A Supratuberosity Anterior Closing-Wedge Proximal Tibial Osteotomy Increases Patellar Height: A Simulated Time Zero Uniplanar Radiographic Study

PURPOSE

To simulate the effect of supratuberosity tibial anterior closing-wedge osteotomy (ACWO) in knees with posterior tibial slope (PTS) ≥12° on patellar height when aiming for a target PTS of 5°.

METHODS

The authors retrospectively reviewed true lateral radiographs of the knees of skeletally mature patients scheduled for primary anterior cruciate ligament reconstruction and included all knees with excessive PTS (≥12°). Coordinates of 11 landmarks were digitized to calculate patellar height (Caton-Deschamps index, CDI) and mid-shaft posterior tibial slope (mPTS). The change in patellar height following a simulated supratuberosity ACWO was calculated and compared for knees with patella norma versus alta. A linear univariable regression model predicted the effect of change in mPTS on CDI.

RESULTS

In the final cohort of 83 patients, a simulated supratuberosity ACWO increased CDI from 1.13 (range, 0.73-1.74) to 1.29 (range, 0.84-1.91; P < .001). In 56 patients with patella norma, a simulated supratuberosity ACWO increased CDI from 1.02 (range, 0.73-1.19) to 1.18 (range, 0.84-1.41; P < .001), whereas in patients with patella alta, a simulated supratuberosity ACWO increased CDI from 1.33 (range, 1.20-1.74) to 1.52 (range, 1.36-1.91; P < .001). The linear regression model revealed that a 1° decrease in mPTS increased CDI by 0.02.

CONCLUSIONS

Simulation of a supratuberosity ACWO revealed that the procedure increases patellar height in all knees but did not induce significant differences in patellar height characteristics between knees with patella norma versus alta. A linear regression model revealed that a 1° decrease in mPTS could theoretically increase CDI by 0.02.

CLINICAL RELEVANCE

If preoperative planning indicates that supratuberosity ACWO would increase patellar height from norma (CDI <1.2) to alta (CDI ≥1.2), the surgeon could consider a trans- or infra-tuberosity ACWO, which is less likely to increase patellar height.

The Original Technique for Tibial Deflexion Osteotomy During Revision Anterior Cruciate Ligament Reconstruction: Surgical Technique

The original technique for tibial deflexion osteotomy (TDO) was first described by Henri Dejour during the Lyon knee meeting in 1991 to reduce excessive posterior tibial slope during second revision anterior cruciate ligament reconstruction (ACLR). The technique is nowadays increasingly performed during first-revision ACLR in patients at risk for graft retear. This Technical Note describes and updates the original TDO technique.

A modified Delphi consensus statement on patellar instability: part II

Aims

The aim of this study was to establish consensus statements on medial patellofemoral ligament (MPFL) reconstruction, anteromedialization tibial tubercle osteotomy, trochleoplasty, and rehabilitation and return to sporting activity in patients with patellar instability, using the modified Delphi process.

Methods

This was the second part of a study dealing with these aspects of management in these patients. As in part I, a total of 60 surgeons from 11 countries contributed to the development of consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered unanimous.

Results

Of 41 questions and statements on patellar instability, none achieved unanimous consensus, 19 achieved strong consensus, 15 achieved consensus, and seven did not achieve consensus.

Conclusion

Most statements reached some degree of consensus, without any achieving unanimous consensus. There was no consensus on the use of anchors in MPFL reconstruction, and the order of fixation of the graft (patella first versus femur first). There was also no consensus on the indications for trochleoplasty or its effect on the viability of the cartilage after elevation of the osteochondral flap. There was also no consensus on postoperative immobilization or weightbearing, or whether paediatric patients should avoid an early return to sport.

Inconsistent repeatability of the Dejour classification of trochlear dysplasia due to the variability of imaging modalities: a systematic review

PURPOSE

The purpose of this systematic review was to critically assess the quality of papers that report on the intra- and inter-observer repeatability of the Dejour classification for trochlear dysplasia, and to identify the possible causes for poor repeatability.

METHODS

Two authors independently conducted an electronic search (four databases) on 8 February 2023 for studies (English or French) that assessed trochlear dysplasia classifications on imaging of skeletally mature participants. Exclusion criteria were reviews of clinical studies, conference proceedings, or editorials. After title, abstract, and full-text screening, characteristics of eligible studies were tabulated (author, year, journal, study design, cohort characteristics, and intra- and/or inter-observer agreement coefficients). The methodological quality of studies was assessed using the Joanna Briggs Institute (JBI) checklist for analytical cross-sectional studies. Authors analysed three components of the included studies: (1) classifications based on true lateral radiographs and slice imaging; (2) dysplasia graded into Type A vs B vs C vs D and 3) coefficients of intra- and/or inter-observer agreement.

RESULTS

The electronic search returned 3,178 references, and after removal of duplicates and irrelevant studies, ten were eligible for data extraction. A second search (31 July 2023) yielded one additional study. Eight studies did not include lateral radiographs, two studies did not explicitly state if radiographs were true lateral views, and one used true lateral radiographs in isolation. Classification of trochlear dysplasia into A vs B vs C vs D using different imaging modalities resulted in moderate to near-perfect intra-observer agreement, and slight to near-perfect inter-observer agreement. Studies distinguished between moderate and severe dysplasia using a variety of combinations: A vs B/C/D, A/B vs C/D and A/C vs B/D.

CONCLUSION

This systematic review revealed that the Dejour classification remains the most widely used to assess trochlear dysplasia and that the majority of studies that assessed the reliability of the Dejour classification, reported moderate to near-perfect inter-observer agreement; however, pooling of results for comparison among the included studies was inappropriate due to substantial variation in imaging protocols and non-standardised criteria to distinguish severe from moderate dysplasia.

LEVEL OF EVIDENCE

Level IV.

TRIAL REGISTRY

The PROSPERO registration number is CRD42023386731.

A modified Delphi consensus statement on patellar instability: part I

Aims

The aim of this study was to establish consensus statements on the diagnosis, nonoperative management, and indications, if any, for medial patellofemoral complex (MPFC) repair in patients with patellar instability, using the modified Delphi approach.

Methods

A total of 60 surgeons from 11 countries were invited to develop consensus statements based on their expertise in this area. They were assigned to one of seven working groups defined by subtopics of interest within patellar instability. Consensus was defined as achieving between 80% and 89% agreement, strong consensus was defined as between 90% and 99% agreement, and 100% agreement was considered to be unanimous.

Results

Of 27 questions and statements on patellar instability, three achieved unanimous consensus, 14 achieved strong consensus, five achieved consensus, and five did not achieve consensus.

Conclusion

The statements that reached unanimous consensus were that an assessment of physeal status is critical for paediatric patients with patellar instability. There was also unanimous consensus on early mobilization and resistance training following nonoperative management once there is no apprehension. The statements that did not achieve consensus were on the importance of immobilization of the knee, the use of orthobiologics in nonoperative management, the indications for MPFC repair, and whether a vastus medialis oblique advancement should be performed.

Management of anterior cruciate ligament revision in adults: the 2022 ESSKA consensus: part II-surgical strategy

PURPOSE

The aim of this ESSKA consensus is to give recommendations based on scientific evidence and expert opinion to improve the diagnosis, preoperative planning, indication and surgical strategy in Anterior Cruciate Ligament revision.

METHODS

Part 2, presented herein, followed exactly the same methodology as Part 1: the so-called ESSKA formal consensus derived from the Delphi method. Eighteen questions were ultimately asked. The quality of the answers received the following grades of recommendation: Grade A (high level scientific support), Grade B (scientific presumption), Grade C (low level scientific support) or Grade D (expert opinion). All answers were scored from 1 to 9 by the raters. Once a general consensus had been reached between the steering and rating groups, the question-answer sets were submitted to the peer-review group. A final combined meeting of all the members of the consensus was then held to ratify the document.

RESULTS

The review of the literature revealed a rather low scientific quality of studies examining the surgical strategy in cases of ACL reconstruction failure. Of the 18 questions, only 1 received a Grade A rating; 5, a Grade B rating; and 9, grades of C or D. The three remaining complex questions received further evaluations for each portion of the question and were looked at in more detail for the following grades: B and D; A, C and D; or A, B, C and D. The mean rating of all questions by the rating group was 8.0 + - 1.1. The questions and recommendations are listed in the article.

CONCLUSION

ACL revision surgery, especially the surgical strategy, is a widely debated subject with many different opinions and techniques. The literature reveals a poor level of standardization. Therefore, this international European consensus project is of great importance and clinical relevance for guiding the management of ACL revision in adults.

LEVEL OF EVIDENCE

Level II.

Management of anterior cruciate ligament revision in adults: the 2022 ESSKA consensus part I-diagnostics and preoperative planning

PURPOSE

The aim of this ESSKA consensus is to give recommendations based on evidence and expert opinion to improve diagnosis, preoperative planning, indication and surgical strategy in ACL revision.

