Patellofemoral osteoarthritis is prevalent and associated with worse symptoms and function after hamstring tendon autograft ACL reconstruction

Initial graft tension affects patellofemoral alignment during anatomical anterior cruciate ligament reconstruction

BACKGROUND

This study aimed to evaluate the effects of the differences in initial graft tension (IGT) on patellofemoral alignment in the axial plane after anatomical anterior cruciate ligament reconstruction (ACLR).

METHODS

A total of 102 patients who underwent primary anatomical ACLR using a bone-patellar-tendon-bone autograft were enrolled. The grafts were fixed with maximum manual force at full knee extension (higher graft tension; H group) and with 5-20 N at 20° knee flexion which corresponded to 80 N at full knee extension (lower graft tension; L group) pulls in 39 and 63 patients, respectively. All patients underwent computed tomography of the bilateral knee joints with knee extension 1 week postoperatively. The patellofemoral alignment (sulcus angle, lateral trochlear inclination angle, lateral patellofemoral angle (LPFA), condylar-patellar angle (CPA) (lateral facet, patellar tilt), congruence angle, and bisect offset index) on the axial computed tomography images were evaluated, and the side-to-side differences (SSDs) between the injured knee and the contralateral knee were calculated.

RESULTS

Congruence angle SSD was remarkably higher in the H group than in the L group (3.8 ± 4.7 vs. 0.4 ± 5.7, P < 0.01). Furthermore, the LPFA SSD and CPA (patellar tilt) SSD were significantly higher in the H group (-1.8 ± 3.1 vs. -0.4 ± 2.7, P = 0.04 and -1.6 ± 2.8 vs. -0.3 ± 2.7, P = 0.04, respectively).

CONCLUSIONS

A higher IGT during anatomical ACLR induces a lateral shift and tilt of the patella against the femur immediately after surgery compared with the lower IGT.

Radiomics analysis of patellofemoral joint improves knee replacement risk prediction: Data from the Multicenter Osteoarthritis Study (MOST)

Objective

Knee replacement (KR) is the last-resort treatment for knee osteoarthritis. Although radiographic evidence of tibiofemoral joint has been widely adopted for prognostication, patellofemoral joint has gained little attention and may hold additional value for further improvements. We aimed to quantitatively analyse patellofemoral joint through radiomics analysis of lateral view radiographs for improved KR risk prediction.

Design

From the Multicenter Osteoarthritis Study dataset, we retrospectively retrieved the initial-visit lateral left knee radiographs of 2943 patients aged 50 to 79. They were split into training and test cohorts at a 2:1 ratio. A comprehensive set of radiomic features were extracted within the best-performing subregion of patellofemoral joint and combined into a radiomics score (RadScore). A KR risk score, derived from Kellgren-Lawrence grade (KLG) of tibiofemoral joint and RadScore of patellofemoral joint, was developed by multivariate Cox regression and assessed using time-dependent area under receiver operating characteristic curve (AUC).

Results

While patellofemoral osteoarthritis (PFOA) was insignificant during multivariate analysis, RadScore was identified as an independent risk factor (multivariate Cox p-value < 0.001) for KR. The subgroup analysis revealed that RadScore was particularly effective in predicting rapid progressor (KR occurrence before 30 months) among early- (KLG < 2) and mid-stage (KLG ​= ​2) patients. Combining two joints radiographic information, the AUC reached 0.89/0.87 for predicting 60-month KR occurrence.

Conclusions

The RadScore of the patellofemoral joint on lateral radiographs emerges as an independent prognostic factor for improving KR prognosis prediction. The KR risk score could be instrumental in managing progressive knee osteoarthritis interventions.

Quantitative MRI Analysis of Patellofemoral Joint Cartilage Health 2 Years After Anterior Cruciate Ligament Reconstruction and Lateral Extra-Articular Tenodesis

BACKGROUND

The addition of an iliotibial band-based lateral extra-articular tenodesis (LET) to anterior cruciate ligament (ACL) reconstruction (ACLR) has been shown to reduce failure rates. However, there are concerns as to the potential overconstraint of tibiofemoral kinematics that may increase the risk of cartilage degradation. To date, no clinical study has investigated the effect of LET on patellofemoral joint articular cartilage health.

HYPOTHESIS

It was hypothesized that at 2 years postoperatively, (1) the addition of LET at the time of ACLR would have no effect on cartilage health on magnetic resonance imaging (MRI), and (2) higher cartilage relaxation values would be associated with worse patient-reported and functional outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A subset of patients from the STABILITY 1 randomized controlled trial were included. All patients underwent primary ACLR with a hamstring autograft. Patients were randomized to either LET augmentation or not. Cartilage status in the patellofemoral joint between the ACLR group and ACLR+LET group was compared using 2-year postoperative quantitative MRI and the ACL osteoarthritis scores of both the surgical and the contralateral nonsurgical knees. Objective functional outcomes and patient-reported outcome measures (PROMs) were attained.

RESULTS

A total of 92 patients (43 patients in the ACLR group; mean age, 18.9 ± 3.2 years; 60.5% female; and 49 patients in the ACLR+LET group; mean age, 18.7 ± 3.2 years, 63.3% female) were included. No significant differences were seen in the mean values (ms) for adjusted T1ρ/T2 relaxation times in the medial patella (47.8/42.2 vs 47.3/43.2), central patella (45.5/42.5 vs 44.1/42.7), lateral patella (48.2/43.5 vs 47.3/43.0), medial trochlea (54.7/50.9 vs 56.4/50.9), central trochlea (53.3/51.1 vs 53.1/52.0), and lateral trochlea (54.9/52.1 vs 53.9/52.6) between the ACLR and ACLR+LET groups. No difference in overall ACL osteoarthritis scores was observed (P = .99). An increase in medial patellar T2 relaxation times was associated with a decreasing International Knee Documentation Committee score (P = .046), Knee injury and Osteoarthritis Outcome Score (KOOS) Symptoms subscale score (P = .01), and total KOOS (P = .01).

CONCLUSION

There was no statistical difference in patellofemoral cartilage health between knees 2 years after primary ACLR with hamstring tendon autograft with or without LET. Statistically significant correlations were found between quantitative MRI relaxation times, functional outcome scores, and PROMs; however, the correlations were weak and the clinical significance is unknown.

REGISTRATION

NCT02018354 (ClinicalTrials.gov identifier).

Recruitment and baseline characteristics of young adults at risk of early-onset knee osteoarthritis after ACL reconstruction in the SUPER-Knee trial

Objectives

The study aims to (1) report the process of recruiting young adults into a secondary knee osteoarthritis prevention randomised controlled trial (RCT) after anterior cruciate ligament reconstruction (ACLR); (2) determine the number of individuals needed to be screened to include one participant (NNS) and (3) report baseline characteristics of randomised participants.

Methods

The SUpervised exercise-therapy and Patient Education Rehabilitation (SUPER)-Knee RCT compares SUPER and minimal intervention for young adults (aged 18-40 years) with ongoing symptoms (ie, mean score of <80/100 from four Knee injury and Osteoarthritis Outcome Score subscales (KOOS4)) 9-36 months post-ACLR. The NNS was calculated as the number of prospective participants screened to enrol one person. At baseline, participants provided medical history, completed questionnaires (demographic, injury/surgery, rehabilitation characteristics) and underwent physical examination.

Results

1044 individuals were screened to identify 567 eligible people, from which 184 participants (63% male) enrolled. The sample of enrolled participants was multicultural (29% born outside Australia; 2% Indigenous Australians). The NNS was 5.7. For randomised participants, mean±SD age was 30±6 years. The mean body mass index was 27.3±5.2 kg/m2, with overweight (43%) and obesity (21%) common. Participants were, on average, 2.3 years post-ACLR. Over half completed <8 months of postoperative rehabilitation, with 56% having concurrent injury/surgery to meniscus and/or cartilage. The most affected KOOS (0=worst, 100=best) subscale was quality of life (mean 43.7±19.1).

Conclusion

Young adults post-ACLR were willing to participate in a secondary osteoarthritis prevention trial. Sample size calculations should be multiplied by at least 5.7 to provide an estimate of the NNS. The SUPER-Knee cohort is ideally positioned to monitor and intervene in the early development and trajectory of osteoarthritis.

Trial registration number

ACTRN12620001164987.

Clinical and Radiological Outcomes After Combined ACL and MPFL Reconstruction Versus Isolated ACL Reconstruction for ACL Injury With Patellar Instability

BACKGROUND

An anterior cruciate ligament (ACL) injury accompanied by patellar instability (PI) is a topic that has gained orthopaedic surgeons' attention recently. Untreated PI is reportedly associated with worse clinical outcomes after isolated ACL reconstruction (ACLR) in patients after an ACL injury with PI. Nevertheless, the appropriate surgical approach and its long-term therapeutic effects in these patients remain unclear.

PURPOSE

(1) To compare the clinical and radiological outcomes between isolated ACLR (iACLR) and combined ACLR and medial patellofemoral ligament reconstruction (cAMR) in patients after an ACL injury with PI and (2) to explore the correlations between these 2 procedures and clinical and radiological outcomes.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

A total of 106 patients diagnosed with an ACL injury accompanied by PI between January 2016 and April 2021 were analyzed in this study. There were 34 patients excluded because of missing postoperative radiological data. Among the remaining 72 patients, 34 patients underwent iACLR, while 38 patients underwent cAMR. Demographic characteristics, intraoperative findings, and patient-reported outcomes (Lysholm score, subjective International Knee Documentation Committee score, and Tegner activity score) were prospectively collected. Patellar alignment parameters and worsening patellofemoral osteoarthritis (PFOA) features (evaluated with the modified Whole-Organ Magnetic Resonance Imaging Score) were analyzed longitudinally on magnetic resonance imaging. The Kujala score was used to evaluate the functional recovery of the patellofemoral joint, and redislocations of the patella were prospectively recorded. Finally, multivariate logistic regression analysis was used to explore the correlations between these 2 procedures and clinical (not achieving the minimal detectable change [MDC] for the Lysholm score) and radiological (worsening PFOA features) outcomes.

RESULTS

The mean follow-up duration was 28.9 ± 6.2 and 27.1 ± 6.8 months for the iACLR and cAMR groups, respectively (P = .231). Significantly higher Lysholm scores (88.3 ± 9.9 vs 82.1 ± 11.1, respectively; P = .016) and subjective International Knee Documentation Committee scores (83.6 ± 11.9 vs 78.3 ± 10.2, respectively; P = .046) were detected in the cAMR group compared with the iACLR group postoperatively. The rates of return to preinjury sports were 20.6% and 44.7% in the iACLR and cAMR groups, respectively (difference, 24.1% [95% CI, 3.3%-45.0%]; P = .030). Moreover, the rates of worsening PFOA features were 44.1% and 18.4% in the iACLR and cAMR groups, respectively (difference, 25.7% [95% CI, 4.9%-46.4%]; P = .018). In addition, significantly higher Kujala scores (87.9 ± 11.3 vs 80.1 ± 12.0, respectively; P = .006), lower redislocation rates (0.0% vs 11.8%, respectively; difference, 11.8% [95% CI, 0.9%-22.6%]; P = .045), and significantly better patellar alignment were detected in the cAMR group compared with the iACLR group postoperatively. Furthermore, multivariate logistic regression analysis determined that iACLR and partial lateral meniscectomy were significantly correlated with not achieving the MDC for the Lysholm score and worsening PFOA features in our study population.

CONCLUSION

In patients after an ACL injury with PI, cAMR yielded better clinical and radiological outcomes compared with iACLR, with better patellar stability and a lower proportion of worsening PFOA features. Furthermore, not achieving the MDC for the Lysholm score and worsening PFOA features were significantly correlated with iACLR and partial lateral meniscectomy. Our study suggests that cAMR may be a more appropriate procedure for patients after an ACL injury with PI, which warrants further high-level clinical evidence.

Postoperative quadriceps weakness and male sex are risk factors for patellofemoral articular cartilage lesions after anatomical anterior cruciate ligament reconstruction

PURPOSE

Patellofemoral (PF) compartment cartilage lesions are a frequent problem after anterior cruciate ligament (ACL) reconstruction. This study aimed to determine the factors that influence PF cartilage lesions after anatomical ACL reconstruction.

