Reconstruction of the Posterolateral Corner After Sequential Sectioning Restores Knee Kinematics

Anatomic Fibular-Based Posterolateral Corner Reconstruction With 2 Femoral Tunnels Shows Lowest Residual Laxity With External Rotation and Varus Stresses: A Systematic Review and Network Meta-analysis of In Vitro Biomechanical Studies

PURPOSE

To perform a systematic review and network meta-analysis of in vitro cadaveric, biomechanical studies evaluating described techniques for posterolateral corner (PLC) reconstruction, including fibular- and tibiofibular-based techniques.

METHODS

The PubMed/MEDLINE, Embase, and Cochrane Library databases were searched in December 2023 for cadaveric studies evaluating PLC reconstruction. After a descriptive summary, a series of frequentist network meta-analyses comparing (1) nonanatomic fibular-based (single femoral tunnel), (2) anatomic fibular-based (double femoral tunnel), and (3) anatomic tibiofibular-based PLC reconstructions with the intact knee were performed for both external rotation (ER) and varus laxity from 0° to 90° of knee flexion. Pooled treatment estimates were calculated as mean differences (MDs) with 95% confidence intervals (CIs) using random-effects models.

RESULTS

A total of 31 studies were included. Nonanatomic fibular-based reconstructions showed increased ER laxity compared with the intact state between 30° and 90° of flexion (MD, 1.66° [95% CI, -0.27° to 3.59°] at 0° [P = .093]; MD, 2.29° [95% CI, 0.44° to 4.13°] at 30° [P = .015]; MD, 3.04° [95% CI, 0.95° to 5.12°] at 60° [P = .004]; and MD, 4.30° [95% CI, 1.41° to 7.19°] at 90° [P = .004]). The anatomic fibular- and tibiofibular-based reconstructions restored ER stability at all flexion values (except at 0° for tibiofibular based). All 3 reconstructions restored varus stability compared with the intact state in all scenarios except the anatomic fibular-based techniques at 0° (MD, 0.85° [95% CI, 0.06° to 1.63°]; P = .034). Across the assessed ER and varus laxity states, the anatomic fibular-based reconstruction was ranked "best" in 5 of 8 scenarios.

CONCLUSIONS

PLC reconstructions using nonanatomic fibular-based techniques showed increased residual laxity in ER from 30° to 90° of knee flexion. Conversely, anatomic fibular- and tibiofibular-based reconstructions showed ER and varus laxity similar to that in the intact knee state across most of the assessed knee flexion values.

CLINICAL RELEVANCE

Various techniques have been described for PLC reconstruction. However, no study has comprehensively compared the biomechanical properties of these reconstructions with one another.

Career Length After Surgically Treated ACL Plus Collateral Ligament Injury in Elite Athletes

BACKGROUND

Limited data are available regarding career length and competition level after combined anterior cruciate ligament (ACL) and medial- or lateral-sided surgeries in elite athletes.

PURPOSE

To evaluate career length after surgical treatment of combined ACL plus medial collateral ligament (MCL) and ACL plus posterolateral corner (PLC) injuries in elite athletes and, in a subgroup analysis of male professional soccer players, to compare career length and competition level after combined ACL+MCL or ACL+PLC surgeries with a cohort who underwent isolated ACL reconstruction (ACLR).

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A consecutive cohort of elite athletes undergoing combined ACL+MCL and ACL+PLC surgery was analyzed between February 2001 and October 2019. A subgroup of male elite soccer players from this population was compared with a previously identified cohort having had isolated primary ACLR without other ligament surgery. A minimum 2-year follow-up was required. Outcome measures were career length and competition level.

