[Minimally invasive augmentation of the medial collateral ligament with autologous hamstring tendons in chronic knee instability]

Comparative Outcomes Occur After Superficial Medial Collateral Ligament Augmented Repair vs Reconstruction: A Prospective Multicenter Randomized Controlled Equivalence Trial

BACKGROUND

Although previous studies have reported good short-term results for superficial medial collateral ligament (sMCL) reconstruction, whether an augmented MCL repair is clinically equivalent remains unclear.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare clinical outcomes between randomized groups that underwent sMCL augmentation repair and sMCL autograft reconstruction. The hypothesis was that there would be no significant differences in objective or subjective outcomes between groups.

STUDY DESIGN

Randomized controlled trial; Level of evidence, 1.

METHODS

Patients were prospectively enrolled between 2013 and 2019 from 3 centers. Grade III sMCL injuries were confirmed via stress radiography. Patients were randomized to anatomic sMCL reconstruction versus augmented repair with surgical treatment, determined after examination under anesthesia confirmed sMCL incompetence. Postoperative visits occurred at 6 weeks and 6 months for repeat evaluation, with repeat stress radiography at final follow-up. Patient-reported outcome measures were obtained pre- and postoperatively at 6 months, 1 year, and final follow-up. The primary outcome measure was side-to-side difference on valgus stress radiographs at a minimum follow-up of 1 year. The two 1-sided t test procedure was used to test clinical equivalence for side-to-side difference in valgus gapping, and the Mann-Whitney U test was used to compare postoperative patient-reported outcome measures between groups.

RESULTS

A total of 54 patients were prospectively enrolled into this study. Of these, 50 patients had 6-month stress radiograph data, while 40 had 1-year postoperative valgus stress radiograph data. The mean (SD) patient age was 38.0 years (14.2), and body mass index was 25.0 (3.6). Preoperative valgus stress radiographs demonstrated 3.74 mm (1.1 mm) of increased side-to-side gapping overall, while it was 4.10 mm (1.46 mm) in the MCL augmentation group and 3.42 mm (0.55 mm) in the MCL reconstruction group. Postoperative valgus stress radiographs at an average of 6 months were obtained in 50 patients after surgery, which showed 0.21 mm (0.81 mm) for the MCL augmentation group and 0.19 mm (0.67 mm) for the MCL reconstruction group (P = .940). At final follow-up (minimum 1 year), median (interquartile range) Lysholm scores were significantly higher in the reconstruction group (90 [83-99]) as compared with the repair group (80 [67-92]) (P = .031). Final International Knee Documentation Committee (IKDC) scores were also significantly higher for the reconstruction group (85 [68-89]) versus the repair group (72 [60-78] (P = .039). Postoperative Tegner scores were not significantly different between the repair group (5 [3.5-6]) and the reconstruction group (5.5 [4-7]) (P = .123). Patient satisfaction was also not significantly different between repair (7.5 [5.75-9.25]) and reconstruction groups (9.0 [7-10]) (P = .184).

CONCLUSION

This study found no difference in objective outcomes between an sMCL augmentation repair and a complete sMCL reconstruction at 1 year postoperatively, indicating equivalence between these procedures. Patient-reported clinical outcomes favored the reconstruction over a repair. In addition, this study demonstrated that anatomic-based treatment of MCL tears with an early knee motion program had a very low risk of graft attenuation and a low risk of arthrofibrosis.

Double-Layered Quadriceps Tendon Autografts Provide Lower Failure Rates and Improved Clinical Results Compared With Hamstring Tendon Grafts in Revision ACL Reconstruction

Background:

We developed a quadriceps-tendon graft technique using a double-layered, partial-thickness, soft tissue quadriceps tendon graft (dlQUAD) for anterior cruciate ligament reconstruction (ACLR). This technique allows simple femoral loop button fixation and a limited harvest depth of the quadriceps tendon.

Purpose:

To evaluate the outcome of patients undergoing revision ACLR using the dlQUAD technique compared with a hamstring tendon graft (HT).

Study Design:

Cohort study; Level of evidence, 3.

