The role of the posterior oblique ligament in controlling posterior tibial translation in the posterior cruciate ligament-deficient knee

[Reconstruction of the medial collateral ligament complex with a flat semitendinosus auto- or allograft]

OBJECTIVE

Replacement of superficial medial collateral ligament (sMCL) and posterior oblique ligament (POL) with an allograft.

INDICATIONS

Chronic 3° isolated medial instability and combined anteromedial or posteromedial instability.

CONTRAINDICATIONS

Infection, open growth plates, restricted range of motion (less than E/F 0-0-90°).

SURGICAL TECHNIQUE

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 a two-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 a flip button. Pulling the two graft ends into the tibial tunnels. Tibial fixation by knotting the suture ends in a 20° 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.

POSTOPERATIVE MANAGEMENT

Six weeks partial weight-bearing, immediately postoperatively splint in the extended position, after 2 weeks movable knee brace for another 4-6 weeks. Mobility: 4 weeks 0-0-60, 5th and 6th weeks 0-0-90.

RESULTS

From 2015-2021, this surgical procedure was performed in 19 patients (5 women, 14 men, age 34 years). Mean Lysholm score at follow-up after at least 2 years was 89 (76-99) points. In 6 patients, there was restricted range of motion 3 months postoperatively, which resulted in further therapy (3 × systemic cortisone therapy, 3 × arthroscopically supported manipulations under anesthesia).

Anatomic reconstruction of the posteromedial corner of the knee: The Versailles technique

INTRODUCTION

Multiligament knee injury with posteromedial laxity is serious and usually requires surgery. Reconstruction is preferable to repair. The main aim of the present study was to report clinical results and laximetry for an original posteromedial corner (PMC) allograft reconstruction technique known as The Versailles Technique. The secondary aim was to determine prognostic factors for surgery. The study hypothesis was that anatomic PMC reconstruction by tendon allograft provides satisfactory medium-term clinical and laximetric results.

METHODS

A retrospective study assessed postoperative clinical and laximetric results after PMC allograft reconstruction at a minimum 12 months' follow-up. Laxity was assessed on comparative bilateral stress X-rays, and functional results on the International Knee Documentation Committee (IKDC) score, the Lysholm score and the Knee injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

Twenty-six patients were included between 2013 and 2019. Mean follow-up was 27.4±9 months. Mean subjective IKDC score was 69.21±17.36, mean Lysholm score 77.78±14.98 and mean KOOS 66.44±18.52.

OBJECTIVE

IKDC results were 77% grade A, 22% grade B, and 0% grade C or D. Mean medial differential laxity in forced varus was 0.83±1.26mm. Mean subjective IKDC scores were poorer in Schenck KD-III than KD-I (p=0.03). Functional results were comparable with acute and with chronic laxity. Age correlated inversely with median KOOS (p=0.009). There was no correlation between postoperative radiologic laxity in forced varus and functional results.

DISCUSSION

Versailles anatomic PMC allograft reconstruction for acute or chronic posteromedial knee laxity showed medium-term efficacy in restoring good objective and subjective stability.

LEVEL OF EVIDENCE

IV; retrospective observational study.

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.

Reconstruction of the Medial Collateral Ligament Complex With a Flat Allograft Semitendinosus Tendon

The aim of this Technical Note is to reconstruct the medial collateral ligament complex with the superior medial collateral ligament and posterior oblique ligament as anatomically as possible. An allograft or contralateral semitendinosus autograft is used for anatomic reconstruction of the superior medial collateral ligament and posterior oblique ligament. After bony fixation, the tendon bundles are sutured to the remnants of the medial collateral ligament complex. Thus, the tubular grafts are pulled apart to form a flat shape that resembles that of the normal medial ligaments.

Association of medial collateral ligament complex injuries with anterior cruciate ligament ruptures based on posterolateral tibial plateau injuries

BACKGROUND

The combined injury of the medial collateral ligament complex and the anterior cruciate ligament (ACL) is the most common two ligament injury of the knee. Additional injuries to the medial capsuloligamentous structures are associated with rotational instability and a high failure rate of ACL reconstruction. The study aimed to analyze the specific pattern of medial injuries and their associated risk factors, with the goal of enabling early diagnosis and initiating appropriate therapeutic interventions, if necessary.

RESULTS

Between January 2017 and December 2018, 151 patients with acute ACL ruptures with a mean age of 32 ± 12 years were included in this study. The MRIs performed during the acute phase were analyzed by four independent investigators-two radiologists and two orthopedic surgeons. The trauma impact on the posterolateral tibial plateau and associated injuries to the medial complex (POL, dMCL, and sMCL) were examined and revealed an injury to the medial collateral ligament complex in 34.4% of the patients. The dMCL was the most frequently injured structure (92.2%). A dMCL injury was significantly associated with an increase in trauma severity at the posterolateral tibial plateau (p < 0.02) and additional injuries to the sMCL (OR 4.702, 95% CL 1.3-133.3, p = 0.03) and POL (OR 20.818, 95% CL 5.9-84.4, p < 0.0001). Isolated injuries to the sMCL were not observed. Significant risk factors for acquiring an sMCL injury were age (p < 0.01) and injury to the lateral meniscus (p < 0.01).