METHODS

The European expert surgeons and scientists were divided into four groups to participate in this consensus. A "literature group" (four surgeons); "steering group" (14 surgeons and scientists); "rating group" (19 surgeons) and finally "peer review group" (51 representatives of the ESSKA-affiliated national societies from 27 countries). The steering group prepared eighteen question-answer sets. The quality of the answers received grades of recommendation ranging from A (high-level scientific support), to B (scientific presumption), C (low level scientific support) or D (expert opinion). These question-answer sets were then evaluated by the rating group. All answers were scored from 1 to 9. The comments of the rating group were incorporated by the steering group and the consensus was submitted to the rating group a second time. Once a general consensus was reached between the steering and rating groups, the question-answer sets were submitted to the peer review group. A final combined meeting of all the members of the consensus was held to ratify the document.

RESULTS

The literature review for the diagnosis and preoperative planning of ACL revision revealed a rather low scientific quality. None of the 18 questions was graded A and six received a grade B. The mean rating of all the questions by the rating group was 8.4 ± 0.3. The questions and recommendations are listed below.

CONCLUSION

ACL revision surgery is a widely debated subject with many different opinions and techniques. The literature reveals a poor level of standardisation. Therefore, this international consensus project is of great importance.

LEVEL OF EVIDENCE

II.

ESSKA consensus initiative: why, when and how?

The goal of a Consensus in clinical practice is to provide daily practitioners with evidence- based recommendations on data from the literature, clinical expertise and expectations of professionals and patients. In this context, a consensus aligns with the principles of evidence-based medicine in clinical practice and is consequently regarded as a scientific work of a certain level of evidence (LOE). It is expected that such a project may contribute to filling the gap observed between scientific evidence and reality of the daily practice.A Clinical Consensus is particularly needed for those topics that are of interest to daily practice but controversial due to lack of evidence, and for which expert agreement can provide valuable support in reaching conclusions.A Consensus requires a strict methodology, based on two principles: an iterative process with independence of the involved groups and pluralism (geographical and professional representation). These processes guarantee the scientific quality of the recommendations.Among the various consensus modalities, ESSKA has adopted the Formal Consensus derived from the Delphi method, and the RAND/UCLA appropriateness method. These two methods are complementary. The first one, based on questions-answers sets, is particularly suitable for questions of terminology, diagnosis, planning, strategy. The second one is based on the concept of scenarios, particularly adapted to treatment indications. These two methods can also be used within the same consensus.The aim of this article is to define what is a consensus initiative, to detail the methodology ESSKA has chosen, and to point out the key role of the dissemination.

First revision ACL reconstruction combined with tibial deflexion osteotomy improves clinical scores at 2 to 7 years follow-up

PURPOSE

To report outcomes of first revision anterior cruciate ligament reconstruction (ACLR) with tibial deflexion osteotomy (TDO) in patients with posterior tibial slope (PTS) >10° at >2 years.

METHODS

The authors studied outcomes of a consecutive series of 16 patients that underwent first revision ACLR with TDO, including Lysholm score, IKDC subjective and objective scores, Lachman test, PTS, and signs of osteoarthritis. One woman was excluded because of early signs of knee arthritis, as the first revision ACLR took place 27 years following the primary ACLR. This left a final cohort of 15 patients assessed at minimum follow-up of 2 years.

RESULTS

The final cohort comprised 14 men and 1 woman aged 25.3 ± 6.6 years (range 16-39) at first revision ACLR. At final follow-up of 4.4 ± 1.5 years (range, 2-7), PTS was corrected from 12.5 ± 1.8° (range 8-15°) to 1.9 ± 3.6° (range - 4 to 8°), and none of the knees had radiographic signs of osteoarthritis. Lysholm score was 83.8±12.5, IKDC subjective score was 80.3±16.2, and IKDC objective score was A in 5 (33%), and B in 10 (67%). The net improvement exceeded the minimal clinically important difference (MCID) in 93% of patients for the IKDC subjective score and in 80% of patients for the Lysholm score. None of the knees had any retears, and only one required a reoperation to re-suture a medial meniscal tear due to trauma.

CONCLUSION

At 2-7 years following revision ACLR combined with TDO, net improvement exceeded the MCID in 93% of patients for IKDC subjective score and in 80% of patients for Lysholm score, with no retears or major complications. These results suggest that TDO is a safe technique to protect the ACL graft and might be considered as of first revision ACLR to correct excessive PTS.

LEVEL OF EVIDENCE

Level IV.

Creation of a specialist core curriculum for the European Society for Sports traumatology, Knee surgery and Arthroscopy (ESSKA)

PURPOSE

The European Society for Sports traumatology, Knee surgery and Arthroscopy (ESSKA) identified the need to develop a core curriculum for clinical specialists that work within the interest areas of ESSKA. A research-based approach was used to define a set of core competencies which could be used to map all of their educational activities, resources and development priorities. This paper describes the aims, development, results and implications of this competency-based core curriculum for orthopaedic conditions relevant to ESSKA members.

METHODS

A Core Curriculum Working Group, with leaders and other experts representing the main specialist areas within ESSKA, reviewed existing curricula and the literature in their own specialist areas. Applying expert group methodology, they iteratively developed a draft list of 285 core competencies for Orthopedic specialists within 6 specialist areas of Knee, Shoulder, Foot/Ankle, Hip, Elbow/Forearm and Sports/Exercise. All ESSKA members were then asked to comment and rate the importance of these competencies, and the Working Group used these findings to critically review and refine the curriculum.

RESULTS

The expert groups defined 56 competencies related to 10 Knee pathologies; 67 related to 15 Shoulder pathologies; 45 related to 9 Foot/Ankle pathologies; 41 related to 6 Hip pathologies; and 34 related to 12 Elbow/Forearm pathologies and 42 related to 8 Sports/Exercise pathologies. Survey respondent mean ratings were at least 'Important' for all competencies, and the Working Group used these results to separate the competencies into three levels of importance.

CONCLUSION

A competency-based core curriculum for Orthopedic specialists was achieved through a systematic and scholarly approach, involving both expert opinion and engagement of the wider ESSKA membership, identifying 285 treatment competencies in 6 specialist areas. It is now being used to guide educational and strategic development for ESSKA and should also be of interest to the wider orthopedic and sports medicine communities.

Bipolar Sealers Do not Improve Blood Loss or Functional Outcomes of Primary Total Knee Arthroplasty

Several methods were introduced to limit perioperative blood loss in total knee arthroplasty (TKA). By transcollation of soft tissues below 100°C, bipolar sealers intend to reduce bleeding and tissue damage, compared with conventional electrocautery. Existing studies report contradictory findings about the performance of bipolar sealers. The purpose of this study was to evaluate the effect of a bipolar sealer on blood loss, transfusions, hospital length of stay (LOS), and functional scores in primary TKA. In this single-center prospective study, 101 patients, undergoing primary TKA in a fast-track setting without tourniquet use, were randomly assigned to either (1) the study group which was operated with a bipolar sealer or (2) the control group operated with conventional electrocautery. The study cohort comprised 49 men and 52 women, aged 71.1 ± 8.8 years. There was no significant difference between the bipolar sealer group and the control group in terms of blood loss at day 3 (1,240 ± 547.4 vs. 1,376 ± 584.4 mL; p = ns [not significant]), transfusion rate (10 vs. 4%; p = ns), surgery time (48.2 ± 10.8 vs. 46.6 ± 9.1 minute; p = ns) or LOS (4.1 ± 2.7 vs 4.3 ± 2.0 days; p = ns). At a mean follow-up of 63.3 ± 4.9 days, there was no significant difference between the bipolar sealer group and the control group in terms of net improvement of Knee Society Score (KSS) knee (26.0 ± 16.7 vs. 23.7 ± 12.3; p = ns) and KSS function (20.4 ± 19.3 vs. 20.8 ± 19.9; p = ns). Compared with the use of conventional electrocautery in primary TKA without tourniquet, we found no effect of bipolar sealer use on blood loss, transfusion rates, LOS, or functional recovery. This is a Level II, prospective cohort study.

Management of traumatic meniscus tears: the 2019 ESSKA meniscus consensus

PURPOSE

The importance of meniscus integrity in the prevention of early osteoarthritis is well known, and preservation is accepted as the primary goal. The purpose of the ESSKA (European Society for Sports Traumatology, Knee Surgery and Arthroscopy) European consensus on traumatic meniscus tears was to provide recommendations for the treatment of meniscus tears based on both scientific evidence and the clinical experience of knee experts.

METHODS

Three groups of surgeons and scientists elaborated and ratified the so-called formal consensus process to define the recommendations for the management of traumatic meniscus tears. A traumatic meniscus tear was defined as a tear with an acute onset of symptoms caused by a sufficient trauma. The expert groups included a steering group of eight European surgeons and scientists, a rating group of another nineteen European surgeons, and a peer review group. The steering group prepared twenty-seven question and answer sets based on the scientific literature. The quality of the answers received grades of A (a high level of scientific support), B (scientific presumption), C (a low level of scientific support) or D (expert opinion). These question and answer sets were then submitted to and evaluated by the rating group. All answers were scored from 1 (= totally inappropriate) to 9 (= totally appropriate) points. Thereafter, the comments of the members of the rating group were incorporated by the steering group and the consensus was submitted to the rating group a second time. Once a general consensus was reached between the steering and rating groups, the finalized question and answer sets were submitted for final review by the peer review group composed of representatives of the ESSKA-affiliated national societies. Eighteen representatives replied.