Methods:

A total of 114 patients who underwent revision ACLR between 2017 and 2018 were included in this retrospective case series. At a mean follow-up of 26.9 ± 3.7 months (range, 24-36), 89 patients (dlQUAD: n = 43, HT: n = 46) were clinically examined. In addition, patients completed the Lysholm score, Tegner activity scale, subjective International Knee Documentation Committee (IKDC), Knee injury and Osteoarthritis Outcome Score, and visual analog scale (VAS) for pain. Postoperative failure of the revision ACLR was defined as a side-to-side difference (SSD) in Rolimeter testing ≥5 mm or a pivot-shift grade of 2 or 3.

Results:

Nine patients (10.1%) were identified with a failed revision ACLR. There was a significantly lower failure rate with dlQUAD versus the HT group (2.3% vs 17.4%; P = .031). The mean postoperative SSD was significantly less in the dlQUAD group (1.3 ± 1.3 mm [range, 0-5] vs 1.8 ± 2.2 mm [range, 0-9]; P = .043). At the latest follow-up, Tegner and IKDC scores significantly improved in the dlQUAD group compared with the HT group (Tegner: 5.8 ± 1.8 vs 5.6 ± 1.5; P = .043; IKDC: 83.8 ± 12.2 vs 78.6 ± 16.8; P = .037). The pain VAS score was also significantly reduced in the dlQUAD group compared with the HT group (0.9 ± 1.1 vs 1.6 ± 2.0; P = .014).

Conclusion:

The dlQUAD and HT techniques both demonstrated significant improvement of preoperative knee laxity and satisfactory patient-reported outcome measures after revision ACLR. Compared with the HT grafts, the dlQUAD technique showed lower failure rates and small increases in Tegner and IKDC scores.

Treatment of Combined Injuries to the ACL and the MCL Complex: A Consensus Statement of the Ligament Injury Committee of the German Knee Society (DKG)

Background:

Different indications and treatment options for combined injuries to the anterior cruciate ligament (ACL) and medial collateral ligament complex (MCL) are not clearly defined.

Purpose:

To perform a modified Delphi process with the Committee for Ligament Injuries of the German Knee Society (DKG) in order to structure and optimize the process of treating a combined injury to the ACL and MCL.

Study Design:

Consensus statement.

Methods:

Scientific questions and answers were created based on a comprehensive literature review using the central registers for controlled studies of Medline, Scopus, and Cochrane including the terms medial collateral ligament, anterior cruciate ligament, MCL, ACL, and outcome used in various combinations. The obtained statements passed 3 cycles of a modified Delphi process during which each was readjusted and rated according to the available evidence (grades A-E) by the members of the DKG Ligament Injuries Committee and its registered guests.

Results:

The majority of answers, including several questions with >1 graded answer, were evaluated as grade E (n = 16) or C (n = 10), indicating that a low level of scientific evidence was available for most of the answers. Only 5 answers were graded better than C: 3 answers with a grade of A and 2 answers with a grade of B. Only 1 answer was evaluated as grade D. An agreement of >80% (range, 83%-100%) among committee members was achieved for all statements.

Conclusion:

The results of this modified Delphi process offer a guideline for standardized patient care in cases of combined injuries to the ACL and MCL.

Lower Failure Rates and Improved Patient Outcome Due to Reconstruction of the MCL and Revision ACL Reconstruction in Chronic Medial Knee Instability

Background:

Concomitant lesion of the medial collateral ligament (MCL) is associated with a greater risk of anterior cruciate ligament (ACL) graft failure.

Purpose:

The aim of this study was to compare two medial stabilization techniques in patients with revision ACL reconstruction (ACLR) and concomitant chronic medial knee instability.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

In a retrospective study, we included 53 patients with revision ACLR and chronic grade 2 medial knee instability to compare medial surgical techniques (MCL reconstruction [n = 17] vs repair [n = 36]). Postoperative failure of the revision ACLR (primary aim) was defined as side-to-side difference in Rolimeter testing ≥5 mm or pivot-shift grade ≥2. Clinical parameters and postoperative functional scores (secondary aim) were evaluated with a mean ± SD follow-up of 28.8 ± 9 months (range, 24-69 months).

