Biomechanical evaluation of PCL reconstruction with suture augmentation

Patient Reported Clinical Outcomes Following PCL Suture Augmentation in Patients with Multiligamentous Knee Injury: A Retrospective Observational Study

Purpose

To compare the patient-reported outcomes between patients with posterior cruciate ligament (PCL) reconstruction or repair alone versus PCL reconstruction or repair with internal bracing (IB) in the context of multi-ligament knee injuries (MLKI).

Methods

All patients who underwent surgical management of MLKI at two institutions between 2006 and 2020 were retrospectively identified and offered participation in the study. Patient reported outcomes were measured via three instruments: Lysholm Knee score, Multiligament Quality of Life (ML-QOL), and the Patient-Reported Outcomes Measurement Information System (PROMIS) computer adaptive testing (CAT). The postoperative outcomes and reoperation rates were compared between the internal bracing and non-internal bracing groups.

Results

Fifty-two patients were analyzed; 34 were included in the IB group (17.6% female; age 33.1 ±1.60 years), and 18 were included in the non-IB group (11.1% female; age 34.1 ±3.72 years). Mean follow-up time of the entire cohort was 1.44 ± 0.22 years (IB: 1.21 ± 0.18; non-IB: 2.1 ±0.65). There were no significant differences between PROMIS CAT [PROMIS Pain (54.4 ±1.78 vs 51.7 ±1.70, p=0.319), Physical Function (44.3 ±2.27 vs 47.9 ±1.52, p=0.294), Mobility (44.0 ±1.71 vs 46.1 ±2.10, p=0.463)], ML-QOL [ML-QOL Physical Impairment (40.7 ±4.21 vs 41.7±5.10, p=0.884), Emotional Impairment (49.2 ±4.88 vs 44.7±5.87, p=0.579), Activity Limitation (43.5 ±4.56 vs 31.5±3.62, p=0.087), Societal Involvement (44.9 ±4.96 vs 37.5 ±5.30, p=0.345)] and Lysholm knee score (61.8 ±4.55 vs 61.0 ±4.95, p=0.916) postoperatively compared to the non-IB group.

Conclusion

In this group of patients, function and patient-reported outcomes between patients treated with PCL reconstruction and repair without internal brace versus those with additional internal brace augmentation were not significantly different. Further research encompassing a larger patient sample is necessary to investigate the efficacy of the internal brace for PCL injury in the context of MLKI injuries.

Technique and Outcomes of Posterior Cruciate Ligament Repair With Augmentation

Background

Posterior cruciate ligament (PCL) injuries to the knee are uncommon, and ideal surgical management of these injuries is unclear. Current surgical techniques include PCL reconstruction with remnant debridement, remnant-preserving techniques, and primary PCL repair. Augmentation of PCL repairs and reconstructions has been proposed to protect repairs or grafts in the postoperative period.

Purpose

To describe PCL repair with the hamstring autograft augmentation technique and examine our preliminary midterm outcomes from a sequential cohort of patients.

Study Design

Case series; Level of evidence, 4.

Methods

The authors identified patients at their institution who underwent remnant-preserving primary PCL repair with hamstring autograft augmentation for both isolated tears and tears associated with multiligament knee injury (MLKI). Patient-reported outcomes were evaluated at a minimum 2-year follow-up using the International Knee Documentation Committee (IKDC) subjective knee form, the 12-item Short Form Survey, and a custom return-to-play questionnaire. Patient-reported outcomes data were summarized, and the predictors of outcomes from the descriptive data and clinical measures were further examined.

Results

A total of 23 patients with a mean follow-up of 5.3 years met the inclusion criteria. Of these patients, 87% were associated with MLKI. The mean IKDC score was 87.7. Approximately 83% of patients were able to successfully return to their sport or occupation. Among 19 athletes, only 2 reported being unable to return to their preinjury level of sport because of limitations from their PCL surgery. Patient-reported outcome scores and return to sport or occupation did not have a statistically significant association with age, sex, body mass index, time from injury to surgery, or follow-up time.