RESULTS

The review of the literature revealed a rather low scientific quality of studies examining the treatment of traumatic meniscus tears. Of the 27 questions, only one question received a grade of A (a high level of scientific support), and another received a grade of B (scientific presumption). The remaining questions received grades of C and D. The mean rating of all questions by the rating group was 8.2 (95% confidence interval 8.1-8.4). A general agreement that MRI should be performed on a systematic basis was not achieved. However, MRI was recommended when arthroscopy would be considered to identify concomitant pathologies. In this case, the indication for MRI should be determined by a musculoskeletal specialist. Based on our data, stable left in situ lateral meniscus tears appear to show a better prognosis than medial tears. When repair is required, surgery should be performed as early as possible. Evidence that biological enhancement such as needling or the application of platelet-rich plasma would improve healing was not identified. Preservation of the meniscus should be considered as the first line of treatment because of an inferior clinical and radiological long-term outcome after partial meniscectomy compared to meniscus repair.

DISCUSSION

The consensus was generated to present the best possible recommendations for the treatment of traumatic meniscus tears and provides some groundwork for a clinical decision-making process regarding the treatment of meniscus tears. Preservation of the meniscus should be the first line of treatment when possible, because the clinical and radiological long-term outcomes are worse after partial meniscectomy than after meniscus preservation. The consensus clearly states that numerous meniscus tears that were considered irreparable should be repaired, e.g., older tears, tears in obese patients, long tears, etc. LEVEL OF EVIDENCE: II.

Influence of operative technique on anterior cruciate ligament reconstruction in patients older than 50 years

BACKGROUND

A consequence of the steady growth in the worldwide population of elderly individuals who remain in good health and continue to engage in sports is an increase in the incidence of anterior cruciate ligament (ACL) rupture occurring after 50 years of age. ACL reconstruction was formerly reserved for young athletes but now seems to produce good outcomes in over 50s. The type of graft and graft fixation method were selected empirically until now, given the absence of investigations into potential relationships of these two parameters with the outcomes. The objective of this study was to assess associations linking the type of graft and the method of femoral graft fixation to outcomes in patients older than 50 years at ACL reconstruction.

HYPOTHESIS

The operative technique is not associated with the clinical outcomes or differential laxity.

MATERIAL AND METHODS

A multicentre retrospective cohort of 398 patients operated between 1 January 2011 and 31 December 2015 and a multicentre prospective cohort of 228 patients operated between 1 January 2016 and 30 June 2017 were conducted. Mean follow-up was 42.7 months in the retrospective cohort and 14.2 months in the prospective cohort. The primary evaluation criterion was the clinical outcome as assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the Tegner Activity Score (TAS). Differential laxity was the secondary evaluation criterion. The Wilcoxon rank sum test and Kruskal-Wallis test were used to compare groups, and p-values<0.05 were considered significant.

RESULTS

In the retrospective and prospective cohorts, hamstring tendons were used in 269 (67.6%) and 197 (86.4%) patients and extensor apparatus tendons in 124 (31.2%) and 31 (13.6%) patients. Femoral fixation in the retrospective cohort was cortical in 81 (20.4%) cases, by press-fit in 112 (28.1%) cases, and by interference screw in 205 (51.5%) cases; corresponding figures in the prospective cohort were 135 (59.2%), 17 (7.5%), and 76 (33.3%). The multivariate analysis of the retrospective data identified no significant associations of graft type or femoral fixation type with the KOOS, TAS, or differential laxity values. In the prospective cohort, hamstring grafts were associated with 0.6mm of additional laxity (p=0.007); compared to cortical fixation, press-fit fixation of patellar tendon grafts was associated with 0.3mm of additional laxity (p=0.029) and a 0.5-point lower TAS value (p=0.033), with no difference in KOOS values. None of these differences were clinically significant.

DISCUSSION

The various ACL reconstruction techniques used in patients older than 50 years produce similar outcomes. The technique can be chosen based on surgeon preference without regard for patient age.

LEVEL OF EVIDENCE

IV.

Tibial slope and medial meniscectomy significantly influence short-term knee laxity following ACL reconstruction

PURPOSE

To determine demographic, anatomic, and surgical factors associated with static and dynamic Anterior Tibial Translation (ATT) following ACL reconstruction. The hypothesis was that both static and dynamic ATT would be greater in knees with high tibial slope or that required meniscectomy.

METHODS

The authors prospectively enrolled 280 consecutive patients that had primary ACL reconstruction using hamstring autografts at one center for which preoperative tear type, meniscal tears, and medial tibial slope were documented. A total of 137 were excluded due to concomitant extra-articular tenodesis or surgical antecedents on either knee, and 18 were lost to follow-up, leaving 125 that were evaluated at a minimum of 6 months including: static ATT on monopodal weight-bearing radiographs, and dynamic ATT on differential stress radiographs using the Telos™ device.

RESULTS

Both postoperative static and dynamic ATT were strongly associated with preoperative static and dynamic ATT (respectively, β = 0.068 and β = 0.50, p < 0.001). Multivariable regression confirmed that postoperative static ATT increased with tibial slope (β = 0.24; CI 0.01-0.47; p = 0.042) and in knees that had partial medial meniscectomy (β = 2.05; CI 0.25-3.84; p = 0.025), while dynamic ATT decreased with age (β = - 0.11; CI - 0.16 to - 0.05; p < 0.001), and increased with tibial slope (β = 0.27; CI 0.04-0.49; p = 0.019) and in knees that had partial medial meniscectomy (β = 2.20; CI 0.35-4.05; p = 0.019).

CONCLUSION

Both static and dynamic ATT following ACL reconstruction increased with tibial slope and in knees that had partial medial meniscectomy. These findings could help surgeons tailor their techniques and 'à la carte' rehabilitation protocols, by preserving the menisci and sometimes delaying full weight-bearing and return to sport in patients at risk, and hence improve outcomes and prevent graft failures.

STUDY DESIGN

Cohort study.

LEVEL OF EVIDENCE

V.

Early outcomes of an anatomic trochlear-cutting patellofemoral arthroplasty: patient selection is key

PURPOSE

The purpose of this study was to report outcomes of a recent anatomic trochlear-cutting patellofemoral arthroplasty (PFA) system at > 3 years. The hypothesis was that its functional scores and revision rates would be at least equivalent to those reported for other 'trochlear-cutting' implants in the literature.

METHODS

Twenty-eight consecutive patients that had received PFA using the same anatomic trochlear-cutting implant (KneeTech PFJ, Corin-Tornier, Montbonnot, France) with a dome-shaped patellar button and had systematic lateral facetectomy without lateral release were enrolled. Radiographic parameters collected pre-operatively included: trochlear dysplasia type and patellar height, TT-TG, patellar tilt and shape. Clinical scores collected pre-operatively and at > 3 years included: Oxford Knee Score (OKS) and Knee Society Score (KSS).

RESULTS

The initial cohort comprised 23 women (82%) and five men (18%), aged 63.3 ± 14.7 years, of which 23 had trochlear dysplasia (82%). One patient (4%) could not be reached, and three (11%) were revised to TKA due to arthritic progression, aged 77, 80 and 83 years at index operation, only one of which had trochlear dysplasia (type A). At final follow-up, none of the remaining 24 patients had complications; their OKS was 35.0 ± 10.3 and KSS symptoms and function were 19.8 ± 5.0 and 71.7 ± 13.6.

CONCLUSION

The anatomic trochlear-cutting PFA granted satisfactory scores and prevented mechanical complications, but the high incidence of early revisions, all due to spread of arthritis hence to improper patient selection. PFA should be restricted to patients with trochlear dysplasia, in whom arthritis was triggered by patellar instability and maltracking rather than degenerative or age-related diseases.

STUDY DESIGN

Retrospective case series, Level IV.

Preoperative laxity in ACL-deficient knees increases with posterior tibial slope and medial meniscal tears

PURPOSE

The aim of this study was to determine patient and anatomic factors that influence anteroposterior and rotational laxity in knees with ACL tears. Based on the findings of biomechanical studies, we hypothesized that static and dynamic anterior tibial translation (ATT) as well as positive pivot shift would increase with female gender, tibial slope, and meniscal tears.

METHODS

The authors prospectively collected preoperative data and intraoperative findings of 417 patients that underwent ACL reconstruction. The exclusion criteria were: revision ACL procedures (n = 53), other surgical antecedents (n = 27), prior osteotomies (n = 7) or concomitant ligament tears on the ipsilateral knee (n = 34), and history of ACL tears in the contralateral knee (n = 45), leaving a study cohort of 251 patients. Their preoperative anteroposterior knee laxity was assessed objectively using 'static' monopodal weight-bearing radiographs and 'dynamic' instrumented differential measurements of ATT. Rotational laxity was assessed subjectively using the pivot shift test.