Results:

Revision ACLR was performed in 53 patients with additional grade 2 medial instability (men, n = 33; women, n = 20; mean age, 31.3 ± 12 years). Failure occurred in 5.9% (n = 1) in the MCL reconstruction group, whereas 36.1% (n = 13) of patients with MCL repair showed a failed revision ACLR (P = .02). In the postoperative assessment, the anterior side-to-side difference in Rolimeter testing was significantly reduced (1.5 ± 1.9 mm vs 2.9 ± 2.3 mm; P = .037), and medial knee instability occurred significantly less (18% vs 50%; P = .025) in the MCL reconstruction group than in the MCL repair group. In the logistic regression, patients showed a 9-times elevated risk of failure when an MCL repair was performed (P = .043). Patient-reported outcomes were increased in the MCL reconstruction group as compared with MCL repair, but only the Lysholm score showed a significant difference (Tegner, 5.6 ± 1.9 vs 5.3 ± 1.6; International Knee Documentation Committee, 80.3 ± 16.6 vs 73.6 ± 16.4; Lysholm, 82.9 ± 13.6 vs 75.1 ± 21.1 [P = .047]).

Conclusion:

MCL reconstruction led to lower failure rates in patients with combined revision ACLR and chronic medial instability as compared with MCL repair. MCL reconstruction was superior to MCL repair, as lower postoperative anterior instability, an increased Lysholm score, and less medial instability were present after revision ACLR. MCL repair was associated with a 9-times greater risk of failure.

Posterior cruciate ligament lesions are mainly present as combined lesions even in sports injuries

PURPOSE

To analyse 1000 consecutive patients, treated with isolated or combined posterior cruciate ligament (PCL) reconstruction in a single centre according to the epidemiological factors and differences in injury patterns depending on the activity during trauma.

METHODS

Between 2004 and 2019, one thousand isolated and combined PCL reconstructions were performed. The medical charts and surgical reports of all patients were analysed regarding epidemiological factors. The PCL lesions were divided into isolated and combined lesions with at least one additional ligamentous injury. The influence of activity during accident and additional injury on the presence of isolated or combined lesions and injury patterns was calculated.

RESULTS

In 388 patients (38.8%), sporting activity was the main activity in PCL lesions, followed by traffic accidents in 350 patients (35.0%). Combined injuries were present in 227 patients (58.5%) with sports injuries and 251 patients (71.7%) with traffic accidents. Only during handball, an isolated PCL lesion (69.1%) was more common than a combined lesion. Highest rate of combined lesions was present in car accidents (91.7%). In all activities except skiing and biking, the most common additional peripheral injury was a tear of the posterolateral corner. In skiing and biking accidents, the most common additional peripheral lesion was a lesion of the medial collateral ligament. In patients with PCL lesion and additional fracture of the same lower extremity, a combined lesion was more common than an isolated lesion (p = 0.001).

CONCLUSION

Combined PCL lesions are more common than isolated lesions, even in sports injuries (except handball). Incidence and injury pattern vary depending on activity during trauma. Main additional peripheral lesion is a lesion of the posterolateral corner, except biking and skiing accidents where a medial lesion is more common.

LEVEL OF EVIDENCE

Level III.

Length-change patterns of the medial collateral ligament and posterior oblique ligament in relation to their function and surgery

PURPOSE

To define the length-change patterns of the superficial medial collateral ligament (sMCL), deep MCL (dMCL), and posterior oblique ligament (POL) across knee flexion and with applied anterior and rotational loads, and to relate these findings to their functions in knee stability and to surgical repair or reconstruction.

METHODS

Ten cadaveric knees were mounted in a kinematics rig with loaded quadriceps, ITB, and hamstrings. Length changes of the anterior and posterior fibres of the sMCL, dMCL, and POL were recorded from 0° to 100° flexion by use of a linear displacement transducer and normalised to lengths at 0° flexion. Measurements were repeated with no external load, 90 N anterior draw force, and 5 Nm internal and 5 Nm external rotation torque applied.

RESULTS

The anterior sMCL lengthened with flexion (p < 0.01) and further lengthened by external rotation (p < 0.001). The posterior sMCL slackened with flexion (p < 0.001), but was lengthened by internal rotation (p < 0.05). External rotation lengthened the anterior dMCL fibres by 10% throughout flexion (p < 0.001). sMCL release allowed the dMCL to become taut with valgus rotation (p < 0.001). The anterior and posterior POL fibres slackened with flexion (p < 0.001), but were elongated by internal rotation (p < 0.001).

