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Please send your letter or proposal to the editors at kssta@esska.org.

ONLY those letters deemed to have scientific impact will be requested to be submitted via the Editorial Manager. These will be officially published online and in print along with the responses.

Others will be treated as communication or exchange between authors and only be published online on the KSSTA website with the title of the article in question, the query and the responses. These will not appear in the print issues and will have no DOIs.

Isolated Type II SLAP Tears Undergo Reoperation More Frequently

DeFazio MW, Özkan S, Wagner ER, Warner JJP, Chen NC. Knee Surg Sports Traumatol Arthrosc. 2021 Jan 2

Query Letter to the Editor

A.J.R. Leenen, PT, MScNorman E. D’hondt, PT, MScMichel P.J. van den Bekerom, MD, PhD

Dear Editor,

We have read the paper “Isolated type II SLAP tears undergo reoperation more 6frequently” by DeFazio, M. W., Özkan, S.,et al. published in Knee Surgery, Sports Traumatology, Arthroscopy(2021) with great interest[3].

We appreciated the authors’ effort to identify risk factors associated with type II superior labrum anterior to posterior (SLAP)repair and reoperation after SLAP repair. However, we have some concerns about the interpretation of the study outcomes and the clinical implications based on how a type II SLAP (re)tear had been established. We therefore encourage the readers to consider the study outcome in light of the following remarks.

1.Interpretation of study outcomes. Based on their multivariable logistic regression model, the authors conclude that “surgeons and patients should take the factors smoking, knotless suture anchors, and having an isolated SLAP repair into account to lower the possibility of unplanned reoperations”. However, the presented model-fits expressed in pseudo-R-squared values for 1) the unplanned reoperation model (0.029), and 2) the failed SLAP repair model (0.074) are very low. Therefore, the outcomes of this model must be interpreted with caution. Besides, only associations between the previous factors and a SLAPII repair failure were established, rather than cause-effect relationship[1]. Thus, although these factors might be of some predictive value for SLAP-II repair failure, they have to be subjected to further investigation (e.g. a prospective controlled study design) to provide clinicians and patients with such significant recommendations.

2.Establishment of type II SLAP (re)tear. We are aware that diagnosing a symptomatic SLAP-lesions can be challenging [5]In general, diagnostic 28modalities used to establish suspicion of a SLAP-lesion vary from 1) history taking [5], to 2) positive clinical provocative SLAP-lesion tests [6,7], 3) SLAP-lesions ruled in by negative results of provocative clinical tests to determine other pathologies than SLAP-tears [5], and4) confirmation by an MR arthrogram [8].However, these diagnostic modalities do not fully confirm the presence of a SLAP tear, nor do they indicate if the SLAP tear is symptomatic or asymptomatic. For example, a type II SLAP-lesion might even be noticed by accident diagnosed during an arthroscopy addressing other pathologies than a SLAP-lesion [2, 4]. Nevertheless, although diagnostic uncertainty is inevitable, the authors do not provide the readers with any information on1) the modalities used to establish a symptomatic SLAP-lesion diagnosis, and 2) criteria to determine whether or not the initial SLAPII repair was indicated. Furthermore, by defining a SLAPII repair failure as “a reoperation that addressed pathology to the biceps and labral complex to include revision SLAP repair or a biceps tenodesis or tenotomy procedure” [3],only the curative procedures are addressed, rather than the reasons to perform a second surgical procedure. Lack of such information leaves the readers uncertain about the specific population to which the assumed risk factors apply and hampers clinical decision making.