Conclusion

Outcomes of our cohort with remnant-preserving primary PCL repairs with hamstring autograft augmentation demonstrated comparable clinical outcomes to previously published PCL data. The advantages of remnant preservation, primary repair, and augmentation with an independent hamstring autograft reconstruction are combined within this technique.

Suture Tape Augmentation Improves Posterior Stability After Isolated Posterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autograft With Single-Bundle Transtibial Technique

PURPOSE

To assess whether posterior cruciate ligament reconstruction (PCLR) with suture tape augmentation can yield more stability after isolated PCLR.

METHODS

A prospective database was retrospectively reviewed to identify patients who underwent primary isolated PCLR (control group) or isolated PCLR with suture tape augmentation (study group) from January 2016 to September 2020. We analyzed subjective International Knee Documentation Committee (IKDC), Lysholm, and Tegner knee scores; posterior drawer test findings; posterior stress radiographs; and return-to-sports activity rates. The minimal clinically important difference (MCID) was used to evaluate clinical relevance (subjective IKDC, Lysholm, and Tegner scores).

RESULTS

A total of 59 patients were included in this analysis (28 in control group and 31 in study group). The average length of follow-up was similar between the study and control groups (48.6 months vs 47.9 months, P = .800). Knee function was significantly improved in the study group in terms of subjective IKDC scores (85.1 ± 6.4 in study group vs 79.8 ± 6.4 in control group, P = .002), Lysholm scores (86.3 ± 7.4 vs 80.8 ± 7.4, P = .005), and Tegner scores (7.0 ± 1.4 vs 5.6 ± 1.7, P = .006). However, the differences between the control and study groups were less than the MCID for the subjective IKDC score and Lysholm score. In the control and study groups, 21.4% of patients (6 of 28) and 48.4% of patients (15 of 31), respectively, returned to their preinjury sports activity levels (P = .031). At last follow-up, the mean side-to-side difference in posterior laxity was significantly improved in the study group compared with the control group (1.52 ± 0.70 mm in study group vs 3.17 ± 2.01 mm in control group, P < .01).

CONCLUSIONS

Primary isolated PCLR with suture tape augmentation provides better posterior stability than PCLR without suture tape augmentation at a minimum of 2 years' follow-up. No differences between the groups were observed in the percentage of patients who met or exceeded the MCID for the subjective IKDC and Lysholm scores.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

Tissue Augmentation Techniques in the Management of Ligamentous Knee Injuries

Despite early reports of high failure rates in knee ligament repair techniques resulting in favor of reconstruction, newer advances in surgical technology have shifted the attention back to repair with the addition of various tissue augmentation techniques. Ligament repair preserves proprioceptors in the native ligament and avoids autograft tendon harvest, minimizing the complications associated with donor site ruptures in reconstruction techniques. Tissue augmentation has been successfully used in knee ligamentous and tendon repair procedures, as well as in some upper extremity procedures. This study provides a clinical update on the surgical techniques, biomechanics, and outcomes with the application of various tissue augmentation techniques in the ligaments surrounding the knee joint.

All-Inside PCL Reconstruction, Double Bundle, With Internal Brace Augmentation

PCL reconstructive techniques are constantly evolving, and further clinical studies are needed to definitively understand the potential benefits of internal brace augmentation and anatomic double-bundle PCL reconstruction. This Technical Note reports an arthroscopic all-inside anatomic double-bundle PCL reconstruction with internal brace augmentation that is effective and reproducible.

Suture Augmentation in Orthopaedic Surgery Offers Improved Time-Zero Biomechanics and Promising Short-Term Clinical Outcomes

Ligament and tendon ruptures have historically been addressed with varying techniques involving either repair or reconstruction. More recently, the potential biomechanical benefits of suture augmentation (SA), also known as internal brace, have attracted substantial attention and helped renew interest in ligament repair surgery. We evaluated the biomechanical and clinical outcomes of SA-based techniques in the following sports medicine procedures: medial ulnar collateral ligament repair of the elbow, thumb collateral ligament repair, anterior cruciate ligament repair, Achilles' tendon repair, and deltoid ligament repair. Published data on the use of SA to augment repairs of the ulnar collateral ligament, thumb collateral ligament, anterior cruciate ligament, Achilles' tendon, and deltoid ligament repair demonstrates improved time-zero biomechanical and promising short to mid-term clinical outcomes. However, surgeons must be wary of potential complications, including joint over-constraint, nerve paresthesia, and infection.

