Posteromedial Instability Research Articles

Reconstruction of the medial collateral ligament complex with aflat semitendinosus auto- or allograft

Replacement of superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL) with an allograft. Chronic 3° isolated medial instability and combined anteromedial or posteromedial instability. Infection, open growth plates, restricted range of motion (less than E/F 0-0-90°). Longitudinal incision from medial epicondyle to superficial pes anserinus and exposure of the medial collateral ligament complex. Thawing of the allogeneic semitendinosus tendon graft at room temperature, reinforcement of the tendon ends with sutures and preparation of atwo-stranded graft. Placement of guidewires in the sMCL and POL insertions and control with image intensifier. Tunnel drilling. Pulling the graft loop into the femoral bone tunnel and fixation with aflip button. Pulling the two graft ends into the tibial tunnels. Tibial fixation by knotting the suture ends in a20° flexion on the lateral cortex. Suture the tendon bundles to the remaining remnants of the medial collateral ligament complex to adopt the flat structure of the natural medial collateral ligament complex. Six weeks partial weight-bearing, immediately postoperatively splint in the extended position, after 2weeks movable knee brace for another 4-6weeks. Mobility: 4weeks 0-0-60, 5th and 6th weeks 0-0-90. From 2015-2021, this surgical procedure was performed in 19patients (5women, 14men, age34years). Mean Lysholm score at follow-up after at least 2years was 89 (76-99) points. In 6patients, there was restricted range of motion 3months postoperatively, which resulted in further therapy (3 ×systemic cortisone therapy, 3 ×arthroscopically supported manipulations under anesthesia).

Medial Ligament Complex Reconstruction With Allograft Using Less Invasive Onlay Fixation and Suture Tape Augmentation

Injury to the medial complex of the knee may result in persisting valgus and rotatory instability. In combination with concomitant meniscotibial ligament disruption, maldistributed contact forces are placed on the medial compartment, which may result in the progression of osteoarthritis. When facing chronic valgus and/or posteromedial instability, definitive treatment with medial ligament complex reconstruction in combination with additional repair of the meniscotibial ligament when necessary should be done to anatomically restore proper knee biomechanics and kinematics. This technique describes reconstruction of both the superficial medial collateral ligament (sMCL) and posterior oblique ligament with a single allograft, with additional suture tape augmentation used to reinforce the sMCL. Additionally, less invasive onlay fixation is used via a knotless loop mechanism to secure the posterior oblique ligament to its tibial insertion and the sMCL at 2 points along its distal tibial insertion.

Arthroscopic Posteromedial Corner Reconstruction: A Novel Technique and Case Series.

This study aimed to introduce a novel arthroscopic treatment for medial and posteromedial instability of the knee and present the primary and follow-up results. All patients who underwent the arthroscopic approach to treat medial and posteromedial corner instability from 2007 to 2017 were included in this report. Overall, 45 patients were included, among which 75.6% were male. The mean age of patients was 32.2 ± 8.4 years. Overall, 44.4% and 15.6% of patients had associated meniscal injuries and chondral lesions, respectively. The mean follow-up duration of patients was 84.2 ± 25.3 months. Overall, 37 patients developed a full range of motion (82.2%), and most patients (95.6%) showed excellent quadriceps strength (grades 4 and 5). All patients had a normal or 1+ posterior drawer test, Pivot shift test, and Lachman test on physical examination. Moreover, 60% had an associated isolated anterior cruciate ligament injury, 17.8% had an isolated posterior collateral ligament injury, and 17.6% had a combination of more than one ligament injury. One patient developed septic arthritis. Two patients experienced pain, and one pain patient developed pain with a bony spur formation in the medial epicondyle. Three patients showed a 2+ medial collateral ligament (MCL) test (moderate instability) at the final follow-up, all of whom had multi-ligament injuries. All patients, except the three patients who had a failed MCL reconstruction, returned to their previous activities. This study described a novel arthroscopic treatment of MCL injury, and the results showed acceptable postoperative and clinical outcomes. As the use of minimally invasive surgery may minimize multiple complications associated with open surgery, it is suggested that further studies be conducted regarding this approach when faced with patients who have MCL injuries requiring surgery.