METHODS

This study enrolled a total of 114 patients who did not manifest PF compartment cartilage lesions during anatomical ACL reconstruction and underwent second-look arthroscopy 18 months postoperatively. Arthroscopy using the International Cartilage Repair Society (ICRS) classification was used to assess cartilage lesions. The correlation between surgical findings, radiographic factors, and clinical factors and change of ICRS grade was analysed. Multivariate regression analysis was conducted to reveal the independent risk factors for PF cartilage lesions among patients' demographic data and parameters that correlated with the change of ICRS grade in the correlation analyses.

RESULTS

ICRS grade changes in PF cartilage were significantly correlated with age, sex, quadriceps strength at 1 year postoperatively, hamstrings strength at pre- and 1 year postoperatively, and single leg hop test at 1 year postoperatively. However, no significant correlation was found between the time between injury and surgery, posterior tibial slope angle, pre- and postoperative Tegner activity scale, graft type, initial graft tension, meniscus injury, meniscus injury treatment, pre- and postoperative range of motion, anteroposterior laxity and preoperative quadriceps strength, and the change in ICRS grade. Multivariate regression analysis revealed male (P = 0.019) and quadriceps strength weakness at 1 year postoperatively (P = 0.009) as independent risk factors for PF cartilage lesions.

CONCLUSIONS

Quadriceps strength weakness 1 year after ACL reconstruction and males were correlated with a new PF cartilage lesion after anatomical ACL reconstruction, with no significant correlation between bone-patellar tendon-bone autograft, initial graft tension, or extension deficit and new PF cartilage lesion. Rehabilitation that focuses on quadriceps strength after ACL reconstruction is recommended to prevent new PF cartilage lesions.

LEVEL OF EVIDENCE

Level IV.

Early patello-femoral condropathy assessment through quantitative analyses via T2 mapping magnetic resonance after anterior cruciate ligament reconstruction

BACKGROUND

Patellar femoral chondropathy (FPC) is a common problem in patients undergoing anterior cruciate ligament reconstruction (ACL-R) surgery, which, if left untreated, predisposes to arthrosis. Magnetic resonance imaging (MRI) is the non-invasive gold standard for morphological evaluation of cartilage, while in recent years advanced MRI techniques (such as T2 mapping) have been developed to detect early cartilage biochemical changes. This study evaluates the different onset of early PFC between B-TP-B and HT through T2 mapping. Secondly, it aims to assess the presence of any concordance between self-reported questionnaires and qualitative MRI.

MATERIALS AND METHODS

19 patients enrolled were divided into two groups based on the type of intervention: B-PT-B and HT. After a median time of 54 months from surgery, patients were subjected to conventional MRI, T2 mapping, and clinical-functional evaluation through three self-reported questionnaires: Knee Injury and Osteoarthritis index (KOOS); Tegner Lysholm Knee Scoring Scale; International Knee Documentation Committee (IKDC).

RESULTS

There is not statistically significant difference in the comparison between the two MRI techniques and the two reconstructive techniques. KOOS and Tegner Lysholm scales showed significant agreement with MRI results on the grading of chondropathy.

CONCLUSIONS

There are no differences between B-TP-B and HT techniques in the early development of PFC detectable through non-invasive methods. Due to the large reduction in the frequency of physical activity following ACL-R and the finding of mild PFC (grade I and II) in a substantial proportion of patients, after a relatively short period from ACL-R, all patients should undergo conservative treatment.

Muscle strength and osteoarthritis of the knee: a systematic review and meta-analysis of longitudinal studies

OBJECTIVE

To evaluate the sex-specific association between low knee extensor and flexor muscle strength and the risk of knee structural worsening.

MATERIALS AND METHODS

Systematic searches in five databases identified longitudinal studies (≥ 1 year follow-up) reporting an association between knee extensor or flexor strength and structural decline in individuals with, or at risk of, knee osteoarthritis. Results were pooled for tibiofemoral and patellofemoral osteoarthritis worsening (and stratified by sex/gender where possible) using a random-effects meta-analysis estimating the risk ratio and 95% confidence interval or a best-evidence synthesis. Risk of bias and overall certainty of evidence were assessed.

RESULTS

Fourteen studies were included with participants (mean age 27-72 years) with osteoarthritis (n = 8), at risk of osteoarthritis (n = 3), or a combination with, or at risk of, osteoarthritis (n = 3). Low knee extensor strength was associated with an increased risk of worsening tibiofemoral (12 studies: RR 1.18, 95% CI 1.04 to 1.35) and patellofemoral osteoarthritis (4 studies: RR 1.62, 95% CI 1.01 to 2.61). Significant associations between low knee extensor strength and worsening tibiofemoral osteoarthritis were observed for women (4 studies: RR 1.25, 95% CI 1.04 to 1.51) but not men (4 studies: RR 1.10, 95% CI 0.87 to 1.39). Low knee flexor strength increased the risk of worsening tibiofemoral osteoarthritis (5 studies: RR 1.16, 95% CI 1.07 to 1.26). Ten studies were high risk of bias, and all estimates were graded as very low certainty of evidence.

CONCLUSION

Low knee extensor and flexor strength increased the risk of worsening tibiofemoral osteoarthritis. Low knee extensor strength increased the risk of worsening patellofemoral osteoarthritis. The relationship between low knee extensor strength and worsening tibiofemoral osteoarthritis may be modified by sex/gender.

Is quadriceps strength associated with patellofemoral joint loading after anterior cruciate ligament reconstruction?

OBJECTIVE

To test whether quadriceps strength is associated with measures of patellofemoral (PF) joint loading during running and hopping in people after an anterior cruciate ligament reconstruction (ACLR).

DESIGN

Cross-sectional study.

SETTING

Biomechanics laboratory.

PARTICIPANTS

Sixty-five participants (24 women; 41 men) 1-2 years post-ACLR.

MAIN OUTCOME MEASURES

Peak isometric quadriceps strength for the surgical limb was measured using a dynamometer. Motion analysis and ground reaction force data were combined with musculoskeletal modelling to measure PF joint loading variables for the reconstructed knee (peak knee flexion angle; peak/impulse of the PF joint contact force; time to peak PF joint contact force) during the stance phase of running and during the landing phase of a standardised forward hop. Linear regression analysis (adjusting for age and sex) assessed the association between quadriceps strength and PF joint loading variables.

RESULTS

Two significant, albeit modest, associations were revealed. Quadriceps strength was associated with the time to peak PF joint contact force during running (β = -0.001; 95%CI -0.002 to -0.000; R2 = 0.179) and the impulse of the PF joint contact force during hopping (β = 0.014; 95%CI 0.003 to 0.024; R2 = 0.159).

CONCLUSIONS

A strong link between quadriceps strength and PF joint loading was not evident in people 1-2 years post-ACLR.

Hip rotation muscle strength is implicated in the progression of early post-traumatic osteoarthritis: A longitudinal evaluation up to 5 years following ACL reconstruction

INTRODUCTION

Following ACL reconstruction (ACLR), deficits in hip muscle strength and relationships to future outcomes are unknown.

METHODS

111 participants one year after ACLR, completed hip external rotation (ER) and internal rotation (IR) strength assessment. At 1 (n = 111) and 5 (n = 74) years post-ACLR, participants completed a battery of functional, symptomatic (Knee Osteoarthritis Outcome Score (KOOS)) and structural assessments (radiography, magnetic resonance imaging (MRI)). Cartilage health of the patellofemoral and tibiofemoral compartments was assessed with the semiquantitative MRI Osteoarthritis Knee Score. Hip rotation strength was compared between-limbs, and relationships between hip strength at 1 year and functional, symptomatic and cartilage outcomes at 1 and 5 years were investigated with regression models.

RESULTS

The index (ACLR) limb had weaker hip ER (but not IR) strength compared to the contralateral side (standardised mean difference ER = -0.33 (95%CI -0.60, -0.07; IR = -0.11 (95%CI -0.37, 0.15). Greater hip ER and IR strength was associated with superior function at 1 and 5 years, and better KOOS-Patellofemoral symptoms at 5 years. Greater hip ER strength was associated with lower odds of worsening tibiofemoral cartilage lesions at 5 years (odds ratio 0.01, 95%CI 0.00, 0.41).

CONCLUSION

Hip rotation strength may play a role in worsening function, symptoms and cartilage health after ACLR.

Patellofemoral joint loading and early osteoarthritis after ACL reconstruction

Patellofemoral joint (PFJ) osteoarthritis is common following anterior cruciate ligament reconstruction (ACLR) and may be linked with altered joint loading. However, little is known about the cross-sectional and longitudinal relationship between PFJ loading and osteoarthritis post-ACLR. This study tested if altered PFJ loading is associated with prevalent and worsening early PFJ osteoarthritis post-ACLR. Forty-six participants (mean ± 1 SD age 26 ± 5 years) approximately 1-year post-ACLR underwent magnetic resonance imaging (MRI) and biomechanical assessment of their reconstructed knee. Trunk and lower-limb kinematics plus ground reaction forces were recorded during the landing phase of a standardized forward hop. These data were input into a musculoskeletal model to calculate the PFJ contact force. Follow-up MRI was completed on 32 participants at 5-years post-ACLR. Generalized linear models (Poisson regression) assessed the relationship between PFJ loading and prevalent early PFJ osteoarthritis (i.e., presence of a PFJ cartilage lesion at 1-year post-ACLR) and worsening PFJ osteoarthritis (i.e., incident/progressive PFJ cartilage lesion between 1- and 5-years post-ACLR). A lower peak PFJ contact force was associated with prevalent early PFJ osteoarthritis at 1-year post-ACLR (n = 14 [30.4%]; prevalence ratio: 1.37; 95% confidence interval [CI]: 1.02-1.85) and a higher risk of worsening PFJ osteoarthritis between 1- and 5-years post-ACLR (n = 9 [28.1%]; risk ratio: 1.55, 95% CI: 1.13-2.11). Young adults post-ACLR who exhibited lower PFJ loading during hopping were more likely to have early PFJ osteoarthritis at 1-year and worsening PFJ osteoarthritis between 1- and 5-years. Clinical interventions aimed at mitigating osteoarthritis progression may be beneficial for those with signs of lower PFJ loading post-ACLR.

Baseline cartilage T1ρ and T2 predicted patellofemoral joint cartilage lesion progression and patient-reported outcomes after ACL reconstruction

This study aims to determine if baseline T1ρ and T2 will predict cartilage morphological lesion progression in the patellofemoral joint (PFJ) and patient-reported outcomes at 2-year after anterior cruciate ligament (ACL) reconstruction (ACLR). Thirty-nine ACL-injured patients were studied at baseline and two-year after ACLR. 3 T MR T1ρ and T2 images and Knee Injury and Osteoarthritis Outcome Score (KOOS) were acquired at both time points. Voxel-based relaxometry (VBR) technique was used to detect local cartilage abnormalities. Patients were divided into progression and non-progression groups based on changes of the whole-organ magnetic resonance imaging scoring (WORMS) grading of cartilage in PFJ from baseline to 2-year, and into lower (more pain) and higher (less pain) KOOS pain groups based on 2-year KOOS pain scores, separately. Voxel-based analyses of covariance were used to compare T1ρ and T2 values at baseline between the defined groups. Using VBR analysis, the progression group at 2-year showed higher T1ρ and T2 compared with the non-progression group at baseline, with the medial femoral condyle showing the largest areas with significant differences. At two-year, 56% of patients were able to recover with respect to KOOS pain. The lower KOOS pain group at 2-year showed significantly elevated T1ρ and T2 in the patella at baseline compared with the higher KOOS pain group. In conclusion, baseline T1ρ and T2 mapping, combined with VBR analysis, may help identify ACLR patients at high risk of developing progressive PFJ cartilage lesions and worse clinical symptoms 2-year after surgery.

Radiographic Incidence of Knee Osteoarthritis After Isolated ACL Reconstruction Versus Combined ACL and ALL Reconstruction: A Prospective Matched Study From the SANTI Study Group

BACKGROUND

Combined anterior cruciate ligament (ACL) reconstruction (ACLR) and anterolateral ligament reconstruction (ALLR) have demonstrated reduced risk of graft rerupture as compared with isolated ACLR. However, concerns remain that the risk of osteoarthritis (OA) may be increased by the addition of ALLR.