REFERENCES

  1. Arnold KF, Davies V, Kamps M de, Tennant PWG, Mbotwa J, Gilthorpe MS (2020) Reflections on modern methods: generalized linear models for prognosis and intervention—theory, practice and implications for machine learning. Int J Epidemiol 49:dyaa049
  2. Bhatnagar A, Bhonsle S, Mehta S (2016) Correlation between MRI and Arthroscopy in Diagnosis of Shoulder Pathology. J Clin Diagnostic Res 10:RC18-21
  3. DeFazio MW, Özkan S, Wagner ER, Warner JJP, Chen NC (2021) Isolated type II SLAP tears undergo reoperation more frequently. Knee Surg Sports Traumatology Arthrosc 1–9
  4. Dougherty MC, Kulenkamp JE, Boyajian H, Koh JL, Lee MJ, Shi LL (2019) Not All SLAPs Are Created Equal: A Comparison of Patients with Planned and Incidental SLAP Repair Procedures. Adv Orthop 2019:1–6
  5. Familiari F, Huri G, Simonetta R, McFarland EG (2019) SLAP lesions: current controversies. Efort Open Rev 4:25–32
  6. Hegedus EJ, Goode A, Campbell S, Morin A, Tamaddoni M, Moorman CT, Cook C (2008) Physical examination tests of the shoulder: a systematic review with meta-analysis of individual tests. Brit J Sport Med 42:80
  7. Hegedus EJ, Goode AP, Cook CE, Michener L, Myer CA, Myer DM, Wright AA (2012) Which physical examination tests provide clinicians with the most value when examining the shoulder? Update of a systematic review with meta-analysis of individual tests. Brit J Sport Med 46:964

Response from authors:

Thank you for your thoughtful comments and your interest regarding our paper. We agree that the definition of retear is difficult to establish. We chose re operation as a metric because it is an unambiguous event that can be well defined. It is important to recognize that we are describing what was done by surgeons and studying these events. We are not trying to establish when a re tear occurs. Again, thank you for your interest in our study.

Anterior cruciate ligament reconstruction with the use of adductor canal block can achieve similar pain control as femoral nerve block

Min, H., Ouyang, Y. & Chen, G. Knee Surg Sports Traumatol Arthrosc 28, 2675–2686 (2020)

Query Letter to the Editor

Dongdong Yu, Li Jiang, Xiaoyu Wang, Jianli Li

Dear Editor,

Anterior cruciate ligament reconstruction (ACLR) is widely accepted as the treatment of first choice for individuals with unstable function due to ligament deficiency. In order to complete this procedure safely and maintain high patient satisfaction, adequate postoperative pain control must be provided. Inadequate early pain management may hinder mobilization and recovery, and ultimately may affect patient satisfaction and long-term outcomes. To alleviate this problem, multimodal analgesia, such as nonsteroidal anti-inflammatory drugs, periarticular anesthetic injections, opioids, and peripheral nerve blocks, have been used to manage postoperative pain [3]. However, the challenge of pain control after ACLR is to provide adequate analgesia while maintaining motor function.

Femoral nerve block (FNB) is known as the gold standard to reduce opiate consumption and decrease postoperative pain scores in ACLR [1]. Unfortunately, it tends to result in motor blockade of the quadriceps muscle and potentially delay postoperative mobilization, as well as increase the risk of falls. Recently, adductor canal block (ACB) has emerged as an alternative to FNB, with the advantage of sparing the motor nerve supply to most of the quadriceps muscle and may lead to a reduction in falls after surgery [2, 5].

With great interest, we read the article by Min et al published in August, 2020 in the Knee Surg Sports Traumatol Arthrosc. The authors performed a meta-analysis and concluded that ACB is recommended as an attractive alternative to FNB as the peripheral nerve block of choice for ACLR [4]. At the outset, we would like to congratulate the authors for writing an informative article with novelty. Nevertheless, we have several suggestions and queries that we would like to communicate with the authors.