Biomechanical Assessment of Bicortical Suspension Device Fixation for Proximal Tibiofibular Joint Instability: Single Versus Double Device

Background: Bicortical suspension device (BCSD) fixation treats proximal tibiofibular joint (PTFJ) instability in both the anterolateral and posteromedial directions. However, biomechanical data are lacking as to whether this technique restores the native stability and strength of the joint. Purpose: To test (1) if BCSD fixation restores the native stability and strength and (2) if using 2 devices is needed. Study Design: Controlled laboratory study. Methods: Sixteen pairs of fresh-frozen cadaveric specimens were obtained. Six pairs were assigned to the control group and 10 matched pairs assigned for transection to model PTFJ and subsequent BCSD fixation (one specimen with 1-device repair and the other with 2-device repair). Joint stability and strength were assessed by translating the fibular head relative to the fixed tibia either anterolaterally or posteromedially. Control specimens received 20 cycles of 0- to 2.5-mm joint displacement tests (subfailure) and then proceeded to load to failure (5 mm). For the experimental group, cyclic tests were repeated after ligament resection and after fixation. Forces and stiffness at 2.5- and 5-mm displacement were recorded for comparisons of joint strength and stability at subfailure and failure loads, respectively. Results: After repair of anterolateral instability, both the single- and double-device fixations successfully restored near-native states, with no significant differences as compared with the intact group for forces at subfailure load (P = .410) or failure load (P = .397). Regarding posteromedial instability, single-device repair did not restore forces to the near-native state at subfailure load (intact: 92.9 N vs single: 37.4 N; P = .001) or failure load (intact: 170.7 N vs single: 70.4 N; P = .024). However, the double-device repair successfully restored near-native posteromedial forces at both subfailure load (P = .066) and failure load (P = .723). Conclusion: For treatment of the most common form of PTFJ instability (anterolateral), this cadaveric study suggests that 1 BCSD is sufficient to restore stability and strength. The current biomechanical results also suggest that 2 devices are needed for restoring PTFJ posteromedial stability and strength. Using 2 devices addresses both types of instability and provides more PTFJ posteromedial stability. Clinical Relevance: The results suggest that 1 device should be used for treating anterolateral instability and 2 devices used for posteromedial instability based on the biomechanical study.

Evaluation of Surgical Approaches to Management of Traumatic Posteromedial Elbow Instability Syndrome: A Systematic Literature Review Protocol.

Posteromedial Instability Syndrome of the Elbow (PMIE) is a condition that arises from injuries to the stabilizing structures of the elbow joint, such as the coronoid process or ulnar lateral collateral ligament. Surgical treatment is commonly performed, but there is uncertainty regarding its results. This systematic review will synthesise the available evidence regarding the efficacy of surgical approaches to PMIE. Published and unpublished primary studies that regard outcomes of patients treated for PMIE, irrespective of approach, will be considered for inclusion. Iterative searches will be performed in the PubMed/MEDLINE, EMBASE, and Cochrane CENTRAL repositories from their inception to May 2023. Grey literature repositories will also be searched. The Cochrane risk of bias tool will be used to assess the quality of eligible interventional studies, while the MINORS tool will be employed for observational studies. If possible, a meta-analysis based on the random-effects model will be conducted. Heterogeneity will be assessed using Cochrane's Q and I2 statistics, and explored through subgroup analyses and sensitivity analyses. Relevant outcomes will include elbow joint functionality as assessed by validated scales, the proportion of patients returning to usual daily life activities, the development of recurrent joint instability in the postoperative period, quality of life and the development of postoperative arthritis. This protocol has been registered in the International Prospective Register of Systematic Reviews (PROSPERO) at the University of York. Its registration number is CRD42023451516.