PURPOSE/HYPOTHESIS

The aim of this study was to evaluate the incidence of OA with isolated ACLR in comparison with ACLR + ALLR at medium-term follow-up. We hypothesized that there would be no differences between the groups.

STUDY DESIGN

Cohort study; Level of evidence, 3.

METHODS

Patients who underwent ACLR + ALLR with hamstring tendon autograft between January 2011 and March 2012 were propensity matched to patients who underwent isolated ACLR with bone-patellar tendon-bone (BPTB) or hamstring tendon autograft in the same period. Medium-term radiographic evaluation was performed using the International Knee Documentation Committee (IKDC) radiographic OA grading scale, modified Kellgren-Lawrence grade, and the surface fit method to assess percentage of joint space narrowing. Clinical outcomes were assessed with the following measures: IKDC, Knee injury and Osteoarthritis Outcome Score (KOOS), Lysholm, Tegner, and ACL Return to Sport after Injury.

RESULTS

A total of 80 patients (42 ACLR + ALLR and 38 isolated ACLR) were analyzed with a mean follow-up of 104 months. There was no significant difference between groups for joint space narrowing in the medial or lateral tibiofemoral or lateral patellofemoral (PF) compartment. However, 36.8% in the isolated ACLR group versus 11.9% in the ACLR + ALLR group had narrowing of the medial PF compartment (P = .0118). A lateral meniscal tear increased the risk of lateral tibiofemoral narrowing by nearly 5 times (odds ratio, 4.9; 95% CI, 1.547-19.367; P = .0123). The risk of medial PF narrowing was >4-fold with an isolated ACLR (odds ratio, 4.8; 95% CI, 1.44-19.05; P = .0179). Between the isolated ACLR group and the ACLR + ALLR group, the secondary meniscectomy rate was 13.2% versus 11.9% (not significantly different). There was no difference between groups in KOOS, Tegner, or IKDC scores. There was also no difference between groups for grades of osteoarthritic change for any classification system. Patients who received a BPTB graft had medial PF joint narrowing in 66.7% of cases as compared with 11.9% in those who received ACLR + ALLR (P = 0.118).

CONCLUSION

ACLR + ALLR did not increase the risk of OA in the lateral tibiofemoral compartment when compared with an isolated ACLR at medium-term follow-up. Isolated ACLR using BPTB was associated with a significantly increased risk of medial PF joint space narrowing.

REGISTRATION

NCT05123456 (ClinicalTrials.gov identifier).

Changes in patellar height after anatomical ACL reconstruction with BTB autograft with a focus on patellar tendon removal volume

BACKGROUND

Although anatomical anterior cruciate ligament reconstruction (ACLR) can provide satisfactory outcomes, little is known about how this procedure impacts patellar height. Since harvesting bone-patellar tendon-bone (BTB) autografts is a potential risk factor for decreased patellar height, we examined changes in patellar height after anatomical ACLR with BTB autograft with a focus on the size of the harvested graft.

METHODS

Subjects were 84 patients (49 males, 35 females; mean age, 23 years) who underwent primary anatomical ACLR with central third BTB autograft. Preoperative to postoperative Caton-Deschamps index (CDI) ratio was calculated using lateral knee radiographs before and 6 months after surgery. The length and cross-sectional area (CSA) of the graft were measured intraoperatively, and the CSA of the contralateral patellar tendon was measured by ultrasound 6 months postoperatively. The difference in graft CSA relative to the contralateral tendon CSA, expressed as a percentage (gCSA:ctCSA percentage), was also calculated.

RESULTS

Patellar height decreased slightly after surgery (preoperative CDI: 0.856 ± 0.113; postoperative CDI: 0.841 ± 0.113), with a mean difference between preoperative and postoperative CDIs of -0.015 (range: -0.293 to 0.101). Although the CDI of male subjects significantly decreased after surgery (preoperative: 0.852 ± 0.117; postoperative: 0.827 ± 0.115), no significant changes were noted in female subjects (preoperative: 0.862 ± 0.108; postoperative: 0.861 ± 0.108). Graft length and CSA did not significantly impact the CDI ratio (r = -0.138 and r = -0.038, respectively). Moreover, no significant relationship was observed between the gCSA:ctCSA percentage and CDI ratio (r = 0.118).

CONCLUSIONS

Although patellar height slightly, but significantly, decreased at 6 months after anatomical ACLR with BTB autograft, it was not affected by the length and CSA of harvested grafts. The decrease in postoperative patellar height was observed only in male subjects, suggesting the potential importance of sex differences in soft tissue healing during the postoperative period.

Early patellofemoral cartilage and bone pathology in a rat model of noninvasive anterior cruciate ligament rupture

OBJECTIVE

Anterior cruciate ligament rupture (ACLR) is a risk factor for the development of post-traumatic osteoarthritis (PTOA). While PTOA in the tibiofemoral joint compartment is well-characterized, very little is known about pathology in the patellofemoral compartment after ACL injury. Here, we evaluated the extent to which ACLR induces early patellofemoral joint damage in a rat model.

METHODS

Adult female Lewis rats were randomized to noninvasive ACLR or Sham. Two weeks post-injury, contrast-enhanced micro-computed tomography (µCT) of femoral and patellar cartilage was performed using 20% v/v ioxaglate. Morphometric parameters of femoral trochlear and patellar cartilage, subchondral bone, and trabecular bone were derived from µCT. Sagittal Safranin-O/Fast-Green-stained histologic sections were graded using the OARSI score in a blinded fashion.

RESULTS

Cartilage and bone remodelling consistent with an early PTOA phenotype were observed in both femoral trochleas and patellae. ACLR caused osteophyte formation of the patella and pathology in the superficial zone of articular cartilage, including surface fibrillation, fissures, increased cellularity, and abnormal chondrocyte clustering. There were significant increases in thickness of patellar and trochlear cartilage. Loss of subchondral bone thickness, bone volume fraction, and tissue mineral density, as well as changes to patellar and trochlear trabecular microarchitecture, were indicative of catabolic bone remodelling. Several injury-induced changes, including increased cartilage thickness and trabecular spacing and decreased trabecular number were more severe in the patella compared to the trochlea.

CONCLUSION

The patellofemoral joint develops mild but evident pathology in the early period following ACL rupture, extending the utility of this model to the study of patellofemoral PTOA.

SUpervised exercise-therapy and Patient Education Rehabilitation (SUPER) versus minimal intervention for young adults at risk of knee osteoarthritis after ACL reconstruction: SUPER-Knee randomised controlled trial protocol

INTRODUCTION

Anterior cruciate ligament injury and reconstruction (ACLR) is often associated with pain, functional loss, poor quality of life and accelerated knee osteoarthritis development. The effectiveness of interventions to enhance outcomes for those at high risk of early-onset osteoarthritis is unknown. This study will investigate if SUpervised exercise-therapy and Patient Education Rehabilitation (SUPER) is superior to a minimal intervention control for improving pain, function and quality of life in young adults with ongoing symptoms following ACLR.

METHODS AND ANALYSIS

The SUPER-Knee Study is a parallel-group, assessor-blinded, randomised controlled trial. Following baseline assessment, 184 participants aged 18-40 years and 9-36 months post-ACLR with ongoing symptoms will be randomly allocated to one of two treatment groups (1:1 ratio). Ongoing symptoms will be defined as a mean score of <80/100 from four Knee injury and Osteoarthritis Outcome Score (KOOS4) subscales covering pain, symptoms, function in sports and recreational activities and knee-related quality of life. Participants randomised to SUPER will receive a 4-month individualised, physiotherapist-supervised strengthening and neuromuscular programme with education. Participants randomised to minimal intervention (ie, control group) will receive a printed best-practice guide for completing neuromuscular and strengthening exercises following ACLR. The primary outcome will be change in the KOOS4 from baseline to 4 months with a secondary endpoint at 12 months. Secondary outcomes include change in individual KOOS subscale scores, patient-perceived improvement, health-related quality of life, kinesiophobia, physical activity, thigh muscle strength, knee function and knee cartilage morphology (ie, lesions, thickness) and composition (T2 mapping) on MRI. Blinded intention-to-treat analyses will be performed. Findings will also inform cost-effectiveness analyses.

ETHICS AND DISSEMINATION

This study is approved by the La Trobe University and Alfred Hospital Ethics Committees. Results will be presented in peer-reviewed journals and at international conferences.

TRIAL REGISTRATION NUMBER

ACTRN12620001164987.

Patellofemoral functional outcome of gracilis sparing compared to gracilis sacrificing ACL reconstruction

Introduction

The hamstring is the most popular autograft used for anterior cruciate ligament reconstruction (ACLR). Despite its excellent outcome, donor site morbidity is also irritating. Patellofemoral problems are reported to be one of the side effects after hamstring autograft harvesting, suggested to be due to both gracilis & semitendinosus sacrificing. Some experts propose retaining gracilis to decrease patellofemoral problems. The all-inside technique is an advantageous ACLR technique that can preserve the gracilis muscle while reducing muscle strength loss of affected limbs and the risk of knee joint instability under rotational load. This study aims to compare the patellofemoral functional outcome of both gracilis sparing and sacrificing using a validated Kujala score three months after ACLR.

Methods

There was total of 20 subjects who underwent ACLR between December 2021 and May 2022 and met the inclusion criteria. They were then grouped into gracilis sparing group (n = 10) and gracilis sacrificing group (n = 10). Follow up assessment (Kujala Score) was conducted during phase II of the rehabilitation program. The assessed variables were surgery technique, time of surgery-to-evaluation, and Kujala Score.

Result

There were no significant differences in Kujala Score between gracilis sparing and gracilis sacrificing groups (p = 0.809). There was a strong positive correlation between the time of surgery-to-evaluation and Kujala Score in each group (p = 0.942 and p = 0.910, respectively).

Conclusion

There are no differences in patellofemoral functional outcomes between patients who undergo gracilis sparing and gracilis sacrificing ACLR with good scores of Kujala, which means both gracilis sparing and sacrificing show no harm to the patellofemoral after the ACLR.

Kinesiophobia, Knee Self-Efficacy, and Fear Avoidance Beliefs in People with ACL Injury: A Systematic Review and Meta-Analysis

BACKGROUND

To improve the understanding of the psychological impacts of anterior cruciate ligament (ACL) injury, a systematic review synthesizing the evidence on knee self-efficacy, fear avoidance beliefs and kinesiophobia following ACL injury is needed.

OBJECTIVE

The aim of this systematic review was to investigate knee self-efficacy, fear avoidance beliefs and kinesiophobia following ACL injury, and compare these outcomes following management with rehabilitation alone, early and delayed ACL reconstruction (ACLR).

METHODS

Seven databases were searched from inception to April 14, 2022. Articles were included if they assessed Tampa Scale of Kinesiophobia (TSK), Knee Self-Efficacy Scale (KSES), or Fear Avoidance Beliefs Questionnaire (FABQ). Risk of bias (RoB) was assessed using domain-based RoB tools (ROBINS-1, RoB 2, RoBANS), and GRADE-assessed certainty of evidence. Random-effects meta-analyses pooled outcomes, stratified by time post-injury (pre-operative, 3-6 months, 7-12 months, > 1-2 years, > 2-5 years, > 5 years).

RESULTS

Seventy-three studies (70% high RoB) were included (study outcomes: TSK: 55; KSES: 22; FABQ: 5). Meta-analysis demonstrated worse kinesiophobia and self-efficacy pre-operatively (pooled mean [95% CI], TSK-11: 23.8 [22.2-25.3]; KSES: 5.0 [4.4-5.5]) compared with 3-6 months following ACLR (TSK-11: 19.6 [18.7-20.6]; KSES: 19.6 [18.6-20.6]). Meta-analysis suggests similar kinesiophobia > 3-6 months following early ACLR (19.8 [4.9]) versus delayed ACLR (17.2 [5.0]). Only one study assessed outcomes comparing ACLR with rehabilitation only.