RESULTS

A total of 98 elite athletes met the inclusion criteria, comprising 50 ACL+PLC and 48 ACL+MCL surgeries. The mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Return-to-play (RTP) time was significantly longer for ACL+PLC injuries (12.8 months; P = .019) than for ACL+MCL injuries (10.9 months). In the subgroup analysis of soccer players, a significantly lower number of players with combined ACL+PLC surgery were able to RTP (88%; P = .003) compared with 100% for ACL+MCL surgery and 97% for isolated ACLR, as well as requiring an almost 3 months longer RTP timeline (12.9 months; P = .002) when compared with the isolated ACL (10.2 months) and combined ACL+MCL (10.0 months) groups. However, career length and competition level were not significantly different between groups.

CONCLUSION

Among elite athletes, the mean career length after surgical treatment of combined ACL+MCL and ACL+PLC injuries was 4.5 years. Professional soccer players with combined ACL+PLC surgery returned at a lower rate and required a longer RTP time when compared with the players with isolated ACL or combined ACL+MCL injuries. However, those who did RTP had the same career longevity and competition level.

Anterior cruciate ligament failure and management

Anterior cruciate ligament (ACL) reconstruction failure can be defined as abnormal knee function due to graft insufficiency with abnormal laxity or failure to recreate a functional knee according to the expected outcome. Traumatic ruptures have been reported as the most common reason for failure. They are followed by technical errors, missed concomitant knee injuries, and biological failures. An in-depth preoperative examination that includes a medical history, clinical examinations, advanced imaging, and other appropriate methods is of utmost importance. There is still no consensus as to the ideal graft, but autografts are the favorite choice even in ACL revision. Concomitant meniscal treatment, ligamentous reconstruction, and osteotomies can be performed in the same surgical session to remove anatomical or biomechanical risk factors for the failure. Patient expectations should be managed since outcomes after ACL revision are not as good as those following primary ACL reconstruction.

Minimizing the risk of graft failure after anterior cruciate ligament reconstruction in athletes. A narrative review of the current evidence

Anterior cruciate ligament (ACL) tear is one of the most common sport-related injuries and the request for ACL reconstructions is increasing nowadays. Unfortunately, ACL graft failures are reported in up to 34.2% in athletes, representing a traumatic and career-threatening event. It can be convenient to understand the various risk factors for ACL failure, in order to properly inform the patients about the expected outcomes and to minimize the chance of poor results. In literature, a multitude of studies have been performed on the failure risks after ACL reconstruction, but the huge amount of data may generate much confusion.The aim of this review is to resume the data collected from literature on the risk of graft failure after ACL reconstruction in athletes, focusing on the following three key points: individuate the predisposing factors to ACL reconstruction failure, analyze surgical aspects which may have significant impact on outcomes, highlight the current criteria regarding safe return to sport after ACL reconstruction.

Biomechanical Assessment of Knee Laxity After a Novel Posterolateral Corner Reconstruction Technique

BACKGROUND

Different techniques to restore knee stability after posterolateral corner (PLC) injury have been described. The original anatomic PLC reconstruction uses 2 separate allografts to reconstruct the PLC. Access to allograft tissue continues to be a significant limitation of this technique, which led to the development of a modified anatomic approach utilizing a single autologous semitendinosus graft fixed on the tibia with an adjustable suspensory loop to enable differential tensioning of the PLC components.

PURPOSE/HYPOTHESIS

The purpose of this study was to compare the modified anatomic technique with the original anatomic reconstruction in terms of varus and external rotatory laxity in a cadaveric biomechanical model. The hypothesis was that both techniques would restore varus and external rotatory laxity after a simulated complete PLC injury.

STUDY DESIGN

Controlled laboratory study.

METHODS

Eight pairs of fresh-frozen cadaveric knee specimens were tested to compare the 2 techniques. Varus and external tibial rotation laxity of the knee were measured while applying 10-N·m varus and 5-N·m external rotatory torques at 0°, 30°, 60°, and 90° of flexion. These measurements were tested under 3 conditions: (1) intact fibular collateral ligament, popliteal tendon, and popliteofibular ligament; (2) complete transection of the fibular collateral ligament, popliteal tendon, and popliteofibular ligament; (3) after PLC reconstruction with either the modified (n = 8) or the original (n = 8) technique.

