models were validated against experimental measures available in the literature and then used to evaluate medial meniscus contact force and internal hoop tension. The models predicted that the loss of anterior cruciate ligament (ACL) constraint increased contact and hoop forces in the medial menisci by a factor of 4 when a 100N anterior tibial force was applied. Contact forces were concentrated in the posterior horn and hoop forces were also greater in this region. No differences were found in contact or hoop tension between the intact and ACL deficient (ACLd) knees when only a 5Nm external tibial torque was applied about the long axis of the tibia. Combining a 100N anterior tibial force and a 5Nm external tibial torque increased posterior horn contact and hoop forces, even in the intact knee. The results of this study show that the posterior horn region of the medial meniscus experiences higher contact forces and hoop tension, making this region more susceptible to injury, especially with the loss of anterior tibia motion constraint provided by the ACL. The contribution of the dMCL in constraining posterior medial meniscus motion, at the cost of higher posterior horn hoop tension, is also demonstrated.

Morphology of the Insertions of the Superficial Medial Collateral Ligament and Posterior Oblique Ligament Using 3-Dimensional Computed Tomography: A Cadaveric Study

PURPOSE

To describe the insertions of the superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL) and their related osseous landmarks.

METHODS

Insertions of the sMCL and POL were identified and marked in 22 unpaired human cadaveric knees. The surface area, location, positional relations, and morphology of the sMCL and POL insertions and related osseous structures were analyzed on 3-dimensional images.

RESULTS

The femoral insertion of the POL was located 18.3 mm distal to the apex of the adductor tubercle (AT). The femoral insertion of the sMCL was located 21.1 mm distal to the AT and 9.2 mm anterior to the POL. The angle between the femoral axis and femoral insertion of the sMCL was 18.6°, and that between the femoral axis and the POL insertion was 5.1°. The anterior portions of the distal fibers of the POL were attached to the fascia cruris and semimembranosus tendon, whereas the posterior fibers were attached to the posteromedial side of the tibia directly. The tibial insertion of the POL was located just proximal and medial to the superior edge of the semimembranosus groove. The tibial insertion of the sMCL was attached firmly and widely to the tibial crest. The mean linear distances between the tibial insertion of the POL or sMCL and joint line were 5.8 and 49.6 mm, respectively.

CONCLUSIONS

This study used 3-dimensional images to assess the insertions of the sMCL and POL and their related osseous landmarks. The AT was identified clearly as an osseous landmark of the femoral insertions of the sMCL and POL. The tibial crest and semimembranosus groove served as osseous landmarks of the tibial insertions of the sMCL and POL.

CLINICAL RELEVANCE

By showing further details of the anatomy of the knee, the described findings can assist surgeons in anatomic reconstruction of the sMCL and POL.

Return to Play After Medial Collateral Ligament Injury

Medial collateral ligament injuries are common in the athletic population. Partial injuries are treated nonoperatively with excellent outcomes. Complete ruptures may be treated nonoperatively, although some will require surgery. A comprehensive rehabilitation program is critical to outcome, but a standardized program for all injuries does not exist. Most of the literature regarding nonoperative and postoperative rehabilitation include observational reports and case studies. Level I studies comparing rehabilitation protocols have not been published. The goal of the injured athlete is to not only return to play with no functional limitations, but to also address risk factors and prevent future injuries.

Posteromedial Corner of the Knee: The Neglected Corner

The posteromedial corner of the knee (PMC) is an important anatomic structure that is easily seen but often overlooked on magnetic resonance (MR) images. Whereas the posterolateral corner has been referred to as the "dark side of the knee" by some authors owing to widespread lack of knowledge of its complex anatomy, even less is written about the PMC; yet it is as important as the posterolateral corner in multiligament injuries of the knee. The PMC lies between the posterior margin of the longitudinal fibers of the superficial medial collateral ligament (MCL) and the medial border of the posterior cruciate ligament (PCL). The anatomy of the PMC can be complex and the literature describing it can be confusing, at times oversimplifying it and at other times adding unnecessary complexity. Its most important structures, however, can be described more simply as five major components, and can be better shown with illustrations that emphasize the anatomic distinctions. Injuries to the PMC are important to recognize, as disruption of the supporting structures can cause anteromedial rotational instability (AMRI). Isolated PMC injuries are rare; most occur in conjunction with injuries to other important stabilizing knee structures such as the anterior cruciate ligament (ACL) and PCL. Unrecognized and unaddressed injury of the PMC is one of the causes of ACL and PCL graft failures. Recognition of PMC injuries is critical, as the diagnosis will often change or require surgical management.

Evaluation and treatment of medial instability of the knee

Medial knee ligament injury and instability has frequently been treated by bracing and physical therapy. That has worked well in many instances and patients have been able to resume preinjury activities. However, there is a subset of patients that remain unstable when treated with conservative measures. A critical question we face is why these knees fail when the majority heal well and regain function? What are the differences that lead to failure and how can surgeons recognize these differences and determine which patients will benefit from primary surgical repair or reconstruction?

Anatomy and biomechanics of the medial side of the knee and their surgical implications

In order to reconstruct the medial knee to restore the original biomechanical function of its ligamentous structures, a thorough understanding of its anatomic placement and relationship with surrounding structures is required. To restore the knee to normal kinematics, the diagnosis and surgical approach have to be aligned, to successfully reconstruct the area of injury. Three important ligaments maintain primary medial knee stability: the superficial medial collateral ligament, posterior oblique ligament, and deep medial collateral ligament. It is important not to exclude the assistance that other ligaments of the medial knee provide, including support of patellar stability by the medial patellofemoral ligament and multiligamentous hamstring tendon attachments. Valgus gapping and medial knee stability is accounted for collectively by every primary medial knee stabilizing structure. The following will review the principal medial knee anatomic and biomechanical properties.