CONCLUSIONS

Knee self-efficacy and kinesiophobia improved from pre-ACLR to 3-6 months following ACLR, with similar outcomes after 6 months. Since the overall evidence was weak, there is a need for high-quality observational and intervention studies focusing on psychological outcomes following ACL injury.

Rehabilitation after anterior cruciate ligament and meniscal injuries: a best-evidence synthesis of systematic reviews for the OPTIKNEE consensus

OBJECTIVE

Synthesise evidence for effectiveness of rehabilitation interventions following ACL and/or meniscal tear on symptomatic, functional, clinical, psychosocial, quality of life and reinjury outcomes.

DESIGN

Overview of systematic reviews with Grading of Recommendations Assessment, Development and Evaluation certainty of evidence.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, SPORTDiscus and Cochrane Library.

ELIGIBILITY CRITERIA

Systematic reviews of randomised controlled trials investigating rehabilitation interventions following ACL and/or meniscal tears in young adults.

RESULTS

We included 22 systematic reviews (142 trials of mostly men) evaluating ACL-injured individuals and none evaluating isolated meniscal injuries. We synthesised data from 16 reviews evaluating 12 different interventions. Moderate-certainty evidence was observed for: (1) neuromuscular electrical stimulation to improve quadriceps strength; (2) open versus closed kinetic chain exercises to be similarly effective for quadriceps strength and self-reported function; (3) structured home-based versus structured in-person rehabilitation to be similarly effective for quadriceps and hamstring strength and self-reported function; and (4) postoperative knee bracing being ineffective for physical function and laxity. There was low-certainty evidence that: (1) preoperative exercise therapy improves self-reported and physical function postoperatively; (2) cryotherapy reduces pain and analgesic use; (3) psychological interventions improve anxiety/fear; and (4) whole body vibration improves quadriceps strength. There was very low-certainty evidence that: (1) protein-based supplements improve quadriceps size; (2) blood flow restriction training improves quadriceps size; (3) neuromuscular control exercises improve quadriceps and hamstring strength and self-reported function; and (4) continuous passive motion has no effect on range of motion.

CONCLUSION

The general level of evidence for rehabilitation after ACL or meniscal tear was low. Moderate-certainty evidence indicates that several rehabilitation types can improve quadriceps strength, while brace use has no effect on knee function/laxity.

Infrapatellar fat pad volume and Hoffa-synovitis after ACL reconstruction: Association with early osteoarthritis features and pain over 5 years

Infrapatellar fat pad (IPFP) morphology and Hoffa-synovitis may be relevant to the development and progression of post-traumatic osteoarthritis (OA). We aimed to compare IPFP volume and Hoffa-synovitis in participants with anterior cruciate ligament reconstruction (ACLR) and uninjured controls, and to determine their association with prevalent and worsening early knee OA features and pain in participants post-ACLR. We assessed IPFP volume and Hoffa-synovitis from magnetic resonance imaging (MRI) in 111 participants 1-year post-ACLR and 20 uninjured controls. Patellofemoral and tibiofemoral cartilage and bone marrow lesions (BMLs) were assessed from MRIs at 1 and 5 years post-ACLR, and worsening defined as any longitudinal increase in lesion size/severity. IPFP volume and Hoffa-synovitis prevalence were compared between groups with analysis of covariance and χ ² tests, respectively. Generalized linear models assessed the relation of IPFP volume and Hoffa-synovitis to prevalent and worsening features of OA and knee pain (Knee injury and Osteoarthritis Outcome Score-Pain Subscale, Anterior Knee Pain Scale). No significant between-group differences were observed in IPFP volume (ACLR 34.39 ± 7.29cm³ , Control 34.27 ± 7.56cm³ ) and Hoffa-synovitis (ACLR 61%, Control 80%). Greater IPFP volume at 1-year post-ACLR was associated with greater odds of patellofemoral BMLs at 1-year (odds ratio [OR] [95% confidence intervals]: 1.104 [1.016, 1.200]) and worsening tibiofemoral cartilage lesions at 5-year post-ACLR (OR: 1.234 [1.026, 1.483]). Hoffa-synovitis at 1-year post-ACLR was associated with greater odds of worsening patellofemoral BMLs at 5-year post-ACLR (OR: 7.465 [1.291, 43.169]). In conclusion, IPFP volume and Hoffa-synovitis prevalence are similar between individuals 1-year post-ACLR and controls. Greater IPFP volume and Hoffa-synovitis appear to be associated with the presence and worsening of some early OA features in those post-ACLR, but not pain.

Patellofemoral and tibiofemoral joint loading during a single-leg forward hop following ACL reconstruction

Altered biomechanics are frequently observed following anterior cruciate ligament reconstruction (ACLR). Yet, little is known about knee-joint loading, particularly in the patellofemoral-joint, despite patellofemoral-joint osteoarthritis commonly occurring post-ACLR. This study compared knee-joint reaction forces and impulses during the landing phase of a single-leg forward hop in the reconstructed knee of people 12-24 months post-ACLR and uninjured controls. Experimental marker data and ground forces for 66 participants with ACLR (28 ± 6 years, 78 ± 15 kg) and 33 uninjured controls (26 ± 5 years, 70 ± 12 kg) were input into scaled-generic musculoskeletal models to calculate joint angles, joint moments, muscle forces, and the knee-joint reaction forces and impulses. The ACLR group exhibited a lower peak knee flexion angle (mean difference: -6°; 95% confidence interval: [-10°, -2°]), internal knee extension moment (-3.63 [-5.29, -1.97] percentage of body weight × participant height (body weight [BW] × HT), external knee adduction moment (-1.36 [-2.16, -0.56]% BW × HT) and quadriceps force (-2.02 [-2.95, -1.09] BW). The ACLR group also exhibited a lower peak patellofemoral-joint compressive force (-2.24 [-3.31, -1.18] BW), net tibiofemoral-joint compressive force (-0.74 [-1.20, 0.28] BW), and medial compartment force (-0.76 [-1.08, -0.44] BW). Finally, only the impulse of the patellofemoral-joint compressive force was lower in the ACLR group (-0.13 [-0.23, -0.03] body weight-seconds). Lower compressive forces are evident in the patellofemoral- and tibiofemoral-joints of ACLR knees compared to uninjured controls during a single-leg forward hop-landing task. Our findings may have implications for understanding the contributing factors for incidence and progression of knee osteoarthritis after ACLR surgery.

Should return to pivoting sport be avoided for the secondary prevention of osteoarthritis after anterior cruciate ligament reconstruction? A prospective cohort study with MRI, radiographic and symptomatic outcomes

OBJECTIVE

To evaluate if returning to pivoting sport following anterior cruciate ligament reconstruction (ACLR) is associated with longitudinal structural and symptomatic osteoarthritis outcomes.

DESIGN

Eighty-one adults aged 18-50 years were followed prospectively 1- to 5-years post-ACLR. Return to pivoting sport was assessed at 1-, 3- and 5-years. Longitudinal changes in osteoarthritis features were evaluated from 1- and 5-year magnetic resonance imaging (MRI)s using MRI Osteoarthritis Knee Score (MOAKS). Radiographic osteoarthritis and self-reported knee symptoms, function and quality of life were assessed using the Osteoarthritis Research Society International (OARSI) atlas and Knee injury Osteoarthritis Outcome Score (KOOS), respectively, at 5 years post-ACLR. Generalised linear models (adjusted for baseline characteristics) assessed whether returning to pivoting sport was associated with risk of worsening osteoarthritis features on MRI, radiographic osteoarthritis and KOOS.

RESULTS

Thirty participants returned to pivoting sport 1-year post-ACLR and 50 returned at any time (i.e., 1-, 3- or 5-years). Returning to pivoting sport was not associated with worsening of any MRI osteoarthritis feature (risk ratio (RR) range: 0.59-2.91) or 5-year KOOS (β range: -2.73-3.69). Returning to pivoting sport at 1-year and up to 5-years post-ACLR was associated with a 50% (RR 0.49, 95%CI 0.10-2.37) and 40% (RR 0.60, 95%CI 0.16-2.17) reduced risk of radiographic osteoarthritis, respectively, but these risk reductions were inconclusive due to wide confidence intervals.

CONCLUSION

After ACLR, returning to pivoting sport was not associated with increased risk of worsening knee osteoarthritis features on MRI, radiographic osteoarthritis or knee symptoms. Participation in pivoting sport need not be avoided as part of osteoarthritis secondary prevention strategies.

Patellar cartilage increase following ACL reconstruction with and without meniscal pathology: a two-year prospective MRI morphological study

Background

Anterior cruciate ligament reconstruction (ACLR) together with concomitant meniscal injury are risk factors for the development of tibiofemoral (TF) osteoarthritis (OA), but the potential effect on the patellofemoral (PF) joint is unclear. The aim of this study was to: (i) investigate change in patellar cartilage morphology in individuals 2.5 to 4.5 years after ACLR with or without concomitant meniscal pathology and in healthy controls, and (ii) examine the association between baseline patellar cartilage defects and patellar cartilage volume change.

Methods

Thirty two isolated ACLR participants, 25 ACLR participants with combined meniscal pathology and nine healthy controls underwent knee magnetic resonance imaging (MRI) with 2-year intervals (baseline = 2.5 years post-ACLR). Patellar cartilage volume and cartilage defects were assessed from MRI using validated methods.

Results

Both ACLR groups showed patellar cartilage volume increased over 2 years (p < 0.05), and isolated ACLR group had greater annual percentage cartilage volume increase compared with controls (mean difference 3.6, 95% confidence interval (CI) 1.0, 6.3%, p = 0.008) and combined ACLR group (mean difference 2.2, 95% CI 0.2, 4.2%, p = 0.028). Patellar cartilage defects regressed in the isolated ACLR group over 2 years (p = 0.02; Z = − 2.33; r = 0.3). Baseline patellar cartilage defect score was positively associated with annual percentage cartilage volume increase (Regression coefficient B = 0.014; 95% CI 0.001, 0.027; p = 0.03) in the pooled ACLR participants.

Conclusions

Hypertrophic response was evident in the patellar cartilage of ACLR participants with and without meniscal pathology. Surprisingly, the increase in patellar cartilage volume was more pronounced in those with isolated ACLR. Although cartilage defects stabilised in the majority of ACLR participants, the severity of patellar cartilage defects at baseline influenced the magnitude of the cartilage hypertrophic response over the subsequent ~ 2 years.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04794-5.

Automated detection of patellofemoral osteoarthritis from knee lateral view radiographs using deep learning: data from the Multicenter Osteoarthritis Study (MOST)

OBJECTIVE

To assess the ability of imaging-based deep learning to detect radiographic patellofemoral osteoarthritis (PFOA) from knee lateral view radiographs.

DESIGN

Knee lateral view radiographs were extracted from The Multicenter Osteoarthritis Study (MOST) public use datasets (n = 18,436 knees). Patellar region-of-interest (ROI) was first automatically detected, and subsequently, end-to-end deep convolutional neural networks (CNNs) were trained and validated to detect the status of patellofemoral OA. Patellar ROI was detected using deep-learning-based object detection method. Atlas-guided visual assessment of PFOA status by expert readers provided in the MOST public use datasets was used as a classification outcome for the models. Performance of classification models was assessed using the area under the receiver operating characteristic curve (ROC AUC) and the average precision (AP) obtained from the Precision-Recall (PR) curve in the stratified 5-fold cross validation setting.

RESULTS

Of the 18,436 knees, 3,425 (19%) had PFOA. AUC and AP for the reference model including age, sex, body mass index (BMI), the total Western Ontario and McMaster Universities Arthritis Index (WOMAC) score, and tibiofemoral Kellgren-Lawrence (KL) grade to detect PFOA were 0.806 and 0.478, respectively. The CNN model that used only image data significantly improved the classifier performance (ROC AUC = 0.958, AP = 0.862).

CONCLUSION

We present the first machine learning based automatic PFOA detection method. Furthermore, our deep learning based model trained on patella region from knee lateral view radiographs performs better at detecting PFOA than models based on patient characteristics and clinical assessments.