RESULTS

Multivariable regression showed that static ATT increases only with tibial slope (β = 0.30; p < 0.001), but dynamic ATT increases with tibial slope (β = 0.19; p = 0.041), medial meniscal tears (β = 1.27; p = 0.007), complete ACL tears (β = 2.06; p < 0.001), and to decrease with age (β = - 0.09; p < 0.001). Multivariable regression also indicated that high-grade pivot shift decreases with age (OR 0.94; p < 0.001) and for women (OR 0.25; p < 0.001), and to be higher for knees with complete ACL tears (OR 3.04; p = 0.002) or medial meniscal tears (OR 2.28; p = 0.010).

CONCLUSION

Contrary to expectations based on biomechanical studies, static ATT was only affected by high posterior tibial slope, while dynamic ATT was affected by both high posterior tibial slopes and medial meniscal tears, but not by gender or lateral meniscal tears. Likewise, pivot shift was affected by gender and medial meniscal tears, but not lateral meniscal tears or posterior tibial slope. These findings are relevant to guide surgeons in optimizing their surgical procedures, such as conserving the menisci when possible, and rehabilitation protocols, by delaying full weight-bearing and return to sports in patients with anatomic and lesional risk factors.

LEVEL OF EVIDENCE

Cohort study, Level IV.

Inadequacy of computed tomography for pre-operative planning of patellofemoral arthroplasty

PURPOSE

To evaluate the accuracy of preoperative planning for patellofemoral arthroplasty (PFA) by comparing: (1) virtual implant positioning simulated on pre-operative images versus (2) real implant positioning from post-operative images.

METHODS

The authors prospectively studied 15 patients that received a PFJ implant (Tornier, Montbonnot France). A pre-operative planning software was established to determine the size and position of the trochlear component. Pre-operative scans were used to perform virtual implantations by two different operators, which were then compared to the post-operative scans to calculate errors (ε) in implant positioning and intra-class correlation coefficients (ICC) for intra- and inter-observer repeatability.

RESULTS

Analysis was performed for 13 patients, for whom agreement between virtual and real surgery was excellent for anteroposterior (AP) position (ICC = 0.84; ε _max = 3.5 mm), fair for proximodistal (PD) position (ICC = 0.50; ε _max  = 9.5 mm), and poor for mediolateral (ML) position (ICC = 0.07; ε _max = 9.0 mm). It was fair for flexum-recurvatum (FR) alignment (ICC = 0.53; ε _max = 8.2°), poor for varus-valgus (VV) alignment (ICC = 0.34; ε _max = 10.0°), and internal-external (IE) rotation (ICC = 0.34; ε _max = 10.6°).

CONCLUSIONS

Pre-operative planning was insufficiently accurate to follow intra-operatively, the greatest errors being angular alignment (VV and FR). The clinical relevance of these findings is that PFA is difficult to plan pre/operatively due to non-visibility of cartilage on CT scans and to trochlear dysplasia in most cases.

LEVEL OF EVIDENCE

Prospective evaluation of operative tools on consecutive patients, Level III.

Results of medial patellofemoral ligament reconstruction compared with trochleoplasty plus individual extensor apparatus balancing in patellar instability caused by severe trochlear dysplasia: a systematic review and meta-analysis

PURPOSE

Many studies have reported satisfactory clinical outcomes and low redislocation rates after reconstruction of the medial patellofemoral ligament (MPFL) for the treatment of lateral patellar instability. Despite uncorrected severe trochlear dysplasia (Dejour type B to D) being acknowledged as a major reason for less favourable clinical outcomes and a higher incidence of patellar redislocations after an isolated MPFL reconstruction, the evidence for a deepening trochleoplasty procedure remains scarce in the current literature. The hypothesis of this systematic review and meta-analysis was that a deepening trochleoplasty in combination with an a la carte extensor apparatus balancing procedure provides lower redislocation rates and superior clinical outcomes than isolated MPFL reconstruction in patients with lateral patellar instability caused by severe trochlear dysplasia.

METHODS

A systematic review of the literature was conducted using specific inclusion and exclusion criteria for clinical studies reporting index operations (trochleoplasty and MPFL reconstruction) for the treatment of patellar instability caused by severe trochlear dysplasia. The Kujala score was analysed as the primary clinical outcome parameter in a random effects meta-analysis.

RESULTS

Ten uncontrolled studies with a total of 407 knees (374 patients) were included in this analysis. The MPFL group comprised 4 studies with a total of 221 knees (210 patients), and the trochleoplasty group comprised 6 studies with a total of 186 knees (164 patients). The mean preoperative Kujala score ranged between 50.4 and 70.5 in the MPFL group and between 44.8 and 75.1 in the trochleoplasty group. The pooled Kujala score increased significantly by 26.4 (95% CI 21.4, 31.3; P < 0.00001) points in the MPFL group and by 26.2 (95% CI 19.8, 32.7; P < 0.00001) points in the trochleoplasty group. The post-operative patellar redislocation/subluxation rate was 7% in the MPFL group and 2.1% in the trochleoplasty group.

CONCLUSION

This analysis found significant post-operative improvements in patient-reported outcomes for patients undergoing both an MPFL reconstruction and in those undergoing a trochleoplasty plus an individual extensor apparatus balancing procedure when assessed using the Kujala score. The likelihood of preventing the patella from subsequent post-operative redislocation/subluxation was, however, greater in patients who underwent trochleoplasty plus extensor balancing.

LEVEL OF EVIDENCE

IV.

Sagittal Plane Corrections around the Knee

Stability of the knee joint depends on soft tissues integrity and bony balance in the frontal and sagittal planes during gait. Although frontal plane imbalance is a well-known knee pathology, commonly treated by high tibial osteotomy, sagittal plane imbalance is less common, with fewer and more challenging surgical treatment options. The purpose of this review is to describe the biomechanical effects of sagittal knee imbalances and to outline the indications, techniques, and outcomes of sagittal knee osteotomies. The article details the reference axes and methods to measure posterior tibial slope (PTS), the principal indicator of sagittal imbalance, and its influence on anteroposterior tibial translations and rotational stability of the joint. The authors also outline the roles of the anterior and posterior cruciate ligaments in maintaining sagittal balance, with focus on the associations between PTS and ligament deficiencies, as well as posterolateral corner injuries. Different techniques and indications of tibial osteotomy in the sagittal plane, both above and below the anterior tibial tubercle, are compared in terms of technical difficulty, clinical benefits, and complication rates. The authors conclude on the importance of understanding sagittal knee imbalance, particularly in cases of ligament deficiencies, where the deformity can be the primary cause for lesions. Surgeons must identify the underlying deformities associated with sagittal imbalance, which can be recognized on weight-bearing X-rays and magnetic resonance imaging scans. Different techniques of sagittal osteotomies offer effective treatments for certain indications and should be considered in selected cases for unstable knees with ligament lesions.

Is There Any Benefit in Anterior Cruciate Ligament Reconstruction in Patients Older Than 60 Years?

BACKGROUND

Results of anterior cruciate ligament (ACL) reconstruction are traditionally excellent in younger and nonarthritic patients. During the past few decades, people older than 60 years have become more active than ever, with more demanding physical lifestyles. An increase also has been noted in active patients with diagnosed ACL injuries. More patients are requesting treatment for ACL deficiency in hopes of returning to preinjury levels of activity.

PURPOSE

The aims of this study were to evaluate the results of ACL reconstruction in patients older than 60 years in terms of functional recovery, return to sports, and postoperative incidence of osteoarthritis and to compare their results with published results of different age groups.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Consecutive patients older than 60 years with isolated ACL tear and no established osteoarthritic lesions (Ahlbäck grade 1 or no arthritis) who were treated from 2008 to 2013 were retrospectively included in this study. Primary ACL reconstruction was performed with the same technique in all patients by means of single-bundle autologous hamstring tendon graft. Meniscal injuries were treated with partial debridement when required. No further treatment on cartilage lesions was performed. Postoperative rehabilitation was the same in every case. The International Knee Documentation Committee (IKDC) objective grade, Lysholm score, and Knee injury and Osteoarthritis Outcome Score (KOOS) were assessed before and after surgery, and the Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) score was recorded during the final follow-up. Postoperative incidence of osteoarthritis was evaluated on weightbearing radiographs during final follow-up, and anteroposterior laxity was measured pre- and postoperatively with the use of stress radiographs.