CONCLUSION

In about one-third of acute ACL ruptures the medial collateral ligament complex is also injured. This might be associated with an increased knee laxity as well as anteromedial rotational instability. Also, this might be associated with an increased risk for failure of revision ACL reconstruction. In addition, we show risk factors and predictors that point to an injury of medial structures and facilitate their diagnosis. This should help physicians and surgeons to precisely diagnose and to assess its scope in order to initiate proper therapies. With this in mind, we would like to draw attention to a frequently occurring combination injury, the so-called "unlucky triad" (ACL, MCL, and lateral meniscus). Level of evidence Level III Retrospective cohort study.

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.

Medial Collateral Ligament Reconstruction: A Gracilis Tenodesis for Anteromedial Knee Instability

The main principle of the present medial collateral ligament reconstruction technique is to address anteromedial knee instability. Therefore, we describe a gracilis tenodesis with 2 functional bundles to reconstruct the deep and superficial medial collateral ligament. The proposed technique may be performed as an isolated or combined procedure with anterior cruciate ligament reconstruction. Valgus instability in extension is a contraindication.

The Control of Anteromedial Rotatory Instability Is Improved With Combined Flat sMCL and Anteromedial Reconstruction

BACKGROUND

Both the superficial medial collateral ligament (sMCL) and the deep MCL (dMCL) contribute to the restraint of anteromedial (AM) rotatory instability (AMRI). Previous studies have not investigated how MCL reconstructions control AMRI.

PURPOSE/HYPOTHESIS

The purpose was to establish the optimal medial reconstruction for restoring normal knee kinematics in an sMCL- and dMCL-deficient knee. It was hypothesized that AMRI would be better controlled with the addition of an anatomically shaped (flat) sMCL reconstruction and with the addition of an AM reconstruction replicating the function of the dMCL.

STUDY DESIGN

Controlled laboratory study.

METHODS

A 6 degrees of freedom robotic system equipped with a force-torque sensor was used to test 8 unpaired knees in the intact, sMCL/dMCL sectioned, and reconstructed states. Four different reconstructions were assessed. The sMCL was reconstructed with either a single-bundle (SB) or a flattened hamstring graft aimed at better replicating the appearance of the native ligament. These reconstructions were tested with and without an additional AM reconstruction. Simulated laxity tests were performed at 0°, 30°, 60°, and 90° of flexion: 10 N·m valgus rotation, 5 N·m internal and external rotation (ER), and an AM drawer test (combined 134-N anterior tibial drawer in 5 N·m ER). The primary outcome measures of this force-controlled setup were anterior tibial translation (ATT; in mm) and axial tibial rotation (in degrees).

RESULTS

Sectioning the sMCL/dMCL increased valgus rotation, ER, and ATT with the simulated AM draw test at all flexion angles. SB sMCL reconstruction was unable to restore ATT, valgus rotation, and ER at 30°, 60°, and 90° of flexion to the intact state (P < .05). Flat MCL reconstruction restored valgus rotation at all flexion angles to the intact state (P > .05). ER was restored at all angles except at 90°, but ATT laxity in response to the AM drawer persisted. Addition of an AM reconstruction improved control of ATT relative to the intact state at all flexion angles (P > .05). Combined flat MCL and AM reconstruction restored knee kinematics closest to the intact state.

CONCLUSION

In a cadaveric model, AMRI resulting from an injured sMCL and dMCL complex could not be restored by an isolated SB sMCL reconstruction. A flat MCL reconstruction or an additional AM procedure, however, better restored medial knee stability.

CLINICAL RELEVANCE

In patients evaluated with a combined valgus and AM rotatory instability, a flat sMCL and an additional AM reconstruction may be superior to an isolated SB sMCL reconstruction.

The posterior oblique ligament in MRI of acute knee trauma

OBJECTIVE

To identify the posterior oblique ligament and assess incidence and patterns of injury to the ligament on MRI of acute knee trauma.

SUBJECTS AND METHODS

One hundred twenty-three MRI studies met the study criteria. For each case, the posterior oblique ligament was identified and scored as injured or normal. Incidence of proximal and distal posterior oblique ligament tears was calculated. Fisher's tests were employed to determine significance of association between tears of the posterior oblique ligament and components of the posteromedial corner and other capsuloligamentous structures of the knee.