RESULTS

After PLC reconstruction, varus laxity was restored with no statistically significant differences from the intact condition after both reconstruction techniques. Similar outcomes were observed for external rotation in extension; however, in terms of the external rotation limit with respect to the intact joint, significant reductions of mean ± SD 4.1°± 6.3° (P = .036) and 5.1°± 6.6° (P = .016) were recorded with the modified technique at 60° and 90° of flexion, respectively. No significant effect was observed on the neutral flexion kinematics from 0° to 90° of flexion, and no significant differences were observed between reconstructions (P = .222).

CONCLUSION

Both PLC reconstruction techniques restored the normal native varus as compared with the intact knee. Although the modified technique constrained end-range external rotation at 60° and 90° of flexion, no differences were noted with neutral flexion kinematics. Care should be taken when tensioning in the modified technique so that the tibia is in a neutral position to avoid overconstraining the knee.

CLINICAL RELEVANCE

The modified technique may prove useful in situations where there are limited graft options, particularly where allografts are not available or are restricted.

ACL and Posterolateral Corner Injuries

PURPOSE OF REVIEW

The importance of the posterolateral corner (PLC) with respect to knee stability, particularly in the setting of anterior cruciate ligament (ACL) deficiency, has become more apparent in recent years. The purposes of this article are to review the current concepts of PLC injuries and to address their role in the ACL-deficient and ACL-reconstructed knee.

RECENT FINDINGS

Recent literature demonstrates that a single staged, combined reconstruction is optimal. Studies further provide more thorough insight into avoidance of tunnel collision during the multiligament reconstruction. In total, reconstruction procedures have demonstrated successful outcomes in over 90% of patients. In summary, we report that in the setting of suspected concomitant PLC and ACL injury, it is essential to address both injuries; appreciating the local anatomy, diagnostic modalities, and surgical techniques are each crucial to achieving desirable clinical outcomes.

Incidence and MRI characterization of the spectrum of posterolateral corner injuries occurring in association with ACL rupture

OBJECTIVE

To determine the incidence and MRI characteristics of the spectrum of posterolateral corner (PLC) injuries occurring in association with anterior cruciate ligament (ACL) rupture.

MATERIALS AND METHODS

We carried out a level IV, retrospective case series study. All patients clinically diagnosed with an ACL rupture between July 2015 and June 2016 who underwent MRI of the knee were included in the study. In addition to standard MRI knee reporting, emphasis was placed on identifying injury to the PLC and a description of involvement of these structures by two musculoskeletal radiologists. Association with PLC involvement was sought with concomitant injuries using correlation analysis and logistic regression.

RESULTS

One hundred sixty-two patients with MRI following ACL rupture were evaluated. Thirty-two patients (19.7%) had an injury to at least one structure of the PLC, including the inferior popliteomeniscal fascicle (n = 28), arcuate ligament (n = 20), popliteus tendon (n = 20), superior popliteomeniscal fascicle (n = 18), lateral collateral ligament (n = 8), popliteofibular ligament (n = 7), biceps tendon (n = 4), iliotibial band (n = 3), and fabellofibular ligament (n = 1). Seventy-five percent of all patients with combined ACL and PLC injuries had bone contusions involving the lateral compartment of the knee. The presence of these contusions strongly correlated with superior popliteomeniscal fascicle lesions (p < 0.05). There was no correlation between injuries to other structures of the PLC and other intra-articular lesions.

CONCLUSION

Missed injuries of the PLC lead to considerable morbidity. The relevance of this study is to highlight that these injuries occur more frequently than previously described and that an appropriate index of suspicion, clinical examination, and MRI are all required to reduce the risk of missed diagnoses. The results of this study support previous suggestions that the rate of concomitant PLC injury in the ACL-deficient knee is under-reported. The rate of combined injuries in this series was 19.7%. The key message of this paper is that PLC injury is common in the presence of ACL injury and should be sought both clinically and radiologically.