Purpose To determine the efect of isolated medial patellofemoral ligament reconstruction (MPFLR) versus concomitant MPFLR and tibial-tubercle osteotomy (TTO) on patient-reported functional outcomes, rate of patellar redislocation, and rate of return to sport in skeletally mature patients with recurrent patellar instability and lateralization as deined by elevated tibial-tubercle trochlear groove (TT-TG) distance. Methods Three databases MEDLINE, PubMed and EMBASE were searched from inception to July 10th, 2022 for literature outlining the management of patients with TT-TG indices greater than 15 mm with either isolated MPFLR or concomitant MPFLR and TTO procedures. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data on functional outcomes via the Kujala anterior knee pain score, redislocation rates, return to sport rates, and complications were recorded. The MINORS score was used for all studies to perform a quality assessment of included studies. Results A total of 31 studies comprising 1405 patients (1452 knees) were included in this review. The mean Kujala score in 13 studies comprising 848 total patients in the isolated MPFLR group was 85.0 (range 80.9-97.5) compared to a score of 83.7 (range 77.2-94.0) in 14 studies comprising 459 patients in the concomitant group. The mean pooled redislocation rate in 19 studies examining isolated MPFLR procedures comprising 948 patients was 3.1% (95% CI 2.1-4.4%, I 2 = 7%) as opposed to 3.2% (95% CI 1.9-5.0%, I 2 = 0%) in 15 studies comprising 486 patients in the concomitant group. The mean pooled return to sport rate in seven studies with 472 total patients in the isolated MPFLR group was 82% (95% CI 78-86%, I 2 = 16%) compared to a score of 92% (95% CI 78-99%, I 2 = 58%) in four studies comprising 54 patients in the concomitant group. There were similar complication rates between both treatment groups, including range of motion deicits, fractures, infections, and graft failures. Conclusion Isolated MPFLR leads to similar anterior knee pain, similar redislocation rates and lower return to sport rates than concomitant MPFLR and TTO procedures in patients with TT-TG distances greater than 15 mm. Information from this review can aid surgeons in their decision to choose MPFLR versus concomitant procedures for this patient population, and can also guide future studies on this topic. Level of evidence Level IV.

Purpose This review aims to elucidate the most commonly reported method to quantify fear of reinjury or kinesiophobia and to identify key variables that inluence the degree of kinesiophobia following primary anterior cruciate ligament reconstruction (ACLR). Methods A systematic search across three databases (Pubmed, Ovid (MEDLINE), and EMBASE) was conducted from database inception to August 7th, 2022. The authors adhered to the PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions. Quality assessment of the included studies was conducted according to the Methodological Index for Non-Randomized Studies (MINORS) criteria. Results Twenty-six studies satisied the inclusion criteria and resulted in 2,213 total patients with a mean age of 27.6 years and a mean follow-up time of 36.7 months post-surgery. The mean MINORS score of the included studies was 11 out of 16 for non-comparative studies and 18 out of 24 for comparative studies. Eighty-eight percent of included studies used variations of the Tampa Scale of Kinesiophobia (TSK) to quantify kinesiophobia and 27.0% used Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI). The results of this study shows a common association between higher kinesiophobia and poor patient-reported functional status measured using International Knee Documentation Committee (IKDC) Scores, Activity of Daily Living (ADL), Quality of Life (QOL), and Sports/Recreation (S/R) subscales of Knee Osteoarthritis and Outcome Score (KOOS) and Lysholm scores. Postoperative symptoms and pain catastrophizing measured using the KOOS pain and symptom subscales and Pain Catastrophizing Score (PCS) also inluenced the degree of kinesiophobia following ACLR. Patients with an increased injury to surgery time and being closer to the date of surgery postoperatively demonstrated higher levels of kinesiophobia. Less common variables included being a female patient, low preoperative and postoperative activity status and low self-eicacy. ConclusionThe most common methods used to report kinesiophobia following primary ACLR were variations of the TSK scale followed by ACL-RSI. The most commonly reported factors inluencing higher kinesiophobia in this patient population include lower patient-reported functional status, more severe postoperative symptoms such as pain, increased injury to surgery time, and being closer to the date of surgery postoperatively. Kinesiophobia following primary ACLR is a critical element afecting post-surgical outcomes, and screening should be implemented postoperatively to potentially treat in rehabilitation and recovery. Level of evidence IV.