CONCLUSION

The structures of the medial ligament complex react differently to knee flexion and applied loads. Structures attaching posterior to the medial epicondyle are taut in extension, whereas the anterior sMCL, attaching anterior to the epicondyle, is tensioned during flexion. The anterior dMCL is elongated by external rotation. These data offer the basis for MCL repair and reconstruction techniques regarding graft positioning and tensioning.

Preoperative medial knee instability is an underestimated risk factor for failure of revision ACL reconstruction

PURPOSE

The purpose of this study was to carefully analyse the reasons for revision ACLR failure to optimize the surgical revision technique and minimize the risk of recurrent re-rupture. Large studies with a minimum of 2 years of follow-up that clinically examine patients with revision ACLR are rare.

METHODS

Between 2013 and 2016, 111 patients who underwent revision ACLR were included in the retrospective study. All patients were examined for a minimum of 2 years after revision surgery (35 ± 3.4 months, mean ± STD) and identified as "failed revision ACLR" (side-to-side difference ≥ 5 mm and pivot-shift grade 2/3) or "stable revision ACLR".

RESULTS

Failure after revision ACLR occurred in 14.5% (n = 16) of the cases. Preoperative medial knee instability (n = 36) was associated with failure; thus, patients had a 17 times greater risk of failure when medial knee instability was diagnosed (p = 0.015). The risk of failure was reduced when patients had medial stabilization (n = 24, p = 0.034) and extra-articular lateral tenodesis during revision surgery (n = 51, p = 0.028). Increased posterior tibial slope (n = 11 ≥ 12°, p = 0.046) and high-grade anterior knee laxity (side-to-side difference > 6 mm and pivot-shift grade 3, n = 41, p = 0.034) were associated with increased failure of revision ACLR. Obese patients had a 9 times greater risk of failure (p = 0.008, n = 30).

CONCLUSION

This study demonstrates the largest revision ACLR patient group with pre- and postoperative clinical examination data and a follow-up of 2 years published to date. Preoperative medial knee instability is an underestimated risk factor for revision ACLR failure. Additionally, high-grade anterior knee laxity, increased PTS and high BMI are risk factors for failure of revision ACLR, while additional medial stabilization and lateral extra-articular tenodesis reduce the risk of failure.

LEVEL OF EVIDENCE

III.

Converting round tendons to flat tendon constructs: Does the preparation process have an influence on the structural properties?

PURPOSE

The structural properties of hamstring tendon grafts were evaluated in a porcine model, after processing it to a flat shape, to better replace or augment anatomic flat structures (e.g. ACL, MPFL or MCL).

METHODS

In this biomechanical study, porcine flexor tendons were used which have a comparable shape to semitendinosus and gracilis tendons. One part of the tendon was prepared to a flat tendon construct by splitting the tendon longitudinally with a knife to half of the diameter of the tendon. The semi-split tendon was scratched out to a flat shape. The other matched part was tested in its original round shape. The tendons (n = 40) have been fixed in a uniaxial testing machine (Zwick/Roell) by cryo-clamps after preparing the fixed ends by 2-0 polyester sutures (2-0 Ethibond^® EXCEL, Ethicon, Somerville, NJ). In every specimen, there was a free 60-mm tendon part between both clamps. The tendons have been loaded to failure to evaluate typical biomechanical parameters such as stiffness, yield load and maximum load.

RESULTS

No statistically significant differences (n.s.) regarding stiffness, yield load and maximum load between natively round and processed flat tendons could be detected.

CONCLUSION

A prepared flat-shaped tendon does not show any different structural properties compared with an original round tendon. Therefore, a flat tendon seems to be a biomechanical stable graft option for anatomic reconstruction or augmentation of injured natively flat-shaped structures such as MCL, MPFL or ACL.

The origin points of the knee collateral ligaments: an MRI study on paediatric patients during growth

PURPOSE

Different femoral origins for both the medial collateral ligament (MCL) and the lateral collateral ligament (LCL) have been reported in the growing skeleton (epiphyseal and metaphyseal). Knowledge about the exact attachment sites is mandatory for anatomically correct reconstruction. This study assesses the femoral origins of the knee collateral ligaments in skeletally immature individuals using magnetic resonance imaging (MRI).

