Time From Injury to Surgery Affects Graft Maturation Following Posterior Cruciate Ligament Reconstruction With Remnant Preservation: A Magnetic Resonance Imaging-Based Study

Good clinical and radiological results following remnant-preserving posterior cruciate ligament reconstruction: a systematic review

PURPOSE

The objective of this systematic literature review was to report the results and complications of recent remnant preservation techniques in posterior cruciate ligament (PCL) reconstruction.

METHODS

A systematic review was conducted based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Two independent reviewers searched the PubMed, Scopus, Embase, and Cochrane Library databases using the terms "posterior cruciate ligament" or "PCL" and "remnant preserving." The outcome measures extracted from the studies were the Lysholm score, the International Knee Documentation Committee's (IKDC) subjective and objective scores, Tegner scores, Orthopädische Arbeitsgruppe Knie (OAK) rate of return to sports, and rate of complications. Data were also extracted from studies that used stress radiographs to perform a quantitative assessment of the preoperative and postoperative anteroposterior stability.

RESULTS

The systematic review included 13 studies. The patient cohort of consisted of 643 participants (544 [84.6%] men and 99 [15.4%] women) with a mean age of 32.9 ± 4.0 years. The mean postoperative follow-up was 34.5 ± 10.9 months (range: 24-96 months), while the mean time from injury to surgery was 14.4 ± 9.9 months (range: 0-240 months). All studies reported clinically significant improvement at final follow-up, as evident from the measured subjective and objective IKDC scores, Lysholm score, Tegner score, and OAK rate. Only three studies reported return to sports activity, with a mean percentage of 90.8% (99/109). All studies showed a significant improvement in posterior translation, from 11.5 ± 1.2 mm to 3.3 ± 1.1 mm, using radiography (side-to-side difference). This systematic review revealed 13 (2.0%) failures and 33 (5.1%) minor complications: 10 (1.6%) cases of stiffness, 21 (4.9%) screws removal, 1 (0.2%) injury of the peroneal nerve, and 1 (0.2%) fibular fracture.

CONCLUSIONS

With the currently available data, all studies included in the review on posterior cruciate ligament reconstruction with remnant preservation demonstrated satisfactory outcomes at mid-term follow-up (> 24 months), despite varying surgical techniques and graft types, and intervals from injury to surgery. For clinical relevance, standard PCL reconstruction is a highly effective operation in terms of improvement in functional status, knee stability, quality of life, and cost effectiveness. The remnant preservation technique requires more comprehensive diagnostic assessments of the PCL remnant patterns and more complicated surgical procedures. Given the absence so far of high quality studies with long-term follow-up, the remnant-preserving techniques should be recommended only by experienced knee arthroscopic surgeons.

LEVEL OF EVIDENCE

Level IV.

STUDY REGISTRATION

reviewregistry1376- www.researchregistry.com .

All-Inside Arthroscopic Modified Broström Technique to Repair Anterior Talofibular Ligament Provides a Similar Outcome Compared With Open Broström-Gould Procedure

PURPOSE

To introduce an all-inside modified Broström technique to suture the anterior talofibular ligament (ATFL) and inferior extensor retinaculum (IER) under arthroscopy and to compare its outcomes with those of the conventional open procedure.

METHODS

All patients who underwent arthroscopic or open repair of the ATFL between June 2014 and December 2017 were included in this study. Visual analog scale (VAS), Karlsson and Peterson (K-P), American Orthopedic Foot and Ankle Society (AOFAS) ankle/hindfoot, and Tegner activity scores, as well as manual anterior drawer test (ADT), were used to evaluate the patients preoperatively and ≥2 years after surgery. The Sefton grading system was used to assess the level of satisfaction after surgery. Detailed surgical data and intraoperative findings were documented at the time of surgery.