Importance of patellofemoral and tibiofemoral cartilage lesions on trajectory of self-reported outcomes in patients at high risk of knee OA: 4-6 years follow-up of patients undergoing meniscal surgery

OBJECTIVE

We evaluated whether patient-reported outcome trajectories (i.e., changes over time) differed by intraoperative compartmental cartilage lesion pattern over 4-6 years following arthroscopic meniscal surgery.

METHODS

In this ancillary study of the Knee Arthroscopy Cohort Southern Denmark cohort, we intraoperatively categorized cartilage lesions as isolated patellofemoral, isolated tibiofemoral, or combined patellofemoral/tibiofemoral. Participants completed the Knee injury and Osteoarthritis Outcome Score (KOOS) pre-operatively, at 3 and 12 months, and at 4-6 years post-operatively and reported overall satisfaction at final follow-up. Our main outcome was KOOS₄ (grand mean of four subscale means). We evaluated whether KOOS₄ scores changed over time according to cartilage lesion patterns using adjusted mixed linear regression. We also estimated probability of treatment satisfaction using logistic regression.

RESULTS

Of 630 participants with complete cartilage scores, 280 (44%) were women, mean (standard deviation) age was 49 (13) years, and BMI was 27.3 (4.4) kg/m². KOOS₄ scores at baseline were slightly lower in all lesion groups compared to the no lesion group, yet only the combined group was statistically significantly lower. KOOS₄ trajectories were similar across cartilage lesion patterns, but by final follow-up, adjusted mean KOOS₄ scores were 6.8 (95% CI 2.2, 11.4) to 9.8 (1.1, 18.5) points lower in groups with cartilage lesions compared to the no lesion group. Probability of patient-reported satisfaction did not differ statistically by group.

CONCLUSIONS

Though KOOS₄ scores were slightly lower in groups with arthroscopically assessed cartilage lesions compared to the no lesion group, trajectories were similar across all groups.

Higher Rate of Patellofemoral Problems After Anterior Cruciate Ligament Reconstruction using Hamstring Autograft

Background: Patellofemoral problems are not uncommon among post-anterior cruciate ligament (ACL) reconstruction patients. Hamstring autograft harvesting-related factor is one of the suspected causes. A lack of tibiofemoral internal rotation force due to strength deficit causes the patella tends to shift laterally. Purposes: Peroneus longus tendon has been proposed as an alternative graft source due to its adequate tensile strength and minimal donor site morbidity to the knee biomechanics, including the patellofemoral joint. This tendon does not cross the knee joint and thus does not affect patellofemoral alignment and biomechanics. This study aims to compare patellofemoral problems between hamstring and peroneus longus autograft harvested-patients following ACL reconstruction. Material and methods: Thirty-one subjects who underwent primary single-bundle ACL reconstruction between September 2018 and September 2019 and met the inclusion criteria were grouped into the hamstring group (n=16) and peroneus longus group (n=15). Both groups were evaluated retrospectively. The follow-up assessment was conducted on the phase II rehabilitation program. The assessed variables were pain, crepitus, and the Indonesian-validated Kujala score. Results: No significant differences in pain and crepitus were found between both groups. There were significant differences in the Kujala score between both groups (P < .001). The peroneus longus group reported an averagely higher score than the hamstring group. Conclusion: Single bundle ACL reconstruction using peroneus longus tendon autograft produces less patellofemoral symptoms and functional limitation than using hamstring tendon autograft.

Early anterior cruciate ligament reconstruction does not affect 5 year change in knee cartilage thickness: secondary analysis of a randomized clinical trial

OBJECTIVE

To compare 5-year change in femorotibial cartilage thickness in 121 young, active adults with an acute anterior cruciate ligament (ACL) tear randomized to a strategy of structured rehabilitation plus early ACL reconstruction (ACLR) or structured rehabilitation plus optional delayed ACLR.

DESIGN

62 patients were randomized to early ACLR, 59 to optional delayed ACLR. Magnetic resonance imaging (MRI) was acquired within 4 weeks of injury, at two- and 5-years follow-up. Main outcome was 5-year change in overall femorotibial cartilage thickness. Secondary outcomes included the location-independent cartilage ChangeScore, summarizing thinning and thickening in 16 femorotibial subregions. An exploratory as-treated comparison was performed additionally.

RESULTS

Baseline and at least one follow-up MRI were available for 117 patients. Over 5 years, a comparable increase in overall femorotibial cartilage thickness was observed for patients randomized to early ACLR (n = 59) and patients randomized to optional delayed ACLR (n = 58, adjusted mean difference: -5 μm, 95% CI: [-118, 108]μm). However, the location-independent cartilage ChangeScore was greater in those treated with early ACLR than in patients treated with optional delayed ACLR (adjusted mean difference: 403 μm [119, 687]μm). As-treated analysis showed no between-group differences for the main outcome, while the location-independent cartilage ChangeScore was greater for patients treated with early (adjusted mean difference: 632 μm [268, 996]μm) or delayed ACLR (adjusted mean difference: 449 μm [108, 791]μm) than for patients treated with rehabilitation alone.

CONCLUSIONS

In young active adults with acute ACL-injury, choice of treatment strategy for the injured ACL did not modify the magnitude of 5-year change in overall femorotibial cartilage thickness.

TRIAL REGISTRATION

ISRCTN84752559.

Exercise-therapy and education for individuals one year after anterior cruciate ligament reconstruction: a pilot randomised controlled trial

BACKGROUND

Guided rehabilitation beyond 6-months is rare following anterior cruciate ligament reconstruction (ACLR), despite high prevalence of unacceptable symptoms and quality of life (QoL). Our primary aim was to determine the feasibility of a randomised controlled trial (RCT) evaluating a physiotherapist-guided intervention for individuals 1-year post-ACLR with persistent symptoms. Our secondary aim was to determine if a worthwhile treatment effect could be observed for the lower-limb focussed intervention (compared to the trunk-focussed intervention), for improvement in knee-related QoL, symptoms, and function.

DESIGN

Participant- and assessor-blinded, pilot feasibility RCT.

METHODS

Participant eligibility criteria: i) 12-15 months post-ACLR; ii) < 87.5/100 on the Knee injury and Osteoarthritis Outcome Score (KOOS) QoL subscale; and either a one-leg rise test < 22 repetitions, single-hop < 90% limb symmetry; or Anterior Knee Pain Scale < 87/100. Participants were randomised to lower-limb or trunk-focussed focussed exercise and education. Both interventions involved 8 face-to-face physiotherapy sessions over 16-weeks. Feasibility was assessed by eligibility rate (> 1 in 3 screened), recruitment rate (> 4 participants/month), retention (< 20% drop-out), physiotherapy attendance and unsupervised exercise adherence (> 80%). Between-group differences for knee-related QoL (KOOS-QoL, ACL-QoL), symptoms (KOOS-Pain, KOOS-Symptoms), and function (KOOS-Sport, functional performance tests) were used to verify that the worthwhile effect (greater than the minimal detectable change for each measure) was contained within the 95% confidence interval.

RESULTS

47% of those screened were eligible, and 27 participants (3 participants/month; 48% men, 34±12 years) were randomised. Two did not commence treatment, and two were lost to follow-up (16% drop-out). Physiotherapy attendance was > 80% for both groups but reported adherence to unsupervised exercise was low (< 55%). Both interventions had potentially worthwhile effects for KOOS-QoL and ACL-QoL, while the lower-limb focussed intervention had potentially greater effects for KOOS-Sport, KOOS-Pain, and functional performance.

CONCLUSIONS

A larger-scale RCT is warranted. All feasibility criteria were met, or reasonable recommendations could be made to achieve the criteria in future trials. Strategies to increase recruitment rate and exercise adherence are required. The potential worthwhile effects for knee-related QoL, symptoms, and function indicates a fully-powered RCT may detect a clinically meaningful effect.

TRIAL REGISTRATION

Prospectively registered ( ACTRN12616000564459 ).

Arthroscopic Articular Cartilage Scores of the Canine Stifle Joint with Naturally Occurring Cranial Cruciate Ligament Disease

OBJECTIVE

 This study aimed to evaluate frequency, location and severity of cartilage pathology in dogs with naturally occurring cranial cruciate ligament (CCL) disease.

STUDY DESIGN

 Stifle arthroscopic video recordings (n = 120) were reviewed. A modified Outerbridge classification system (MOCS) (0-4) was used to score cartilage at 10 locations in the femorotibial (medial and lateral femoral condyles and tibial plateaus) and patellofemoral compartments (proximal, middle and distal locations of the patella and femoral trochlear groove) of the stifle joint. Synovial pathology was scored and the presence of a medial meniscal tear was recorded. A Kruskal-Wallis test was used to evaluate association of location and synovitis with cartilage score; and presence of meniscal tear with cartilage and synovitis scores. Bonferroni correction was utilized and p < 0.05 was considered significant.

RESULTS

 Cartilage pathology and synovitis were identified in all joints. Overall cartilage severity scores were low (median MOCS 1). The median MOCS of the proximal trochlear groove (2) was significantly higher than all other locations evaluated. Higher synovitis scores were significantly associated with higher cartilage severity scores and a medial meniscal tear had no association with cartilage severity scores or synovitis.

CONCLUSION

 Arthroscopic articular cartilage lesions are common in dogs with CCL disease at the time of surgical intervention, although the severity of cartilage damage is mild. The proximal trochlear groove of the femur had the most severe cartilage score in the stifle joint.

Is patellofemoral pain preventable? A systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To evaluate the effectiveness of interventions to reduce the risk of incident patellofemoral pain.

DESIGN

Systematic review and meta-analysis, with strength of evidence evaluated separately for each intervention type.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, Web of Science and SPORTDiscus.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials evaluating the effectiveness of interventions to reduce patellofemoral pain risk compared with a control/non-exposed group.

RESULTS

Thirteen trials of mostly military recruits and young athletes analysed six different interventions. There was low certainty evidence from two trials (227 participants) that patellofemoral braces worn during physical activity (compared with no brace) effectively reduced the risk of patellofemoral pain (risk ratio (RR) 0.40, 95% CI 0.22 to 0.73; I2=24.0%). There was low certainty evidence from one trial (320 participants) that running technique retraining to (run softer) reduced patellofemoral pain risk (RR 0.21, 95% CI 0.07 to 0.60). There was low certainty evidence from four trials (3364 participants) that multicomponent (strengthening/neuromuscular) exercise programmes did not significantly reduce the risk of patellofemoral pain (RR 0.49, 95% CI 0.18 to 1.36; I2=64.9%), although broad CIs may reflect exercise dose variations among studies. There was very low certainty evidence from four trials (2314 participants) that foot orthoses (compared with flat inserts/no orthosis) did not significantly reduce the risk of patellofemoral pain (RR 0.63, 95% CI 0.35 to 1.13; I2=0.0%). Static stretching and a running programme that progressed intensity (compared with volume) did not significantly influence patellofemoral pain risk (single studies).

CONCLUSION

There is low-level evidence that patellofemoral braces and running technique retraining can reduce the risk of patellofemoral pain by 60%-79%.

Poor Associations Between Radiographic Tibiofemoral Osteoarthritis and Patient-Reported Outcomes at 16 Years After Anterior Cruciate Ligament Reconstruction

Background

Radiographic tibiofemoral (TF) osteoarthritis (OA) is common in patients after anterior cruciate ligament (ACL) reconstruction at long-term follow-up. The association between radiographic OA and patient-reported outcomes has not been thoroughly investigated.

Purpose

To determine the association between radiographic TF OA and patient-reported outcome measure (PROM) scores at 16 years after ACL reconstruction.

Study Design

Case-control study; Level of evidence, 3.

Methods

This study was based on 2 randomized controlled studies comprising 193 patients who underwent unilateral ACL reconstruction. A long-term follow-up was carried out at 16.4 ± 1.7 years after surgery and included a radiographic examination of the knee and recording of PROM scores. Correlation analyses were performed between radiographic OA (Kellgren-Lawrence [K-L], Ahlbäck, and cumulative Fairbank grades) and the PROMs of the International Knee Documentation Committee (IKDC) subjective knee form, Lysholm score, and Tegner activity scale. A linear univariable regression model was used to assess how the IKDC score differed with each grade of radiographic OA.