METHODS

MRIs of 336 knee joints (median age 15 years (range 2-18 years), m = 209 and f = 127) were retrospectively analysed to assess the distances between the femoral origins of the MCL and LCL to the distal femoral growth plate. In 175 patients, the body sizes were additionally retrieved from medical records.

RESULTS

Both MCL and LCL ligament origins were invariably located on the epiphysis. Mean MCL origin-growth plate distance was 9.6 mm (SD 2.1 mm; range 2.2-13.6 mm) in boys and 8.6 mm (SD 1.5 mm; range 3.4-12.0 mm) in girls. Mean LCL origin-growth plate distance was 9.3 mm (SD 1.8 mm; range 4.3-13.0 mm) in boys and 8.2 mm (SD 1.5 mm; range 3.4-11.8 mm) in girls. The distance between the growth plate and both collateral ligaments as well as the length of the LCL correlated positively with patients' age and body size (MCL R(2) = 0.673 and 0.556, LCL R (2) = 0.734 and 0.645, LCL length R(2) = 0.589 and 0.741; all p < 0.001).

CONCLUSIONS

During growth, the femoral origins of the MCL and the LCL are constantly located on the distal femoral epiphysis. There is a linear increase in the distances from the ligaments' origins to the growth plate according to age and body size. This new information may be of clinical importance for reconstructive surgery of the knee's collateral ligaments.

Surgical Techniques for the Reconstruction of Medial Collateral Ligament and Posteromedial Corner Injuries of the Knee: A Systematic Review

PURPOSE

To systematically review reconstruction techniques of the medial collateral ligament (MCL) and associated medial structures of the knee (e.g., posterior oblique ligament).

METHODS

A systematic review of Medline/PubMed Database (1966 to November 2013), reference list scanning and citation searches of included articles, and manual searches of high-impact journals (2000 to July 2013) and conference proceedings (2009 to July 2013) were performed to identify publications describing MCL reconstruction techniques of the knee. Exclusion criteria included (1) MCL primary repair techniques or advancement procedures, (2) lack of clear description of MCL reconstruction technique, (3) animal models, (4) nonrelevant study design, (5) and foreign language articles without available translation.

RESULTS

After review of 4,600 references, 25 publications with 359 of 388 patients (92.5%) were isolated for analysis, including 18 single-bundle MCL and 10 double-bundle reconstruction techniques. Only 2 techniques were classified as anatomic reconstructions, and clinical and objective outcomes (n = 28; 100% <3 mm side-to-side difference [SSD]) were superior to those with nonanatomic reconstruction (n = 182; 79.1% <3 mm SSD) and tendon transfer techniques (n = 114; 52.6% <3 mm SSD).

CONCLUSIONS

This systematic review demonstrated that numerous medial reconstruction techniques have been used in the treatment of isolated and combined medial knee injuries in the existent literature. Many variations exist among reconstruction techniques and may differ by graft choices, method of fixation, number of bundles, tensioning protocol, and degree of anatomic restoration of medial and posteromedial corner knee restraints. Further studies are required to better ascertain the comparative clinical outcomes with anatomic, non-anatomic, and tendon transfer techniques for medial knee reconstruction.

LEVEL OF EVIDENCE

Level IV, systematic review of level IV studies and surgical techniques.

[Acute medial collateral ligament injuries of the knee: diagnostics and therapy]

The medial collateral ligament complex (MCL) is the most commonly damaged ligamentous stabilizer of the human knee. The diagnostic algorithm comprises patient history, clinical examination and magnetic resonance imaging (MRI). It is important to distinguish between incomplete and complete ruptures of the MCL. For adequate treatment the classification and exact knowledge about concomitant injuries are important. A nonoperative treatment of incomplete ruptures (grades I and II) is widely accepted and usually results in a good clinical outcome but the treatment of complete ruptures (grade III) is a subject of controversy. Complete intraligamentous ruptures with a correct approximation of the stumps and intact dorsomedial joint capsule can also be treated nonoperatively with good and excellent results. In contrast, ruptures close to the abutment and bony avulsions tend to heal better through operative treatment. Dehiscence or dislocation of the ligament stumps in MRI is an indication for operative treatment. In the context of a multiligamentous injury or complex instability, the majority of authors suggest an operative stabilization. As the treatment of chronic instability can be challenging, the initial and adequate treatment of acute ruptures is of great importance.