RESULTS

Twelve patients with mean age (±SD) of 61.0 ± 1.4 years at the time of surgery were included. They were followed-up for a mean period of 49.6 ± 24.0 months. Eight patients had associated meniscal tears, and 6 patients had International Cartilage Repair Society stage 1 or 2 chondral lesions. Preoperatively, the objective IKDC grades were B in 4 patients, C in 5, and D in 3. After surgery, the IKDC grades were A in 4 patients, B in 7, and grade C in 1. The mean subjective IKDC and Lysholm scores were a respective 43.4 ± 8.4 and 55.7 ± 12.4 preoperatively and 83.8 ± 9.4 and 93.2 ± 9.0 at the final follow-up ( P < .05). Ten patients (83%) reported recovery of sports activities, with 6 patients (50%) reaching the same level as before injury. The mean ACL-RSI score was 76.2%. Preoperatively, 50% (n = 6) of patients had Ahlbäck stage 1 medial compartment arthritis, versus 58% (n = 7) at the final follow-up ( P = nonsignificant). The side-to-side difference in anterior tibial translation on stress radiographs was 7.2 ± 6.4 mm preoperatively and 1.9 ± 4.3 mm postoperatively ( P < .05). No major complications were reported.

CONCLUSION

ACL reconstruction in active patients older than 60 years without arthritis restored knee stability in all treated cases. In these patients, as in younger age groups, ACL reconstruction showed good results on functional recovery while not increasing the risk of midterm functional knee deterioration or evolution of knee arthritis. The majority of patients returned to activities at their preinjury level. These data show that older and active patients with nonarthritic ACL-deficient knees need not be excluded from surgical treatment.

Management of Patellofemoral Arthritis: From Cartilage Restoration to Arthroplasty

The management of patellofemoral cartilage lesions is controversial and should begin with a comprehensive nonsurgical treatment plan. Patients with patellofemoral cartilage lesions in whom nonsurgical treatment fails may be candidates for surgical treatment. Surgical treatment strategies for the management of patellofemoral cartilage lesions are guided by the size, quality, and location of the defect. Recent advancements in cartilage restoration and arthroplasty techniques as well as appropriate patient selection and meticulous surgical technique have resulted in promising outcomes for patients with patellofemoral cartilage lesions who undergo surgical treatment.

Evolution of trochlear compartment geometry in total knee arthroplasty

BACKGROUND

The study aimed to compare trochlear profiles in recent total knee arthroplasty (TKA) models and to determine whether they feature improvements compared to their predecessors. The hypothesis was that recent TKA models have more anatomic trochlear compartments and would display no signs of trochlear dysplasia.

METHODS

The authors analyzed the geometry of the 6 following TKA models using engineering software: PFC and Attune (DePuy), NexGen and Persona (Zimmer), Noetos and KneeTec (Tornier). The mediolateral trochlear profiles were plotted at various flexion angles (0°, 15°, 30° and 45°) to deduce the sulcus angle.

RESULTS

Analysis of sulcus angles reveals general convergence of recent designs towards anatomic values. At 0° of flexion, sulcus angles of recent implant models were between 156.0-157.4°, while those of previous generation models between 154.5-165.5°. At 30° of flexion, sulcus angles of recent models also lie within 145.7-148.6°, but those of previous models are between 149.5-152.0°. All three manufacturers deepened their trochlear profile at 30° of flexion in recent models compared to earlier designs. Sulcus angles converge towards anatomic values but still exceed radiologic signs of dysplasia by 2-5°.

CONCLUSIONS

Recent TKA designs have more anatomic trochlear geometries than earlier TKA models by the same manufacturers, but trochlear compartments still exceed radiologic signs of trochlear dysplasia by 2° to 5°. The hypothesis that recent TKA models display no signs of trochlear dysplasia is therefore refuted. Surgeons should be aware of design limitations to optimize choice of implant and extensor mechanisms alignment.

LEVEL OF EVIDENCE

IV geometric implant analysis.

Do outcomes of outpatient ACL reconstruction vary with graft type?

BACKGROUND

Studies establishing the feasibility of anterior cruciate ligament (ACL) reconstruction as an outpatient procedure in France were usually conducted with hamstring tendon grafts. The objective of this study was to evaluate the outcomes of outpatient ACL reconstruction according to whether the graft was harvested from the hamstring tendons or patellar tendon.

HYPOTHESIS

Outpatient ACL reconstruction can be performed using any type of graft.

METHODS

A single-centre retrospective study was conducted in consecutive patients older than 16 years who had primary ACL reconstruction using patellar tendon or hamstring tendons, with or without lateral tenodesis. Patients who underwent other procedures on bones or peripheral ligaments and those with a previous history of ACL reconstruction were excluded. The primary evaluation criterion was the occurrence of complications within 45 days after surgery. Secondary evaluation criteria were the visual analogue scale (VAS) for pain during the first 3 postoperative days, patient satisfaction on day 3, and the IKDC and Lysholm clinical scores on day 45.

RESULTS

The analysis included 104 knees (one knee per patient). Hamstring tendons were used in 77 (74%) knees and patellar tendon in 27 (26%) knees. In the hamstring group, 2 (2.6%) patients spent the first postoperative night in the hospital and 2 others were re-admitted. No hospitalisations were recorded in the patellar-tendon group. None of the patients required revision surgery within 45 days of the reconstruction procedure. None of the postoperative criteria studied showed statistically significant differences between the two groups.

DISCUSSION

ACL reconstruction can be performed on an outpatient basis using any type of graft. The main determinants of successful outpatient ACL reconstruction are a standardised clinical management strategy and an appropriate anaesthesia protocol.

LEVEL OF EVIDENCE

Level IV, retrospective study.

Tibial slope correction combined with second revision ACL produces good knee stability and prevents graft rupture

PURPOSE

Revision ACL reconstruction requires careful analysis of failure causes particularly in cases of two previous graft ruptures. Intrinsic factors as excessive tibial slope or narrow femoral notch increase failure risks but are rarely addressed in revision surgery. The authors report outcomes, at minimum follow-up of 2 years, for second revision ACL reconstructions combined with tibial deflexion osteotomy for correction of excessive slope (>12°).

METHODS

Nine patients that underwent second revision ACL reconstruction combined with tibial deflexion osteotomy were retrospectively studied. The mean age was 30.3 ± 4.4 years (median 28; range 26-37), and mean follow-up was 4.0 ± 2.0 years (median 3.6; range 2.0-7.6). Autografts were harvested from the quadriceps tendon (n = 8) or hamstrings (n = 1), and tibial osteotomy was done by anterior closing wedge, without detachment of the patellar tendon, to obtain a slope of 3° to 5°.

RESULTS

All patients had fused osteotomies, stable knees, and there were no intraoperative or postoperative complications. The mean posterior tibial slope decreased from 13.2° ± 2.6° (median 13°; range 12°-18°) preoperatively to 4.4° ± 2.3° (median 4°; range 2°-8°) postoperatively. The mean Lysholm score was 73.8 ± 5.8 (median 74; range 65-82), and the IKDC-SKF was 71.6 ± 6.1 (median 72.8; range 62.2-78.5).

CONCLUSION

The satisfactory results of second revision ACL reconstruction combined with tibial deflexion osteotomy at minimum follow-up of 2 years suggest that tibia slope correction protects reconstructed ACL from fatigue failure in this study. The authors stress the importance of careful analysis failure causes prior to revision ACL reconstruction, and recommend correction of tibial slope if it exceeds 12°, to reduce the risks of graft retear.

LEVEL OF EVIDENCE

III.

Does patellofemoral geometry in TKA affect patellar position in mid-flexion?

PURPOSE

This study aimed to compare the position of the patella at 90° of flexion before and after implantation of two TKA models with identical tibiofemoral geometry but different trochlear and patellar designs. The hypothesis was that the design with the deeper 'anatomic' trochlea could produce more natural patellar positions.

METHODS

Intra-operative navigation data were collected from 22 consecutive cases that received two TKA designs (9 HLS Noetos(®) and 13 HLS KneeTec(®)). Both implants were cemented postero-stabilised TKAs with mobile tibial inserts and patellar resurfacing. Operations were guided by a non-image-based system that recorded relative femoral, tibial and patellar positions pre- and post-operatively.

RESULTS

The two groups exhibited little difference in femoral internal-external rotation and anterior-posterior translation during knee flexion. The two groups exhibited significant differences in patellar position at 90° of flexion. Post-operatively, the patella was similarly shifted medially relative to the femur (Noetos 6.9 mm, KneeTec 6.0 mm, n.s.). Patellar flexion was equivalent in native knees (Noetos 18.3°, KneeTec 20.5°, n.s.), but in implanted knees, it was considerably different (Noetos 6.3°, KneeTec 23.5°, p = 0.031).

CONCLUSIONS

The present study compared intra-operative navigation data from two patient series that received TKA implants with identical tibiofemoral articular geometry but different patellofemoral designs. The results confirm that tibiofemoral kinematics are unchanged, but that patellar positions at 90° of flexion offer greater mechanical advantage to the quadriceps using the KneeTec than using the Noetos. The findings raise awareness of influence of patellofemoral geometry on mid-flexion kinematics and help surgeons select the most suitable implant for patients with weak quadriceps muscles or with history of patellar instability.

LEVEL OF EVIDENCE

Comparative study, Level III.

The effect of trochlear dysplasia on patellofemoral biomechanics: a cadaveric study with simulated trochlear deformities

BACKGROUND

Trochlear dysplasia appears in different geometrical variations. The Dejour classification is widely used to grade the severity of trochlear dysplasia and to decide on treatment.