RESULTS

The posterior oblique ligament was reliably identified as a distinct structure in 123 MRI scans that met the criteria and was consistently labeled as intact or torn. Posterior oblique ligament tear was seen in 61.7% of knee trauma with proximal injury in 56.5% and distal injury in 97.3% of positive cases. Posterior oblique ligament disruption was a part of multiligamentous injury in 94.7% of positive cases. Posterior oblique ligament injuries (n = 76) had an extremely significant relationship with oblique popliteal ligament tears (n = 27) (p = 0.0001), semimembranosus tendon insertion tears (n = 15) (p = 0.0005), and medial collateral ligament tears (n = 15) (p = 0.0005) and a highly significant association with medial meniscus tears (n = 68) (p = 0.0049) and posterior cruciate ligament tears (n = 12) (p = 0.0033). The association with anterior cruciate ligament tears (n = 53) was not significant.

CONCLUSIONS

The posterior oblique ligament is a distinct radiological entity consistently identified in acute trauma MRI. Disruptions of the distal posterior oblique ligament are frequent in complex knee injury, notably in association with oblique popliteal ligament, medial collateral ligament, and semimembranosus tendon tears.

MCL Reconstruction Using a Flat Tendon Graft for Anteromedial and Posteromedial Instability

The main principles of the present medial collateral ligament (MCL) reconstruction techniques are (1) to approximate the natural anatomy and (2) to restore the main passive restraining structures in anteromedial and posteromedial knee instability. Therefore, we describe a technique using a flat tendon graft instead of tubular grafts with point-to-point bone fixation. Moreover, we address the deep MCL, a relevant restraint to anteromedial instability.

The Medial structures of the knee have a significant contribution to posteromedial rotational laxity control in the PCL-deficient knee

PURPOSE

Various reconstruction techniques have been employed to restore normal kinematics to PCL-deficient knees; however, studies show that failure rates are still high. Damage to secondary ligamentous stabilizers of the joint, which commonly occurs concurrently with PCL injuries, may contribute to these failures. The main objective of this study was to quantify the biomechanical contributions of the deep medial collateral ligament (dMCL) and posterior oblique ligament (POL) in stabilizing the PCL-deficient knee, using a joint motion simulator.

METHODS

Eight cadaveric knees underwent biomechanical analysis of posteromedial stability and rotatory laxity using an AMTI VIVO joint motion simulator. Combined posterior force (100 N) and internal torque (5 Nm) loads, followed by pure internal/external torques (± 5 Nm), were applied at 0, 30, 60 and 90° of flexion. The specimens were tested in the intact state, followed by sequential sectioning of the PCL, dMCL, POL and sMCL. The order of sectioning of the dMCL and POL was randomized, providing n = 4 for each cutting sequence. Changes in posteromedial displacements and rotatory laxities were measured, as were the biomechanical contributions of the dMCL, POL and sMCL in resisting these loads in a PCL-deficient knee.

RESULTS

Overall, it was observed that POL transection caused increased posteromedial displacements and internal rotations in extension, whereas dMCL transection had less of an effect in extension and more of an effect in flexion. Although statistically significant differences were identified during most loading scenarios, the increases in posteromedial displacements and rotatory laxity due to transection of the POL or dMCL were usually small. However, when internal torque was applied to the PCL-deficient knee, the combined torque contributions of the dMCL and POL towards resisting rotation was similar to that of the sMCL.

CONCLUSION

The dMCL and POL are both important secondary stabilizers to posteromedial translation in the PCL-deficient knee, with alternating roles depending on flexion angle. Thus, in a PCL-deficient knee, concomitant injuries to either the POL or dMCL should be addressed with the aim of reducing the risk of PCL reconstruction failure.

Sequential Changes in Posterior Tibial Translation After Posterior Cruciate Ligament Reconstruction: Risk Factors for Residual Posterior Sagging

Background:

Residual posterior sagging may occur after posterior cruciate ligament (PCL) reconstruction (PCLR), yet when it mainly occurs is not fully understood.

Purpose:

To elucidate sequential changes in radiographic posterior tibial translation (PTT) after PCLR.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

The authors retrospectively investigated the radiographic findings from 22 patients who underwent bisocket double-bundle PCLR for isolated PCL injury with at least 2 years of follow-up (mean, 4.5 years; range, 2-10 years). Injury severity was assessed using PTT on lateral radiographs with gravity sag views and was stratified according to side-to-side difference in the tibial-femoral stepoff: grade 1 (<5 mm), grade 2 (5 to <10 mm), or grade 3 (≥10 mm). Measurements were taken preoperatively and then immediately, 3 months, 6 months, 1 year, and ≥2 years postoperatively. The authors also investigated the risk factors for residual posterior sagging, indicated when PTT was ≥5 mm (grade ≥2) at the minimum 2-year follow-up.

Results:

Preoperatively, 13 patients had a grade 2 injury, and 9 had grade 3 injury. The PTT, restored immediately after PCLR, significantly increased at 3 months (P < .001) but remained unchanged thereafter ≥2 years. There were 7 cases of postoperative PTT ≥5 mm on radiographs. Patients with residual posterior sagging had significantly larger mean PTT than did those without residual posterior sagging at all time points except for immediately postoperatively (preoperatively, 9.1 ± 1.6 vs 12.2 ± 2.3 mm; 3-month follow-up, 2.7 ± 1.6 vs 7.0 ± 1.8 mm; ≥2-year follow-up, 3.4 ± 1.0 vs 6.5 ± 1.4 mm; P < .001 for all). Multivariate logistic regression analysis showed that preoperative grade 3 injury was independently associated with residual posterior sagging (OR, 26.809; 95% CI, 1.257-571.963; P < .001).