Firstly, four electronic databases (PubMed, EMBASE, Cochrane Library, and SCOPUS databases) were systematically searched by the authors. It would make the outcomes more convincing by obtaining more literature if the authors searched other databases, like BIOSIS previews, clinicaltrials.gov, and NLM Gateway. Secondly, the manual search protocols should also be included in this meta-analysis. Essential literature will be ignored if the manual search protocol is incomplete, and unpublished data such as gray literature should be included. Thirdly, why did the authors use the standardised mean difference as summary statistic rather than mean difference for continuous outcomes? Could the authors give a reasonable explanation? Fourthly, the authors used an inverse variance (IV) random effects model to pool the data in this review. In our opinion, studies should be combined by using the DerSimonian and Laird random effects model, which considers both within- and between-study variations. Fifthly, for the ten outcomes addressed in this current review, while they can sometimes be necessary, can make the review unfocused, unmanageable for users, and are prone to selective outcome reporting bias. The Cochrane Handbook for Systematic Reviews, recommend no more than seven outcomes. Thus, it would be better to select only core or critical sets of outcomes of most relevance to the review question, and to form a “summary of findings” table or other summary versions. Finally, different types of anaesthesia may compromise the reliability of meta-analysis; as a result, the researchers should carry out subgroup analysis or sensitivity analysis based on the above-mentioned risk factors.

We respectfully appreciate that Min et al provided us with an important meta-analysis which can provide a guide for clinical decision-making. However, more studies with large sample size and good scientific design should be carried out to clarify this issue. We would welcome some comments by the authors as this would help to further support the findings of this important clinical trial.

References

  1. Borys M, Domagała M, Wencław K, Jarczyńska-Domagała J, Czuczwar M (2019) Continuous femoral nerve block is more effective than continuous adductor canal block for treating pain after total knee arthroplasty: A randomized, double-blind, controlled trial. Medicine (Baltimore) 98(39):e17358.
  2. Edwards MD, Bethea JP, Hunnicutt JL, Slone HS, Woolf SK (2020) Effect of Adductor Canal Block Versus Femoral Nerve Block on Quadriceps Strength, Function, and Postoperative Pain After Anterior Cruciate Ligament Reconstruction: A Systematic Review of Level 1 Studies. Am J Sports Med 48(9):2305-2313.
  3. Li D, Alqwbani M, Wang Q, Yang Z, Liao R, Kang P (2020) Ultrasound-guided adductor canal block combined with lateral femoral cutaneous nerve block for post-operative analgesia following total knee arthroplasty: a prospective, double-blind, randomized controlled study. Int Orthop.
  4. Min H, Ouyang Y, Chen G (2020) Anterior cruciate ligament reconstruction with the use of adductor canal block can achieve similar pain control as femoral nerve block. Knee Surg Sports Traumatol Arthrosc 28(8):2675-2686.
  5. Zhang Z, Wang Y, Liu Y (2019) Effectiveness of continuous adductor canal block versus continuous femoral nerve block in patients with total knee arthroplasty: A PRISMA guided systematic review and meta-analysis. Medicine (Baltimore) 98(48):e18056.

Response from the authors:

We appreciate the comments by Yu et al. regarding our article entitled “Anterior cruciate ligament reconstruction with the use of adductor canal block can achieve similar pain control as femoral nerve block” published in 2020 in the Knee Surg Sports Traumatol Arthrosc [1]. Some flaws in our article initiated this discussion.

We acknowledge that we only searched four electronic databases in the literature search. Additional searches of other databases, including BIOSIS Preview, ClinicalTrials.gov, and the NLM Gateway, were not able to find any new articles. Furthermore, the reference lists of the included studies were also checked for additional studies that were not identified with the database search. In the results section, we used the standardised mean difference as summary statistic rather than mean difference for continuous outcomes. Effect sizes expressed as standardised mean differences are a useful method to compare the effect of an intervention across studies when different measures (such as pain scores) are used.

In our study, sensitivity analysis was used to explain the heterogeneity among the included studies. Among the outcomes with high heterogeneity, sensitivity analysis showed that excluding any one single study did not change the statistical results. Therefore, we believe that the inverse variance (IV) random effects model is also suitable for our study. Many of the outcomes for pain scores and opioid consumption were subgroup analyses, so the outcomes in our study were not actually more than seven. Moreover, all outcomes were separately listed in the form of charts in the article. Finally, spinal anaesthesia was only used in the study of Seangleulur et al., and the statistical results did not change when it was excluded [2].

Finally, we would like to thank the commentators for their questions regarding our article. This gave us the chance to revisit our article and demonstrates the need for large multi-center randomized controlled trials.