Results

Of 193 patients at baseline, 147 attended the long-term follow-up. At long-term follow-up, 44.2% of the patients had a K-L grade of ≥2 in the injured leg, compared with 6.8% in the uninjured leg. The mean IKDC score at follow-up was 71.2 ± 19.9. Higher grades of radiographic OA were significantly correlated with lower IKDC and Lysholm scores (r = -0.36 to -0.22). Patients with a K-L grade of 3 to 4 had significantly lower IKDC scores compared with patients without radiographic OA (K-L grade 0-1). Adjusted beta values were -15.7 (95% CI, -27.5 to -4.0; P = .0093; R ² = 0.09) for K-L grade 3 and -25.2 (95% CI, -41.7 to -8.6; P = .0033; R ² = 0.09) for K-L grade 4.

Conclusion

There was a poor but significant correlation between radiographic TF OA and more knee-related limitations, as measured by the IKDC form and the Lysholm score. Patients with high grades of radiographic TF OA (K-L grade 3-4) had a statistically significant decrease in IKDC scores compared with patients without radiographic TF OA at 16 years after ACL reconstruction. No associations were found between radiographic TF OA and the Tegner activity level.

Is Self-Reported Knee Stability Associated With Symptoms, Function, and Quality of Life in People With Knee Osteoarthritis After Anterior Cruciate Ligament Reconstruction?

OBJECTIVE

This study aimed to investigate the association of self-reported knee stability with symptoms, function, and quality of life in individuals with knee osteoarthritis after anterior cruciate ligament reconstruction (ACLR).

SETTING

Cross-sectional.

PARTICIPANTS

Twenty-eight individuals with knee osteoarthritis, 5 to 12 years after ACLR.

MAIN OUTCOME MEASURES

Self-reported knee stability was assessed using visual analogue scales (VAS) during hop for distance (HD), side-to-side hop (SSH), and one-leg rise (OLR). Symptoms [Knee Injury and Osteoarthritis Outcome Score (KOOS) pain, Anterior Knee Pain Scale (AKPS), and International Knee Documentation Committee form], self-reported function (KOOS-sport/rec), performance-based function (hopping and OLR), and quality of life (KOOS-QOL) were assessed. K-means clustering categorized individuals into low (n = 8) and high self-reported knee stability (n = 20) groups based on participants' VAS scores during functional tasks.

RESULTS

The low self-reported knee stability group had worse knee symptoms than the high self-reported knee stability group [KOOS-pain: mean difference -17 (95% confidence interval, -28 to -5); AKPS: -10 (-20 to -1)], and worse self-reported function [KOOS-sport/rec: -33 (-48 to -18)] and performance-based function [HD: -28 (-53 to -3); SSH: -10 (-20 to -1), OLR: -18 (-32 to -50)].

CONCLUSION

Low self-reported stability is associated with worse symptoms, and worse self-reported and performance-based function. Further research is required to determine the causation relation of self-reported knee stability to knee symptoms and function in individuals with knee osteoarthritis after ACLR.

Patient-Reported Outcomes One to Five Years After Anterior Cruciate Ligament Reconstruction: The Effect of Combined Injury and Associations With Osteoarthritis Features Defined on Magnetic Resonance Imaging

OBJECTIVE

Persistent symptoms and poor quality of life (QoL) are common following anterior cruciate ligament reconstruction (ACLR). We aimed to determine the influence of a combined ACL injury (i.e., concomitant meniscectomy and/or arthroscopic chondral defect at the time of ACLR and/or secondary injury/surgery to ACLR knee) and cartilage defects defined on magnetic resonance imaging (MRI), bone marrow lesions (BMLs), and meniscal lesions on patient-reported outcomes 1 to 5 years after ACLR.

METHODS

A total of 80 participants (50 men; mean ± SD age 32 ± 14 years) completed the Knee Injury and Osteoarthritis Outcome Score (KOOS) and the International Knee Documentation Committee (IKDC) questionnaires as well as a 3T MRI assessment at 1 and 5 years after ACLR. Median patient-reported outcome scores were compared between isolated and combined ACL injuries and with published normative values. Using multivariate regression, we evaluated the association between compartment-specific MRI cartilage, BMLs, and meniscal lesions and patient-reported outcomes at 1 and 5 years.

RESULTS

Individuals with a combined injury had significantly worse scores in the KOOS subscale of function in sport and recreation (KOOS sport/rec) and in the IKDC questionnaire at 1 year, and worse scores in the KOOS subscales of pain (KOOS pain), symptoms (KOOS symptoms), and QoL (KOOS QoL) and in the IKDC questionnaire at 5 years compared to those with an isolated injury. Although no feature on MRI was associated with patient-reported outcomes cross-sectionally at 1 year, patellofemoral cartilage defects at 1 year were significantly associated with worse 5-year KOOS symptoms (β = -9.79, 95% confidence interval [95% CI] -16.67, -2.91), KOOS sport/rec (β = -7.94, 95% CI -15.27, -0.61), KOOS QoL (β = -8.29, 95% CI -15.28, -1.29), and IKDC (β = -4.79, 95% CI -9.34, -0.24) scores. Patellofemoral cartilage defects at 5 years were also significantly associated with worse 5-year KOOS symptoms (β = -6.86, 95% CI -13.49, -0.24) and KOOS QoL (β = -11.71, 95% CI -19.08, -4.33) scores.

CONCLUSION

Combined injury and patellofemoral cartilage defects shown on MRI are associated with poorer long-term outcomes. Clinicians should be vigilant and aware of individuals with these injuries, as such individuals may benefit from targeted interventions to improve QoL and optimize symptoms.

Between-Limb Differences in Patellofemoral Joint Forces During Running at 12 to 24 Months After Unilateral Anterior Cruciate Ligament Reconstruction

BACKGROUND

Patellofemoral joint (PFJ) osteoarthritis may occur after anterior cruciate ligament reconstruction (ACLR). The mechanisms underpinning the development of PFJ osteoarthritis are not known but may relate to altered PFJ loading. Few studies have assessed PFJ loads during high-impact tasks, such as running, beyond the acute rehabilitation phase (ie, >12 months) after ACLR.

PURPOSE/HYPOTHESIS

The purpose was to compare between-limb joint angles, joint moments, and PFJ contact force during running in individuals at 12 to 24 months after unilateral ACLR. We hypothesized that peak knee flexion angle, knee extension moment, and PFJ contact force during stance would be lower in the ACLR limb compared with the uninjured limb.

STUDY DESIGN

Controlled laboratory study.

METHODS

A total of 55 participants (mean ± SD age, 28 ± 7 years), 12 to 24 months after ACLR, ran at a self-selected speed (2.9 ± 0.3 m/s). Measured kinematics and ground-reaction forces were input into musculoskeletal models to calculate joint moments and muscle forces. These values were subsequently input into a PFJ model to calculate contact force peak and impulse. Outcome measures were compared between the ACLR and uninjured limbs.

RESULTS

In the ACLR limb, compared with the uninjured limb, the PFJ contact force displayed a lower peak (ACLR, 6.1 ± 1.3 body weight [BW]; uninjured, 6.7 ± 1.4 BW; P < .001) and impulse (ACLR, 0.72 ± 0.17 BW*seconds [BWs]; uninjured, 0.81 ± 0.17 BWs; P < .001). At the time of the peak PFJ contact force, the knee extension moment was lower in the ACLR limb (ACLR, 14.0 ± 2.4 %BW*height [%BW*HT]; uninjured, 15.5 ± 2.5 %BW*HT; P < .001). The opposite was true for the ankle plantarflexion moment (ACLR, 12.1 ± 2.6 %BW*HT; uninjured, 11.5 ± 2.7 %BW*HT; P = .019) and the hip extension moment (ACLR, 2.3 ± 2.5 %BW*HT; uninjured, 1.6 ± 2.3 %BW*HT; P = .013). The foot-ground center of pressure was located more anteriorly with respect to the ankle joint center (ACLR, 5.8 ± 0.9 %height [%HT]; uninjured, 5.4 ± 1.0 %HT; P = .001). No differences were found for the sagittal plane hip, knee, and ankle angles.

CONCLUSION

The ACLR limb experienced lower peak PFJ loads during running, explained by a small anterior shift in the foot-ground center of pressure during stance that offloaded the torque demand away from the ACLR knee.

CLINICAL RELEVANCE

Lower net PFJ loading during running in the ACLR limb more than 12 months after ACLR suggests that underloading might play a role in the onset of PFJ osteoarthritis after ACLR.

Limb symmetry index on a functional test battery improves between one and five years after anterior cruciate ligament reconstruction, primarily due to worsening contralateral limb function

OBJECTIVE

Evaluate change in functional performance from 1- to 5-years after anterior cruciate ligament reconstruction (ACLR).

METHODS

59 participants (38 men) aged 29 ± 16 years completed three hops and one-leg rise 1- and 5-years following ACLR. Linear mixed-effects models evaluated differences in change between the ACLR and contralateral limbs. Participants were classified with stable, improving or worsening function relative to previously published minimal detectable change thresholds. Healthy controls completed the three hops (n = 41) and one-leg rise (n = 31) as reference data.

RESULTS

The contralateral limb had a significantly greater decrease in functional performance between 1- and 5-years for the three hops, compared to the ACLR limb. Worsening was more common in the contralateral limb than the ACLR limb; resulting in significant improvements in the LSI for the single hop (mean 87% at 1-year to 95% at 5-years), side hop (77%to 86%) and one-leg rise (76% to85%). Performance of both ACLR and contralateral limbs and the LSI remained below the healthy controls.

CONCLUSION

Functional performance changes differ between limbs between 1- and 5-years post-ACLR. The LSI should not be used in isolation to evaluate functional performance changes after ACLR, as it may overestimate functional improvement, due to worsening contralateral limb function.

Eight-year results of transtibial nonanatomic single-bundle versus double-bundle anterior cruciate ligament reconstruction: Clinical, radiologic outcomes and survivorship

PURPOSE

To compare the long term outcomes of transtibial nonanatomic single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) reconstruction.

METHODS

Between January 2008 and September 2010, we retrospectively evaluated 377 patients who underwent primary ACL reconstruction and who were available at 8 years of follow-up. Patients who received transtibial nonanatomic SB ACL reconstruction ( n = 263) were assigned to group SB and DB ACL reconstruction ( n = 114) to group DB. The patients were assessed with the International Knee Documentation Committee (IKDC), the Lysholm scores, Tegner activity score, knee joint stability tests, and patellofemoral osteoarthritis (OA) findings using the Kellgren-Lawrence (K-L) classification. Contralateral ACL (CACL) injury was also evaluated.

RESULTS

Thirteen patients underwent revision ACL surgery during the follow-up. Ultimately, 256 patients in group SB and 108 patients in group DB were available at the 8-year follow-up. At final follow-up, the IKDC subjective score ( p = 0.04) and Lysholm score ( p = 0.02) showed significantly superior results in group DB compared to group SB. However, there was no significant difference of Tegner activity score ( p = 0.30), range of motion ( p = 0.81), and knee joint stability tests. There was significant progression of patellofemoral OA between preoperative and final follow-up in ipsilateral knee of both groups but not significant progression in contralateral knee. However, there was no significant difference between the two groups at the follow-up. There were 2.7% ipsilateral ACL graft failure in group SB, compared with 5.2% in group DB ( p = 0.12) and 6.4% CACL tear in group SB, compared with 5.2% in group DB ( p = 0.65). The mean survivorship of ACL graft was 9.47 ± 0.05 years (95% confidence interval (CI), 9.36-9.58) in group SB and 9.87 ± 0.16 years (95% CI, 9.54-10.20) in group DB, and there was no significant difference ( p = 0.25).

CONCLUSION

DB ACL reconstruction resulted in significantly better clinical IKDC subjective scores and Lysholm scores. However, most of the differences in clinical scores were small, and the clinical relevance of this difference is unknown. In addition, there was no significant difference in Tegner activity score, knee joint stability tests, patellofemoral OA, and survivor rate of the ACL graft and CACL after reconstruction after a minimum of 8-year follow-up. Level of Evidence: Cohort study; level of evidence, 3.

Poor functional performance 1 year after ACL reconstruction increases the risk of early osteoarthritis progression

Background

Not meeting functional performance criteria increases reinjury risk after ACL reconstruction (ACLR), but the implications for osteoarthritis are not well known.