PURPOSE

To investigate the effect of trochlear dysplasia on patellofemoral biomechanics and to determine if different types of trochlear dysplasia have different effects on patellofemoral biomechanics.

STUDY DESIGN

Controlled laboratory study.

METHODS

Trochlear dysplasia was simulated in 4 cadaveric knees by replacing the native cadaveric trochlea with different types of custom-made trochlear implants, manufactured with 3-dimensional printing. For each knee, 5 trochlear implants were designed: 1 implant simulated the native trochlea (control condition), and 4 implants simulated 4 types of trochlear dysplasia. The knees were subjected to 3 biomechanical tests: a squat simulation, an open chain extension simulation, and a patellar stability test. The patellofemoral kinematics, contact area, contact pressure, and stability were compared between the control condition (replica implants) and the trochlear dysplastic condition and among the subgroups of trochlear dysplasia.

RESULTS

The patellofemoral joint in the trochlear dysplastic group showed increased internal rotation, lateral tilt, and lateral translation; increased contact pressures; decreased contact areas; and decreased stability when compared with the control group. Within the trochlear dysplastic group, the implants graded as Dejour type D showed the largest deviations for the kinematical parameters, and the implants graded as Dejour types B and D showed the largest deviations for the patellofemoral contact areas and pressures.

CONCLUSION

Patellofemoral kinematics, contact area, contact pressure, and stability are significantly affected by trochlear dysplasia. Of all types of trochlear dysplasia, the models characterized with a pronounced trochlear bump showed the largest deviations in patellofemoral biomechanics.

CLINICAL RELEVANCE

Investigating the relationship between the shape of the trochlea and patellofemoral biomechanics can provide insight into the short-term effects (maltracking, increased pressures, and instability) and long-term effects (osteoarthritis) of different types of trochlear dysplasia. Furthermore, this investigation provides an empirical explanation for better treatment outcomes of trochleoplasty for Dejour types B and D dysplasia.

Evidence of trochlear dysplasia in femoral component designs

PURPOSE

The study aimed to compare trochlear profiles of various total knee arthroplasty (TKA) models to anatomic profiles observed in healthy and pathologic knees and to evaluate trochlear designs against radiologic indicators for PF disorders and trochlear dysplasia.

METHODS

The trochlear profiles of 14 different TKA models were digitized using a coordinate measurement machine at various flexion angles (0°, 15°, 30° and 45°) to deduce the following variables: sulcus angle, trochlear groove orientation, height of lateral facet, and mediolateral groove position. The effect of externally rotating the femoral component on those variables was simulated.

RESULTS

The sulcus angle was greater than the indicators for trochlear dysplasia of 144° in 11 implants at 45° flexion, and in 13 implants at 30° flexion. The lateral facet height was less than average anatomic values of 5 mm in eight specimens through the entire range of early flexion (0°-30°). The trochlear groove was oriented laterally in 13 specimens (3.3°-11.7°) and was vertical in one specimen (0.3°). Applying an external rotation up to 6° resulted in noticeable lateral translation of the trochlear groove and facets, but negligible posterior translation.

CONCLUSIONS

The study presented a detailed description of previously overlooked TKA design parameters and revealed that some femoral components exhibit characteristics of trochlear dysplasia. The clinical relevance of this descriptive study is that surgeons should be aware of such design limitations to improve choice of implant for patients with history of PF disorders and to adapt surgical techniques as necessary to optimize PF tracking.

LEVEL OF EVIDENCE

Case-control study, Level III.

Comparison of stability and kinematics of the natural knee versus a PS TKA with a 'third condyle'

PURPOSE

The goal of this study was to compare the kinematics of knees before and after total knee arthroplasty (TKA) that relies on an inter-condylar 'third condyle'. The hypothesis was that the 'third condyle' provides sufficient flexion stability and induces a close to normal femoral rollback, thus granting natural joint kinematics.

METHODS

Intra-operative navigation data were collected from 29 consecutive cases that received a cemented TKA (HLS Noetos, Tornier SA, France) designed with an inter-condylar 'third condyle' that engages within the tibial insert beyond 35° flexion. Operations were guided by a non-image-based system (BLU-IGS, Orthokey Italia srl, Italy) that recorded relative femoral and tibial positions in native and implanted knees during: passive range of motion, anterior drawer test at 90° flexion, and varus-valgus stress tests at full extension and at 30° flexion.

RESULTS

The total internal tibial rotation during flexion was similar for native (8.2 ± 4.2°) and implanted knees (8.0 ± 5.4°). The lateral femoral condyle was more posterior in implanted knees (1.2 ± 9.4 mm) than in native knees (9.5 ± 3.6 mm) throughout early flexion (p < 0.01), but this difference diminished beyond 100° flexion (n.s.). The implanted knees did not exhibit paradoxical external tibial rotation. Varus-valgus laxity in full extension was lower for implanted knees than for native knees (p = 0.0221), but at 30° flexion was almost identical for both native and implanted knees. Anteroposterior laxity was similar in implanted and native knees.

CONCLUSIONS

The 'third condyle' TKA provides similar anteroposterior and mediolateral stability to the natural knee. This feature granted an adequate balance between laxity and constraint to reproduce natural joint kinematics, including smooth femoral rollback, without causing paradoxical external tibial rotation.

The incidence of trochlear dysplasia in anterior cruciate ligament tears

PURPOSE

The purpose of the present epidemiologic study is to record the radiographic presence of trochlear dysplasia and patella alta in patients who undergo anterior cruciate ligament (ACL) reconstruction as a potential underlying factor for post-operative anterior knee pain (AKP).

METHODS

All consecutive cases of skeletally-mature ACL-deficient knees that would undergo ACL reconstruction in three different hospitals were prospectively included during a six-month period. Inclusion criteria were acute and sub-acute ACL injury with no previous ipsilateral knee operation. Patients with chronic ACL tears, prior-to-ACL-injury history of patellar instability or other PF disorders were excluded from the study.

RESULTS

A total of 299 knees were included (mean age 32 ± ten years). Forty-four (14.7 %) knees had a positive 'crossing sign' in the lateral X-rays and 255 (85.3 %) had no sign of trochlear dysplasia (p < 0.01). Among the cases with trochlear dysplasia, 41 (93 %) had type A trochlear dysplasia with the presence only of the 'crossing sign' and three (7 %) had type C trochlear dysplasia. Patellar height results included a mean Caton-Deschamps index of 1.0 ± 0.14 (0.5-1.4). Twenty (6.6 %) knees had an index of less than 0.8, and two (0.6 %) knees had an index less than 0.6. In contrast, 15 (5.0 %) knees had an abnormal value of more than 1.2, indicating patella alta.

CONCLUSIONS

The most important finding of the study is the increased prevalence of trochlear dysplasia and patella alta in patients with ACL injury, when compared to the incidence of trochlear dysplasia and patella alta in the general population in the literature. This finding could sound as an alert of a possible additional risk factor for post-operative anterior knee pain after ACL reconstruction.

Patellofemoral joint: from instability to arthritis

Disorders of the patellofemoral joint are commonly seen in musculoskeletal clinics. In recent years, the expansion of imaging techniques, improvements in correlative injury anatomy, and more focused physical examinations have resulted in new knowledge about patellofemoral disorders. To achieve optimal patient outcomes, it is helpful for orthopaedic surgeons who treat knee problems to review the management of patellar dislocations and isolated patellofemoral arthritis, including treatment algorithms.

The introduction of a new MRI index to evaluate sagittal patellofemoral engagement

INTRODUCTION

Patella alta is one of the primary factors of patellofemoral instability and its importance lies in the reduced engagement between patella and trochlea during the early degrees of flexion. The evaluation of patellar height is based on conventional x-rays, CT scan and, more recently, MRI. The objective of this multicentric prospective study is to describe a novel index to assess in the sagittal plane the functional engagement between patella and trochlea.

MATERIALS AND METHODS

One hundred and thirty-five patients with objective patellar dislocation were prospectively enrolled between April 2010 and September 2011 and were compared with a second group of 45 controls. All patients underwent a standard MRI and a complete radiographic study. Sagittal engagement was measured as the ratio between the articular cartilage of the patella and the trochlear cartilage length measured on two different MRI slices.

RESULTS

The mean Sagittal Patellofemoral Engagement (SPE) index was 0.43 ± 0.18 and ranged from 0.02 to 0.913 in the Objective Patellar Dislocation group versus 0.42 ± 0.11 range 0.22 to 0.55 in controls. In the Patellar Dislocation group the mean Caton-Deschamps index was 1.18 ± 0.21 (range 0.71 to 1.91). There were 58 patients with patella alta, in whom the mean SPE was 0.39 ± 0.18 (range 0.02 to 0.87). Sagittal engagement was significantly higher when compared with patients in the Patellar Dislocation group who had no patella alta (mean 0.46 ± 0.16, range 0.1-0.913).