RESULTS

A total of 67 patients, 31 in the arthroscopic group and 36 in the open group, were included in this study (43 men and 24 women, mean body mass index 24.00, range 19.53 to 30.03). The surgical duration in the arthroscopic group (median, 34 minutes; range, 25 to 74) was significantly shorter than that in the open group (mean, 43.08 ± 8.11 minutes; 95% confidence interval [CI] 40.34 to 45.83) (P = .007). At the last follow-up, the subjective functional scores and ADT results improved significantly in both cohorts (P < .001). However, no significant difference was found in the VAS score (1.74 ± 1.24, 95% CI 1.29 to 2.2, in the open group versus 1.58 ± 1.2, 95% CI 1.18 to 1.99, in the arthroscopic group; P = .581), AOFAS score (91.71 ± 5.46, 95% CI 89.71 to 93.71, versus 90.67 ± 5.59, 95% CI 88.78 to 92.56; P = .444), K-P score (87.52 ± 7.59, 95% CI 84.73 to 90.3, versus 88.75 ± 5.56, 95% CI 86.87 to 90.63; P = .446), and ADT evaluation (normal: 96.77% versus 94.44%, P = .557) between the arthroscopic and open groups, respectively. In addition, 28 cases (90.32%) in the arthroscopic group and 32 (88.89%) in the open group achieved satisfactory results based on the Sefton grading system (P = .736). Seventeen patients (47.2%) in the open group and 18 patients (58.1%) in the arthroscopic group underwent Tegner evaluation after surgery, which showed no significant difference (5, interquartile range [IQR] 1 in the open group versus 5, IQR 3 in the arthroscopic group; P = .883). Complications were reported in 4 (11.1%) and 2 (6.5%) patients who underwent open and arthroscopic surgeries, respectively (P = .813).

CONCLUSIONS

Both open and arthroscopic modified Broström surgeries generated favorable outcomes, with a significant improvement compared with the preoperative condition. Compared with the open Broström-Gould procedure, the all-inside arthroscopic modified Broström technique produced equivalent functional and clinical results at a minimum of 2 years after the operation, with a shorter surgical duration. Arthroscopic repair might be a safe and viable alternative to open surgery for lateral ankle stabilization.

LEVEL OF EVIDENCE

III.

Editorial Commentary: The Posterior Cruciate Ligament Posteromedial Bundle Is Small but Vital to Posterior Cruciate Ligament Biomechanics: Don't Ignore the Underdog

Posterior cruciate ligament (PCL) reconstruction leads to outcomes less favorable than those of anterior cruciate ligament reconstruction. In recent years, we have seen a surge of publications regarding PCL anatomy, isometry, and reconstruction techniques. PCL reconstruction has been revolutionized with lessons learned from analysis of PCL behavior, such as the distinct role of the posteromedial bundle (PMB) in the biomechanics of the knee at different flexion angles, as well as its co-dominant role with its counterpart, the anterolateral bundle. With the knee in extension, the PMB serves to restrict posterior translation, whereas in knee flexion, the PMB restricts internal rotation. It is rather too early to know whether the biomechanical advantage of double-bundle reconstruction will result in better clinical outcomes in the long term; however, the increased interest and the refinement of both single- and double-bundle reconstruction techniques will certainly advance our knowledge, ultimately translating into better patient outcomes.

Remnant-Preserving Posterior Cruciate Ligament Reconstruction Over Remnant Fibers Using a Figure-of-Four Position and a Posterior Trans-Septal Portal

Anatomic tunnel formation and remnant preservation are the recent trends in posterior cruciate ligament (PCL) reconstruction. However, it is difficult to observe the anatomical PCL footprint and perform the operation in the process of remnant‐preserving PCL reconstruction. This study describes a single‐bundle, transtibial PCL reconstruction technique with anatomic graft passage over the remnant PCL fibers. A femoral tunnel of PCL is created at 2 mm medial to the roof of the intercondylar notch and 3 mm proximal to the margin of the articular cartilage. The tibial insertion of PCL is observed using a figure‐of‐four position through a posterior trans‐septal portal. A tibial bone tunnel is made below the distal center portion of the tibial insertion of residual PCL fibers. The graft is passed over the PCL through the tibial bone tunnel, the space between the anterior cruciate ligament (ACL) and the residual PCL fibers, to the femoral socket and is fixed by the EndoButton and screw. This technique is able to ensure a reasonable intra‐articular length and optimal isometry. It has been applied in patients with PCL rupture and posterior instability of the knee joint, and no intraoperative or postoperative complications occurred. Our technology provides a valuable new treatment option for PCL rupture. Future comparative studies are needed to further clarify its beneficial effect.