Objective

To determine if poor functional performance post-ACLR is associated with risk of worsening early osteoarthritis features, knee symptoms, function and quality of life (QoL).

Methods

Seventy-eight participants (48 men) aged 28±15 years completed a functional performance test battery (three hop tests, one-leg-rise) 1 year post-ACLR. Poor functional performance was defined as <90% limb symmetry index (LSI) on each test. At 1 and 5 years, MRI, Knee injury Osteoarthritis Outcome Score (KOOS) and International Knee Documentation Committee (IKDC) subjective form were completed. Primary outcomes were: (i) worsening patellofemoral and tibiofemoral MRI-osteoarthritis features (cartilage, bone marrow lesions (BMLs) and meniscus) and (ii) change in KOOS and IKDC scores, between 1 and 5 years.

Results

Only 14 (18%) passed (≥90% LSI on all tests) the functional test battery. Poor functional performance on the battery (all four tests <90% LSI) 1 year post-ACLR was associated with 3.66 times (95% CI 1.12 to 12.01) greater risk of worsening patellofemoral BMLs. A triple-crossover hop <90% LSI was associated with 2.09 (95% CI 1.15 to 3.81) times greater risk of worsening patellofemoral cartilage. There was generally no association between functional performance and tibiofemoral MRI-osteoarthritis features, or KOOS/IKDC scores.

Conclusion

Only one in five participants met common functional performance criteria (≥90% LSI all four tests) 1 year post-ACLR. Poor function on all four tests was associated with a 3.66 times increased risk of worsening patellofemoral BMLs, and generally not associated with decline in self-reported outcomes.

Hop Testing Lacks Strong Association With Key Outcome Variables After Primary Anterior Cruciate Ligament Reconstruction: A Systematic Review

BACKGROUND

Single-legged hop tests are commonly used assessments in return to sport (RTS) testing after anterior cruciate ligament reconstruction (ACLR). Although these tests are commonly used, their predictive validity has not yet been established.

PURPOSE

To determine the strength of association between hop testing and RTS, knee reinjury, subjective report of knee function, and posttraumatic knee osteoarthritis (PTOA) after primary ACLR. Secondarily, to determine whether hop testing is able to predict a favorable result on the same outcome variables.

STUDY DESIGN

Systematic review.

METHODS

A systematic, computer-assisted literature search was performed in PubMed/MEDLINE, CINAHL, EMBASE, SPORTDiscus, Cochrane Library, and ClinicalTrials.gov. The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed when conducting and reporting this review. Primary outcome variables for this review were self-report of knee function, return to preinjury level of activity, presence of reinjury, and presence of PTOA. The Oxford Centre for Evidence-Based Medicine Levels of Evidence tool was used to assess the level of evidence for each included study. Quality assessment of each included study was performed through use of a modified Downs and Black scale. Available metrics were tabulated based on outcome variables.

RESULTS

Overall, 21 studies (4476 patients) met inclusion for this review. The majority of evidence (95.2%) was of moderate to high methodologic quality. The most commonly associated outcome measure was the International Knee Documentation Committee (IKDC) score, with Pearson correlation coefficients ranging from 0.20 to 0.60. The strength of association between the Knee injury and Osteoarthritis Outcome Score (KOOS) and hop testing ranged from -0.10 to 0.62 in 4 studies. In all, 10 studies examined the relationship between hop testing and RTS, with variable association statistics reported. No meaningful association was found between hop testing and knee reinjury in 2 studies. Worse preoperative hop testing was associated with PTOA in 1 study.

CONCLUSION

Hop testing appears to possess fair association to subjective report of knee function measured by the KOOS and IKDC and a patient's ability to RTS after ACLR. Insufficient evidence is available to determine the relationship between hop testing and PTOA and knee reinjury. Predictive validity cannot be established based on available literature.

Sex affects gait adaptations after exercise in individuals with anterior cruciate ligament reconstruction

BACKGROUND

Osteoarthritis after anterior cruciate ligament reconstruction has been linked with changes in gait. Individuals with reconstruction demonstrate gait changes after exercise, however there is no information on altered gait after exercise based on sex. The purpose of this study was to examine the association of sex on changes in running gait after exercise in individuals with reconstruction compared to healthy.

METHODS

Forty females (22 reconstructed) and 22 men (11 reconstructed) ran before and after exercise. Triplanar lower extremity kinematics and kinetics were measured on the involved limb. Data were reduced to 0-100% of gait. Change scores were calculated for each 1% with 90% confidence intervals. Mean differences were calculated for all significant differences.

FINDINGS

After exercise, females with reconstruction increased knee valgus (1.81°), knee external rotation (2.02°), lateral trunk flexion (1.24°) and trunk rotation (2.15°) compared to healthy females. Females with reconstruction increased knee extension moment (0.07 Nm/kg), knee abduction moment (0.08 Nm/kg), hip extension moment (0.14 Nm/kg) and hip internal rotation moment (0.04 Nm/kg) compared to healthy females. After exercise, males with reconstruction decreased knee varus (-4.83°), hip adduction (-1.99°), and hip internal rotation (-4.44°), however increased lateral trunk flexion (1.94°) compared to healthy males. Males with reconstruction increased knee extension moment (0.07 Nm/kg), knee adduction moment (0.31 Nm/kg), knee internal rotation moment (0.13 Nm/kg), hip flexion moment (0.17 Nm/kg), and hip external rotation moment (0.05 Nm/kg) compared to healthy males.

INTERPRETATION

Males with reconstruction increased hip loading while women with reconstruction increased trunk motion post-exercise. Sex should be considered when evaluating response to exercise after reconstruction.

Patellofemoral MRI Alterations Following Single Bundle ACL Reconstruction with Hamstring Autografts Are Associated with Quadriceps Femoris Atrophy

High incidence of patellofemoral pain and patellofemoral joint osteoarthritis was found following anterior cruciate ligament (ACL) reconstruction. The unstability of patellofemoral joint might be an important contribution factor. This study was designed to define the relationship between the unstability of patellofemoral joint and quadriceps femoris atrophy. Twenty patients underwent MRI scan before ACL reconstruction and every two weeks after surgery, until 12 weeks. The merchant's patellar congruence angle, lateral inclination angle, and quadriceps femoris muscle cross-sectional area were measured and the relationship between the changes of angles and the ratio of quadriceps femoris atrophy was studied by multiple regression analysis. Significant quadriceps femoris atrophy was observed after ACL reconstruction during the follow-up period of 12 weeks. The merchant's patellar congruence angle and lateral inclination angle significantly changed after surgery. The alterations of the merchant's patellar congruence angle were significantly correlated with the atrophy ratio of vastus medialis (coefficient=-15.76) and vastus lateralis (coefficient=8.35) during the follow-up period of 12 weeks. The alterations of lateral inclination angle were significantly correlated with the atrophy ratio of vastus medialis (coefficient=20.62), vastus lateralis (coefficient=-11.38) and rectus femoris (coefficient=-0.469) during the follow-up period 12 weeks. To sum up, ACL reconstruction can alleviate the dysfunction of patellofemoral joint to a certain extent. But, the unbalanced atrophy of quadriceps femoris once again destroyed the stability of patellofemoral joint following the operation, which might be one cause of patellofemoral joint pain and early onset of osteoarthritis after ACL reconstruction. So, rehabilitation training that focuses on quadriceps femoris especially the vastus medialis shortly following operation is suggested.

Posttraumatic cartilage degradation progresses following anterior cruciate ligament reconstruction: A second-look arthroscopic evaluation

BACKGROUND

Several studies have demonstrated that posttraumatic knee osteoarthritis progresses even after anterior cruciate ligament reconstruction. Few reports described zone-specific cartilaginous damages after anterior cruciate ligament reconstruction. This study aimed to compare the status of articular cartilage at anterior cruciate ligament reconstruction with that at second-look arthroscopy.

METHODS

This study included 20 patients (20 knees, 10 males and 10 females, mean age 22.4 years, Body mass index 24.4 kg/m²) that underwent arthroscopic anatomic double-bundle anterior cruciate ligament reconstruction and second-look arthroscopy. Mean periods from injury to reconstruction and from reconstruction to second-look arthroscopy were 3.4 and 15.3 months, respectively. Cartilage lesions were evaluated arthroscopically in the 6 articular surfaces and 40 articular subcompartments independently, and these features were graded with the International Cartilage Repair Society articular cartilage injury classification; comparisons were made between the grades at reconstruction and at second-look arthroscopy. Furthermore, clinical outcomes were assessed at reconstruction and at second-look arthroscopy, using the Lysholm knee score, Tegner activity scale, International Knee Documentation Committee score, Knee injury and Osteoarthritis Outcome Score, side-to-side difference of the KT-2000 arthrometer, and pivot shift test.

RESULTS

Each compartment showed a deteriorated condition at second-look arthroscopy compared with the pre-reconstruction period. A significant worsening of the articular cartilage was noted in all compartments except the lateral tibial plateau and was also observed in the central region of the medial femoral condyle and trochlea after reconstruction. However, each clinical outcome was significantly improved postoperatively.

CONCLUSIONS

Good cartilage conditions were restored in most subcompartments at second-look arthroscopy. Furthermore, posttraumatic osteoarthritic changes in the patellofemoral and medial compartments progressed even in the early postoperative period, although good knee stability and clinical outcomes were obtained. Care is necessary regarding the progression of osteoarthritis and the appearance of knee symptoms in patients undergoing anterior cruciate ligament reconstruction.

One-leg rise performance and associated knee kinematics in ACL-deficient and ACL-reconstructed persons 23 years post-injury

BACKGROUND

Research indicates reduced knee function and stability decades after anterior cruciate ligament (ACL) injury. Assessment requires reliable functional tests that discriminate such outcomes from asymptomatic knees, while providing suitable loading for different populations. The One-leg rise (OLR) test is common in clinics and research but lacks scientific evidence for its implementation. Our cross-sectional study compared performance including knee kinematics of the OLR between ACL-injured persons in the very long term to controls and between legs within these groups, and assessed the within-session reliability of the kinematics.

METHODS

Seventy ACL-injured individuals (mean age 46.9 ± 5.4 years) treated with either reconstructive surgery and physiotherapy (ACL_R; n = 33) or physiotherapy alone (ACL_PT; n = 37), on average 23 years post-injury, and 33 age- and sex-matched controls (CTRL) attempted the OLR. Participants completed as many repetitions as possible to a maximum of 50 while recorded by motion capture. We compared between all groups and between legs within groups for total repetitions and decomposed the OLR into movement phases to compare phase completion times, maximum and range of knee abduction and adduction angles, and mediolateral knee control in up to 10 repetitions per participant.

RESULTS

ACL_PT performed significantly fewer OLR repetitions with their injured leg compared to the CTRL non-dominant leg (medians 15 and 32, respectively) and showed significantly greater knee abduction than ACL_R and CTRL (average 2.56°-3.69° depending on phase and leg). Distribution of repetitions differed between groups, revealing 59% of ACL_PT unable to complete more than 20 repetitions on their injured leg compared to 33% ACL_R and 36% CTRL for their injured and non-dominant leg, respectively. Within-session reliability of all kinematic variables for all groups and legs was high (ICC 3,10 0.97-1.00, 95% CI 0.95-1.00, SEM 0.93-1.95°).

CONCLUSIONS

Negative outcomes of OLR performance, particularly among ACL_PT, confirm the need to address aberrant knee function and stability even decades post-ACL injury. Knee kinematics derived from the OLR were reliable for asymptomatic and ACL-injured knees. Development of the OLR protocol and analysis methods may improve its discriminative ability in identifying reduced knee function and stability among a range of clinical populations.

Prevalence of patellofemoral joint osteoarthritis after anterior cruciate ligament injury and associated risk factors: A systematic review

Background

The prevalence of patellofemoral joint (PFJ) osteoarthritis (OA) after anterior cruciate ligament (ACL) injury was inconsistently reported in the literature. This review summarises the reported prevalence of PFJ OA and risk factors of PFJ OA after ACL injury.