References

  1. Min H, Ouyang Y, Chen G (2020) Anterior cruciate ligament reconstruction with the use of adductor canal block can achieve similar pain control as femoral nerve block. Knee Surg Sports Traumatol Arthrosc 28(8):2675
  2. Seangleulur A, Manuwong S, Chernchujit B, Worathongchai S, Sorin T (2019) Comparison of post-operative analgesia between adductor canal block and femoral nerve block after arthroscopic anterior cruciate ligament reconstruction: a randomized controlled trial. J Med Assoc Thai 102(3):335–342.

The deep lateral femoral notch sign: a reliable diagnostic tool in identifying a concomitant anterior cruciate and anterolateral ligament injury

Dimitriou, D., Reimond, M., Foesel, A. et al. Knee Surg Sports Traumatol Arthrosc 29, 1968–1976 (2021).

Query Letter to the Editor

Konrad Malinowski, Michał Ebisz, Paweł Skowronek, Robert F LaPrade, Marcin Mostowy

Dear Editor,

With great interest we have read the paper: “The deep lateral femoral notch sign: a reliable diagnostic tool in identifying a concomitant anterior cruciate and anterolateral ligament injury” by Dimitriou D., Reimond M., et al. published in Knee Surgery, Sports Traumatology, Arthroscopy (2021) [3].

We acknowledge the authors’ efforts to confirm the efficacy of deep lateral femoral notch sign (DLFNS) for the diagnosis of anterolateral ligament (ALL) injury.

Nevertheless, we would like to raise a concern.

As stated in the study by Dimitriou et al., “An ACL rupture was confirmed clinically by a positive Lachman and anterior drawer test [7, 12], whereas an ALL rupture was confirmed clinically with a positive pivot-shift test” [3].

We are concerned about how this paper oversimplifies the concept of rotatory instability. Without referencing any studies, the authors deemed a positive pivot-shift test to be a sign of an ALL rupture. To our knowledge there is no study “equalizing” a positive pivot shift with a clinical confirmation of ALL injury. The main source of positive pivot-shift is an ACL injury itself [1, 14, 19]. In their classic study, Parsons et al. evaluated the contribution of different structures to an  internal rotation moment, describing knee rotational stability [14]. In 25 degrees of knee flexion, the ACL percentage contribution was 30%, 95%CI 21-38%; while at  the same knee flexion angle, the ALL percentage contribution to internal rotation moment was 18%, 95%CI 12-23% [14]. This biomechanical claim is also supported by the recent meta-analysis by Mouarbes et al., who reported that an ACL reconstruction with a quadriceps tendon autograft and no additional anterolateral procedures resulted in a negative (grade 0) pivot shift in 84.8% of cases (95% CI, 82.4% – 87.1%) and in a negative or trace pivot-shift (grade 0 or 1) in 97.0% of cases (95% CI, 95.9% – 98.1%) [11]. Therefore, while an ALL injury obviously plays a role in rotatory instability and may increase the grade of pivot-shift test, we would like to emphasize that the main source of positive pivot-shift is an ACL injury.

In addition, there are numerous studies pointing out pathologies or osseous morphology other than an ALL injury that increase the risk of pivot-shift presence or grade, such as meniscal injuries [7, 8, 12, 13, 18], Kaplan fibers injuries [4, 5], tibial slope [16, 18] or distal femoral morphology [15, 17]. Recent publication by Jacquet et al. presented the results of a group of 266 patients who all had a high-grade pivot shift preoperatively and underwent ACL reconstruction with or without additional anterolateral procedure. Their data proved that “repairing a pre-existing meniscal lesion was more effective than performing LET to decrease the presence of a high-grade pivot-shift at follow-up” [8]. To add up, Dimitriou et al. assessed rotatory instability in patients with a positive DLFNS. Multiple studies have reported the presence of a DLFNS to be associated with an increased risk of LM injuries, especially lateral meniscus posterior root tears [2, 6, 10], and the role of the LM in rotatory stability of the knee is well established [7, 13, 18]. It is also not known whether deep impaction fractures of the lateral femoral condyle (LFC) do not cause a “bony” instability, similarly to the Hill-Sachs lesion in the shoulder [6, 9].

