The aim of the this study was to determine the effect of the knee flexion angle (KFA) during tibial anterior cruciate ligament (ACL) graft fixation on patient reported outcomes, graft stability, extension loss and re-operation following anatomic single-bundle ACL reconstruction. All 169 included patients (mean age 28.5 years, 65% male) were treated with anatomic single bundle ACL reconstruction using patellar tendon autograft and randomized to tibial fixation of the ACL graft at either 0o (n=85) or 30o (n=84). The primary outcome was the Knee Injury and Osteoarthritis Outcome Score (KOOS) two years following surgery. Secondary outcomes were the Marx Activity Scale (MAS), the rate of re-operation, and physical exam findings at one year including KT-1000 and side to side differences in knee extension. The follow-up rate was 82% (n=139) for the primary outcome. Graft failure rate at two years was 1% (n=2, 1 per group). ACL tibial graft fixation at 0o or 30o did not have a significant effect on KOOS scores at two years following ACLR. Patients whose graft was fixed at a knee flexion angle of 0o had greater scores on the Marx Activity Scale (mean 9.6 [95%CI 8.5-10.6] versus 8.0 [95%CI 6.9-9.1, p=0.04) and a greater proportion of patients who achieved the minimal clinical important difference (MCID) for the KOOS pain subscale (94% vs 81%, p=0.04). There was no significant difference in knee extension loss, KT-1000 measurements or re-operation between the two groups. In the setting of anatomic single-bundle ACLR using patellar tendon autograft and anteromedial portal femoral drilling, there was no difference in KOOS scores among patients fixed at 0o and 30o. Patient fixed in full extension did demonstrate higher activity scores at 2 years following surgery and a greater likelihood of achieving the MCID for KOOS pain

The bone-patellar tendon-bone (BTB) autograft has a lower rate of graft failure but a higher rate of contralateral anterior cruciate ligament (ACL) injury after primary ACL reconstruction. Subsequent contralateral injury may be a marker of success of the BTB graft, but it is unclear whether the type of graft influences the rate of return to sport. This study aimed to compare the rates of return to weekly sport and return to preinjury activity levels between the BTB and hamstring tendon autografts following primary ACL reconstruction.

Prospective data on primary ACL reconstructions recorded in the New Zealand ACL Registry between April 2014-November 2019 were analyzed. The primary outcome was return to weekly sport, defined as a Marx activity score of 8, at 2-year follow-up. The secondary outcome was return to preinjury activity level, defined as a post-operative Marx activity score that was equal or greater to the patient's preinjury Marx score. Return to sport was compared between the BTB and hamstring tendon autografts via multivariate binary logistic regression with adjustment for patient demographics.

4259 patients were analyzed, of which 50.3% were playing weekly sport (n = 2144) and 28.4% had returned to their preinjury activity level (n = 1211) at 2-year follow-up. A higher rate of return to weekly sport was observed with the BTB autograft compared to the hamstring tendon autograft (58.7% versus 47.9%, adjusted odds ratio = 1.23, p = 0.009). Furthermore, the BTB autograft had a higher rate of return to preinjury activity levels (31.5% versus 27.5%, adjusted odds ratio = 1.21, p = 0.025).

The BTB autograft is associated with a higher return to sport and may explain the higher rate of contralateral ACL injury following primary ACL reconstruction.

The bone-patellar tendon-bone (BTB) autograft is associated with difficulty kneeling following anterior cruciate ligament (ACL) reconstruction, however it is unclear whether it results in a more painful or symptomatic knee when compared to the hamstring tendon autograft. This study aimed to identify the rate of significant knee pain and difficulty kneeling following primary ACL reconstruction and clarify whether graft type influences the risk of these complications.

Primary ACL reconstructions prospectively recorded in the New Zealand ACL Registry between April 2014 and November 2019 were analyzed. The Knee Injury and Osteoarthritis Outcome Score (KOOS) was analyzed to identify patients who reported significant knee pain, defined as a KOOS Pain subscale score of ≤72 points, and kneeling difficulty, defined as a patient who reported “severe” or “extreme” difficulty when they kneel. The rate of knee pain and kneeling difficulty was compared between graft types via univariate Chi-square test and multivariate binary logistic regression with adjustment for patient demographics.

4492 primary ACL reconstructions were analyzed. At 2-year follow-up, 9.3% of patients reported significant knee pain (420/4492) and 12.0% reported difficulty with kneeling (537/4492). Patients with a BTB autograft reported a higher rate of kneeling difficulty compared to patients with a hamstring tendon autograft (21.3% versus 9.4%, adjusted odds ratio = 3.12, p<0.001). There was no difference between graft types in the rate of significant knee pain (9.9% versus 9.2%, p = 0.49) or when comparing absolute values of the KOOS Pain (mean score for BTB = 88.7 versus 89.0, p = 0.37) and KOOS Symptoms subscales (mean score for BTB = 82.5 versus 82.1, p = 0.49).