Conclusion:

The initially reduced postoperative PTT significantly increased within 3 months using conventional rehabilitation protocols, but no progression was observed up to 4.5 years after PCLR. Preoperative grade 3 injury was independently associated with residual posterior sagging.

Anatomical evaluation of the femoral attachment of the posterior oblique ligament

INTRODUCTION

Tibiofemoral joint instability reduces patient satisfaction after total knee arthroplasty (TKA). However, surgeons sometimes encounter excessive medial joint laxity without medial over-release on the tibial side. It was hypothesized that over-resection of the posteromedial femoral condyle can injure the medial stabilizers, especially the posterior oblique ligament (POL) at its femoral attachments.

MATERIALS AND METHODS

Thirteen fixed cadaveric knees were exposed, and 3 anatomical points were identified: the posterior edge and midpoint of the POL femoral attachment, and the posterior edge of the superficial medial collateral ligament (sMCL) femoral attachment. The distance from the surface of the posteromedial femoral condyle to each point was measured. Correlations between each point and the anterior-posterior or medial-lateral dimensions of the distal femur were also calculated.

RESULTS

The average distances to the posterior edge and midpoint of the POL femoral attachment and the posterior edge of the sMCL femoral attachment were 13.7 mm (9.0-18.4), 17.9 mm (11.5-22.6), and 22.7 mm (14.7-29.4), respectively. There were moderate correlations between the distance to each point and the anterior-posterior or medial-lateral dimensions of the distal femur.

CONCLUSIONS

The minimal distance from the surface of the posteromedial condyle to the POL posterior edge was 9.0 mm. Over-resection of the posteromedial femoral condyle, even with a general TKA femoral component, might injure the POL at its femoral attachments, especially in patients with small distal femurs, while the sMCL is rarely damaged.

LEVEL OF EVIDENCE

Level IV.

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.

Evolving evidence in the treatment of primary and recurrent posterior cruciate ligament injuries, part 1: anatomy, biomechanics and diagnostics

The posterior cruciate ligament (PCL) represents an intra-articular structure composed of two distinct bundles. Considering the anterior and posterior meniscofemoral ligaments, a total of four ligamentous fibre bundles of the posterior knee complex act synergistically to restrain posterior and rotatory tibial loads. Injury mechanisms associated with high-energy trauma and accompanying injury patterns may complicate the diagnostic evaluation and accuracy. Therefore, a thorough and systematic diagnostic workup is necessary to assess the severity of the PCL injury and to initiate an appropriate treatment approach. Since structural damage to the PCL occurs in more than one third of trauma patients experiencing acute knee injury with hemarthrosis, background knowledge for management of PCL injuries is important. In Part 1 of the evidence-based update on management of primary and recurrent PCL injuries, the anatomical, biomechanical, and diagnostic principles are presented. This paper aims to convey the anatomical and biomechanical knowledge needed for accurate diagnosis to facilitate subsequent decision-making in the treatment of PCL injuries.Level of evidence 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.

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.

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.

The Laxity of the Native Knee: A Meta-Analysis of in Vitro Studies

BACKGROUND

Although soft-tissue balancing plays an important role in knee arthroplasty, we are aware of no objective target parameters describing the soft-tissue tension of the native knee. In the present study, we aimed to meta-analyze data from studies investigating native knee laxity to create a guide for creating a naturally balanced knee joint.

METHODS

PubMed and Web of Science were searched for studies with laxity data published from 1996 through 2016. Graphs were digitally segmented in cases in which numerical data were not available in text or table form. Three-level random-effects meta-analyses were conducted.

RESULTS

Seventy-six studies evaluating knee laxity at various flexion angles (0° to 90°) were included. Knee laxity was significantly different between 0° and 90° of flexion (p < 0.001) in all 6 testing directions, with mean differences of 0.94 mm and -0.35 mm for anterior and posterior translation, 1.61° and 4.25° for varus and valgus rotation, and 1.62° and 6.42° for internal and external rotation, respectively.

CONCLUSIONS

Knee laxity was dependent on the flexion angle of the knee joint in all degrees of freedom investigated. Furthermore, asymmetry between anterior-posterior, varus-valgus, and internal-external rotation was substantial and depended on the joint flexion angle.

CLINICAL RELEVANCE

If the goal of knee arthroplasty is to restore the kinematics of the knee as well as possible, pooled laxity data of the intact soft tissue envelope could be useful as a general guide for soft-tissue balancing in total knee arthroplasty.