POSTEROMEDIAL ELBOW DISLOCATION WITH IPSILATERAL DISTAL RADIUS FRACTURE

Distal radius fractures with concomitant ipsilateral elbow dislocation are a rare injury pattern. Only a few cases of a distal radius fracture with ipsilateral elbow dislocation have been reported. We discuss the case of a 46-year-old gentleman presenting with posteromedial elbow dislocation with an ipsilateral closed extra-articular fracture of the distal radius. Plain radiographs showed a right posterior-medial elbow dislocation and ipsilateral distal radius fracture. CT scans of the elbow showed impaction fractures of the coronoid and trochlea, suggesting a concomitant posteromedial varus elbow dislocation injury. CT scans of the wrist showed the presence of a comminuted, extra-articular distal radius fracture. Surgical fixation of the distal radius was performed, as well as repair of the right elbow lateral capsule-ligamentous complex with suture anchors. Proper recognition of the posteromedial varus instability type injury to the elbow, as in this case is important, should be addressed. If VPMRI is missed, it can lead to ulno-humeral osteoarthritis of the elbow joint.

Anterior elbow fracture dislocation with ulnar nerve palsy in a six-year-old child

Background. Anterior elbow fracture dislocation is rare, especially in paediatric age group. Of the reported cases to date, three-quarter were posterior dislocation of the elbow. Anterior elbow dislocation is rarely reported, with incidence of only 2%.
 Clinical case. A 6-year-old girl presented to casualty with left elbow deformity and pain after she tripped and fell in the toilet. Ulnar clawing was present with reduced sensation over ulnar nerve distribution. No wound was found, distal pulses and circulation were good. The X-rays showed anterior dislocation of the left elbow with olecranon fracture. Closed manual reduction was attempted but failed. Open reduction and percutaneous K-wire insertion under general anaesthesia was performed. Medial approach of the elbow was done. Intra-operatively ulnar nerve was found impinged by the distal ulnar fragment but was in continuity. The transverse olecranon fracture was fixed with two K-wires and the radial head was reduced. Ulnar nerve was mobilised until tension-free. Ulnar collateral ligament was repaired. The elbow was immobilised with a splint. Ulnar claw was resolved at 2 weeks. The fracture heals and the K-wires were removed at 6 weeks. At 8 weeks, range of movement of the elbow was full. The elbow was stable in varus and valgus.
 Discussion. Anterior elbow dislocation is a high energy trauma and one should be cautious of neurovascular injury. There was no clear recommendation in the literature regarding surgical approach. We chose medial approach of the elbow for ulnar nerve exploration and olecranon fixation.
 Conclusion. This rare injury should be treated with high index of suspicious. Surgical approach should be tailored individually according to the instability of the elbow joint and neurovascular status, as in this case was the posteromedial instability associated with ulnar nerve palsy.

An In Vitro Biomechanical Analysis of the Contributions of Medial Ligaments to the Stability of the PCL-Deficient Knee