One should not  assume a  positive pivot-shift equates to a concomitant ALL injury, because an  isolated ACL injury can cause a positive pivot-shift by itself. It is also inconclusive whether an ALL injury is really the most important concomitant “enhancer” of rotatory instability. In light of current evidence, an increased pivot shift grade is the result of an interplay between  knee anatomy and complex injury morphology rather than being straightforwardly caused by a single ligament tear. We believe that the abovementioned clarifications will be of value, especially for young surgeons with less experience in the evaluation of injured knee. While simplifying the concepts concerning knee instability allows for an easier understanding of the topic, we believe that solely equalizing a positive pivot-shift with a presumed concomitant clinical confirmation of ALL injury is oversimplification.

  1. Barrera CM, Arizpe A, Wodicka R, Lesniak BP, Baraga MG, Kaplan L, Jose J (2018) Anterolateral ligament injuries on magnetic resonance imaging and pivot-shift testing for rotational laxity. J Clin Orthop Trauma 9:312–316
  2. Bernholt DL, DePhillipo NN, Crawford MD, Aman ZS, Grantham WJ, LaPrade RF (2020) Incidence of Displaced Posterolateral Tibial Plateau and Lateral Femoral Condyle Impaction Fractures in the Setting of Primary Anterior Cruciate Ligament Tear. Am J Sports Med 48:545–553
  3. Dimitriou D, Reimond M, Foesel A, Baumgaertner B, Zou D, Tsai TY, Helmy N (2020) The deep lateral femoral notch sign: a reliable diagnostic tool in identifying a concomitant anterior cruciate and anterolateral ligament injury. Knee Surgery, Sport Traumatol Arthrosc 29:1968–1976
  4. Geeslin AG, Chahla J, Moatshe G, Muckenhirn KJ, Kruckeberg BM, Brady AW, Coggins A, Dornan GJ, Getgood AM, Godin JA, LaPrade RF (2018) Anterolateral Knee Extra-articular Stabilizers: A Robotic Sectioning Study of the Anterolateral Ligament and Distal Iliotibial Band Kaplan Fibers. Am J Sports Med 46:1352–1361
  5. Geeslin AG, Moatshe G, Chahla J, Kruckeberg BM, Muckenhirn KJ, Dornan GJ, Coggins A, Brady AW, Getgood AM, Godin JA, LaPrade RF (2018) Anterolateral Knee Extra-articular Stabilizers: A Robotic Study Comparing Anterolateral Ligament Reconstruction and Modified Lemaire Lateral Extra-articular Tenodesis. Am J Sports Med 46:607–616
  6. Herbst E, Hoser C, Tecklenburg K, Filipovic M, Dallapozza C, Herbort M, Fink C (2015) The lateral femoral notch sign following ACL injury: frequency, morphology and relation to meniscal injury and sports activity. Knee Surgery, Sport Traumatol Arthrosc 23:2250–2258
  7. Hoshino Y, Hiroshima Y, Miyaji N, Nagai K, Araki D, Kanzaki N, Kakutani K, Matsushita T, Kuroda R (2020) Unrepaired lateral meniscus tears lead to remaining pivot-shift in ACL-reconstructed knees. Knee Surgery, Sport Traumatol Arthrosc 28:3504–3510
  8. Jacquet C, Pioger C, Seil R, Khakha R, Parratte S, Steltzlen C, Argenson JN, Pujol N, Ollivier M (2021) Incidence and Risk Factors for Residual High-Grade Pivot Shift After ACL Reconstruction With or Without a Lateral Extra-articular Tenodesis. Orthop J Sport Med 9:doi: 10.1177/23259671211003590
  9. Kanakamedala AC, Burnham JM, Pfeiffer TR, Herbst E, Kowalczuk M, Popchak A, Irrgang J, Fu FH, Musahl V (2018) Lateral femoral notch depth is not associated with increased rotatory instability in ACL-injured knees: a quantitative pivot shift analysis. Knee Surgery, Sport Traumatol Arthrosc 26:1399–1405
  10. Kim SH, Seo J-H, Kim D-A, Lee J-W, Kim K-I, Lee SH (2021) Steep posterior lateral tibial slope, bone contusion on lateral compartments and combined medial collateral ligament injury are associated with the increased risk of lateral meniscal tear. Knee Surgery, Sport Traumatol Arthrosc doi: 10.1007/s00167-021-06504-z