The use of allograft tissue in posterior cruciate, collateral and multi-ligament knee reconstruction

PURPOSE

Currently both autograft and allograft tissues are available for reconstruction of posterior cruciate, collateral and multi-ligament knee injuries. Decision-making is based on a complex interplay between anatomical structures, functional bundles and varying biomechanical requirements. Despite theoretically better biological healing and reduced risk of disease transmission autografts are associated with donor site morbidity as well as being limited by size and quantity. The use of allografts eliminates donor-site morbidity but raises cost and issues of clinical effectiveness. The purpose of this paper is to review current concepts and evidence for the use of allografts in primary posterior cruciate, collateral and multi-ligament reconstructions.

METHODS

A narrative review of the relevant literature was conducted for PCL, collateral ligament and multi-ligament knee reconstruction. Studies were identified using a targeted and systematic search with focus on recent comparative studies and all clinical systematic reviews and meta-analyses. The rationale and principles of management underpinning the role of allograft tissue were identified and the clinical and functional outcomes were analysed. Finally, the position of postoperative physiotherapy and rehabilitation was identified.

RESULTS

The review demonstrated paucity in high quality and up-to-date results addressing the issue especially on collaterals and multi-ligament reconstructions. There was no significant evidence of superiority of a graft type over another for PCL reconstruction. Contemporary principles in the management of posterolateral corner, MCL and multi-ligament injuries support the use of allograft tissue.

CONCLUSION

The present review demonstrates equivalent clinical results with the use of autografts or allografts. It remains, however, difficult to generate a conclusive evidence-based approach due to the paucity of high-level research. When confronted by the need for combined reconstructions with multiple grafts, preservation of synergistic muscles, and adapted postoperative rehabilitation; the current evidence does offer support for the use of allograft tissue.

LEVEL OF EVIDENCE

IV.

Preoperative MRI for the Multiligament Knee Injury: What the Surgeon Needs to Know

The multiligament knee injury is devastating and potentially limb threatening. Preoperative magnetic resonance imaging for the evaluation of the multiligament knee injury is an invaluable clinical tool, and when the radiologist is familiar with how certain injury patterns influence management, optimal outcomes can be achieved. We provide a detailed description of the relationship between salient imaging features of the multiligament knee injury, focusing on the preoperative magnetic resonance imaging, and their influence on clinical decision-making.

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.

The relationship between anteroposterior stability and medial-lateral stability of the bi-cruciate stabilized total knee arthroplasty

BACKGROUND

Acquisition of appropriate anteroposterior (AP) stability depends on the prosthetic design and intraoperative soft tissue handling. A bi-cruciate stabilized (BCS) total knee arthroplasty (TKA) has a two cam-post mechanism, which substitutes for the anterior cruciate ligament and posterior cruciate ligament (PCL). Therefore, appropriate AP stability is expected. Because the PCL is sacrificed during BCS TKA, medial stability and lateral stability are thought to be important factors to determine AP stability. However, no previous study has reported AP stability after BCS TKA and the relationship between AP and medial-lateral stability.

METHODS

AP stability was measured using a navigation system intraoperatively and the KT 2000 device postoperatively. Intraoperative joint laxity of the medial and lateral compartments was evaluated separately using a compartment-specific ligament tensioner. The relationship between AP stability and medial-lateral laxity was assessed.

RESULTS

Intraoperative AP translation at 30° and 90° knee flexion angles was 7.7 ± 3.1 mm and 5.9 ± 2.0 mm, respectively. Postoperative AP translation at 30° was 5.9 ± 1.7 mm. AP translation correlated positively with medial joint laxity at 30° (R = 0.29) and 90° (R = 0.40). The intraoperative and postoperative AP translations at 30° flexion had a positive relationship (R = 0.61).

CONCLUSION

AP stability of the BCS TKA had a positive relationship with intraoperative medial stability. Therefore, surgical soft tissue handling focusing on medial stability is also appropriate for AP stability of BCS TKA. Additionally, intraoperative AP translation turned out to be a predictive indicator for postoperative knee AP stability at 30° flexion.

Lateral soft-tissue structures contribute to cruciate-retaining total knee arthroplasty stability

Little information is available to surgeons regarding how the lateral structures prevent instability in the replaced knee. The aim of this study was to quantify the lateral soft-tissue contributions to stability following cruciate-retaining total knee arthroplasty (CR TKA). Nine cadaveric knees were tested in a robotic system at full extension, 30°, 60°, and 90° flexion angles. In both native and CR implanted states, ±90 N anterior-posterior force, ±8 Nm varus-valgus, and ±5 Nm internal-external torque were applied. The anterolateral structures (ALS, including the iliotibial band), the lateral collateral ligament (LCL), the popliteus tendon complex (Pop T), and the posterior cruciate ligament (PCL) were transected and their relative contributions to stabilizing the applied loads were quantified. The LCL was found to be the primary restraint to varus laxity (an average 56% across all flexion angles), and was significant in internal-external rotational stability (28% and 26%, respectively) and anterior drawer (16%). The ALS restrained 25% of internal rotation, while the PCL was significant in posterior drawer only at 60° and 90° flexion. The Pop T was not found to be significant in any tests. Therefore, the LCL was confirmed as the major lateral structure in CR TKA stability throughout the arc of flexion and deficiency could present a complex rotational laxity that cannot be overcome by the other passive lateral structures or the PCL. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1902-1909, 2017.