Comparison of Posterior Cruciate Ligament Reconstruction Using an All-Inside Technique With and Without Independent Suture Tape Reinforcement

Background

Biomechanical studies support the use of suture tape reinforcement for limiting graft elongation and increasing strength in knee ligament reconstructions.

Purpose

To compare posterior cruciate ligament (PCL) laxity, complication and reoperation rates, and patient-reported outcomes (PROs) after all-inside single-bundle PCL reconstruction (PCLR) with versus without independent suture tape reinforcement.

Study Design

Cohort study; Level of evidence, 3.

Methods

A retrospective cohort study of consecutive patients who underwent primary, all-inside allograft single-bundle PCLR with and without independent suture tape reinforcement at a single academic institution from 2012 to 2019. Medical records were reviewed for patient characteristics, additional injuries, and concomitant procedures. PRO scores (including the International Knee Documentation Committee [IKDC], Tegner activity scale, and Lysholm scores), bilateral comparison kneeling radiographs, and physical examination findings were collected at a minimum of 2 years postoperatively.

Results

Included were 50 patients: 19 with suture tape reinforcement (mean age 30.6 ± 2.9 years) and 31 without suture tape reinforcement (control group; mean age 26.2 ± 1.6 years). One PCLR graft in the suture tape group failed. Posterior drawer examination revealed grade 1+ laxity in 4 of 19 (21%) of the suture tape cohort versus 6 of 31 (19%) of the control cohort (P > .999). Bilateral kneeling radiographs showed similar side-to-side differences in laxity between the groups (suture tape vs control: mean, 1.9 ± 0.4 vs 2.6 ± 0.6 mm; P = .361). There were no statistically significant differences between the groups in postoperative IKDC (suture tape vs control: 79.3 vs 79.6; P = .779), Lysholm (87.5 vs 84.3; P = .828), or Tegner activity (5.6 vs 5.7; P = .562) scores.

Conclusion

All-inside single-bundle PCLR with and without independent suture tape reinforcement demonstrated low rates of graft failure, complications, and reoperations, with satisfactory PROs at a minimum 2-year follow-up. Radiographic posterior tibial translation was comparable between the 2 groups.

Posterior cruciate ligament reconstruction with independent internal brace reinforcement: surgical technique and clinical outcomes with a minimum two year follow-up

PURPOSE

We developed an augmentation technique for PCL reconstruction with independent internal brace reinforcement and evaluated the functional outcome after PCL reconstruction employing autologous hamstrings augmented with an internal brace system for patients with isolated or combined grade 3 posterior instability who were treated with this technique.

METHODS

From January 2016 to January 2018, patients with isolated or combined grade 3 PCL tears who underwent single-bundle PCL reconstruction using autologous hamstrings augmented with independent internal braces were studied. The function of the operated knee was evaluated according to the International Knee Documentation Committee (IKDC) score, Lysholm score, and Tegner activity score. The patients were asked the level of returned to their previous sport. Posterior knee laxity was examined with a KT-1000 arthrometer, and data on range of motion (ROM), re-operation, and other complications were collected.

RESULTS

A total of 33 consecutive patients who received single-bundle PCL reconstruction using autologous hamstrings augmented with independent internal braces with a minimum two years follow-up were included in this study. Two patients had undergone this procedure during the study period and were not included in this study (one had combined bone fractures, and one patient had previous meniscus surgery). Thirty-one patients were available for final analysis. The mean follow-up was 45.35 ± 10.88 months (range 29-66 months). The average IKDC subjective knee evaluation scores from 51.65 ± 12.35 to 84.52 ± 6.42, the Lysholm score from 53.90 ± 11.86 to 85.68 ± 4.99, and the Tegner score from 2.81 ± 0.79 to 6.71 ± 1.83 (P < 0.05 for all). The mean total posterior side-to-side difference in knee laxity, assessed using a KT-1000 arthrometer, decreased from 12.13 ± 2.66 mm pre-operatively to 1.87 ± 0.56 mm post-operatively at 70° (P < 0.05). Most patients (29/31) had normal or near normal knee ROM post-operatively; two patients revealed a 6-15° loss of knee flexion compared with the contralateral knee. Twenty-nine patients (93.55%) returned to a normal daily exercise level. Twenty-three patients (74.19%) returned to competitive sports with high-level sports (Tegner score of 6 or above; eleven patients (35.48%) reported to be on the same level as well as the Tegner level); six patients (19.35%) returned to recreational sports (Tegner score of 4 or 5). Two patients had Tegner scores of 2 and 3, indicating poor function level. No patient needed PCL revision surgery during the follow-up period.