DISCUSSION

The present study introduces a new method to measure the SPE with the use of MRI. The evaluation of the functional engagement of the patella with the femoral trochlea in the sagittal plane can serve as a supplementary tool to the existing methods of evaluating patellar height, and may help to better identify the cases where inadequate engagement is recorded despite the absence of patella alta, so that the need for tibial tuberosity osteotomy may be re-assessed.

Axial MRI index of patellar engagement: a new method to assess patellar instability

INTRODUCTION

The aim of this study was to define a new index to measure lateral patellar displacement (LPD) using nuclear magnetic resonance imaging (MRI), an axial index of engagement of the patella (AEI) obtained from two different axial MRI views then to validate its use in a prospective series of patients presenting an objective patellar instability (OPI).

MATERIALS AND METHODS

One hundred and thirty-five patients with OPI and no history of surgery of the patella were included in a prospective study organized by the French Society of Arthroscopy performed between June 2010 and August 2012. All patients underwent axial and sagittal MRI. The AEI was obtained by projecting predefined patellar and trochlear landmarks (cartilaginous landmarks) on 2 different axial MRI views (one trochlear and one patellar). The results were compared with a series of controls (n=45).

RESULTS

The preoperative AEI of the patella was 0.94 ± 0.09 for the control group and 0.84 ± 0.16 for OPI group (P=0.000016). The AEI could be obtained in 100% of the cases if it was measured on 2 MRI views while it could not be measured in 38.5% of the cases if the measurement was only obtained from one MRI view or whenever the widest part of the patella was not across from the femoral trochlea. The AEI did not significantly depend on dysplasia or the presence of a supratrochlear spur. The lowest AIE values were associated with trochlear dysplasia with a supratrochlear spur (P=0.0023) and a more prominent trochlea (P=0.0016). The AEI was correlated with patellar tilt (P<0.000001) and TT-TG on MRI (P<0.000001).

DISCUSSION

AEI is a new index to measure LPD. It can be obtained in all cases because it is obtained from two different MRI views. The normal value is close to 1. It can be used to measure patellar instability on the axial plane in patients with OPI, especially in the most severe cases.

The influence of medial patellofemoral ligament on patellofemoral joint kinematics and patellar stability

PURPOSE

Retinacular restraints have a critical role in patellar tracking, limiting the movement of the patella in the trochlear groove. The medial patellofemoral ligament (MPFL) is probably the main stabilizer against lateral displacement; few studies are focused on MPFL role on patellofemoral kinematics and patellar stability. The main goal of this in vitro study was to analyse the influence of the MPFL on the kinematics of the patellofemoral joint and patellar stability.

METHODS

Using a non-image-based navigation system, kinematics and anatomical data of six fresh-frozen specimens were collected. A passive flexion-extension from 0° to 90° and static acquisitions at 0°, 30°, 60° and 90°, with and without 25 N of lateral load, were performed with intact and resected MPFL with a 60 N axial force applied to the isolated quadriceps tendon. Patellar tilt and shift were analysed.

RESULTS

The MPFL intact state showed a shift in medial direction during the first degrees of knee flexion-that disappeared in MPFL resected condition-followed by a lateral shift, similar to that of MPFL resected condition. Tilt analysis showed that patella rotated laterally until 85° of knee flexion for intact MPFL condition and until 70° for resected MPFL condition and after rotated medially. Static tests showed that patellar stability was significantly affected by MPFL resected condition in particular at 30° and 60°.

CONCLUSIONS

The MPFL has an aponeurotic nature. It works as a restraint during motion, with an active role under high stress on lateral side, but with a small contribution during neutral knee flexion. Its biomechanical behaviour under loading conditions should be kept into account when performing surgical reconstruction of this ligamentous structure.

Results of a French multicentre retrospective experience with four hundred and eighteen failed unicondylar knee arthroplasties

PURPOSE

By means of a multicentre retrospective study based on the failure of 418 aseptic unicondylar knee arthroplasties (UKA) our aims were to present the different types of revision procedure used in failed UKAs, to establish a clear operative strategy for each type of revision and to better define the indications for each type of revision.

METHODS

Aseptic loosening was the principal cause of failure (n = 184, 44%) of which 99 cases were isolated tibial loosening (23.5 % of the whole series and 54% of all loosening), 25 were isolated femoral loosening (six and 13.6%) and 60 were both femoral and tibial loosening (14.3 and 32.6%). The next most common causes of failure were progression of arthritis (n = 56, 13.4%), polyethylene wear (n = 53, 12.7%), implant positioning errors (n = 26), technical difficulties (n = six) and implant failure (n = 16, 3.8% of cases). Data collection was performed online using OrthoWave software (Aria, Bruay Labuissiere, France), which allows collection of all details of the primary and revision surgery to be recorded.

RESULTS

A total of 426 revisions were performed; 371 patients underwent revision to a total knee arthroplasty (TKA) (87%), 33 patients (7.7%) were revised to an ipsilateral UKA, 11 (2.6%) patients underwent contralateral UKA (ten) or patellofemoral arthroplasty (one) and 11 patients (2.6%) underwent revision without any change in implants.

CONCLUSIONS

Before considering a revision procedure it is important to establish a definite cause of failure in order to select the most appropriate revision strategy. Revision to a TKA is by far the most common strategy for revision of failed UKA but by no means the only available option. Partial revisions either to an alternative ipsilateral UKA or contralateral UKA are viable less invasive techniques, which in carefully selected patients and in experienced hands warrant consideration.

Are the tubular grafts in the femoral tunnel in an anatomical or isometric position in the reconstruction of medial patellofemoral ligament?

PURPOSE

The purpose of this study was to evaluate the biomechanical results from the in vitro reconstruction of medial patellofemoral ligament (MPFL) using a navigation-assisted technique on a cadaveric model and its effects on patellar stability and kinematics. The authors investigated the hypothesis that patellar kinematics after reconstruction with a tubular graft are not optimal when compared with the original fan-shaped MPFL.

METHODS

In six fresh-frozen cadaveric knees, lateral loads (25 N) were applied on the patella at 0°, 30°, 60° and 90° of knee flexion in three different MPFL states: intact, cut and reconstructed. The arrangement allowed positional measurements of patellar motion to be tracked in six degrees of freedom. Medial to lateral patellar translation and patellar tilt were recorded. The kinematics after a technique of MPFL reconstruction, performed with a gracilis tendon in a blind femoral tunnel guided by navigation, were compared against kinematics recorded in the MPFL intact state. A temporary fixation of adequate tension to engage the lateral patellar facet in extension was applied to the MPFL and, after graft cycling, the final fixation was done at 70° knee flexion with an interference screw.

RESULTS

There was a comparable medial to lateral patellar translation and tilting of the patella in the MPFL-intact and the MPFL-reconstructed state. Static patellar translation in the MPFL-reconstructed state, with and without the application of load, was comparable to patellar translation in the MPFL-intact state. The dynamic patellofemoral shift kinematics recorded an under-constraint in early flexion and over-constraint in late flexion, while an opposite effect was recorded in patellar tilt. However, these differences were not statistically significant.

CONCLUSION

The study confirmed the major role of the MPFL in case of medial loading between 0° and 60°, by focusing on the importance of kinematically identifying the proper femoral point for fixation. While the study demonstrates the importance of kinematic determination of the proper femoral point of fixation, as the anatomical insertion remains difficult to identify. Even in dissected cadavers, the authors recorded a slightly anterior placement than native MPFL. After reconstruction, patellar stability in terms of lateral translation and tilt was similar to the intact MPFL, but patellar kinematics were not optimal with the use of a smaller and tubular graft than the native wider and fan-shaped MPFL.

Indications for and results of arthroscopy in the arthritic knee: a European survey

PURPOSE

The place of arthroscopic treatment in osteoarthritis of the knee has generated much controversy. A survey was initiated to collect the opinion of experienced surgeons.

METHODS

Of the 211 surgeons interviewed, 170 (80.6%) replied to the electronic questionnaire. Respondents had at least ten years of experience in arthroscopy and currently perform more than 100 arthroscopies per year. Various indications and treatment modalities for arthroscopy in osteoarthritis of the knee had to be evaluated on a scale from "excellent" to "no indication".

RESULTS

The respondents generally believe that an improvement is more likely in low-grade osteoarthritis (p < 0.001) and in neutral leg axis (p < 0.001). The outcome was rated better if symptoms had persisted for less than six months (p < 0.001) and for patients that were younger than 60 years (p < 0.001). Partial meniscectomy and notchplasty in cases of extension deficit were considered as successful treatment options. Debridement was an accepted indication, with an outcome mainly rated as fair. A majority saw no indication for joint lavage, arthroscopic treatment of arthrofibrosis and removal of osteophytes. The outcome appears to be poor if a bone edema is diagnosed on magnetic resonance imaging prior to arthroscopy. Only 55.9% of respondents were comfortable with the current definition of osteoarthritis.

CONCLUSIONS

Experienced arthroscopic surgeons all over Europe believe arthroscopy in osteoarthritis is appropriate, under certain conditions. The major task for surgeons is to select the right patients who are likely to benefit from this intervention.