An in vitro analysis of medial structures and a medial soft tissue reconstruction in a constrained condylar total knee arthroplasty

PURPOSE

The aim of this study was to quantify the medial soft tissue contributions to stability following constrained condylar (CC) total knee arthroplasty (TKA) and determine whether a medial reconstruction could restore stability to a soft tissue-deficient, CC-TKA knee.

METHODS

Eight cadaveric knees were mounted in a robotic system and tested at 0°, 30°, 60°, and 90° of flexion with ±50 N anterior-posterior force, ±8 Nm varus-valgus, and ±5 Nm internal-external torque. The deep and superficial medial collateral ligaments (dMCL, sMCL) and posteromedial capsule (PMC) were transected and their relative contributions to stabilising the applied loads were quantified. After complete medial soft tissue transection, a reconstruction using a semitendinosus tendon graft was performed, and the effect on kinematic behaviour under equivocal conditions was measured.

RESULTS

In the CC-TKA knee, the sMCL was the major medial restraint in anterior drawer, internal-external, and valgus rotation. No significant differences were found between the rotational laxities of the reconstructed knee to the pre-deficient state for the arc of motion examined. The relative contribution of the reconstruction was higher in valgus rotation at 60° than the sMCL; otherwise, the contribution of the reconstruction was similar to that of the sMCL.

CONCLUSION

There is contention whether a CC-TKA can function with medial deficiency or more constraint is required. This work has shown that a CC-TKA may not provide enough stability with an absent sMCL. However, in such cases, combining the CC-TKA with a medial soft tissue reconstruction may be considered as an alternative to a hinged implant.

Imaging of Athletic Injuries of Knee Ligaments and Menisci: Sports Imaging Series

Acute knee injuries are a common source of morbidity in athletes and if overlooked may result in chronic functional impairment. Magnetic resonance (MR) imaging of the knee has become the most commonly performed musculoskeletal MR examination and is an indispensable tool in the appropriate management of the injured athlete. Meniscal and ligamentous tearing are the most frequent indications for surgical intervention in sports injuries and an understanding of the anatomy, biomechanics, mechanisms of injury, and patterns of injury are all critical to accurate diagnosis and appropriate management. These will be discussed in reference to meniscal tears and injuries of the cruciate ligaments as well as injuries of the posterolateral and posteromedial corners of the knee. (©) RSNA, 2016.

Surgical treatment of medial knee ligament injuries: current indications and techniques

The medial collateral ligament (MCL) and the posterior oblique ligament (POL) are the main static valgus restraints of the knee.

Most isolated medial injuries can be treated with bracing and early knee motion.

Combined MCL and ACL (anterior cruciate ligament) injuries can be managed with bracing of the knee followed by a delayed reconstruction of the ACL.

Residual medial laxity may be addressed at the time of ACL surgery.

Bony avulsions, incarceration of the distal MCL under the meniscus or over the pes anserinus tendons, open injuries, MCL tears combined with PCL or bi-cruciate injuries should be treated surgically.

Chronic symptomatic medial instability can be managed with the recently described reconstruction techniques using free tendon grafts located at anatomical insertion sites.

Cite this article: Tandogan NR, Kayaalp A. Surgical treatment of medial knee ligament injuries: Current indications and techniques. EFORT Open Rev 2016;2:27-33. DOI: 10.1302/2058-5241.1.000007.

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.

The effects of posterior cruciate ligament deficiency on posterolateral corner structures under gait- and squat-loading conditions: A computational knee model

Objectives

The aim of the current study was to analyse the effects of posterior cruciate ligament (PCL) deficiency on forces of the posterolateral corner structure and on tibiofemoral (TF) and patellofemoral (PF) contact force under dynamic-loading conditions.

Methods

A subject-specific knee model was validated using a passive flexion experiment, electromyography data, muscle activation, and previous experimental studies. The simulation was performed on the musculoskeletal models with and without PCL deficiency using a novel force-dependent kinematics method under gait- and squat-loading conditions, followed by probabilistic analysis for material uncertain to be considered.

Results

Comparison of predicted passive flexion, posterior drawer kinematics and muscle activation with experimental measurements showed good agreement. Forces of the posterolateral corner structure, and TF and PF contact forces increased with PCL deficiency under gait- and squat-loading conditions. The rate of increase in PF contact force was the greatest during the squat-loading condition. The TF contact forces increased on both medial and lateral compartments during gait-loading conditions. However, during the squat-loading condition, the medial TF contact force tended to increase, while the lateral TF contact forces decreased. The posterolateral corner structure, which showed the greatest increase in force with deficiency of PCL under both gait- and squat-loading conditions, was the popliteus tendon (PT).