CONCLUSION

Single-bundle PCL reconstruction with internal brace augmentation for PCL injury exhibited satisfactory posterior stability and clinical outcomes in patients with isolated or combined grade 3 PCL injuries at a minimum two year follow-up.

Effect of Squid Cartilage Chitosan Molecular Structure on the Properties of Its Monofilament as an Absorbable Surgical Suture

Suture is an important part of surgery, and wounds closing after surgery remains a challenge for postoperative care. Currently, silk, linen fiber, and cotton are available in the market as non-absorbable suture biomaterials. So, there is an urgent need to develop a novel suture with advantageous characteristics compared to the ones available on the market. In present study, a series of ultra-high molecular weight chitosan with different DD and M_V were prepared from squid cartilage by alkaline treatment and ultrasonic degradation. The corresponding chitosan monofilaments were prepared by a wet spinning process and were characterized as sutures. The effects of the DD and M_V of chitosan on the properties of its monofilament were studied, including surface morphology, mechanical property, swelling ratio, ash content, in vitro enzymatic degradation, and in vitro cytotoxicity. According to the results, AS-85 was chosen to be the best suitable as an absorbable surgical suture, which was spun from squid cartilage chitosan with DD~85% and M_V~1.2 × 10⁶. The outcome of the present study might derive tremendous possibilities for the utilization of squid cartilage β-chitin for biomedical applications.

ANALYSIS OF THE MECHANICAL BEHAVIOR OF THE POSTERIOR CRUCIATE LIGAMENT IN A PORCINE MODEL

INTRODUCTION

The knee has shown a significant increase in the frequency of injury due to sports practice. This increase and the improvement of surgical techniques of ligament reconstruction have led to a greater indication of this treatment to achieve a function close to normal.

OBJECTIVE

To conduct a preliminary analysis of the ligament behavior.

METHODS

The study consisted of the validation of an anatomical model of the pig, in which five models were subjected to mechanical tests. The data on the loads of the in situ model and the strains of the posterior cruciate ligament were collected.

RESULTS

The analysis of the tensile load showed, at first, a nonlinear increase in stresses. Subsequently, the pig's knee showed a relatively linear intermediate response until failure around 1,200 N. Strain × time showed a response of the posterior cruciate ligament, which also has a relatively linear response.

CONCLUSION

We observed a linear behavior in the range of 1,000 to 5,000 microstrains in the strain of the posterior cruciate ligament. We suggest further studies to understand knee ligaments regarding their behavior in their function. Level of Evidence IV, Biomechanical Study.

[Damage of the knee posterior cruciate ligament: biomechanics, basic diagnostics, treatment and secondary osteoarthritis prevention directions]

The analysis of literature data was performed on the pathogenesis, diagnosis and treatment of injuries of the posterior cruciate ligament (PCL) of the knee joint. PCL is the largest intra-articular ligament of the knee joint, can withstand the maximum loads compared with other ligaments. It was noted that, in general, in cases of damage to the PCL, it is necessary to use a set of diagnostic methods, and the basic principles for the choice of optimal treatment plan for this patient. It considered the results of the conservative treatment of PCL partial ruptures, and it is indicated that this approach increases the risk of degenerative anatomical structures and functional disorders of the joint. It was noted that it is advisable to conduct surgical treatment to restore the stability of the knee joint and normalize function, while a number of methods for the reconstruction of PCL have been proposed to date. The usage of chondroprotectors for prevention of the secondary osteoarthrosis of the knee joint affected by posterior cruciate ligament rupture was analyzed in the literature data.