  11. Mouarbes D, Menetrey J, Marot V, Courtot L, Berard E, Cavaignac E (2019) Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis of Outcomes for Quadriceps Tendon Autograft Versus Bone–Patellar Tendon–Bone and Hamstring-Tendon Autografts. Am J Sports Med 47:3531–3540
  12. Mouton C, Magosch A, Pape D, Hoffmann A, Nührenbörger C, Seil R (2020) Ramp lesions of the medial meniscus are associated with a higher grade of dynamic rotatory laxity in ACL-injured patients in comparison to patients with an isolated injury. Knee surgery, Sport Traumatol Arthrosc 28:1023–1028
  13. Musahl V, Citak M, O’Loughlin PF, Choi D, Bedi A, Pearle AD (2010) The effect of medial versus lateral meniscectomy on the stability of the anterior cruciate ligament-deficient knee. Am J Sports Med 38:1591–1597
  14. Parsons EM, Gee AO, Spiekerman C, Cavanagh PR (2015) The biomechanical function of the anterolateral ligament of the knee. Am J Sports Med 43:669–674
  15. Pfeiffer TR, Burnham JM, Kanakamedala AC, Hughes JD, Zlotnicki J, Popchak A, Debski RE, Musahl V (2019) Distal femur morphology affects rotatory knee instability in patients with anterior cruciate ligament ruptures. Knee Surg Sports Traumatol Arthrosc 27:1514–1519
  16. Rahnemai-Azar AA, Abebe ES, Johnson P, Labrum J, Fu FH, Irrgang JJ, Samuelsson K, Musahl V (2017) Increased lateral tibial slope predicts high-grade rotatory knee laxity pre-operatively in ACL reconstruction. Knee Surg Sports Traumatol Arthrosc 25:1170–1176
  17. Saita Y, Schoenhuber H, Thiébat G, Ravasio G, Pozzoni R, Panzeri A, Galli M, Nagao M, Takazawa Y, Ikeda H, Kaneko K (2019) Knee hyperextension and a small lateral condyle are associated with greater quantified antero-lateral rotatory instability in the patients with a complete anterior cruciate ligament (ACL) rupture. Knee surgery, Sport Traumatol Arthrosc 27:868–874
  18. Song G, Zhang H, Wang Q, Zhang J, Li Y, Feng H (2016) Risk Factors Associated With Grade 3 Pivot Shift After Acute Anterior Cruciate Ligament Injuries. Am J Sports Med United States 44:362–369
  19. Tanaka M, Vyas D, Moloney G, Bedi A, Pearle AD, Musahl V (2012) What does it take to have a high-grade pivot shift? Knee Surgery, Sport Traumatol Arthrosc 20:737–742

Response from authors

Dear Editor,

With great interest, we have read the letter to the Editor regarding our paper: “The deep lateral femoral notch sign: a reliable diagnostic tool in identifying a concomitant anterior cruciate and anterolateral ligament injury” by Dimitriou D., et al. published in Knee Surgery, Sports Traumatology, Arthroscopy (2021).[2]

We would like to thank the authors for their invaluable input and the concern they raised.

The diagnosis of a concomitant anterior cruciate ligament (ACL) anterolateral ligament (ALL) rupture is nowadays still challenging. For the above-mentioned study, we used both MRI findings suggestive of an ALL injury The ALL was identified according to the recommendations suggested by Patel et al. (Fig. 2a). An ALL rupture was diagnosed on MRI according to Muramatsu et al.’s recommendations as warping, thinning, iso-signal changes of the ALL, or loss of continuity (Fig. 2b)” but also the clinical findings as the authors mentioned “An ACL rupture was confirmed clinically by a positive Lachman and anterior drawer test, whereas an ALL rupture was confirmed clinically with a positive pivot-shift test”. Furthermore, as mentioned in the paper “if there was a discrepancy between the clinical and MRI findings, the patients were excluded from the study”.