Midterm results of comprehensive surgical reconstruction including sulcus-deepening trochleoplasty in recurrent patellar dislocations with high-grade trochlear dysplasia

BACKGROUND

Trochlear dysplasia is one of the most consistent anatomic factors that can lead to recurrent patellar dislocations. Various trochleoplasty procedures have been described to treat patellar dislocations in high-grade dysplasia by creating a new congruent trochlea.

PURPOSE

To present the midterm efficacy and outcome of the sulcus-deepening trochleoplasty procedure in patients with recurrent patellar dislocations due to high-grade trochlear dysplasia. The clinical evaluation results, the amount of radiological correction, and the prevalence of arthritis were recorded.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A total of 27 skeletally mature patients (31 knees) with recurrent patellar dislocations due to high-grade trochlear dysplasia without any previous surgery were retrospectively included from September 1993 to September 2006. All patients underwent sulcus-deepening trochleoplasty combined with a bony and/or soft tissue procedure according to concomitant etiological factors to patellar dislocations: medial patellofemoral ligament reconstruction (16.1%), vastus medialis obliquus plasty (83.8%), tibial tuberosity distalization (51.6%), tibial tuberosity medialization (67.7%), and lateral retinaculum release (67.6%). Mean follow-up was 7 years (range, 2-9 years).

RESULTS

The mean sulcus angle decreased significantly (P < .01) from 152° ± 16° preoperatively to 141° ± 9° postoperatively, tibial tuberosity-trochlear groove distance decreased significantly (P < .001) from 19 ± 4 mm to 12 ± 5 mm, and patellar tilt decreased significantly (P < .001) from 37° ± 7° to 15° ± 8°. No recurrence was observed, and there was no case of stiffness. Apprehension signs remained positive in 19.3% of the cases, patellar tracking was normal in all cases, and the lateral patellar glide test finding was negative in 96.8%. The mean preoperative International Knee Documentation Committee (IKDC) score was 51 (range, 25-80), and the mean postoperative IKDC score was 82 (range, 40-100) (P < .001), while the mean Kujala score improved from a preoperative 59 (range, 28-81) to 87 (range, 49-100) postoperatively (P < .001). There was no radiographic evidence of patellofemoral arthritis at the latest follow-up.

CONCLUSION

Sulcus-deepening trochleoplasty is a valid option for the primary surgical treatment of carefully selected patients with recurrent patellar dislocations with high-grade trochlear dysplasia type B and D. Concomitant etiological factors must be cautiously corrected in an associated procedure. Midterm follow-up showed satisfactory restoration of patellar stability and improvement of knee scores with no complication of subsequent arthritis.

The diagnostic value of clinical tests, magnetic resonance imaging, and instrumented laxity in the differentiation of complete versus partial anterior cruciate ligament tears

PURPOSE

To evaluate the question of whether different arthroscopically confirmed anterior cruciate ligament (ACL) injury patterns have distinctive preoperative findings on clinical examination, instrumented laxity, and magnetic resonance imaging (MRI).

METHODS

Three hundred consecutive ACL-deficient patients with isolated ACL tears were evaluated with the Lachman test (LT), the pivot-shift test (PST), stress radiographs using the Telos Stress Device (Metax, Hungen, Germany), and MRI. After arthroscopic confirmation of the ACL injury, we grouped patients into 4 different ACL tear types (complete, partial anteromedial [AM] bundle intact, posterolateral [PL] bundle intact, and posterior cruciate ligament [PCL] healing), and partial tears were further evaluated for mechanical integrity and functionality of the remaining fibers.

RESULTS

PST grades of +2 and +3 were consistent with complete ACL tears (86%; P < .00001), whereas PST grades of 0 or +1 were strongly related to partial tears (76%; P < .00001). Instrumented laxity results showed a significant difference in side-to-side difference (SSD) of anterior tibial translation in complete tears (9.1 ± 3.4 mm) versus partial tears (5.2 ± 2.9 mm; P < .0001). Most PL-intact cases were "functional" (67%), with lower instrumented laxity values (SSD, 4.3 ± 2.3 mm) than the "nonfunctional" cases (SSD, 6.7 ± 2.9 mm; P < .001). The contrary was not observed for AM-intact cases (17% functional). Partial ACL tears with functional remaining fibers had PST grades of 0 or +1 and less than a 4 mm SSD in stress radiographs (sensitivity, 0.76; specificity, 0.90). Partial ACL tears with nonfunctional fibers had positive PST results and an SSD of anterior tibial displacement from 4 to 9 mm (sensitivity, 0.56; specificity, 0.92). Positive PST results and an SSD greater than 9 mm was recorded in complete ACL tears (sensitivity, 0.88; specificity, 0.96). MRI analysis revealed overlapping results between complete and partial tears.

CONCLUSIONS

Preoperative evaluation of different ACL tear types showed differences between complete and partial ACL tears with functional fibers in clinical examination and instrumented laxity tests. The combination of clinical tests and stress radiographs produced threshold values that distinguished complete from partial ACL tears, which may help the surgeon in the early identification of the presence of remaining functional fibers.

LEVEL OF EVIDENCE

Level III, case-control study.

Comparative study between mono-bundle bone-patellar tendon-bone, double-bundle hamstring and mono-bundle bone-patellar tendon-bone combined with a modified Lemaire extra-articular procedure in anterior cruciate ligament reconstruction

PURPOSE

The aim of the study was to compare three different procedures performed by the same surgeon: mono-bundle patellar tendon reconstruction (bone-patellar tendon-bone, BPTB), double-bundle hamstring reconstruction (DBH) and mono-bundle patellar tendon combined with extra-articular reconstruction (Lemaire) (BPTB + L).

METHODS

A total of 75 patients (25 in each group) were evaluated at a mean follow-up of 25 months. Laxity was assessed pre- and post-operatively with Telos™ stress radiographs (15 kg). The amount of anterior tibial translation (ATT) corrected by the surgery was quantified. Secondary outcomes were International Knee Documentation Committee (IKDC) scores, pivot shift grading, pain complaints, sensory deficits, subsequent surgical procedures, return to sports and patients' ability to kneel or squat on their affected knee.

RESULTS

Absolute correction of ATT for the internal compartment was not statistically significant [analysis of variance (ANOVA), p=0.377]. For the external compartment BPTB + L (8.2 mm) showed superiority over DBH (5.6 mm) and BPTB (4.1 mm) (ANOVA, p=0.0001, Tukey's test). Kneeling was better in the DBH group (ANOVA, p=0.0001, Tukey's test). In 22 patients it felt normal, while only in seven in the BPTB and eight in the BPTB + L groups. Sensory deficits were present in 11 patients from the DBH group, while in 17 in the BPTB and 19 in the BPTB + L groups (ANOVA, p=0.052). Mean IKDC values, presence of anterior knee pain, subsequent operations, ability to squat and return to sports were not statistically different between groups.

CONCLUSIONS

Absolute correction of ATT was not statistically different for the medial compartment, but the patellar tendon reconstruction combined with the extra-articular procedure achieved the best lateral compartment ATT correction. Sensory deficits and kneeling seem to be worse in the groups where the patellar tendon is harvested.

A comparison of Telos™ stress radiography versus Rolimeter™ in the diagnosis of different patterns of anterior cruciate ligament tears

INTRODUCTION

Our knowledge on anterior cruciate ligament (ACL) pathomechanics has increased. The diagnosis of partial ACL tears must be accurate in order to adjust the operative planning to anatomic status and injury severity. Instrumented measurement of knee laxity is a useful preoperative tool to quantify anterior tibial translation and several laximetry tests are available. Yet, their accuracy remains to be established.

HYPOTHESIS

Clinical examination combined to instrumented laximetry with Telos™ 15 kg and/or Rolimeter™ would increase their sensitivity and specificity in the diagnosis of various ACL injury patterns.

MATERIALS AND METHODS

One hundred and seventy-seven patients were prospectively included. The ACL status was validated by arthroscopy. Around 69.5% had a complete ACL tear and 30.5% had a partial ACL tear.

RESULTS

Gross laxity with positive clinical tests was associated with complete ACL tears. Mean side-to-side difference was significantly greater with both laximetry methods in complete versus partial ACL tears. Laximetry results among different types of partial tears were not significantly different. Telos™ results were consistent with gross laxity confirmed by pivot-shift test, while this was not recorded with Rolimeter™. Gross laxity with clinical tests and anterior tibial translation more than 5mm with Telos™ were substantially associated with complete ACL tears.

DISCUSSION

The combination of standard clinical examination with Telos™ was more accurate than with Rolimeter™ in the preoperative identification of the ACL injury pattern. Applying additional diagnostic tools can help the surgeon to preoperatively diagnose partial or complete ACL ruptures and propose an injury-specific surgical treatment.

LEVEL OF EVIDENCE

Level III (case-control study).

Double-bundle bone-patellar tendon-bone and gracilis in ACL reconstruction

An original technique for the reconstruction of the anterior cruciate ligament is explained. Two bundles are reconstructed using the central third of the patellar tendon and the gracilis tendon, passed through four tunnels but requiring only two interference screws for fixation. Level of evidence V.