Objectives:Approximately 95% of PCL injuries are multi-ligament injuries, yet it remains unclear if simultaneous injuries sustained to medial-side knee stabilizers such as the posterior oblique ligament (POL) and deep medial collateral ligament (dMCL) also need to be addressed. Pathomechanical kinematics that still exists after PCL reconstructions may be the result of residual instability due to deficiency of these secondary stabilizers. The objective of this study is to characterize the relative contributions of the POL, dMCL and superficial medial collateral ligament (sMCL) in PCL-deficient knees. We hypothesize that the POL would contribute to stability in extension only, whereas the dMCL would provide stability throughout the entire flexion range of motion.Methods:Eight specimens (aged 40-63, 5 female, 1 male, 2 pairs) were potted and the PCL was dissected arthroscopically. Each specimen was mounted onto a VIVO joint motion simulator (AMTI) and flexed from 0 to 90 degrees with a 10 N compressive load applied along the long axis of the tibia. During this motion, a 5 Nm internal or external moment was applied to the tibia, and the resulting kinematics were recorded. Recorded kinematics were applied back on the specimen, while the joint’s reaction torque to this rotation was measured. The decrease in reaction torque was measured following randomized dissection of the POL and dMCL (4 POL first and 4 dMCL first); the sMCL was always dissected last. The contribution of each ligament to this reaction torque was measured by calculating the change in the reaction torque caused by the ligament’s dissection at 0, 30, 60 and 90 degrees. Each ligament’s relative contribution was compared to the net reaction torque of the joint to calculate the percentage contribution of the ligament. The contribution of each ligament was analyzed using a one-way repeated measure ANOVA with a significance value of 0.05.Results:With an internal torque applied, the dMCL’s contribution to the reaction torque was greatest at 30 degrees, accounting for up to 23% +/- 19% of the overall reaction torque; its contribution was not significantly affected by flexion angle (p>0.05). The POL’s contribution was significantly affected by flexion angle (p=0.007), accounting for 40% +/- 15% of the reaction torque at 0 degrees but only 6% +/- 4% at 90 degrees. The sMCL’s contribution was also sensitive to flexion angle (p=0.006), accounting for 14% ± 16% of the reaction torque at 0 degrees and increasing to 28% +/- 12% at 90 degrees. With an external torque applied, the dMCL’s contribution accounted for 12% +/- 4% of the reaction torque at 0°, but this decreased to 4% +/- 2% at 90 degrees; its contribution was significantly affected by flexion angle (p=0.038). The POL’s contribution accounted for 12% +/- 3% of the reaction torque at 0 degrees and 3% +/- 3% at 90 degrees and the flexion angle changed this contribution significantly (p=0.003). A large portion of the reaction torque was provided by the sMCL, accounting for 52% +/- 7% at 90 degrees.Conclusions:Our results show that, with internal torques applied to the tibia, the POL plays an important role in resisting motion when the joint is near full extension. Conversely, the dMCL’s (and sMCL’s) contribution is largest in flexion. Neither the POL nor dMCL have a large contribution towards resisting external tibial torques; the sMCL seems to be the primary ligament resisting external rotation among medial ligaments. Thus, there is the potential for increased posteromedial instability if POL and dMCL injuries are not addressed, increasing the risk of a failed PCL reconstruction.

Arthroscopic Dissection of the Distal Semimembranosus Tendon: An Anatomical Perspective on Posteromedial Instability and Ramp Lesions

Ramp lesions are increasingly recognized as a hallmark of posteromedial knee instability. Although the precise mechanisms through which these lesions occur is not completely understood, the distal semimembranosus complex has been implicated in their pathogenesis due to its attachment to the posterior horn of the medial meniscus (PHMM). Arthroscopic dissection of the distal semimembranosus tendon, and the application of traction to it, results in posterior translation of the PHMM and stretching of the meniscocapsular region. This demonstrates a mechanism through which ramp lesions can occur. Furthermore, the subsequent open dissection highlights the complex anatomical relationships of the distal semimembranosus tendon complex, particularly its tensioning effect on the posterior oblique ligament. The clinical relevance of this is that when a ramp lesion occurs, it is likely to be part of a spectrum of posteromedial injury and it should be considered a hallmark of posteromedial instability rather than an isolated meniscocapsular injury.

Classifications in Brief: Regan-Morrey Classification of Coronoid Fractures.

Classifications in Brief: Regan-Morrey Classification of Coronoid Fractures.

The Posterior Bundle's Effect on Posteromedial Elbow Instability After a Transverse Coronoid Fracture: A Biomechanical Study.

There has been increased interest in the role of the posterior bundle of the medial collateral ligament (pMUCL) in the elbow, particularly its effects on posteromedial rotatory stability. The ligament's effect in the context of an unfixable coronoid fracture has not been the focus of any study. The purposes of this biomechanical study were to evaluate the stabilizing effect of the pMUCL with a transverse coronoid fracture and to assess the effect of graft reconstruction of the ligament. We simulated a varus and internal rotatory subluxation in 7 cadaveric elbows at 30°, 60°, and 90° elbow flexion. The amount of ulnar rotation and medial ulnohumeral joint gapping were assessed in the intact elbow after we created a transverse coronoid injury, after we divided the pMUCL, and finally, after we performed a graft reconstruction of the pMUCL. At all angles tested, some stability was lost after cutting the pMUCL once the coronoid had been injured, because mean proximal ulnohumeral joint gapping increased afterward by 2.1, 2.2, and 1.3 mm at 90°, 60°, and 30°, respectively. Ulnar internal rotation significantly increased after pMUCL transection at 90°. At 60° and 30° elbow flexion, ulnar rotation increased after resection of the coronoid but not after pMUCL resection. An uninjured pMUCL stabilizes against varus internal rotatory instability in the setting of a transverse coronoid fracture at higher flexion angles. Further research is needed to optimize graft reconstruction of the pMUCL. The pMUCL is an important secondary stabilizer against posteromedial instability in the coronoid-deficient elbow. In the setting of an unfixable coronoid fracture, the surgeon should examine for posteromedial instability and consider addressing the pMUCL surgically.