The BTB autograft is a risk factor for post-operative kneeling difficulty, but it does not result in a more painful or symptomatic knee when compared to the hamstring tendon autograft.

Reconstruction of the anterior cruciate ligament (ACL) allows to restore stability of the knee, in order to facilitate the return to activity (RTA). Although it is understood that the tendon autograft undergoes a ligamentous transformation postoperatively, knowledge about longitudinal microstructural differences in tissue integrity between types of tendon autografts (ie, hamstring vs. patella) remains limited. Diffusion tensor imaging (DTI) has emerged as an objective biomarker to characterize the ligamentization process of the tendon autograft following surgical reconstruction. One major limitation to its use is the need for a pre-injury baseline MRI to compare recovery of the graft, and inform RTA. Here, we explore the relationship for DTI biomarkers (fractional anisotropy, FA) between knees bilaterally, in healthy participants, with the hypothesis that agreement within a patient's knees may support the use of the contralateral knee as a reference to monitor recovery of the tendon autograft, and inform RTA. Fifteen participants with no previous history of knee injuries were enrolled in this study (age, 26.7 +/− 4.4 years; M/F, 7/8). All images were acquired on a 3T Prisma Siemens scanner using a secured flexible 18-channel coil wrapped around the knee. Both knees were scanned. A 3D anatomical Double Echo Steady State (DESS) sequence was acquired on which regions of interest (ROI) were placed consistent with the footprints of the ACL (femur, posteromedial corner on medial aspect of lateral condyle; tibia, anteromedial to intercondylar eminence). Diffusion images were acquired using fat saturation based on optimized parameters in-house. All diffusion images were pre-processed using the FMRIB FSL toolbox. The footprint ROIs of the ACL were then used to reconstruct the ligament in each patient with fiber-based probabilistic tractography (FBPT), providing a semi-automated approach for segmentation. Average FA was computed for each subject, in both knees, and then correlated against one another using a Pearson correlation to assess the degree of similarity between the ACLs. A total of 30 datasets were collected for this study (1/knee/participant; N=15). The group averaged FA (+/− standard deviation) for the FBPT segmented ACLs were found to equal 0.1683 +/− 0.0235 (dominant leg) and 0.1666 +/− 0.0225 (non-dominant leg). When comparing both knees within subjects, reliable agreement was found for the FBPT-derived ACL with a linear correlation coefficient (rho) equal to 0.87 (P < 0 .001). We sought to assess the degree of concordance in FA between the knees of healthy participants with hopes to provide a method for using the contralateral “healthy” knee in the comparison of autograft-dependent longitudinal changes in microstructural integrity, following ACL reconstruction. Our results suggest that good agreement in anisotropy can be achieved between the non-dominant and dominant knees using DTI and the FBPT segmentation method. Contralateral anisotropy of the ACL, assuming no previous injuries, may be used as a quantitative reference biomarker for monitoring the recovery of the tendon autograft following surgical reconstruction, and gather further insight as to potential differences between chosen autografts. Clinically, this may also serve as an index to supplement decision-making with respect to RTA, and reduce rates of re-injuries

Recurrent patellar instability is a common problem and there are multiple demographic and pathoanatomic risk factors that predispose patients to dislocating their patella. The most common of these is trochlear dysplasia. In cases of severe trochlear dysplasia associated with patellar instability, a sulcus deepening trochleoplasty combined with a medial patellofemoral ligament reconstruction (MPFLR) may be indicated. Unaddressed trochlear pathology has been associated with failure and poor post-operative outcomes after stabilization. The purpose of this study is to report the clinical outcome of patients having undergone a trochleoplasty and MPFLR for recurrent lateral patellofemoral instability in the setting of high-grade trochlear dysplasia at a mean of 2 years follow-up. A prospectively collected database was used to identify 46 patients (14 bilateral) who underwent a combined primary MPFLR and trochleoplasty for recurrent patellar instability with high-grade trochlear dysplasia between August 2013 and July 2021. A single surgeon performed a thin flap trochleoplasty using a lateral para-patellar approach with lateral retinaculum lengthening in all 60 cases. A tibial tubercle osteotomy (TTO) was performed concomitantly in seven knees (11.7%) and the MPFLR was performed with a gracilis tendon autograft in 22%, an allograft tendon in 27% and a quadriceps tendon autograft in 57% of cases. Patients were assessed post-operatively at three weeks and three, six, 12 and 24 months. The primary outcome was the Banff Patellar Instability Instrument 2.0 (BPII 2.0) and secondary outcomes were incidence of recurrent instability, complications and reoperations. The mean age was 22.2 years (range, 13 to 45), 76.7% of patients were female, the mean BMI was 25.03 and the prevalence of a positive Beighton score (>4/9) was 40%. The mean follow-up was 24.3 (range, 6 to 67.7) months and only one patient was lost to follow-up before one year post-operatively. The BPII 2.0 improved significantly from a mean of 27.3 pre-operatively to 61.1 at six months (p < 0 .01) and further slight improvement to a mean of 62.1 at 12 months and 65.6 at 24 months post-operatively. Only one patient (1.6%) experienced a single event of subluxation without frank dislocation at nine months. There were three reoperations (5%): one for removal of the TTO screws and prominent chondral nail, one for second-look arthroscopy for persistent J-sign and one for mechanical symptoms associated with overgrowth of a lateral condyle cartilage repair with a bioscaffold. There were no other complications. In this patient cohort, combined MPFLR and trochleoplasty for recurrent patellar instability with severe trochlear dysplasia led to significant improvement of patient reported outcome scores and no recurrence of patellar dislocation at a mean of 2 years. Furthermore, in this series the procedure demonstrated a low rate (5%) of complications and reoperations