Purpose To determine the reliability and diagnostic accuracy of tibial tubercle-trochlear groove (TT-TG) distance versus tibial tubercle-posterior cruciate ligament (TT-PCL) distance, and to determine cutof values of these measurements for pathological diagnosis in the context of patellar instability. Methods Three databases MEDLINE, PubMed and EMBASE were searched from inception to October 5, 2022 for literature outlining comparisons between TT-TG and TT-PCL in patellar instability patients. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data on inter-rater and intra-rater reliability, receiver-operating characteristic (ROC) curve parameters such as area under the curve (AUC), sensitivity and speciicity, as well as odds ratios, cutof values for pathological diagnosis and correlations between TT-TG and TT-PCL were recorded. The MINORS score was used for all studies in order to perform a quality assessment of included studies. Results A total of 23 studies comprising 2839 patients (2922 knees) were included in this review. Inter-rater reliability ranged from 0.71 to 0.98 and 0.55 to 0.99 for TT-TG and TT-PCL, respectively. Intra-rater reliability ranged from 0.74 to 0.99 and 0.88 to 0.98 for TT-TG and TT-PCL, respectively. AUC measuring diagnostic accuracy of patellar instability for TT-TG ranged from 0.80 to 0.84 and 0.58 to 0.76 for TT-PCL. Five studies found TT-TG to have more discriminatory power than TT-PCL at distinguishing patients with patellar instability from patients who do not. Sensitivity and speciicity ranged from 21 to 85% and 62 to 100%, respectively, for TT-TG. Sensitivity and speciicity ranged from 30 to 76% and 46 to 86%, respectively, for TT-PCL. Odds ratio values ranged from 1.06 to 14.02 for TT-TG and 0.98 to 6.47 for TT-PCL. Proposed cutof TT-TG and TT-PCL values for predicting patellar instability ranged from 15.0 to 21.4 mm and 19.8 to 28.0 mm, respectively. Eight studies reported signiicant positive correlations between TT-TG and TT-PCL. Conclusion TT-TG resulted in overall similar reliability, sensitivity and speciicity as TT-PCL; however, TT-TG has better diagnostic accuracy than TT-PCL in the context of patellar instability as per AUC and odds ratio values. Level of evidence Level IV.

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PurposeTo determine what knee morphological factors are associated with the development of mucoid degeneration of the anterior cruciate ligament (ACL). Methods Three databases MEDLINE, PubMed and EMBASE were searched from inception to January 29th, 2023 for literature outlining knee morphological factors that potentially lead to the development of mucoid degeneration of the ACL. The authors adhered to the PRISMA and R-AMSTAR guidelines as well as the Cochrane Handbook for Systematic Reviews of Interventions. Data on receiver operating characteristic (ROC) curve parameters such as area under the curve (AUC), sensitivity and speciicity, odds ratios, as well as p values for comparisons of values between mucoid degeneration of the ACL and control patients were recorded. The Methodological Index for Non-Randomized Studies (MINORS) score was used for all studies to perform a quality assessment of included studies. Results A total of 7 studies comprising 1326 patients (1330 knees) were included in this review. Four studies reported a signiicant association between increasing posterior tibial slope angles and mucoid degeneration of the ACL presence, with one study specifying that posterolateral tibial slope had a greater association than posteromedial tibial slope. Two studies reported a signiicant association between lower notch width index values and mucoid degeneration of the ACL presence. One study found that the presence of trochlear dysplasia was correlated with mucoid degeneration of the ACL and two studies found that increased tibial tuberosity-trochlear groove distance (TT-TG) was associated with mucoid degeneration of the ACL. Conclusion Increased posterior tibial slope, decreased notch width index, and elevated TT-TG and trochlear dysplasia were associated with the presence of mucoid degeneration of the ACL. Information from this review can aid surgeons in understanding what morphological features predispose their patients to the development of mucoid degeneration of the ACL. Identifying what features predispose patients to mucoid degeneration of the ACL can help determine if regular screening or preventative strategies are necessary. Level of evidence Level III.