Methods

PubMed, Embase, WoS, and MEDLINE (OVID) were searched up to 1 March 2019. A modified version of the Coleman methodology score was used to assess the methodological quality of the included studies. Prevalence of PFJ OA was pooled depended on different interventions in ACL injured populations.

Results

Thirty-eight studies were included. Five different radiographic classification methods were used: the Kellgren and Lawrence Grade 2, IKDC Grade B, Fairbank Grade 1, joint space narrowing of Grade 2 based on OARSI, and Ahlbäck Grade 1. One included study used MRI Osteoarthritis Knee Score to evaluate PFJ degenerative changes. The overall prevalence of PFJ OA after ACL injury in included studies varied between 4.5% and 80%. The large variation of PFJ OA prevalence is mainly because of different follow-up period and surgical techniques. The pooled data showed that bone-patellar tendon-bone graft, single-bundle ACL reconstruction (ACLR), and delayed ACLR are likely associated with PFJ degenerative changes after ACL injury. ACLR, delayed ACLR, body mass index (BMI), meniscectomy, patellofemoral chondral lesions, age at surgery, and TFJ OA were identified in the literature inducing PFJ OA after ACL injury.

Conclusions

Large variations of PFJ OA after ACL injury are associated with different follow-up period and surgical techniques. ACL reconstructed population with bone-patellar tendon-bone graft, single-bundle reconstruction, and delayed operation time has a high prevalence of PFJ OA.

The translational potential of this article

This review focuses more on the effect of surgical technique factors on the degenerative changes on PFJ. The results reveal that BPTB, single-bundle reconstruction, and delayed ACLR are more likely associated with PFJ degenerative changes after ACL injury. These findings imply that awareness of PFJ problems after surgical intervention will remind of surgeons taking PFJ into consideration in operations, which is likely to reduce the incidences of anterior knee pain, patellar maltracking, and over-constrained patella in the early stage after surgery.

3D bone-shape changes and their correlations with cartilage T1ρ and T2 relaxation times and patient-reported outcomes over 3-years after ACL reconstruction

PURPOSE

(1) To identify bone-shape changes from baseline to 3-years after anterior cruciate ligament reconstruction (ACLR). (2) to assess association between changes in bone-shape from baseline to 6-months and changes in cartilage matrix and patient functions and symptoms from baseline to 3-years after ACLR.

METHODS

Bilateral knees of 30 patients with unilateral ACL injuries were scanned at baseline, 6-months, 1-, 2-, and 3-years after ACLR. Bilateral knees of 13 controls were scanned at baseline, 1- and 3-years. Mean T1ρ and T2 values of each cartilage compartment were computed. Bone shape was quantified using statistical shape modeling (SSM) and 3D-MRI. Patient functions and symptoms were evaluated using Knee Injury and Osteoarthritis Outcome Score (KOOS).

RESULTS

Statistically significant changes were observed in Femur 2 (medial femoral condyle [MF] shape), Femur 6 (intercondylar notch width), Tibia 1 (tibia plateau area), and Tibia 7 (medial tibia slope) over 3-years after ACLR. Statistically significant differences were observed between injured and control knees in several modes. Statistically significant correlations were found between changes in bone shape (ΔFemur 6, ΔFemur 8 [trochlea inclination and MF height], ΔTibia 1) from baseline to 6-months and that of cartilage T1ρ and T2 and KOOS from baseline to 3-years after ACLR.

CONCLUSION

Bone shape remodeling occurs after ACLR, and early bone shape changes (within 6 months) correlated with cartilage matrix and patient outcomes at 3-years after ACLR. Bone shape can be a promising imaging biomarker that stratifies patients at high risk for post-traumatic osteoarthritis (PTOA).

Stifle joint osteoarthritis at the time of diagnosis of cranial cruciate ligament injury is higher in Boxers and in dogs weighing more than 35 kilograms

Osteoarthritis is a ubiquitous disease in dogs. The purpose of this retrospective study was to characterize the severity and distribution of osteoarthritis (OA) within the joint and to identify differences among dog breeds in the severity of OA in the cranial cruciate ligament (CCL)-deficient stifle joint. Radiographs of 240 stifles from 51 Boxers, 66 German Shepherds, 100 Labrador Retrievers, and 23 Siberian Huskies with confirmed CCL rupture were included. Radiographs of the stifle joint were evaluated and OA severity was graded at 33 sites within and around the joint, and patella alta was graded as present or absent for a potential total stifle OA score of 100. Osteophyte size was correlated to OA severity score. Total OA scores were calculated and compared within and between breeds globally as well as at each joint site. Dogs weighing >35 kg had a higher total OA score than those weighing <35 kg. Osteoarthritis scores were highest at the apical patella, proximolateral tibia, and sesamoid bones, corresponding to the proximal, lateral, and caudal aspects of the joint, respectively. No statistically significant differences were found among the mean OA scores of various stifle joint regions. Boxer dogs had a higher total OA score than other breeds. We concluded that dogs have a consistent distribution pattern of OA within the stifle joint after CCL injury. Radiographic OA is more severe in the proximal, lateral, and caudal aspects of the joint. Boxers had more severe OA than the other breeds evaluated in the study.

Patellofemoral kinematic characteristics in anterior cruciate ligament deficiency and reconstruction

Background

It is very important to dynamically evaluate the functional outcome in the knee after anterior cruciate ligament (ACL) reconstruction under physiological weight bearing. The objective of the current study is that we would like to compare the patellofemoral joint kinematics in three ACL status: ACL intact, ACL deficiency, ACL reconstruction.

Methods

Twenty patients with unilateral ACL deficient knees were recruited as preoperative group. Six months after ACL reconstruction, these ten subjects were included as postoperative subjects. Ten normal subjects with healthy knees as the control group. Each subject was asked to walk up a custom set of stairs and a single-plane fluoroscopic imaging system was used to determine the 6DOF kinematics of the injured knees, ACL reconstructed knees, and intact knees.

Results

ACL deficient knees showed reduced patellar flexion angle and reduced distal patellar translation during knee flexion. ACL reconstructed knees showed abnormal patellofemoral joint kinematics compared to ACL intact and ACL deficient knees, exhibiting increased patellar external rotation, lateral tilt, lateral translation during knee flexion.

Conclusion

These findings imply that some alterations persist after ACL deficiency and ACL reconstruction. These abnormal changes will be the onset of degeneration in patellofemoral joint even if the ACL is reconstructed in a way that restores the clinical anteroposterior stability of the knee. Some biomechanical changes should be made to improve the outcome of intervention especially in surgical treatment like ACL reconstruction.

Loss of patellofemoral cartilage thickness over 5 years following ACL injury depends on the initial treatment strategy: results from the KANON trial

OBJECTIVES

To evaluate changes in patellofemoral cartilage thickness over 5 years after anterior cruciate ligament (ACL) injury and to determine the impact of treatment strategy.

METHODS

121 adults (ages 18-35 years, 26% women) had an ACL injury and participated in the KANON randomised controlled trial. Of those, 117 had available MRIs at baseline (<4 weeks post-ACL rupture) and at least one follow-up measurement (2, 5 years). Patellofemoral cartilage thickness was analysed by manual segmentation (blinded to acquisition order). Patellar, trochlear and total patellofemoral cartilage thickness changes were compared between as-randomised (rehabilitation+early ACL reconstruction (ACLR) (n=59) vs rehabilitation+optional delayed ACLR (n=58)) and as-treated groups (rehabilitation+early ACLR (n=59) vs rehabilitation +delayed ACLR (n=29) vs rehabilitation alone (n=29)).

RESULTS

Patellofemoral cartilage thickness decreased -58 µm (95% CI -104 to -11 µm) over 5 years post-ACL rupture, with the greatest loss observed in trochlea during the first 2 years. Participants randomised to rehabilitation+early ACLR had significantly greater loss of patellar cartilage thickness compared with participants randomised to rehabilitation+optional delayed ACLR over the first 2 years (-25 µm (-52, 1 µm) vs +14 µm (-6 to 34 µm), p=0.02) as well as over 5 years (-36 µm (-78 to 5 µm) vs +18 µm (-7, 42 µm), p=0.02). There were no statistically significant differences in patellofemoral cartilage thickness changes between as-treated groups.

CONCLUSION

Patellofemoral (particularly trochlear) cartilage thickness loss was observed in young adults following acute ACL rupture. Early ACLR was associated with greater patellofemoral (particularly patellar) cartilage thickness loss over 5 years compared with optional delayed ACLR, indicating that early surgical intervention may be associated with greater short-term structural patellofemoral cartilage deterioration compared with optional delayed surgery.

TRIAL REGISTRATION NUMBER

ISRCTN84752559; Post-results.

Does patellar alignment or trochlear morphology predict worsening of patellofemoral disease within the first 5 years after anterior cruciate ligament reconstruction?

PURPOSE

We described patellofemoral alignment and trochlear morphology at one and five years after anterior cruciate ligament reconstruction (ACLR), and evaluated the associations between alignment and trochlear morphology (at one year) and worsening patellofemoral osteoarthritis (OA) features by five years. We also evaluated the associations between alignment and morphology to self-reported pain and function (Knee injury and Osteoarthritis Outcome Score, KOOS) at five years.

MATERIALS AND METHODS

In this longitudinal observational study, we followed 73 participants (mean age 29[9] years, 40% women) from one- to five-years after ACLR. Using MRI, we measured alignment and morphology, and scored cartilage and bone marrow lesions at both time points. We used mixed effects and linear regression models to achieve our stated aims.

RESULTS

Greater lateral patella displacement increased risk of cartilage worsening (Odds Ratio [95% CI]: 1.09 [1.01, 1.16]); while less lateral tilt (0.91 [0.83, 0.99]) and greater trochlear angle (0.88 [0.77, 1.00]) were protective. Greater medial trochlear inclination increased risk of bone marrow lesion worsening (1.12 [1.04, 1.19]); while greater trochlear angle was protective (0.80 [0.67, 0.96]). Greater lateral displacement was associated with worse self-reported KOOS sport and recreation scores (β [95% CI]: -11.0 [-20.9, -1.2]) and quality of life scores (-10.5 [-20.4, -0.7]).

CONCLUSIONS

Lateral displacement, lateral tilt, and morphology at 1 year post-ACLR altered the risk of worsening patellofemoral OA features four years later. Lateral displacement was the only measure associated with worse self-reported symptoms at five years. These findings may lead to novel treatment strategies for secondary prevention after ACLR.

Lateral displacement, sulcus angle and trochlear angle are associated with early patellofemoral osteoarthritis following anterior cruciate ligament reconstruction

PURPOSE

Patellofemoral osteoarthritis (PFOA) occurs in approximately half of anterior cruciate ligament (ACL)-injured knees within 10-15 years of trauma. Risk factors for post-traumatic PFOA are poorly understood. Patellofemoral alignment and trochlear morphology may be associated with PFOA following ACL reconstruction (ACLR), and understanding these relationships, particularly early in the post-surgical time period, may guide effective early intervention strategies. In this study, patellofemoral alignment and trochlear morphology were investigated in relation to radiographic features of early PFOA 1-year post-ACLR.

METHODS

Participants (aged 18-50 years) had undergone ACLR approximately 1 year prior to being assessed. Early PFOA was defined as presence of a definite patellofemoral osteophyte on lateral or skyline radiograph. Sagittal and axial plane alignment and trochlear morphology were estimated using MRI. Using logistic regression, the relationship between alignment or morphology and presence of osteophytes was evaluated.

RESULTS

Of 111 participants [age 30 ± 8.5; 41 (37%) women], 19 (17%) had definite osteophytes, only two of whom had had patellofemoral chondral lesions noted intra-operatively. One measure of patellar alignment (bisect offset OR 1.1 [95% confidence interval 1.0, 1.2]) and two measures of trochlear morphology (sulcus angle OR 1.1 [1.0, 1.2], trochlear angle OR 1.2 [1.0, 1.5]) were associated with patellofemoral osteophytes.

CONCLUSIONS

Patellofemoral malalignment and/or altered trochlear morphology were associated with PFOA 1 year following ACLR compared to individuals post-ACLR without these features. Clarifying the role of alignment and morphology in post-traumatic PFOA may contribute to improving early intervention strategies aimed at secondary prevention.

LEVEL OF EVIDENCE

IV.