The authors stated that without referencing any studies, we deemed that a positive pivot-shift test is a sign of an ALL rupture, and they add up that no study “equalizing” a positive pivot shift with a clinical confirmation of an ALL injury. As far as we know, we are not aware of how a study could clinically confirm an ALL injury other than a pivot-shift test.  Nevertheless, several biomechanical studies support that an ALL-rupture in an ACL-deficient knee results in a significant increase in internal rotation and pivot shift. Specifically, Bonanzing et al.[1] in biomechanical analysis of 10 fresh-frozen knees under intact ACL, deficient ACL, and deficient ACL + ALL reported that cutting of the ACL showed no significant difference in acceleration during the manual pivot-shift test, whereas the ACL+ALL deficient knee had significantly more acceleration than the intact knee during the pivot-shift test. Another biomechanical study from Inderhaug et al.[4] investigated cadaveric knees in the following 8 conditions (1) intact knee, (2) ACL-transected, (3) combined ACL plus ALL lesion, (4) isolated ACL reconstruction, (5) ACL reconstruction combined with ALL reconstruction, (6) ACL reconstruction and a combined MacIntosh procedure, (7) ACL reconstruction and a combined Lemaire procedure deep to the LCL, and (8) ACL reconstruction and a combined Lemaire procedure superficial to the LCL under 90-N anterior drawer force, 5-N internal tibial torque, and combined 90-N anterior drawer force and 5-N internal tibial torque, across 0° to 90° of knee flexion. They concluded that isolated intra-articular ACL reconstruction leaves residual knee laxity, in terms of anterior translation and internal rotation, when a combined ACL plus anterolateral lesion is present. Furthermore, numerous studies reported a significant increase in tibial internal rotation or pivot shift after ALL resection in ACL-deficient knees [7] [10]

The authors also claim that the main source of positive pivot-shift is an ACL injury itself and reference the study by Parsons et al.[9], which states that in 25 degrees of knee flexion, the ACL percentage contribution was 30%, 95%CI 21-38%; while at the same knee flexion angle, the ALL percentage contribution to internal rotation moment was 18%, 95%CI 12-23% [14]. However, the same study states that the knee flexion angles greater than 30°, the contribution of the ALL exceeded that of the ACL[9]. For example, at 60° of knee flexion, the contribution of ALL is 44%, 95%CI 37-50%, while at the same knee flexion angle, the ACL percentage contribution to internal rotation moment was only 15%, 95% CI 10-20%  [9]. The authors, to support their thesis, reference a recent meta-analysis by Mouarbes et al. [8], who reported that an ACL reconstruction with a quadriceps tendon autograft and no additional anterolateral procedures resulted in a negative (grade 0) pivot shift in 84.8% of cases [8]. However, in the abovementioned meta-analysis, it was not mentioned whether the patients had a positive pivot-shift test preoperative. Several studies reported that the most important risk factor for residual pivot shift after ACL reconstruction was the preoperative pivot shift [5] [11].  Furthermore, the rest 15% of the patients with a residual pivot-shift complies with the percentage of patients with concomitant ACL/ALL lesion reported in our study [2].