Purpose. Elective ACLR is indicated for symptomatic instability of the knee. Despite being a common procedure, there are numerous surgical techniques, graft and fixation choices. Many have been directly compared in randomized trials and meta-analyses. The typical operation is arthroscopic-assisted, uses autograft tendon and screw fixation. Research in elective joint replacement surgery has demonstrated an inverse relationship between surgeon volume and revision and complication rates. How patient demographics, provider characteristics and graft/fixation choices influence ACLR revision rates has not been reported on a population level. We hypothesized that ACLR using tendon autograft and screw fixation performed by high volume surgeons will have the lowest rate of revision. In contrast, the risk of contralateral ACLR in the same cohort will be influenced only by patient factors. Method. All ACLR performed in Ontario from July 2003 to March 2008 on Ontario residents aged 14 to 60 were identified using physician billing, procedural and diagnostic codes from administrative databases. Data was accessed through the Institute for Clinical Evaluative Sciences. The main outcomes were revision and contralateral ACLR sought from inception until end of 2009. Patient factors (age, gender, income, co-morbidity), surgical choices (allograft or autograft tendon; screw, biodegradable or endobutton/staple fixation) and associated procedures (meniscal repair, collateral ligament surgery) were entered as covariates in a cox proportional hazards survivorship model. Mean cohort patient characteristics were chosen as reference groups. Surgical options and associated procedures were analyzed in a binary fashion (yes/no). Results. We identified 13,997 primary ACLR with a mean follow up of 3.2 years. The rate of revision ACLR was 1.8% (mean 1.9 years), and primary contralateral ACLR 2.0% (mean 2.0 years). In the cox model, younger age (14–19 yrs; HR 2.9, p<0.001), teaching hospital (HR 2.1, p<0.001) and the use of endobutton/staple fixation (HR 4.4, p=0.01) conferred a higher risk of revision. No effect of graft type or surgeon volume was found. Only younger age (14–19 yrs; HR 1.9, p=0.0005) and not any provider or surgical covariates conferred a significant risk of contralateral ACLR. Conclusion. Our results confirm that young age confers a higher risk of both revision and contralateral ACLR and these patients should be counseled accordingly pre-operatively. The use of endobutton or a staple for fixation was an independent risk for revision ACLR. This finding needs to be explored further in a direct fashion. Finally, we report that the mean time to revision ACLR was almost two years a fact that should impact future randomized controlled trial design and prompt re-evaluation of those already published which typically use only 1–2 years as the endpoint of data collection

Background of study. Medial patellofemoral ligament (MPFL) reconstructions are often performed using gracilis autografts, this can be associated with donor site morbidity and complications. The use of synthetic material can circumvent a harvest operation and have previously been demonstrated to be effective in other types of reconstructive procedures and may be effective in MPFL reconstruction. We report our experience and clinical results with the use of FiberTape (FT) in MPFL reconstruction and compare it to the same surgical technique using standard autografts. Materials and Methods. Data were collected prospectively in 50 MPFL reconstructions. The first 27 underwent reconstruction using autograft; the following 23 patients were treated with FT. All patients were clinically and radiologically assessed and underwent pre- and post-operative scoring using the Kujala score, Bartlett score, Modified Tegner activity rating scale, SF 12 score and Lysholm score. Statistical significance was tested between groups using ANOVA with repeated measures. Results. There was no significant differences in the pre-operative scores between the FT and GT groups (p>0.05). Both groups showed significant improvement across all scoring modalities between pre- and post-operative periods 12, 24 and 48 months of follow-up (p<0.05). There were no significant differences in knee function scores between the GT and FT groups. Conclusion. The use of FT in MPFL reconstruction is safe and effective, it significantly improved patient's quality of life and related postoperative outcome measures. There were no significant differences in all knee scores compare to GT autografts. Tendon harvesting is unnecessary and FT is a feasible option for MPFL reconstruction