Conclusion

PCL deficiency is a factor affecting the variability of force on the PT in dynamic-loading conditions, and it could lead to degeneration of the PF joint.

Cite this article: K-T. Kang, Y-G. Koh, M. Jung, J-H. Nam, J. Son, Y.H. Lee, S-J. Kim, S-H. Kim. The effects of posterior cruciate ligament deficiency on posterolateral corner structures under gait- and squat-loading conditions: A computational knee model. Bone Joint Res 2017;6:31–42. DOI: 10.1302/2046-3758.61.BJR-2016-0184.R1.

The superficial medial collateral ligament is the primary medial restraint to knee laxity after cruciate-retaining or posterior-stabilised total knee arthroplasty: effects of implant type and partial release

PURPOSE

The aim of this study was to quantify the contributions of medial soft tissues to stability following cruciate-retaining (CR) or posterior-stabilised (PS) total knee arthroplasty (TKA).

METHODS

Using a robotic system, eight cadaveric knees were subjected to ±90-N anterior-posterior force, ±5-Nm internal-external and ±8-Nm varus-valgus torques at various flexion angles. The knees were tested intact and then with CR and PS implants, and successive cuts of the deep and superficial medial collateral ligaments (dMCL, sMCL) and posteromedial capsule (PMC) quantified the percentage contributions of each structure to restraining the applied loads.

RESULTS

In implanted knees, the sMCL restrained valgus rotation (62 % across flexion angles), anterior-posterior drawer (24 and 10 %, respectively) and internal-external rotation (22 and 37 %). Changing from CR TKA to PS TKA increased the load on the sMCL when resisting valgus loads. The dMCL restrained 11 % of external and 13 % of valgus rotations, and the PMC was significant at low flexion angles.

CONCLUSIONS

This work has shown that medial release in the varus knee should be minimised, as it may inadvertently result in a combined laxity pattern. There is increasing interest in preserving constitutional varus in TKA, and this work argues for preservation of the sMCL to afford the surgeon consistent restraint and maintain a balanced knee for the patient.

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.

Results of multiple ligament injured knees operated by three different strategies

BACKGROUND

Multiple ligament injured knee is generally described for a scenario when at least 2 of the 4 major ligaments are ruptured. The most effective treatment for these injuries remains controversial. This study presents the clinical outcome of 3 surgical strategies based on personalized treatment.

MATERIALS AND METHODS

Thirty two patients with multiple ligament injured knee were treated by 3 surgical strategies in the acute phase. (1) One-stage: Twelve patients treated by repair and reconstruction of all ruptured ligaments in a single operation. (2) Staged: Eleven patients treated by repair or reconstruction of the extraarticular (EA) ligaments and then intraarticular ligaments in 2(nd) stage. (3) EA ligament repair: Nine patients underwent only EA ligaments repair.

RESULTS

The patients were followed up for an average of 34.7 ± 12.1 months. Significant improvements in knee stabilities (P < 0.01), Lysholm score (P < 0.01) and International Knee Documentation Committee grade (P < 0.01) were noticed in all groups. Of the 32 patients, none had gross mal alignment or gait abnormalities at the latest followup. Comparing the 3 groups, a significant difference in Lysholm score was shown between the one stage group and the EA repair group (P = 0.040); additionally, significant differences were found in 2 subscales of knee injury and osteoarthritis outcome score (P < 0.05).

CONCLUSION

Satisfactory clinical and functional outcomes could be achieved adopting the 3 surgical strategies based on personalized treatment. However, a combination of EA repair and intraarticular repair or reconstruction might be more reasonable options for the young and active patients.

Surgical Repair of Medial Collateral Ligament and Posteromedial Corner Injuries of the Knee: A Systematic Review

PURPOSE

To systematically evaluate surgical techniques and objective clinical outcomes of primary repair of the medial collateral ligament (MCL) and posteromedial corner of the knee.

METHODS

A systematic review of the PubMed/Medline Database (1966 to August 2014) was performed to identify all clinical studies describing MCL and other medial-based repairs of the knee. Exclusion criteria were applied to reconstruction techniques, animal models, and non-English publications. Descriptive analysis identified surgical technique, International Knee Documentation Committee (IKDC) objective form valgus stability subscore, functional outcome measures, and laxity on valgus stress.

RESULTS

After exclusion of 165 references, 16 publications with 355 knees were included in the final analysis. Fixation construct included suture-only repair (49.5%), staples (12.1%), suture anchors (11.2%), and mixed or unknown fixation (27.0%). When isolating knees with available relative valgus stress opening (n = 223), 75.8% had side-to-side difference of <3 mm or <1+ (n = 169; 10 studies; range, 36% to 100%). Similarly, an IKDC valgus stability grade of A or B was identified in 126 of 140 knees (90.0%; 6 studies; range, 60% to 100%). Of 93 knees with quantified values, the mean side-to-side difference in medial joint space opening was 1.25 mm (SD ± 0.85) after primary repair. Thirteen of 212 knees (6.1%) met the criteria for failure, and the average Lysholm score was 91.6 (n = 210; range, 85.5 to 98.5).