We agree with the authors that osseous morphology increases the risk of pivot-shift presence or grade, that is why we excluded those patients from our study. As stated, Exclusion criteria were age > 40 years, history of patellofemoral instability, previous surgery or symptoms in the affected knee, posterior tibia slope > 7°, clinically excessive varus/valgus leg axis, and Segond fracture (as these patients were treated with a combined intra-articular ACL reconstruction and extra-articular tenodesis)”. The authors also cited the study from Jacquet et al. [5], to support the idea that repairing a pre-existing meniscal lesion was more effective than performing an extra-articular tenodesis (LET) to decrease the presence of a high-grade pivot-shift at follow-up. However, the same study concluded that “1 in 4 patients with high-grade pivot-shift before ACLR with or without LET was at risk of residual rotatory knee laxity at mean 44-month follow-up, regardless of the technique used” [5]. Furthermore, it should be noted that the  LET graft was fixed in 20° of knee flexion in that study[5]. A biomechanical study by Inderhaug et al.[3] concluded that in combined anterolateral procedure plus intra-articular ACL reconstruction, the knee flexion angle is important when fixing the graft. Although a modified Lemaire procedure could restore intact knee laxities when fixation was performed at 0°, 30°, or 60° of flexion, the ALL procedure could restore normal laxities only when fixation occurred in full extension. The MAKS group in a large multicenter study with 368 patients analyzed the risk factors for residual pivot-shift following a single-bundle ACL reconstruction (without ALL reconstruction or LET) and found that 15% of the patients had a residual high-grade pivot-shift [11]. The meniscus repair or meniscectomy was also not a risk factor for residual instability. Also, the ALL has attachments to the body of the lateral meniscus [6]. As reported by Van Dyck et al.[12], in patients with an ACL rupture and intact ALL, 31 % had a torn lateral meniscus as compared to 61 % with an abnormal ALL (p = 0.008). These data might suggest that a torn lateral meniscus might be a confounder to the rotational instability and not the cause for the rotational instability, as it might hide an undiagnosed ALL-rupture. The authors also state a bony instability similar to the Hill-Sachs might result in rotational instability. However, to the best of our knowledge, no biomechanical or clinical studies support this theory.

We agree with the statement of the authors that it should not be assumed that a positive pivot-shift equates to a concomitant ALL injury, but we believe that the MRI images of patients with high-grade pivot shift test should be carefully evaluated to look for associated injuries, especially at the anterolateral/posterolateral corner of the knee. Although the ACL might be the main constrain to internal rotation of the tibia or pivot-shift test (at least until 30° of flexion), in ACL deficient knees, the role of ALL or the anterolateral corner of the knee should not be ignored. As the pivot-shift test is subjective and challenging to perform in an acute injury due to pain, a DLFNS>1.8 mm could be a valuable and straightforward screening tool without extra costs to detect a concomitant injury to the lateral corner of the knee. Whether an ALL reconstruction or LET is needed, we could not address that in our study, but it should be stated that according to the literature, 15% of the patients with a high pivot-shift test preoperative demonstrate a residual rotational instability following a single-bundle ACL reconstruction without a LET [11].

 

  1. Bonanzinga T, Signorelli C, Grassi A, Lopomo N, Bragonzoni L, Zaffagnini S, et al. (2017) Kinematics of ACL and anterolateral ligament. Part I: Combined lesion. Knee Surgery, Sports Traumatology, Arthroscopy 25:1055-1061
  2. Dimitriou D, Reimond M, Foesel A, Baumgaertner B, Zou D, Tsai T-Y, et al. (2020) The deep lateral femoral notch sign: a reliable diagnostic tool in identifying a concomitant anterior cruciate and anterolateral ligament injury. Knee Surgery, Sports Traumatology, Arthroscopy 1-9
  3. Inderhaug E, Stephen JM, Williams A, Amis AA (2017) Anterolateral tenodesis or anterolateral ligament complex reconstruction: effect of flexion angle at graft fixation when combined with ACL reconstruction. The American journal of sports medicine 45:3089-3097
  4. Inderhaug E, Stephen JM, Williams A, Amis AA (2017) Biomechanical comparison of anterolateral procedures combined with anterior cruciate ligament reconstruction. The American journal of sports medicine 45:347-354
  5. Jacquet C, Pioger C, Seil R, Khakha R, Parratte S, Steltzlen C, et al. (2021) Incidence and Risk Factors for Residual High-Grade Pivot Shift After ACL Reconstruction With or Without a Lateral Extra-articular Tenodesis. Orthopaedic Journal of Sports Medicine 9:23259671211003590
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