Anterior cruciate ligament reconstruction with remnant preservation: current concepts

Anterior cruciate ligament (ACL) tears are a common knee injury, and anatomic ACL reconstruction (ACLR) is now the standard of care to restore knee stability. Nevertheless, re-tear rates exceeding 5% are commonly reported, with an even higher percentage of patients unable to achieve preinjury knee function. As the torn ACL remnant contains elements (eg, cells, blood vessels and mechanoreceptors) essential to ACL function, it has been hypothesised that ACLR with remnant preservation may improve graft remodelling, in turn more quickly and completely restoring ACL structure and function. In this Current Concepts review, we summarise the present understanding of ACLR with remnant preservation, which includes selective bundle reconstruction of partial (one-bundle) ACL tears and single- and double-bundle ACLR with minimal to partial debridement of the torn ACL stump. Reported benefits of remnant preservation include accelerated graft revascularisation and remodelling, improved proprioception, decreased bone tunnel enlargement, individualised anatomic bone tunnel placement, improved objective knee stability and early mechanical support (with selective bundle reconstruction) to healing tissues. However, clinical studies of ACLR with remnant preservation are heterogeneous in the description of remnant characteristics and surgical technique. Presently, there is insufficient evidence to support the superiority of ACLR with remnant preservation over the standard technique. Future studies should better describe the ACL tear pattern, remnant volume, remnant quality and surgical technique. Progress made in understanding and applying remnant preservation may inform, and be reciprocally guided by, ongoing research on ACL repair. The goal of research on ACLR with remnant preservation is not only to achieve anatomic structural restoration of the ACL but also to facilitate biologic healing and regeneration to ensure a more robust and functional graft.

Stem Cell-Conditioned Medium Promotes Graft Remodeling of Midsubstance and Intratunnel Incorporation After Anterior Cruciate Ligament Reconstruction in a Rat Model

BACKGROUND

Stem cell-conditioned medium (CM) has been increasingly used in regenerative medicine. However, its effect on graft-host integration after anterior cruciate ligament (ACL) reconstruction (ACLR) remains unclear.

PURPOSE

To examine the effect of human bone marrow stem cell (hBMSC)-CM on graft-bone integration and graft midsubstance ligamentization in a rat model of ACLR.

STUDY DESIGN

Controlled laboratory study.

METHODS

CM was obtained from the supernatant of commercially available hBMSCs in serum-free Dulbecco's modified Eagle medium (DMEM). In a rat model of an ACL injury, isometric ACLR was performed. Three groups were established: CM injection group (CM; n = 40), control injection group (CI; n = 40) with serum-free DMEM injections, and no injection group (NI; n = 40). An intra-articular injection was performed weekly. Micro-computed tomography was conducted at 2, 4, and 8 weeks postoperatively. Histological and biomechanical analyses were conducted at 4 and 8 weeks postoperatively. The NIH3T3 fibroblast was utilized as a model in vitro to examine the effect of CM using the cell counting kit-8 (CCK-8) assay and immunofluorescence staining of Ki-67, α-smooth muscle actin (α-SMA), and collagen 1 (Col 1).

RESULTS

At 4 and 8 weeks, the femoral and tibial bone tunnel areas as well as the interface between the graft and host bone were smaller, while the bone volume/total volume ratio was higher, in the CM group. Sharpey-like fibers formed at 8 weeks in the CM group. At 4 and 8 weeks, more Col 1 was noticed in the CM group than in the NI group (both P < .001) or CI group (both P < .001). Immunohistochemically, the α-SMA-positive area was up-regulated at the graft-bone interface at 4 weeks (P < .001) and declined at 8 weeks (P < .001) in the CM group compared with the other 2 groups. At the midsubstance, α-SMA expression decreased from 4 to 8 weeks in all groups and was significantly lower in the CM group than in the NI group (P < .01) or CI group (P < .05) at 8 weeks. The CCK-8 assay showed that CM increased NIH3T3 viability (P < .001) and the level of Ki-67 (P < .05), α-SMA (P < .001), and Col 1 (P < .001) in CM-educated NIH3T3 cells.

CONCLUSION

hBMSC-CM accelerates graft-bone incorporation and midsubstance ligamentization and enhances the proliferation, differentiation, and collagen synthesis of fibroblasts.

CLINICAL RELEVANCE

Graft-host integration is essential after ACLR. The current study identified a novel agent, that is, hBMSC-CM, as a candidate for promoting integration.

Editorial Commentary: Could Time From Injury to Surgery Affect Decision Making for Posterior Cruciate Ligament Reconstruction?

How long should a trial of conservative treatment of posterior cruciate ligament injuries continue before surgical intervention? A recent study demonstrates that time from injury to surgery could be negatively correlated with graft maturation and remnant preservation. Considering the improvements in arthroscopic posterior cruciate ligament reconstruction outcomes, early intervention could be considered in high functional demand patients with high grades of instability. Yet it remains to be seen whether graft maturation and remnant preservation result in improved clinical outcomes regardless of the time to surgical intervention.