Comparative study on effect of coronoid fixation with lateral collateral ligament repair versus hinged external fixator in treatment of elbow varus posteromedial rotational instability

Objective To compare the effect of coronoid fixation combined with lateral collateral ligament repair versus hinged external fixator in treatment of elbow varus posteromedial rotational instability. Methods This retrospective cohort research included 34 patients with elbow varus posteromedial rotational instability operated between January 2011 and June 2015. All patients had coronoid process fractures of O' Driscoll type Ⅱ (six with subtype 1, 24 with subtype 2 and four with subtype 3). Fifteen of the 34 patients were operated by coronoid fixation combined with lateral collateral ligament repair (Group A) and other 19 patients were operated by coronoid fixation combined with placing hinged external fixator (Group B). Interval between injury and operation, operation time and blood loss were recorded. At final follow-up, elbow range of motion, Mayo elbow performance score (MEPS) and Hastings and Graham heterotopic ossification classification were measured. Results There were no significant differences in the interval between injury and operation, operation time and blood loss between the two groups (P>0.05). Median period of follow-up was 30 months in Group A and 40 months in Group B. Last follow-up showed flexion of the affected elbow in Group B [145° (135°-150°)] was better than that in Group A [140° (130°-145°)] (P 0.05). MEPS in Group A scored 100 in 10 patients, 90 in three, 85 in one and 70 in one; MEPS in Group B scored 100 in 13 patients, 90 in one, 85 in four and 80 in one. There was no significant difference in MEPS between the two groups (P>0.05). Conclusion For treating elbow varus posteromedial rotational instability, either lateral collateral ligament repair or hinged external fixation after anatomic reduction and coronoid fixation can achieve good results. Key words: Elbow joint; Intra-articular fractures; Coronoid process

Revision Posterior Cruciate Ligament Surgery.

Successful posterior cruciate ligament (PCL) reconstruction surgery results from identification and treatment of associated pathology such as posterolateral instability, posteromedial instability, and lower extremity malalignment. The use of strong graft material, properly placed tunnels to as closely as possible approximate the PCL insertion sites, and minimization of graft bending also enhance the probability of PCL reconstruction success. In addition, mechanical graft tensioning, primary and back-up PCL graft fixation, and the appropriate postoperative rehabilitation program are also necessary ingredients for PCL reconstruction success. Both single-bundle and double-bundle PCL reconstruction surgical techniques are successful when evaluated with stress radiography, KT 1000 arthrometer measurements, and knee ligament rating scales. PCL reconstruction failure may result when any or all of these surgical principles are violated. The purpose of this manuscript was to discuss revision PCL surgery. This presentation will include causes of unsuccessful PCL reconstruction, surgical indications and goals, patient evaluation, surgical decision making, graft selection, surgical technique, associated surgical procedures, postoperative rehabilitation, and revision PCL reconstruction results.

Arthroscopic Transtibial Tunnel Posterior Cruciate Ligament Reconstruction

The goals leading to successful posterior cruciate ligament (PCL) reconstruction surgery include identification and treatment of associated pathology such as posterolateral instability, posteromedial instability, and lower extremity malalignment. The use of strong graft material, properly placed tunnels to as closely as possible approximate the posterior cruciate ligament insertion sites, and the minimization of graft bending also enhance the probability of the PCL reconstruction success. In addition, mechanical graft tensioning, primary and backup PCL graft fixation, and the appropriate postoperative rehabilitation program are also necessary ingredients for PCL reconstruction success. Both single- and double-bundle PCL reconstruction surgical techniques are successful when evaluated with stress radiography, KT-1000 arthrometer measurements, and knee ligament rating scales. Indications for double-bundle PCL reconstruction as of this writing include severe hyperextension of the knee and revision PCL reconstruction. About 2–18-year postsurgical results in combined PCL, ACL, and medial- and lateral-side knee injuries (global laxity) revealed very successful PCL reconstruction using the arthroscopic transtibial tunnel surgical technique. The purpose of this chapter is to describe the arthroscopic transtibial tunnel PCL reconstruction surgical technique and present results with this surgical procedure.