Anteromedial rotatory laxity

This paper describes anteromedial rotatory laxity of the knee joint. Combined instability of the superficial MCL and the structures of the posteromedial corner is the pathological background anteromedial rotatory laxity. Anteromedial rotatory instability is clinically characterized by anteromedial tibial plateau subluxation anterior to the corresponding femoral condyle. The anatomical and biomechanical background for anteromedial laxity is presented and related to the clinical evaluation, and treatment decision strategies are mentioned. A review of the clinical studies that address surgical treatment of anteromedial rotatory instability including surgical techniques and clinical outcomes is presented. Level of evidence V.

A novel technique for combined medial collateral ligament and posterior oblique ligament reconstruction: technical note

PURPOSE

In the last year, we have performed a new technique for combined medial collateral ligament (MCL) and posterior oblique ligament (POL) reconstruction in chronic setting of anterior cruciate ligament and MCL complex deficiency. Autogenous semitendinosus tendon with the tibial attachment preserved has been used for the medial/posteromedial compartment reconstruction. We describe the operative technique.

METHODS

Between January and December 2014, 12 consecutive patients with multiligamentous injuries underwent concomitant MCL/POL using a novel technique. The usefulness of the novel technique is the semitendinosus sling on the semimembranosus tendon and the POL fixation with the knee in full extension.

RESULTS

An ideal anteroposterior and rotational stability avoiding the medial compartment over constraint was achieved, in the immediate after surgery, due to the sequence of the bundle fixations and to the semitendinosus sling below the semimembranosus tendon.

CONCLUSIONS

This technique is easily reproducible and useful and restores the medial stability immediately after surgery.

Femoral Tunnel Drilling Angles for Posteromedial Corner Reconstructions of the Knee

PURPOSE

To determine the best angle to drill the femoral tunnels of the superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL) with concomitant posterior cruciate ligament (PCL) reconstruction to avoid either short tunnels or tunnel collisions.

METHODS

Eight cadaveric knees were studied. Double-bundle PCL femoral tunnels were arthroscopically drilled. Drilling of the sMCL and POL tunnels was performed in 4 different combinations of 0° and 30° axial (anteriorly directed) and coronal (proximally directed) angulations. Specimens were scanned with computed tomography to document the relations of the sMCL and POL tunnels to the intercondylar notch and PCL tunnels. A minimum tunnel length of 25 mm was required.

RESULTS

When the sMCL femoral tunnel was drilled at 0° axial and 30° coronal (proximally directed) angulations or 30° axial (anteriorly directed) and 0° coronal angulations, the risk of tunnel collision with the PCL tunnels increased in comparison with the remaining evaluated angulations (P < .001). No POL tunnels collided with either PCL tunnel bundle with the exception of tunnels drilled at 0° axial and 30° coronal (proximally directed) angulations, which did so in 3 of 8 cases (P < .001). The minimum required tunnel length was obtained in all the sMCL and POL tunnels (P < .001 and P = .02, respectively). However, some of those angled at 0° on the axial plane violated the intercondylar notch.

CONCLUSIONS

When one is performing posteromedial reconstructions with concomitant PCL procedures, the sMCL and POL femoral tunnels should be drilled anteriorly and proximally at both 30° axial and 30° coronal angulations. The POL femoral tunnel may also be angled 0° in the coronal plane. Tunnels at 0° axial angulations showed a shorter distance to the intercondylar notch and a higher risk of collision with the PCL tunnels.

CLINICAL RELEVANCE

Specific drilling angles are necessary to avoid short tunnels or collisions between the drilled tunnels when sMCL and POL femoral tunnels are placed with concomitant PCL reconstruction.

Management of acute isolated medial and posteromedial instability of the knee

Medial-sided knee injuries are very common, the medial collateral ligament being the most commonly injured ligament of the knee. Injuries to the medial side of the knee can occur in isolation or concomitant with other knee ligament injuries. Isolated grade I and II injuries have been typically treated nonoperatively with excellent results. Isolated grade III injuries, however, are less common and more controversial. Although some recent literature has shown acceptable results with nonoperative treatment of isolated grade III injuries, most authors recommend surgical treatment. A variety of operative techniques have been described, including repair, augmentation, and reconstruction, all with favorable outcomes. Choice of treatment method should be based on injury pattern with the goal of regaining valgus and anteromedial rotatory stability of the knee.

Management of Chronic Combined PCL Medial Posteromedial Instability of the Knee

Currently, there is no collective consensus on the most effective treatment method for medial collateral ligament injuries with or without associated structural deficiencies. An in-depth understanding of relevant anatomic structures and diagnostic tools is critical to determining an appropriate treatment strategy. This article presents an overview for management of chronic combined posterior cruciate ligament (PCL) and posteromedial instability of the knee, and the results of treatment within the context of the PCL-based multiple ligament injured knee. Recognition and correction of the varying types of posteromedial instability is the key to successful PCL reconstruction in combined PCL posteromedial instability. Reasons for failure of PCL reconstruction include failure to address associated collateral ligament instability, associated limb malalignment, and improper tunnel position. The principles of reconstruction in the combined PCL posteromedial injured knee are to identify and treat all pathology, accurately place tunnels to approximate ligament anatomic insertion sites, utilize strong graft material, employ mechanical graft tensioning, provide secure graft fixation, and perform a deliberate postoperative rehabilitation program. Results of treatment indicate that multiple techniques of posterior ligament reconstruction and posteromedial reconstruction are successful and return patients functional activity with long-term follow-up.