CONCLUSIONS

This systematic review demonstrated that repair of the MCL and posteromedial corner of the knee may be an effective and reliable treatment for medial-sided knee injuries, resulting in improved valgus stability and patient-reported functional scores with low rates of secondary failure. However, repair techniques may vary significantly depending on the chronicity and extent of medial ligamentous knee injuries, and appropriate patient selection is critical in determining ultimate clinical outcomes.

LEVEL OF EVIDENCE

IV.

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.

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.

Side-to-side differences of three-dimensional knee kinematics during walking by normal subjects

[Purpose] The purpose of this study was to determine the normal range of the side-to-side difference in three dimensional knee kinematics measured by the point cluster technique (PCT). [Subjects] The subjects were twenty-one healthy normal volunteers without knee pain or an episode of injury to the legs. [Methods] The subjects were tested bilaterally at a self-selected normal walking speed and six degrees of freedom knee kinematics were measured using the PCT, and the 95% confidence intervals of the average side-to-side differences in flexion-extension (FE), adduction-abduction (AA), internal-external (IE) rotation, and anterior-posterior (AP), medial-lateral (ML), superior-inferior (SI) translation in each stage of the gait cycle were determined. [Results] The average side-to-side differences and their 95% confidence intervals in rotation/translation in each stage of the gait cycle were determined. The side-to-side differences in AA rotation and AP translation of the tibia were significantly larger in the swing phase than in the stance phase. [Conclusion] The side-to-side differences in AA rotation and AP translation were highly dependent on the stage of the gait cycle. Therefore, the normal ranges of the side-to-side differences in knee kinematics in each stage of the gait cycle, in particular AA rotation and AP translation of the tibia, is useful information for evaluating knee kinematics during walking.

Medial injury in knee dislocations: what are the common injury patterns and surgical outcomes?

BACKGROUND

When associated with a knee dislocation, management of the medial ligamentous injury is challenging, with little literature available to guide treatment.

QUESTIONS/PURPOSES

We (1) compared MRI findings of medial ligament injuries between Schenck KDIIIM and KDIV injuries, (2) compared clinical outcomes and health-related quality of life as determined by Lysholm and Veterans Rand 36-Item Health Survey (VR-36) scores, respectively, of reconstructed KDIIIM and KDIV injured knees, and (3) determined reoperation rates of reconstructed KDIIIM and KDIV injured knees.

METHODS

Over a 12-year period, we treated 65 patients with knee dislocations involving bicruciate ligament injury and concomitant medial ligament injuries, without or with posterolateral corner injuries (Schenck KDIIIM and KDIV, respectively); 57% were available for followup at a mean of 6.2 years (range, 1.1-11.6 years). These patients were contacted, and prospectively measured clinical outcomes scores (Lysholm and VR-36) were obtained and compared between subsets of patients. Preoperative MRIs (available for review on 49% of the patients) were rereviewed to characterize the medial ligament injuries.

RESULTS

KDIIIM injuries more frequently had complete deep medial collateral ligament tears and posterior oblique ligament tears compared to KDIV injuries. KDIIIM knees had better Lysholm scores (88 versus 67, p = 0.027) and VR-36 scores (88 versus 70, p = 0.022) than KDIV knees. Female sex (Lysholm: 55 versus 85, p = 0.005; VR-36: 59 versus 85, p = 0.003) and an ultra-low-velocity mechanism (injury that occurs during activity of daily living in obese patients) (Lysholm: 55 versus 80-89, p = 0.002-0.013; VR-36: 60 versus 79-88, p = 0.001-0.017) were associated with worse outcomes. The overall reoperation rate was 28%, and the most common indication for reoperation was stiffness.

CONCLUSIONS

Medial ligament injury is common in knee dislocations. Females who sustain these injuries and patients who have an ultra-low-velocity mechanism should be counseled at the time of injury about the likelihood of inferior outcomes. As ROM deficits are the most commonly encountered complication, postoperative rehabilitation should focus on early ROM exercises as stability and wound healing allow. Future prospective studies are needed to definitively determine whether operative or nonoperative management is appropriate for particular medial ligamentous injury patterns.

Tibial inlay reconstruction of the medial collateral ligament using Achilles tendon allograft for the treatment of medial instability of the knee

Although various surgical procedures have been described for the medical collateral ligament (MCL) reconstruction, none can accurately reestablish its original anatomy and orientation. The purpose of this study was to present a technique restoring the anatomy and stability of the medial knee with an Achilles tendon allograft using a tibial inlay technique. The bone block was fixed into a cancellous trough created on the medial surface of the tibia with a cancellous screw and washer, while the tendinous portion was fixed into the femoral insertion site of the superficial MCL with a bioabsorbable interference screw. This technique can successfully reproduce the native anatomy and orientation of the MCL.