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.

Management of Acute Combined ACL-Medial and Posteromedial Instability of the Knee.

Medial collateral ligament (MCL) injuries are the most common ligamentous injury of the knee. The extent of injury can range from a minor first-degree (1-degree) sprain to an extensive third-degree (3-degree) sprain that can propagate across the knee, rupturing one or both cruciate ligaments, and result in a knee subluxation or dislocation. A common pattern involves the combined anterior cruciate ligament (ACL) and MCL injury that is the focus of this chapter. The vast majority of these combined medial-sided injuries are treated nonoperatively with delayed reconstruction of the ACL injury in athletically active individuals. The MCL and associated medial structures are carefully assessed on physical examination, and classification of injury is based upon abnormal limits of joint motion. In vitro cadaveric biomechanical testing has given us a better understanding of ligament deficiency and altered joint motion. Consistency in terminology is necessary for proper classification of injury and reproducible categorization of injury patterns to be able to compare both nonoperative and operative treatment of various injury patterns.

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 ACL Medial Posteromedial Instability of the Knee

The medial collateral ligament is the most commonly injured ligament in the knee. High-grade medial collateral injuries are associated with injuries to the posteromedial structures of the knee. Chronic medial-sided instability is rare due to the intrinsic capacity of the medial ligamentous structures to heal. However, when combined with anterior cruciate ligament deficiency, significant anterior, valgus, and rotatory laxity of the knee occurs. In this review, we discuss the important biomechanical, clinical, and surgical considerations in the management of chronic combined anterior cruciate ligament, medial, and posteromedial instability of the knee.

Paper 280: Reconstruction of the Posterior Oblique Ligament (POL) and the PCL in Knees with Posteromedial Instability

Paper 280: Reconstruction of the Posterior Oblique Ligament (POL) and the PCL in Knees with Posteromedial Instability

Reconstruction of the Posterior Oblique Ligament and the Posterior Cruciate Ligament in Knees With Posteromedial Instability

Posterior cruciate ligament (PCL) injuries are often associated with injuries of the posteromedial structures of the knee. The motivation for this study was the attempt to test different reconstruction techniques for the structures of the posteromedial corner in a biomechanical experiment. Kinematic studies were carried out on 10 cadaveric knees exposed to a 134-N posterior tibial load, 10-Nm valgus torque, and 5-Nm internal torque at 0°, 30°, 60°, and 90° of flexion. The resulting posterior tibial translation (PTT) was determined using a robotic/universal force-moment sensor testing system for (1) intact knees, (2) PCL-deficient knees, (3) knees with deficiency of the PCL and the posteromedial structures, (4) knees with only the PCL reconstructed, (5) knees with the PCL and posterior oblique ligament (POL) reconstructed, and (6) knees with the PCL, medial collateral ligament (MCL), and POL reconstructed. Kinematic data were analyzed by a 2-factor repeated analysis of variance. When both the PCL and the posteromedial structures were cut, PTT increased significantly at all flexion grades under a posterior tibial load (P < .05). Reconstruction of only the PCL could not restore PTT at 0°, 30°, 60°, and 90° of flexion under loading conditions in a knee with combined injury of the PCL and the posteromedial structures (P > .05). Additional reconstruction of the POL improved PTT at all flexion angles in comparison with only the PCL-reconstructed knee. Reconstruction of the MCL had no significant effect on PTT. This study shows that reconstruction of the POL contributes significantly to the normalization of coupled PTT in knees with combined injury of the PCL and the posteromedial structures under valgus or internal rotational moment. The supplementary reconstruction of the MCL did not provide significant improvement in knee kinematics. The POL should be addressed in the patient with combined injuries of the PCL and the posteromedial structures.